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Christian7e c13.tex V2 - 08/13/2013 1:49 P.M Page 399 Chapter Thirteen POTENTIOMETRIC ELECTRODES AND POTENTIOMETRY Chapter 13 URLs Learning Objectives WHAT ARE SOME OF THE KEY THINGS WE WILL LEARN FROM THIS CHAPTER? ● Types of electrodes and electrode potentials from the Nernst equation (key equations: 13.3, 13.10, 13.16), pp 400, 401, 402 ● The pH glass electrode (key equation: 13.42), p 413 ● Liquid junctions and junction potentials, p 405 ● Standard buffers and the accuracy of pH measurements, pp 418 ● Reference electrodes, p 407 ● The pH meter, p 421 ● Accuracy of potentiometric measurements (key equation: 13.36), p 412 ● Ion-selective electrodes, p 424 ● The selectivity coefficient (key equation: 13.46), p 428 In Chapter 12, we mentioned measurement of the potential of a solution and described a platinum electrode whose potential was determined by the half-reaction of interest This was a special case, and there are a number of electrodes available for measuring solution potentials In this chapter, we list the various types of electrodes that can be used for measuring solution potentials and how to select the proper one for measuring a given analyte The apparatus for making potentiometric measurements is described along with limitations and accuracies of potentiometric measurements The important glass pH electrode is described, as well as standard buffers required for its calibration The various kinds of ion-selective electrodes are discussed The use of electrodes in potentiometric titrations is described in Chapter 14 Potentiometric electrodes measure activity rather than concentration, a unique feature, and we will use activities in this chapter in describing electrode potentials An understanding of activity and the factors that affect it are important for direct potentiometric measurements, as in pH or ion-selective electrode measurements You should, therefore, review the material on activity and activity coefficients in Chapter Potentiometry is one of the oldest analytical methods, with foundations of electrode potentials and electrochemical equilibria laid down by J Willard Gibbs (1839–1903) and Walther Nernst (1864–1941) Inert electrodes are used as indicating electrodes for redox titrations, and may be used in automatic titrators The pH electrode is the most widely used potentiometric electrode Ion selective electrodes are now more widely used than redox electrodes, for selectively measuring particular ions The measurement of fluoride, for example in toothpaste, is one of the more important applications since fluoride is not easily measured otherwise Clinical analyzers measure the electrolytes sodium, potassium, lithium (used in the treatment of manic depression), and calcium in blood using ion selective electrodes Review activities in Chapter 6, for an understanding of potentiometric measurements 399 Christian7e c13.tex V2 - 08/13/2013 1:49 P.M Page 400 CHAPTER 13 POTENTIOMETRIC ELECTRODES AND POTENTIOMETRY 400 13.1 Metal Electrodes for Measuring the Metal Cation An electrode of this type is a metal in contact with a solution containing the cation of the same metal An example is a silver metal electrode dipping in a solution of silver nitrate For all electrode systems, an electrode half-reaction can be written from which the potential of the electrode is described The electrode system can be represented by M/Mn+ , in which the line represents an electrode–solution interface For the silver electrode, we have (13.1) Ag|Ag+ and the half-reaction is Ag+ + e− Ag (13.2) The potential of the electrode is described by the Nernst equation: E = EAg + ,Ag − Increasing cation activity always causes the electrode potential to become more positive (if you write the Nernst equation properly) The indicator electrode is the one that responds to the analyte 2.303RT log nF aAg+ (13.3) where aAg+ represents the activity of the silver ion (see Chapter 6) The value of n here is We will use the more correct unit of activity in discussions in this chapter because, in the interpretation of direct potentiometric measurements, significant errors would result if concentrations were used in calculations The potential calculated from Equation 13.3 is the potential relative to the normal hydrogen electrode (NHE—see Section 13.3) The potential becomes increasingly positive with increasing Ag+ (the case for any electrode measuring a cation) That is, in a cell measurement using the NHE as the second half-cell, the voltage is Emeasd = Ecell = Eind vs NHE = Eind − ENHE (13.4) where Eind is the potential of the indicator electrode (the one that responds to the test solution, Ag+ ions in this case) Since ENHE is zero, Ecell = Eind (13.5) Eref | solution | Eind (13.6) Ecell = Eright − Eleft = Eind − Eref = Eind − constant (13.7) corresponds to writing the cells as and The reference electrode completes the cell but does not respond to the analyte It is usually separated from the test solution by a salt bridge Any pure substance does not numerically appear in the Nernst equation (e.g., Cu, H2 O); their activities are taken as unity where Eref is the potential of the reference electrode, whose potential is constant Note that Ecell (or Eind ) may be positive or negative, depending on the activity of the silver ion or the relative potentials of the two electrodes This is in contrast to the convention used in Chapter 12 for a voltaic cell, in which a cell was always set up to give a positive voltage and thereby indicate what the spontaneous cell reaction would be In potentiometric measurements, we, in principle, measure the potential at zero current so as not to disturb the equilibrium, i.e., don’t change the relative concentrations of the species being measured at the indicating electrode surface—which establishes the potential (see measurement of potential, below) We are interested in how the potential of the test electrode (indicating electrode) changes with analyte concentration, as measured against some constant reference electrode Equation 13.7 is arranged so that changes in Ecell reflect the same changes in Eind , including sign This point is discussed further when we talk about cells and measurement of electrode potentials The activity of silver metal above, as with other pure substances, is taken as unity So an electrode of this kind can be used to monitor the activity of a metal ion in solution There are few reliable electrodes of this type because many metals tend to form an oxide coating that changes the potential Christian7e c13.tex 13.2 METAL–METAL SALT ELECTRODES FOR MEASURING THE SALT ANION V2 - 08/13/2013 1:49 P.M Page 401 401 13.2 Metal–Metal Salt Electrodes for Measuring the Salt Anion The general form of this type of electrode is M|MX|Xn− , where MX is a slightly soluble salt An example is the silver–silver chloride electrode: Ag|AgCl(s) |Cl− (13.8) The (s) indicates a solid, (g) is used to indicate a gas, and (l) is used to indicate a pure liquid A vertical line denotes a phase boundary between two different solids or a solid and a solution The half-reaction is AgCl + e− Ag + Cl− (13.9) where the underline indicates a solid phase and the potential is defined by E = EAgCl,Ag − 2.303RT log aCl− F (13.10) The number of electrons, n, does not appear in the equation because here n = This electrode, then, can be used to measure the activity of chloride ion in solution Note that, as the activity of chloride increases, the potential decreases This is true of any electrode measuring an anion—the opposite for a cation electrode A silver wire is coated with silver chloride precipitate (e.g., by electrically oxidizing it in a solution containing chloride ion, the reverse reaction of Equation 13.9) Actually, as soon as a silver wire is dipped in a chloride solution, a thin layer of silver chloride and is usually not required Note that this electrode can be used to monitor either aCl− or aAg+ It really senses only silver ion, and the activity of this is determined by the solubility of the slightly soluble AgCl Since aCl− = Ksp /aAg+ , Equation 13.10 can be rewritten: Ksp 2.303RT log F aAg+ (13.11) 2.303RT 2.303RT log Ksp − log F F aAg+ (13.12) − E = EAgCl,Ag − E = EAgCl,Ag Comparing this with Equation 13.3, we see that 0 EAg + ,Ag = EAgCl,Ag − 2.303RT log Ksp F (13.13) ◦ (see Chapter 6), since activities, Ksp here is the thermodynamic solubility product Ksp rather than concentrations, were used in arriving at it in these equations We could have arrived at an alternative form of Equation 13.10 by substituting Ksp /aCl− for aAg+ in Equation 13.3 (see Example 13.1) In a solution containing a mixture of Ag+ and Cl− (e.g., a titration of Cl− with + Ag ), the concentrations of each at equilibrium will be such that the potential of a silver wire dipping in the solution can be calculated by either Equation 13.3 or Equation 13.10 This is completely analogous to the statement in Chapter 12 that the potential of one half-reaction must be equal to the potential of the other in a chemical reaction at equilibrium Equations 13.2 and 13.9 are the two half-reactions in this case, and when one is subtracted from the other, the result is the overall chemical reaction Ag+ + Cl− − + AgCl (13.14) Note that as Cl is titrated with Ag , the former decreases and the latter increases Equation 13.10 predicts an increase in potential as Cl− decreases; and similarly, Equation 13.12 predicts the same increase as Ag+ increases Increasing anion activity always causes the electrode potential to decrease The Ag metal really responds to Ag+ , whose activity is determined ◦ and aCl− by Ksp Christian7e c13.tex V2 - 08/13/2013 1:49 P.M Page 402 CHAPTER 13 POTENTIOMETRIC ELECTRODES AND POTENTIOMETRY 402 The silver electrode can also be used to monitor other anions that form slightly soluble salts with silver, such as I− , Br− , and S2− The E0 in each case would be that for the particular half-reaction AgX + e− Ag + X− Another widely used electrode of this type is the calomel electrode, Hg, Hg2 Cl2(s) |Cl− This will be described in more detail when we talk about reference electrodes Example 13.1 Given that the standard potential of the calomel electrode is 0.268 V and that of the Hg/Hg2 2+ electrode is 0.789 V, calculate Ksp for calomel (Hg2 Cl2 ), for 298K Solution For Hg2 2+ + 2e− Hg, 0.05916 log aHg2 2+ (1) 0.05916 log(aCl− )2 (2) Ksp 0.05916 log aHg2 2+ (3) 0.05916 0.05916 log Ksp − log 2 aHg2 2+ (4) E = 0.789 − For Hg2 Cl2 + 2e− 2Hg + 2Cl− , E = 0.268 − Since Ksp = aHg2 2+ · (aCl− )2 , E = 0.268 − E = 0.268 − From (1) and (4), 0.789 = 0.268 − 0.05916 log Ksp Ksp = 2.44 × 10−18 13.3 Redox Electrodes—Inert Metals In the redox electrode, an inert metal is in contact with a solution containing the soluble oxidized and reduced forms of the redox half-reaction This type of electrode was mentioned in Chapter 12 The inert metal used is usually platinum The potential of such an inert electrode is determined by the ratio at the electrode surface of the reduced and oxidized species in the half-reaction: Ma+ + ne− M(a−n)+ (13.15) E = EM a+ ,M(a−n)+ − a (a−n)+ 2.303RT log M nF aMa+ (13.16) An example is the measurement of the ratio of MnO4 − /Mn2+ : MnO4 − + 8H+ + 5e− E = EMnO − ,Mn2+ − Mn2+ + 4H2 O aMn2+ 2.303RT log 5F aMnO4 − · (aH+ )8 (13.17) (13.18) Christian7e c13.tex 13.3 REDOX ELECTRODES— —INERT METALS V2 - 08/13/2013 1:49 P.M Page 403 403 H2 HCI solution H2 Platinized Pt electrode Fig 13.1 Hydrogen electrode The pH is usually held constant, and so the ratio aMn2+ /aMnO4 − is measured, as in a redox titration A very important example of this type of electrode is the hydrogen electrode, Pt|H2 , H+ : (13.19) H+ + e− H2 E = EH + ,H − (pH2 )1/2 2.303RT log F aH+ (13.20) The construction of the hydrogen electrode is shown in Figure 13.1 A layer of platinum black must be placed on the surface of the platinum electrode by cathodically electrolyzing in a H2 PtCl6 solution The platinum black provides a larger surface area for adsorption of hydrogen molecules and catalyzes their oxidation Too much platinum black, however, can adsorb traces of other substances such as organic molecules or H2 S, causing erratic behavior of the electrode The pressure of gases, in atmospheres, is used in place of activities If the hydrogen pressure is held at atm, then, since E0 for Equation 13.19 is defined as zero, 2.303RT 2.303RT log pH E= =− (13.21) F aH+ F For gases, we will use pressures, p (in atmospheres), in place of activity (or the thermodymic equivalent term for gases, fugacity) Example 13.2 Calculate the pH of a solution whose potential at 25◦ C measured with a hydrogen electrode at an atmospheric pressure of 1.012 atm (corrected for the vapor pressure of water at 25◦ C) is −0.324 V (relative to the NHE) Solution From Equation 13.20, −0.324 = −0.05916 log (1.012)1/2 aH+ = −0.05916 log(1.012)1/2 − 0.05916 pH pH = 5.48 The vapor pressure of water above the solution must be subtracted from the measured gas pressure Christian7e c13.tex 404 V2 - 08/13/2013 1:49 P.M Page 404 CHAPTER 13 POTENTIOMETRIC ELECTRODES AND POTENTIOMETRY While the hydrogen electrode is very important for specific applications (e.g., establishing standard potentials or the pH of standard buffers—see below), its use for routine pH measurements is limited First, it is inconvenient to prepare and use The partial pressure of hydrogen must be established at the measurement temperature The solution should not contain other oxidizing or reducing agents since these will alter the potential of the electrode 13.4 Voltaic Cells without Liquid Junction—For Maximum Accuracy It is possible to construct a cell without a salt bridge For practical purposes, this is rare because of the tendency of the reference electrode potential to be influenced by the test solution This cell is used to accurately measure the pH of “standard buffers.” See Section 13.12 To make potential measurements, a complete cell consisting of two half-cells must be set up, as was described in Chapter 12 One half-cell usually is comprised of the test solution and an electrode whose potential is determined by the analyte we wish to measure This electrode is the indicator electrode The other half-cell is any arbitrary half-cell whose potential is not dependent on the analyte This half-cell electrode is designated the reference electrode Its potential is constant, and the measured cell voltage reflects the indicator electrode potential relative to that of the reference electrode Since the reference electrode potential is constant, any changes in potential of the indicator electrode will be reflected by an equal change in the cell voltage There are two basic ways a cell may be set up, either without or with a salt bridge The first is called a cell without liquid junction An example of a cell of this type would be Pt|H2 (g), HCl(solution)|AgCl(s)|Ag (13.22) The solid line represents an electrode–solution interface An electrical cell such as this is a voltaic one, and the cell illustrated above is written for the spontaneous reaction by convention (positive Ecell —although we may actually measure a negative cell voltage if the indicator electrode potential is the more negative one; we haven’t specified which of the half-reactions represents the indicator electrode) The hydrogen electrode is the anode, since its potential is the more negative (see Chapter 12 for a review of cell voltage conventions for voltaic cells) The potential of the left electrode would be given by Equation 13.20, and that for the right electrode would be given by Equation 13.10, and the cell voltage would be equal to the difference in these two potentials: ⎛ ⎞ pH2 2.303RT 2.303RT 0 ⎠ log aCl− − ⎝EH log − Ecell = EAgCl,Ag + ,H − F F aH+ (13.23) Ecell = EAgCl,Ag − EH + ,H a +a − 2.303RT log H Cl1 − F (pH2 ) (13.24) The cell reaction would be (half-reaction)right − (half-reaction)left (to give a positive Ecell and the spontaneous reaction), or AgCl + e− −(H+ + e− AgCl + 12 H2 Ag + Cl− (13.25) H2 ) (13.26) Ag + Cl− + H+ (13.27) Christian7e c13.tex 13.5 VOLTAIC CELLS WITH LIQUID JUNCTION— —THE PRACTICAL KIND V2 - 08/13/2013 1:49 P.M Page 405 405 Equation 13.23 would also represent the voltage if the right half-cell were used as an indicating electrode in a potentiometric measurement of chloride ion and the left cell were the reference electrode (see Equations 13.6 and 13.7) That is, the voltage (and hence the indicator electrode potential) would decrease with increasing chloride ion If we were to use the hydrogen electrode as the indicating electrode to measure hydrogen ion activity or pH, we would reverse the cell setup in Equation 13.22 from left to right to indicate what is being measured Equation 13.23 will be reversed as well, and the voltage (and indicator electrode potential) would increase with increasing acidity or decreasing pH (Ecell = Eind − Eref , Equation 13.7) Cells without liquid junction are always used for the most accurate measurements because there are no uncertain potentials to account for and were used for measuring the pH of NIST standard buffers (see below) However, there are few examples of cells without liquid junction (sometimes called cells without transference), and they are inconvenient to use Therefore, the more convenient (but less accurate) cells with liquid junction are commonly used 13.5 Voltaic Cells with Liquid Junction—The Practical Kind An example of this type of cell is Hg|Hg2 Cl2 (s)|KCl(saturated)||HCl(solution), H2 (g)|Pt (13.28) The double line represents the liquid junction between two dissimilar solutions and is usually in the form of a salt bridge The purpose of this is to prevent mixing of the two solutions In this way, the potential of one of the electrodes will be constant, independent of the composition of the test solution, and determined by the solution in which it dips The electrode on the left of cell 13.28 is the saturated calomel electrode, which is a commonly used reference electrode (see below) The cell is set up using the hydrogen electrode as the indicating electrode to measure pH LIQUID-JUNCTION POTENTIAL——WE CAN’T IGNORE THIS The disadvantage of a cell of this type is that there is a potential associated with the liquid junction, called the liquid-junction potential The potential of the above cells is Ecell = (Eright − Eleft ) + Ej (13.29) where Ej is the liquid-junction potential; Ej may be positive or negative The liquidjunction potential results from the unequal diffusion of the ions on each side of the boundary A careful choice of salt bridge (or reference electrode containing a suitable electrolyte) can minimize the liquid-junction potential and make it reasonably constant so that a calibration will account for it The basis for such a selection is discussed as follows A typical boundary might be a fine-porosity sintered-glass frit with two different solutions on either side of it; the frit prevents appreciable mixing of the two solutions The simplest type of liquid junction occurs between two solutions containing the same electrolyte at different concentrations An example is HCl (0.1 M)||HCl (0.01 M), illustrated in Figure 13.2 Both hydrogen ions and chloride ions will migrate across the boundary in both directions, but the net migration will be from the more concentrated to the less concentrated side of the boundary, the driving force for this migration being proportional to the concentration difference Hydrogen ions migrate about five The presence of a liquid-junction potential limits the accuracy of potentiometric measurements Christian7e c13.tex 406 CHAPTER 13 POTENTIOMETRIC ELECTRODES AND POTENTIOMETRY H + (0.1 M ) H + (0.01 M ) Equilibrium Cl − (0.01 M ) Cl − (0.1 M ) Fig 13.2 Representation of liquid-junction potential We minimize the liquid-junction potential by using a high concentration of a salt whose ions have nearly equal mobility, for example, KCl V2 - 08/13/2013 1:49 P.M Page 406 Boundary − − − − + + + + +40 mV times faster than chloride ions Therefore, a net positive charge is built up on the right side of the boundary, leaving a net negative charge on the left side; that is, there is a separation of charge, and this represents a potential A steady state is rapidly achieved by the action of this build-up positive charge in inhibiting the further migration of hydrogen ions; the converse applies to the negative charge on the lefthand side Hence, a constant potential difference is quickly attained between the two solutions The Ej for this junction is +40 mV, and Ecell = (Eright − Eleft ) + 40 mV This Ej is very large, owing to the rapid mobility of the hydrogen ion As the concentration of HCl on the left side of the boundary is decreased, the net charge built up will be less, and the liquid-junction potential will be decreased until, at equal concentration, it will be zero, because equal amounts of HCl diffuse in each direction A second example of this type of liquid junction is 0.1 M KCl/0.01 M KCl This situation is completely analogous to that above, except that in this case the K+ and Cl− ions migrate at nearly the same rate, with the chloride ion moving only about 4% faster So a net negative charge is built up on the right side of the junction, but it will be relatively small Thus, Ej will be negative and is equal to −1.0 mV HOW DO WE MINIMIZE THE LIQUID-JUNCTION POTENTIAL? The nearly equal migration of potassium and chloride ions makes it possible to significantly decrease the liquid-junction potential This is possible because, if an electrolyte on one side of a boundary is in large excess over that on the other side, the flux of the migration of the ions of this electrolyte will be much greater than that of the more dilute electrolyte, and the liquid-junction potential will be determined largely by the migration of this more concentrated electrolyte Thus, Ej of the junction KCl (3.5 M)|| H2 SO4 (0.05 M) is only −4 mV, even though the hydrogen ions diffuse at a much more rapid rate than sulfate Some examples of different liquid-junction potentials are given in Table 13.1 (The signs are for those as set up, and they would be the signs in a potentiometric measurement if the solution on the left were used for the salt bridge and the one on the right were the test solution If solutions on each side of the junction were reversed, the signs of the junction potentials would be reversed.) It is apparent that the liquid junction potential can be minimized by keeping a high concentration of a salt such as KCl, the ions of which have nearly the same mobility, on one side of the boundary Ideally, the same high concentration of such a salt should be on both sides of the junction This is generally not possible for the test solution side of a salt bridge However, the solution in the other half-cell in which the other end of the salt bridge forms a junction can often be made high in KCl to minimize that junction potential As noted before, this half-cell, which is connected via the salt bridge to form a complete Christian7e c13.tex 13.6 REFERENCE ELECTRODES: THE SATURATED CALOMEL ELECTRODE V2 - 08/13/2013 1:49 P.M Page 407 407 Table 13.1 Some Liquid-Junction Potentials at 25◦ Ca Boundary Ej (mV) 0.1 M KCl||0.1 M NaCl 3.5 M KCl||0.1 M NaCl 3.5 M KCl||1 M NaCl 0.01 M KCl||0.01 M HCl 0.1 M KCl||0.1 M HCl 3.5 M KCl||0.1 M HCl 0.1 M KCl||0.1 M NaOH 3.5 M KCl||0.1 M NaOH 3.5 M KCl||1 M NaOH +6.4 +0.2 +1.9 −26 −27 +3.1 +18.9 +2.1 +10.5 a Adapted from G Milazzo, Electrochemie Vienna: Springer, 1952; and D A MacInnes and Y L Yeh, J Am Chem Soc., 43 (1921) 2563 cell, is the reference electrode See the discussion of the saturated calomel electrode below As the concentration of the (dissimilar) electrolyte on the other side of the boundary (in the test solution) increases, or as the ions are made different, the liquid-junction potential will get larger Very rarely can the liquid-junction potential be considered to be negligible The liquid-junction potential with neutral salts is less than when a strong acid or base is involved The variation is due to the unusually high mobilities of the hydrogen ion and the hydroxyl ion Therefore, the liquid-junction potential will vary with the pH of the solution, an important fact to remember in potentiometric pH measurements A potassium chloride salt bridge, at or near saturation, is usually employed, except when these ions may interfere in a determination Ammonium chloride or potassium nitrate may be used if the potassium or chloride ion interferes Various types of electrolyte junctions or salt bridges have been designed, such as a ground-glass joint, a porous glass or ceramic plug, or a fine capillary tip The reference electrode solution then contains saturated KCl solution, which slowly leaks through the bridge to create the liquid junction with the test solution Liquid-junction potentials are highly pH dependent because of the high mobilities of the proton and hydroxide ions 13.6 Reference Electrodes: The Saturated Calomel Electrode A requirement of a reference electrode is that its potential be fixed and stable, unaffected by the passage of small amounts of current required in making potentiometric measurements (ideally, the current in the measurement is zero, but in practice some small current must be passed—see below) Metal–metal salt electrodes generally possess the needed properties A commonly used reference electrode is the saturated calomel electrode (SCE) The term “saturated” refers to the concentration of potassium chloride; and at 25◦ C, the potential of the SCE is 0.242 V versus NHE An SCE consists of a small amount of mercury mixed with some solid Hg2 Cl2 (calomel), solid KCl, and enough saturated KCl solution to moisten the mixture This is contacted with a saturated KCl solution containing some solid KCl to maintain saturation A platinum electrode is immersed in the paste to make contact with the small mercury pool formed, and the connecting wire from that goes to one terminal of the potential measuring device A salt bridge serves as the contact between the KCl solution and the test solution and is usually Reference electrodes are usually metal–metal salt types The two most common are the Hg/Hg2 Cl2 (calomel) and the Ag/AgCl electrodes Christian7e c13.tex V2 - 08/13/2013 1:49 P.M Page 408 CHAPTER 13 POTENTIOMETRIC ELECTRODES AND POTENTIOMETRY 408 Pt wire sealed in the inner tube to make contact with the paste Paste of Hg, Hg2Cl2, and KCl Hole for filling with KCl solution Pinhole for contact of paste with the KCI solution To potentiometer Fig 13.3 Saturated KCI solution Commercial saturated calomel electrode (Source: Courtesy of Arthur H Thomas Company.) Porous ceramic junction (salt bridge) a fiber or porous glass frit wetted with the saturated KCl solution If a different salt bridge is needed to prevent contamination of the test solution (you can’t use the SCE for chloride measurements!), then a double-junction reference electrode is used in which the KCl junction contacts a different salt solution that in turn contacts the test solution This, of course, creates a second liquid-junction potential, but it is constant A commercial probe-type SCE is shown in Figure 13.3 This contains a porous fiber or frit as the salt bridge in the tip that allows very slow leakage of the saturated potassium chloride solution It has a small mercury pool area and so the current it can pass without its potential being affected is limited (as will be seen below, a small current is usually drawn during potential measurements) The fiber salt bridge has a resistance of ∼ 2500 satisfactory for use with any modern high input impedance voltmeter, including a pH meter Example 13.3 Calculate the potential of the cell consisting of a silver electrode dipping in a silver nitrate solution with aAg+ = 0.0100 M and an SCE reference electrode Solution Neglecting the liquid-junction potential, Ecell = Eind − Eref Ecell = EAg + ,Ag − 0.05916 log = 0.799 − 0.05916 log = 0.439 V aAg+ − ESCE − 0.242 0.0100 Christian7e a06.tex V2 - 08/13/2013 8:54 A.M Page 812 ANSWERS TO PROBLEMS 812 15 10.01 mg CaCO3 /mL EDTA CHAPTER 11 16 10.01 (mg CaCO3 /L · H2 O)/mL EDTA s = 2.1 × 10−4 M; [IO3 − ] = 1.5 × 10−4 M; [HIO3 ] = 6.9 × 10−5 M 17 2.89 × 10 ppm s = 6.1 × 10−3 M; [HF] = 1.20 × 10−2 M; [F− ] = 8.01 × 10−5 M 18 9.93 mg/dL; 4.95 meq/L 19 98.79% s = 2.7 × 10−15 M; [H2 S] = 2.7 × 10−5 M; [HS− ] = 2.7 × 10−10 M; [S2− ] = 2.9 × 10−18 M 20 3.04 ppm 21 119 mg/L s = 8.4 × 10−3 M; [Ag(en)+ ] = 5.96 × 10−5 M; [Ag(en)2 + ] = 8.4 × 10−3 M 22 20.4 % [Ag+ ] = 1.8 × 10−4 M (2.1 × 10−4 M if include HIO3 formation) CHAPTER 10 [Pb2+ ] = 2.7 × 10−5 M 10 16.2 g 8.4 × 10−3 M = s (7.0 × 10−3 M if correct for en consumed by reiteration) 11 82.2 g 12 0.2138, 1.902, 0.1314, 0.6474 10 5.434 g/L 13 0.586 g 11 0.029 mL excess titrant 14 98.68% 12 Yes 15 0.6888 g 16 1.071% 17 636 mg CHAPTER 12 18 26 mL O3 , HClO, Hg2+ , H2 SeO3 , H3 AsO4 , Cu2+ , Co2+ , Zn2+ , K+ 19 1.75% 10 Ni, H2 S, Sn2+ , V3+ , I− , Ag, Cl− , Co2+ , HF 20 24.74 g 11 (a) Fe2+ − MnO4 − (b) Fe2+ − Ce4+ (HClO4 ) (c) H3 AsO3 − MnO4 − (d) Fe3+ − Ti2+ 21 2.571 g 22 42.5% Ba, 37.5% Ca 12 (a) VO2+ /Sn2+ (b) Fe(CN)6 3− /Fe2+ (d) I2 /I2 (e) H2 O2 /Fe2+ 23 79.98% 24 0.846 g AgCl, 1.154 g AgBr 25 (a) Ksp = [Ag+ ][SCN− ] (b) Ksp = [La3+ ][IO3 − ]3 (c) Ksp = [[Hg2 2+ ][Br− ]2 (d) Ksp = [Ag+ ][[Ag(CN)2 − ] (e) Ksp = [Zn2+ ]2 [Fe(CN)6 4− ] (f) Ksp = [Bi3+ ]2 [S2− ]3 26 8.20 × 10−19 −4 M Ag , 6.5 × 10 −8 M 27 1.3 × 10 28 1.9 × 10 + −5 M CrO4 2− 29 1.3 × 10−17 M 30 5.1 × 10−7 M, 1.0 × 10−9 M 31 3.8 34 AB : s = × 10−9 M, AC2 : s = × 10−6 M 35 Bi2 S3 is × 107 times more soluble than HgS! 36 0.33 M excess F− needed Is feasible 39 4.1 × 10−4 g 14 (a) Pt/Fe2+ , Fe3+ //Cr2 O7 2− , Cr3+ , H+ /Pt (b) Pt/I− , I2 //IO3 − , I2 , H+ /Pt (c) Zn/Zn2+ //Cu2+ /Cu (d) Pt/H2 SeO3 , SeO4 2− , H+ //Cl2 , Cl− /Pt 15 (a) 2V2+ + PtCl6 2− = 2V3+ + PtCl4 2− + 2Cl− (b) Ag + Fe3+ + Cl− = AgCl + Fe2+ (c) 3Cd + ClO3 − + 6H+ = 3Cd2+ + Cl− + 3H2 O (d) 2I− + H2 O2 + 2H+ = I2 + H2 O 16 1.24V 17 0.419 V 19 0.216 V 33 1.7 × 10−6 M 38 2.0 × 10−5 M 13 15.62% 18 0.65 V 32 1.4 × 10−6 M 37 (a) Ksp fBa2+ fSO4 2− (c) Ag+ /Cu (b) Ksp fAg+ fCrO4 2− 20 PtCl6 2− + 2V2+ = PtCl4 2− + 2V3+ + 2Cl− , 0.94 V 21 (a) 0.57 V (b) 0.071 V (c) 0.09 V 22 2VO2 + + U4+ = 2VO2+ + UO2 2+ , 0.67 V 23 0.592 V 24 (1) Cu: 0.286 V; Ag: 0.740 V; cathode (3) 0.277 V; anode (2) 0.706 V; cathode Christian7e a06.tex V2 - 08/13/2013 8:54 A.M Page 813 CHAPTER 17 813 16 4.96 meq/L CHAPTER 13 5.4 × 10−13 17 11.5% Na2 HAsO3 , 3.54 % As2 O5 0.799 V 18 1.47 mL 10 (a) −0.028 V 11 (a) 1.353 V (b) 0.639 V (c) 0.84 V 19 3.8 × 10−3 M (b) 0.034 12 3PVF + AuCl4 − = 3PVF+ + Au + Cl− , K = 6.9 × 1070 (b) −0.020 V 13 (a) 0.845 V (c) −0.497 V 14 0.446 V 15 (a) × 10−4 % (b) 0.084 V CHAPTER 15 7.7 × 10−5 M 10 [Fe3+ ]/[Fe2+ ] = : (c) 0.261 V 11 c 16 −0.505 V 17 (a) 0.02 pH unit, 1.2 mV, 4.8% (b) 0.002 pH unit, 0.12 mV, 0.48% 18 (a) 5.78 (b) 10.14 (c) 12.32 (d) 13.89 CHAPTER 16 29 0.25 μ m, 250 nm 20 11.2 30 7.5 × 1014 Hz, 25, 000 cm−1 ˚ 5, 000 − 670 cm−1 31 20, 000 − 150, 000 A; 21 0.015 M 32 9.5 × 104 cal einstein−1 19 (a) −0.419 V (b) −0.472 V (d) −0.524 V 33 0.70 A, 0.10 A, 0.56 T, 0.10 T 22 0.0079 M −4 23 4.8 × 10 M 34 20 24 (a) 0.16) (b) 18.9 mV 35 4.25 × 103 cm−1 mol−1 L 25 0.020 36 (a) 0.492 (b) 67.8% 26 9.5 × 10 37 5.15 × 10 cm−1 mol−1 L 27 1.07 × 104 38 1.25 −4 39 0.528 g CHAPTER 14 40 79.0% (a) IO3 − + 5I− + 6H+ = 3I2 + 3H2 O (b) 4Se2 Cl2 + 6H2 O = 2H2 SeO3 + 6Se + 8Cl− + 8H+ (c) H3 PO3 + 2HgCl2 + H2 O = H3 PO4 + Hg2 Cl2 + 2H+ + 2Cl− (a) 3MnO4 2− + 2H2 O = MnO2 + 2MnO4 − + 4OH− (b) 2MnO4 − + 5H2 S + 6H+ = 2Mn2+ + 5S + 8H2 O (c) 2SbH3 + 4Cl2 O + 3H2 O = H4 Sb2 O7 + 8Cl− + 8H+ (d) FeS + 3NO3 − + 6H+ = Fe3+ + S + 3NO2 + 3H2 O (e) 8Al + 3NO3 − + 5OH− + 2H2 O = 8AlO2 − + 3NH3 (f) 5FeAsS + 14ClO2 + 12H2 O = 5Fe3+ + 5AsO4 3− + 5SO4 2− + 14Cl− + 24H+ (g) 5K2 NaCo(NO2 )6 + 12MnO4 − + 36H+ = 10K+ + 5Na+ + 5Co3+ + 30NO3 − + 12Mn2+ + 18H2 O 41 (a) 0.152 g/L (b) 0.193 g/day 42 0.054 mg 43 0.405 ppm N 44 1.593 45 4.62 mg/L, 2.61 mg/L 46 0.332% Ti, 1.62% V 48 (a) 1.3 × 10−7 M (b) 200 50 (b) slope = εb2 as c → and εb1 as c → ∞ 51 (a) 256 nm (b) Deuterium or xenon-arc LEDs also available (c) Quartz or fused silica cells CHAPTER 17 10 0.715 V, 0.771 V, 1.35 V, 1.46 V 24 1.5 ppm per 0.0044 A 11 0.360 V 12 E = [(1)E0 Fe3+ , Fe2+ + (2)E0 Sn4+ ,Sn2+ ]/[(1) + (2)] 13 E = (nFe E0 Fe3+ ,Fe2+ + nMn E0 MeO4− ,Mn2+ )/(nFe + nMn ) − [(8)(0.059)/(nFe + nMn )]pH, 1.33 V (for pH 0.68) 14 (a) 0.319 V, −0.780 V, 1.6 × 1012 2.6 × 1022 15 8.9 ppm (b) 0.691 V, −0.154 V, (c) 120 49 551 nm 1.127 V 0.735 V, 0.771 V, 1.218 V, 1.28 V (c) 0.25 25 13% 26 4.5 × 10−9 % 27 190 ppm 28 5.9 ppm 29 84 ppm 30 79 M&Ms in the bag Christian7e a06.tex V2 - 08/13/2013 8:54 A.M Page 814 ANSWERS TO PROBLEMS 814 98 κ = 6.37 × 103 cm−1 CHAPTER 18 12 D = KD (1 + 2Kp KD [HBz]a )/(1 + Ka /[H+ ]a ) 13 8.0 14 48% 15 95% 99 G = 23.5 nS 103 pH 9.00: μeo = 2.3 × 10−8 m2 /V s Net flow is towards the negative electrode pH 3.00, μeo = −2.0 × 10−8 m2 /V s Net flow is towards the positive electrode 16 0.016 M 104 Rs = 28 17 96.2% extracted with 10 mL; 99.45% extracted with × mL 106 5.1 18 2.7% 19 (a) 1.3 × 10−7 (b) 200 107 0.119 mM 109 35.22, 34.92, 32.41 ng/mL (c) 123 CHAPTER 22 CHAPTER 19 0.041 cm/plate 16 217.07017 Da 1.06 × 10 cm 17 [M − H]− , m/z 155 = 100%; M + 1, m/z 156 = 7.7%; M + 2, m/z 157 = 33% 10 mL/min, N, H: 120.2, 2420, 0.123; 90.3, 2500, 0.120; 71.8, 2550, 0.118; 62.7, 2380, 0.126, 50.2, 2230, 0.135; 39.9, 1830, 0.164; 31.7, 1640, 0.183 Optimum near 75 mL/min 11 Rs = 0.96 Not quite resolved 18 R = 69, 692 19 RFWHM = 10, 665 20 R = 34 21 −2.03 ppm CHAPTER 20 22 v = 6.67 × 105 m s−1 23 14 ns 10 2810 torr inlet pressure 11 20.9 ppm CHAPTER 23 CHAPTER 21 80 (a) 2058 plates (b) 0.014 cm (c) 1.09 (d) 57 cm (e) tRA = 29.86 min; tRB = 32.56 81 270 mmol/L 12 48.5 s 13 38 min; 19 min, 3.4 14 12.7 h 82 6.7 g resin 83 (a) HCl (b) H2 SO4 11 33.2 min, 66.5 (c) HClO4 (d) H2 SO4 86 Hz 87 61 μg/mL 15 132 h 16 3.82% 17 Km = 1.20 ± 0.05 mM 88 277.5 nm 90 120 nL; CCl /CIO3 = 0.53 CHAPTER 26 91 CCl /CIO3 = 0.25 3.3 × 10−6 g/Lair 94 MeOH : H2 O: 141 psi; acetronitrile : H2 O: 73.5 psi 380 ppt 95 For 0.02 μM LiOH, 54.4 S/cm; For H2 O, 54,8 nS/cm 96 149.85 μS/cm 97 (a) DK+ = 1.95 × 10−9 m2 s−1 ; DCl− = 2.03 × 10−9 m2 s−1 (b) rK+ = 0.125 nm; rCl− = 0.120 nm CHAPTER G 16 ATTGCATTCCGTA Christian7e bindex.tex V1 - 08/21/2013 12:29 A.M Page 815 Index Pages preceded by a letter are for text website materials: C Clinical chemistry, Chapter 25 E Experiments EN Environmental, Chapter 26 G Genomics, Chapter G P Periodic table, Appendix E S Safety, Appendix D A Absolute cell reference, 114 video, 115 Absolute error, 71 Absolute method, 13 Absolute uncertainty, 66 Absorbance, 495 optimal range, 526 Absorbance calibration, 518 Absorbance ratio plotting, 682 Absorption spectrum mechanism, 531 Absorptivity, 496 Accelerated solvent extraction, 585 Accuracy, 62 relative, 71 in validation, 137 Acid concentrations, inside back cover Acid-base concepts, 222 Acid-base equilibria in water, 225 Acid-base reactions in different solvents, 224 Acid-base theories, 223 Acid-base titration experiment, E12 Acid-base titrations, amino acids, 309 polyprotic acid, 310 strong acid, 282 weak acid, 290 weak base, 295 Acidic solution, 229 Acidosis, 261 Activated complex, 772 Activation overpotential, 470 Activity, 212 enzyme, 774 Activity coefficient, 212 in dilute solution, 212 calculation of, 213 properties of, 216 nonelectrolytes, 217 neutral species, 217 Adenine, G3 Adsorption chromatography, 604 Adsorption indicators, table of, 380 Affinity chromatography, 654 Air analysis sampling train, EN4 Air monitoring, 642 Air sample analysis, EN7 Air sample bags, EN7 Air sample collection, EN2 aerosol constituents, EN6 sample size, EN3 Air sampling devices, EN6 Air sampling pumps, EN5 Albumin determination, C6 Aliquot, 31 Alkali reserve, 261 Alkaline solution, 229 Alpha(α)-values, 248 log-concentration diagram from, 276 Chapter website Amino acids, thin-layer chromatography separation, E67 titration, 309 Ammonia buffer pH 10 solution, E20 Amperometric electrode, enzymatic, 473 oxygen, 472 Amphoteric, 691 Amphoteric salts, 255 Analgesics, HPLC determination, E71 Analysis sample, Analysis variance, 111 Analyte, 8, 16 Analytical balance, 23 electronic, 25 micro, 26 semimicro, 26 use of, E1 Analytical chemistry history, Analytical chemistry journals, 794 Analytical concentration, 156, 195, 248 Analytical methodology, hierarchy of, 144 Analytical methods, comparison of, 13 Analytical process, defining the problem, Analytical results, expressions of, 159 Analytical science, definition, Analyze, 16 Angstrom, 214 Anion exchange resins, 659 separation of metal ions, 660 Anode, 385 Anodic current, 469 Antibody, C7 monoclonal, C10 Antibonding orbital, 485 Anticoagulant, 9, C3 Antigen, C7, C8 Antigen-antibody complex, C7 affinity, C8 avidity, C8 Antimony, iodine titration, E34 Anti-serum, C7 APC tablets, UV analysis, E54 Archimede’s principal, 26 Argon ionization (β-ray) detector, 633 Array spectrometer, 522 Arrhenius, Svante, 223 Arrhenius theory, 223 acid, 223 base, 223 Ascarite, 42 53 Aspirin, back titration of, E17 HPLC determination, E71 standard solution, E71 UV determination, E54 Asymmetry potential, 414, 416 Atomic absorption spectrometry, 556 background correction, 564 ionization interference, 566 light sources, 558 spectral interferences, 564 Atomic emission spectrometry, 569 Atomic fluorescence spectrometry, 549, 574 Atomic spectrometry, 572 physical interferences, 567 sample preparation, 567 Atomic weight, 149 Atomic weights, inside front cover ATR, 548 Attenuated total reflectance, 525 Autocatalytic decomposition, 452 Automated devices, 785 815 Christian7e bindex.tex INDEX 816 Automated instruments,775 Automatic devices, 784 Automatic instruments, 787 Automatic titrator, 463, 785 Automation, 784 Autoprotolysis, 226 Autoprotolysis constant, 226 Auxiliary electrode, 467 Auxochrome, 485 Average linear velocity, 610 Avogadro’s number, 150, 151 proposed change, 150 B BAC, G7 Back extraction, 585, 586 Background electrolyte, 711 Back titration, 177 of aspirin, E16 Bacterial artificial chromosome, G7 Balance, see Analytical balance Balancing redox reactions, 437 Balometer, 517 0–0 Band, 531 Band broadening, 607 Bandpass, 518 Bandwidth, 518 Base concentrations, inside back cover Base peak, 737 Baseline method, 503 Bases, conjugate acids, 234 Basic solution, 229 Batch instruments, 788 Bates, Roger, 419 Bates-Guggenheim convention, 419 Bathochromic shift, 486 Beckman, Arnold, 409 Beer’s law deviations, chemical, 527 instrumental, 529 Beer’s law, 494 and mixtures, 498 Beta(β)-values, 336 BGE, see Background electrolyte Bicarbonate in blood, titration of, E18 Biogel, 653 Biohazard hood, 45 Bioluminescence, 539 Biot’s law, 685 Biuret rection, 488 Blank, 11 Blank solution, 520 Blood collection, C3 Blood composition, C2 normal ranges of constituents, C2 Blood glucose determination, C4 Blood pH, 231 measurement of, 442 standard buffer for, 420 Blood plasma, 10, C2 Blood serum, 9, C2 Blood urea nitrogen determination, C4 Boosted discharge hollow cathode lamp, 575 Boosted HCLs, 559 V1 - 08/21/2013 12:29 A.M Page 816 Boundary potential, 416 Boyle, Robert, Breathalyzer, 491 Bromcresol green solution, E15 Bromthymol blue, 288 Brønsted acid, salt of weak base, 236 Brønsted base, salt of weak acid, 234, 236 Brønsted-Lowry theory, acid, 224 base, 224 Buffer, composition, 238 definition, 238 Buffer calculations, 238 polyprotic acids, 245 Buffer capacity, 307 Buffer index, 240 Buffer intensity, 240, 292 derivation of, supplement 8.11 website program for, 307 Buffer region, 292 Buffering capacity, 240 maximum, 243 total, 292 Buffering intensity, maximum, 241 Buffering mechanism, 240 Buffers (see also Standard buffers), biological, 263 clinical, 263 Good, 265 phosphate, 245, 263 physiological, 261 Tris, 264 Bunsen, Robert 548 Buret, 35 calibration of, 40 use of, E2 Burners for flame spectrometry, 554 C Caffeine UV, determination, E54 Calcium, atomic absorption determination, E57 EDTA titration in blood, 336 standard solution, E58 Calcium-selective electrode, 425 Calgamite indicator, 335 Calibration curve, 13 calculation of unknown with spreadsheet, 502 potentiometric, 411 spreadsheet plotting of, 117 Calibration of glassware, 37 Calomel electrode, 402 Capacity factor, 609 Capillary column manufacturers, 626 Capillary electrochromatography, 725 Capillary electrophoresis, 708, 711 detectors, 715 injection modes, 712 micro-chip, 723 plate numbers, 721 resolution, 721 separation efficiency, 716 Capillary gel electrophoresis, 708 Capillary isoelectric focusing, 710 Capillary zone electrophoresis, 708 Carbon dioxide removal, 697 Carbon electrode, 471 Carrier gas, 620, 621 Catalyst, 193, 771 Catalytic combustion detector, 632 Catalytic electrode, 473 Cathode, 385 Cathodic current, 469 Cation exchange resins, 381, 659 CCD, see Charge coupled device CD, see Cyclodextrin CE, see Capillary electrophoresis Cell constant, 677 Cell potential, 385 Cell voltage, 388 and reaction tendency, 392 Cell without liquid junction, 404 Cell without transference, 404 Cerium (IV) primary standard, 453 Certified standards, 15 CF, see Cyclofructan 21 CFR, Part 11, 145 Characteristic of logarithm, 70, 798 Charge balance equations, 205 Charge balance method, Excel for acid-base titration, 285 pH of phosphoric acid, 253 Charge concentration, 205 Charge transfer transition, 489 Charge-coupled device, 516 Chelate effect, 326 Chelate, 325 light absorption mechanism, 489 solvent extraction, 336 Chelating agent, 168, 325 gravimetric precipitate, 354 Chelometric titration, 325 Chelon effect, 326 Chemical abstracts, 794 Chemical literature, Chemically modified electrode, 472 Chemiluminescence, 538 Chiral chromatography, 654 Chiral compounds, separation of, 644 Chiral stationary phases, 663 Chloride, Fajan determination, E23 FIA determination, E79 gravimetric determination of, E6 potentiometric titration, E40 spectrophotometric determination, E79 standard solution, E79 Chlorofluorocarbon determination, EN8 Chromatogram, 604 Chromatographic separations, principles of, 603 Chromatographic technique types, 604 Chromatography nomenclature, 605 Chromatography resolution, 615 Chromatography terms, 606 Chromatography, adsorption, 604 column efficiency, 607 (see also Column efficiency) ion exchange, 605 IUPAC definition, 597 Christian7e bindex.tex V1 - 08/21/2013 12:29 A.M Page 817 INDEX meaning, 597 normal-phase, 605 numerical simulation, 600 partition, 605 resolution equation, 615 reversed-phase, 605 simulation software, 616 size exclusion, 605 types, 597 Chromium, spectrophotometric determination, E50 standard solution E51 Chromogen, 485 Chromophore, 485 conjugated, 487 Chromosomes, G1 Chromosorb P, W, 620, 623 Circular dichroism, 685 Clausius, Rudolf Julius Emanuel, 192 Clinical chemistry, C1 common determinations, C4 CME, 472 Codon, G14 Coefficient of determination, 105 spreadsheet calculation, 118 Coefficient of variation, 74 Coenzyme, 774 Cold vapor AAS, 549 Cold vapor generation, 563 Colloidal particles, 346 Color, complementary, 478, 481 Column bleed, and GC-MS, 628, 745 Column efficiency, and particle size, 614 Combination absorption bands, 491 Combination pH electrode, 415 COMERRR, 145 Common ion effect, 203 Complementary color, 478, 481 Complex, 194 Concentration, analytical, 156, 195, 248 charge, 205 effective, 212 equilibrium, 156, 195, 248 from electrode potential, 411 volume/volume for gases, EN2 Concentration sensitive detectors, 637 Confidence interval, 84 Confidence level, 84 Confidence limit, 75, 84 using the range, 99 Conjugate pair, 224 Conjugated chromophore, 487 Continuous analyzers, 786 Continuum source AAS, 563 Control charts, in quality assurance, 143 Control limits, 83 Control sample, 15 Control-loop, 786 Copper, iodometric determination, E32 Coprecipitation, 347 Correlation coefficient, 104 Cotton effect, 685 Countercurrent extraction, 598 Craig, Lyman C., 600 Critical micelle concentration, 725 817 Crosslinking of resins, 659 Crown ether, 427 Crucible holder, 46 Crucible, Gooch, 46 porcelain filter, 46 sintered glass, 46 CSP, see Chiral stationary phase Current, anodic, 469 cathodic, 469 Current-voltage curve, 468 Cyclodextrins, 644, 664 Cyclofructans, 664 Cytosine, G3 CZE, see Capillary zone electrophoresis D Dalton, 150 Dark current, 513 Dark response, 520 Data analysis regression, video, 87 Davies equation, 215 Davy, Humphry, 222 Dead time, 786 Deaeration, 471 Debye, Peter J W., 213 Debye-H¨uckel equation, 213 Davies modification, 215 Extended, 213 Decomposition potential, 468 Defining the analytical problem, Degeneracies, 550 Degrees of freedom, 72 pooled standard deviation, 90 Dehydrite, 53 Dehydrogenase reactions, 779 Denatured protein, 773 Density, 155 of air, 26 Deoxyribonucleic acid, G3 (see also DNA) Depolarized electrode, 469 Depolarizer, 469 Derivative titration curves, program for,304 Derivative titration, 458 Desiccator, 43 vacuum, 43 Detection limit, 105 Determinate error, 63, 75 (see also Systematic error) Determine, 16 Deviation factor, 99 Dichlorofluorescein solution, E23 Dideoxynucleotides, G8 Diffraction grating, 506 dispersion, 508 resolving power, 508 Diffraction grating equation, 507 Diffraction order, 507 Diffusion layer, 469 Diffusion potential, 416 Digestion of precipitates, 345 Dihydrogen phosphate pH, 256 Dilution calculations, 156 Dimensional analysis, 153 Dipole moment, 489 Discrete analyzers, 787 Dissociation constant, 323 Dissociation constants for acids, 801 Dissociation constants for bases, 802 Dissolving samples, 52 inorganic solids, 52 Distribution coefficient, 579 Distribution ratio, 580 Dithizone, 336, 584 Diverse ion effect, 217 on acids and bases, 266 Diverse salt effect, 212 DME, 471 DNA, G3 (see also Deoxyribonucleic acid) DNA annealing, G6 DNA chips, G-12 DNA hybridization, G6 DNA microarrays, G-12 DNA oligonucleotide, G3 DNA polymerase, G6 DNA replication, G6 DNA sequencing, G8 Donnan potential, 654 Double-antibody technique, C10 Draft genome, G13 Dropping mercury electrode, 471 Drude’s equation, 685 Dry ashing, 11, 52 Dry electrolytic detector, 636 Drying agents, 44 Drying oven, 45 Drying samples, 51 Dry-test meter, EN4 E Eddy diffusion, 610 EDTA, 325 ladder diagram 327 pH, 260 primary standard, 335 standard solution, E20 titration curves, 331 EDTA complexes, formation constants of, 805 EDTA equilibria, 326 pH effect, 328 Effective concentration, 212 e-folding time, 672 EGTA, 349 Einstein relation, 677 Electrical conductance, 677 Electrical mobility, 676 Electrocatalyst, 473 Electrochemical cell, 384 (see also Voltaic cell) Electrochemical sensor, 472 Electrode, ultramicro, 474 Electrode offset, 441 Electrode potential, 385 limitations, 395 measuring, 385 Electrodeless discharge lamp, 559 Electrolytic cell, 384 Electromagnetic radiation, 479 absorption of, 480 Electromagnetic spectrum, 479 Christian7e bindex.tex INDEX 818 Electrometer, 409 Electron capture detector, 634 Electron multiplier, 746 Electroneutrality principle, 205 Electronic balance, 25 use of, E1 Electronic notebook, 23 Electronic records, 145 Electronic signatures, 145 Electronic transition, 481, 482 kinds of, 485 Electroosmotic flow, 711, 717 Electrophoresis, 708 (see also Capillary electrophoresis) Electrophoretic mobility, 719 Electrostacking, 714 Electrostatic precipitator, EN6 Electrothermal AAS, 549 Electrothermal atomization, 561 Electrothermal atomizer, detection limits, 563 ELISA, C11 Emission filter, 535 End point, 35, 167, 282, 288 End-capping, 655 Endonuclease, G5 Enthalpy, 191, 326 standard, 191 Entropy, 191, 326 standard, 191 Enzymatic analysis examples, 779 Enzyme activity, 774 Enzyme determinations, 781 Enzyme electrode, amperometric, 473 Enzyme immunoassay, C11 Enzyme inhibitor determination, 782 Enzyme inhibitors, 774 Enzyme kinetics, 772 pseudo first-order, 773 Enzyme nomenclature, 776 Enzyme specificity, 776 Enzyme substrate determination, 777 Enzyme-linked immunosorbent assay, C11 Enzymes, 772 competitive inhibitors, 774 determination of, 777 molecular activity, 774 noncompetitive inhibition, 774 properties of, 802 specific activity, 774 substrate inhibition, 774 EOF, see Electroosmotic flow EPA performance-based analysis, EN13 Equilibria, concentration effects, 193 heterogeneous, 211 pressure effects, 192 types, 190 Equilibrium calculations, approximation approach steps, 207 chemical reactions, 195 dissociating species, 201 Goal Seek, 198, 204 simplifying assumptions, 200 systematic approach steps, 207 Equilibrium concentration, 156, 195, 248 Equilibrium constant, V1 - 08/21/2013 12:29 A.M Page 818 acid, 225 concentration, 217 and Gibbs free energy, 191 molar, 189, 227 redox reaction calculation, 438 temperature effects, 192 thermodynamic, 217 Equilibrium constants, precipitates, 194 stepwise, 194 strong electrolytes, 194 weak electrolytes, 194 Equilibrium potential, 391 Equivalence point potential, 440 Equivalence point, 167, 282 Equivalent conductance at infinite dilution, 677 Equivalent weight, 154, text website Chp5 in clinical chemistry, 154 Eriochrome Black T, 334 Eriochrome BlackT solution, E20 Error, 75 (see also Propagation of errors) absolute, 71 mean, 71 relative, 71 types of, 15 Error bars, video, 102 Erythrocytes, C1 Ethylenediaminetetraacetic acid, 325 (see also EDTA) Evanescent wave, 541 Excel Solver, see Solver Excel, see Spreadsheets, Videos Exchange capacity of resin, 659 Excitation filter, 535 Excited state, 504 Exclusion limits in gel chromatography, 653 Exonuclease, G5 Exponents, 797 Expression profiling, G13 Extended Debye-H¨uckel equation, 213 F F values table, 87 Fab fragment, C7 Fajan determination, E23 Fajan’s method, 380 Faraday cup, 763 Faraday’s scheme, 685 Far-IR region, 480, 482 Fast LC, 701 Fc fragment, C7 Feedback mechanism, 786 Fellget’s advantage, 524 Femto, 159 Ferric alum indicator solution, E21 FIA, see Flow injection analysis Fiber optic sensors, 540 Fiber optics, numerical aperture, 511 Fibrin, Fibrinogen, 9, C1 Filter papers, ashless, 46 types of, 47 Filtration, of precipitates, 348 techniques of, 46 Fingerprint IR region, 490 Fingerprints, fluorescence detection, 538 Firebrick, 620 First derivative titration, for Gran plot, 461 First-order reaction, 770 pseudo, 771 Flame AAS, principles, 557 Flame AAS, 549 Flame atomization, 560 Flame emission spectrometery, 549, 553 Flame ionization detector, 632 Flame photometer, 553 Flame photometry, 549 flames 553 Flame spectrometry burners, 554 Flame thermionic detector, 633 Flow injection analysis, 789 system characterization, E76 Fluorescein indicator, 380 Fluorescence immunoassay, C10 Fluorescence inhibition, 533 Fluorescence instrumentation, 535 Fluorescence quenching, 533 Fluorescence spectrometry, 505 Fluorescence, and chemical structure, 533 and concentration, 534 gated measurements, 537 lifetime measurements, 537 mechanism, 530 phase-resolved, 537 time-resolved, 537 Fluoride, ion-selective electrode determination, E25 standard solution, E26 Fluoride-selective electrode, 425 Fluorometer, 535 Fluorometry, 530 Foley Dorsey equation, 608, 609 Forbidden transition, 491, 532 Formal electrode potentials, 806 Formal potential, 394 Formality, 155 Formation constant, 323 Ca-EDTA, 327 conditional, 329 cumulative, 336 Formation constants of EDTA complexes, 805 Formula weight, 150 Formula weights, inside front cover Fourier transform infrared spectrometer, 523 Fourier transformation, 524 Fourier transform-ion cyclotron resonance (FT-ICR), 761 Franklin and Germann theory, 224 Fraunhofer, Joseph von, 548 Fraunhofer lines, 549 Free energy, standard, 191 Frequency domain spectrum, 524 Frequency, 479 Fresenius, Karl Remigius, Fresnel loss, 527 F-test, 86 video, 88 Christian7e bindex.tex V1 - 08/21/2013 12:29 A.M Page 819 INDEX FTIR, see Fourier transform infrared spectrometer Full spectrum analysis, 522 Full-width half maximum, 505 Fume hood, 45 Fusion, 52 fw, 150 FWHM, 505 G Galvanic cell, see Voltaic cell Gaol Seek, limitation of, 199 Gas adsorption tubes, EN6 Gas analyzer calibration, EN9 Gas chromatography, 619 adsorption, 619 of chiral compounds, 644 compounds determined, 622 high speed, 643 partition, 619 pyrolysis, 642 quantitative measurements, 639 temperature programming, 638 temperature selection, 638 two-dimensional, 645 of volatile organic compounds, 643 Gas chromatography columns, capillary, 624 manufacturers, 626 packed, 623 porous-layer open-tubular (PLOT), 625 support coated open tubular (SCOT), 625 wall-coated open-tubular (WCOT), 624 Gas chromatography detectors, 630 argon ionization (β-ray), 633 atomic emission, 634 catalytic combustion, 632 concentration vs mass flow sensitive, 637 dry electrolytic, 636 electron capture, 634 flame ionization, 632 flame thermionic, 633 Hall electrolytic conductivity, 635 helium ionization, 634 nitrogen-phosphorus, 633 phosphorus, 633 photoionization, 635 pulsed discharge, 634 sulfur, 633 sulfur and nitrogen chemiluminescence, 635 thermal conductivity, 630 vacuum ultraviolet, 637 Gas chromatography experiment, E69 Gas chromatography-mass spectrometry, 622, 741 (see also GC-MS) column bleeding, 745 ionization sources, 741 Gas chromatography stationary phases, 626 carbowax, 626 ionic-liquid, 628 retention indices, 628 selection of, 628 Gas constant, 191 Gaussian curve, 64 819 Gaussian distribution, of analyte in bulk material, 109 Gay-Lussac, Joseph, 378 GC x GC, 619, 623, 645 (see also Two-dimensional chromatography) GC, see Gas chromatography GC-MS, 622 (see also Gas chromatography-mass spectrometry) GC-MS experiment, E72 GC-VUV, 637 Gel filtration chromatography, 653 Gel permeation chromatography, 653 Gene expression profiling, G13 Gene expression, G1 Gene sequencing, G3 Genetic code, G14 Genomic library, G7 Genomics, G13 GF, see Gravimetric factor Gibbs free energy, 191 (see also Free energy and equilibrium constant) Gibbs, J Willard, 191 Gibbs-Stockholm convention, 386 Glass pH electrode, acid error, 418 alkaline error, 416 calibration, 414, E24 high pH (full range), 417 mechanism, 415 principle of, 413 Glassware calibration, E4 Glassware cleaning, 729, E3 Globar, 528 Globulin determination, C6 GLP, see Good laboratory practice Glucose, enzymatic determination, E74 standard solution, E75 Glucose determination, 780 Glucose electrode, 473 Glucose oxidase, 776 Glycolysis, C3 GMP, see Good manufacturing practice Goal seek, charge balance method titration curve, 285, 293 equilibrium calculation, 198 eliminating premature solution, 202 method of charge balance for pH, 253 pH of phosphoric acid, 253 polynomial equation solution, 199 shortcomings and solution, 202 Golay, Marcel J E., 624 Golay equation, 613 Gooch crucible, 46 Good buffers, 265 Good laboratory practice, 133 in TLC, 703 Good manufacturing practice, 145 Grab sample, Grades of chemicals, inside back cover Gradient elution in HPLC, 701 in HPTLC, 706 Gradient elution in HPLC, pumping systems, 668 Gran plot, 459 advantage, 460 from first derivative, 461 volume correction, 460 Graphing, using spreadsheets, 112 Graphite Furnace AAS, 549 Grating, see Diffraction grating Gravimetric analysis, 12 examples, 353 precipitation conditions, 345 precipitation process, 344 steps of, 343 weight relationships, 180 Gravimetric calculations, 349 mixtures, 352 Gravimetric factor, 181, 349 examples, 182 Gross sample, Ground state, 482 Groundwater sampling, EN10 Grubbs test for outliers, 97 Guanine, G3 Guard column, 672 Gylcolyis, prevention, E19 H Hagen-Poiseuille equation, 676 Hair shampoo pH determination, E24 Half-life, 770 second-order reaction, 771 Half-reaction potential, 386, 438 Half-reaction, 386, 438 Half-wave potential, 469 Hall electrolytic conductivity detector, 635 Hamilton syringe cleaning, E69 HCL, see Hollow cathode lamp Headspace analysis, 641 Helium ionization detector, 634 Helmholtz, Hermann L F Von, 717 Helmholtz plane, 717 Hemolysis, C3 Henderson-Hasselbalch equation, 238 thermodynamic equilibrium constant, 266 Heparin, 830, C3 Heptane, GC determination, E69 Heterogeneous equilibria, 211 Hexane, GC determination, E69 High performance liquid chromatography, 651 (see also HPLC) principles of, 651 stationary phases, 654 (see also HPLC stationary phases) subclasses, 652 High performance thin-layer chromatography, 703, 704 gradient elution, 706 High speed gas chromatography, 643 HILIC, see Hydrophilic interaction chromatography Hollow cathode lamp, 558 boosted, 559 boosted discharge, 575 Horseradish peroxidase, 780 HPLC, 651 (see also High performance liquid chromatography) Christian7e bindex.tex INDEX 820 HPLC (continued) gradient elution, 701 open tubular, 702 narrow bore columns, 701 subclasses, 652 two-dimensional, 699 HPLC detectors, aerosol charge, 681 amperometric, 686 capacitive coupled contactless conductivity (C4 D), 681 chemiluminescence, 688 chiral, 685 condensation nucleation light scattering, 681 coulometric, 686 criteria for, 672 electrical conductivity, 676 evaporative light scatter, 779 fluorescence, 684 mulitangle light scattering, 676 photodiode array (PDA), 682 polarimetric, 685 position sensitive, 674 pulsed amperometric, 686 radioactive, 689 refractive index, 673 universal, 673 UV-Visible, 682 viscosity, 676 HPLC equipment, 665 column designs, 670 column oven, 672 detectors, 672 (see also HPLC detectors) guard column, 672 pumps, 667 sample injection system, 669 solvent delivery system, 666 HPLC method development, 700 HPLC-MS (see Liquid chromatography-mass spectrometry) HPLC stationary phases, alumina, 665 high-purity silica, 654 microporous particles, 655 monolithic, 661 perfusion packings, 656 porous graphitic carbon, 665 nonporous packings, 657 superficially porous particles, 657 titania, 665 zirconia, 665 HPTLC, see High performance thin-layer chromatography Huber equation, 613 H¨uckel, Erich, 213 Human Genome Project, G3 Hybridization, G6 Hydride generation, 563 Hydrochloric acid, standardization of, E15 standard solution of, 42 Hydrogen electrode, 403 (see also NHE) Hydrolysis, 234 Hydrolysis constant, salt of weak acid, 235 salt of weak base, 237 V1 - 08/21/2013 12:29 A.M Page 820 Hydronium ion, 225 Hydrophilic interaction chromatography, 653 stationary phases, 663 Hydrophilic, 347 Hydrophobic, 347 8-Hydroxyquinoline, see Oxine Hyperchromic shift, 486 Hyperchromism, 486 Hyperconjugation, 487 Hypochlorite, iodometric titration, E30 Hypochromism, 486 Hypsochromic shift, 486 I IC, see Ion chromatography ICP-MS, 572 (see also Inductively coupled plasma-mass spectrometry) IEC, see Ion exchange chromatography Immunoassay, heterogeneous, C11 homogeneous, C11 principles of, C7 Immunoassay specificity, C9 Immunoglobulins, C7 Immunology, C7 Impactor, EN6 Impedance, high input, 410 Impinger, EN6 Inclusion in precipitates, 347 Indeterminate error, 64 (see also Random error) Indicator electrode, 400, 404 Indicator, 167, 288 (see also pH indicator) adsorption, 378, 380 chelometric, 334 pH transition range, 288 precipitation, 378 Induction coupled plasma, 569 Induction coupled plasma spectrometry, 549, 569 (see also Inductively coupled plasma spectrometry) Induction coupled plasma mass spectrometry, 550 Inductively coupled plasma-mass spectrometry, 753 (see also Induction coupled plasma mass spectrometry) isobaric interferences, 753 Infrared radiation, absorption of, 489 Infrared spectra, 490 quantitative measurements, 503 Ingamell’s sampling constant, 108 Inner-filer effect, 534 Instability constant, 323 Instrument standardization, 13 Instrumental analysis, 12 Intercept, spreadsheet calculation, 118 standard deviation of, 102 Interferogram, 523 Interferometer operation, 523 Interferometer, 505 Internal conversion, 531 Internal standard calibration, 14 Internal standard, in atomic spectrometry, 567 in gas chromatography, 640 isotopically labeled, 747 International unit, 774 Intersystem crossing, 531 Iodide, potentiometric titration, E40 Iodimetry, 447 Iodine solution, standardization, E34 Iodometric calculations, 450 Iodometry, 449 end point detection, 450 potentiometric titration, E40 Ion chromatography, 653, 692 anion, 693 cation, 693 carbon dioxide removal, 697 electrodialytic eluent generation, 697 membrane suppressors, 696 nonsuppressed, 694 suppressor column, 693 Ion chromatography exclusion, 654 Ion cyclotron resonance, 760 Ion detectors, 763 Ion exchange chromatography, 605 of amino acids, 691 Ion exchange chromatography, 652 Ion exchange phases in modern chromatography, 660 Ion exchange resins, 658 anion, 659 cation, 659 gel-type, 658 macroreticular, 659 Ion exclusion chromatography, 654 Ion mobility spectrometry, 762 Ion pair chromatography, 699 Ion size parameter table, 214 Ion size parameter, 214 Ionic mobility, 676 Ionic strength, 212 weak acids, 213 Ionophore, 426 Ion-selective electrodes, advantages and disadvantages, 431 glass membrane, 424 liquid-liquid, 425 measurements with, 430 mechanism of response, 427 plastic membrane-ionophore, 426 potential of, 427 selectivity coefficient, 428 selectivity coefficient determination, 430 sensitivity of, 430 solid-state, 424 in titrations, 458 IR absorption requirement, 489 IR absorption, and molecular structure, 489 iR drop, 467 IR region, 480 Iron, dichromate titration, E27 spectrophotometric determination, E41, E43 standard solution, E42 Irreversible reaction, 398, 447 Irreversible reduction/oxidation, 470 Isoelectric focusing, 710, G15 Christian7e bindex.tex INDEX Isoelectric point, 691 Isoenzyme, 781 Isomorphous replacement, 347 Isopotential point, 421 Isosbestic point, 526 Isotachophoresis, 726 Isotopes, relative abundances, 737 J Jacquinot’s advantage, 524 Johnson noise, 526 Joule heating, 719 K Kelvin, Lord, Kinetics, 769 of enzyme reactions, 772 Kirchoff, Gustav 548 Kjeldahl, Johan, 310 Kjeldahl analysis, 310 micro, 312 Kjeldahl digestion, 54 Kjeldahl flask, 57 Knox equation, 613 Kovats retention index, 628 L Laboratory information management systems (LIMs), 792 Laboratory materials, properties, 23 Laboratory notebook, 20 documentation of, 22 electronic, 23 Laboratory safety, 57, S1 Laboratory sample, Lactic acid dehydrogenase, 779 Ladder diagram, EDTA 327 Ladder diagrams, 247 Laminar flow, 716 Laminar-flow hood, 45 Laser ablation ICP, 573 Laser induced fluorescence, 685 Lavoisier, Antoine, Law of mass action, 188 LC-MS (see Liquid chromatography-mass spectrometry) LCW, fluorescence detector, 535 LCW, see Liquid core waveguide Le Chˆatelier, Henry-Louise, 192 Le Chˆatelier’s principle, 192, 193, 203 Lead, spectrophotometric determination, E47 standard solution, E47 Lead poisoning treatment with EDTA, 336 Least-squares line, significant figures, 120 Least-squares plots, 100 Leukocytes, C1 Lewis, Gilbert N., 225 Lewis theory, acid, 225 base, 225 Ligand, 323 bidentate, 325 V1 - 08/21/2013 12:29 A.M Page 821 821 Limit of detection, 105 in validation, 139 Limit of quantitation, 106 in validation, 139 Limiting current, 469 Limiting equivalent conductance, 677 Limiting molar conductivity, 679 LIMs, 792 Linear least squares, 99 (see also Least squares) Linearity, in validation, 136 LINEST Excel statistical programs, 120 LINEST, video, 120 Lineweaver-Burk equation, 774 Liquid chromatography-mass spectrometry, 242, 746 ionization sources, 741 of proteins, 747 Liquid core waveguide, 511, 684 Liquid junction, 405 Liquid-junction potential, 405 pH effect, 407 minimizing, 406 residual, 411 temperature effect, 420 Liquid-phase microextraction, 592 Literature of analytical chemistry, 794 Logarithmic concentration diagram, 266 acetic acid, 7.16.2 website from alpha-values, 267, Chapter website ammonium acetate, 269 phosphoric acid, 7.16.3 website spreadsheet construction, 267 system point, 7.16.2 website Logarithms, 797 characteristic, 70, 798 mantissa, 70, 798 significant figures, 70 logC-pH diagrams, master spreadsheet, 267 Longitudinal diffusion, 610 Lovelock, James E., 634 Lowry, Thomas, 224 Low-temperature ashing, 53 L’vov, Boris, 562 M MADI, 750 MALDI-TOF, G15 Manganese, spectrophotometric determination, E50, E52 standard solution, E50 Mantissa of logarithm, 70, 798 Martin, Archer J.P., 597 Masking agent,322 Mass action law, 188 Mass analyzers, 753 Mass balance equations, 204 multiple equilibria, 368 Mass flow sensitive detectors, 637 Mass spectrometry imaging, 752 Mass spectrometry, atmospheric pressure chemical ionization, 746, 748 atmospheric pressure ionization, 746 atmospheric pressure photoionization, 746, 749 base peak, 737 chemical ionization, 744 desorption analysis in real time (DART), 749 desorption electrospray ionization, (DESI) 749 desorption/ionization (NALDI), 751 double-focusing sector, 756 electron ionization, 741 electrospray ionization, 746 elemental formula determination, 740 inlet types, 741 ion cyclotron resonance, 760 ion trap mass analyzer, 757 ionization sources, 740, 741 (see also specific sources) laser desorption/ionization, 750 mass accuracy, 738 mass analyzers, 753 matrix-assisted laser desorption/ionization (MALDI), 750, G15 molecular ion, 742 MS/MS, 765 nanoparticle-assisted laser desorption/ionization (NALDI), 751 negative chemical ionization, 745 nitrogen rule, 740 parent ion, 742 principles, 735 quadrupole mass analyzer, 756 resolution, 737 rule of 13, 740 secondary ion, 752 tandem, 765 time-of-flight analyzer, 758 types of masses in, 736 unit resolution, 738 Mass spectrum, 737 Mass transfer term, 611 Mass, 24 Material safety data sheets, 58 Matrix, 136 Matrix-assisted laser desorption ionization (MALDI), 750, G15 Matrix effect, 136 Maxwell-Boltzmann distribution, 550 McReynolds constants, 629 Mean error, 71 Mean free path, 740, 754 Mechanical slit width, 518 Median, 97 efficiency of, 98 MEKC, 724 Meniscus, 30 Messenger ribonucleic acid (mRNA), G13 Metallic reductors, 476 Method of standard additions, see Standard additions Method of successive approximations, 199 Method validation, 134 Method validation experiment, E82 Methyl purple solution, E39 Methyl red solution, E36 Methyl red, solid-phase extraction of, E61 Micellar electrokinetic chromatography, 724 Michaelis constant, 774 Microbalance, 26 Christian7e bindex.tex INDEX 822 Microburet construction, E37 Microextraction, 590 Microliter, 159 Microplate reader, determination of manganese in steel, E52 spectrophotometric determination of iron, E43 volumetric measurements, E4 Microscale titration, E36 Microsoft Excel, see Spreadsheets Microsoft Excel, see Videos Microtiter plates for SPE, 589 Microwave digestion, 55 Microwave ovens, laboratory, 56 Microwave region, 482 Microwave-assisted extraction, 585 Migration current, 470 Millequivalent, 165 Milliequivalents, text websiteChp5 Milligram percent, 161 Milligrams per deciliter (mg/dL), 162 Millimole, 151 Minimum number of measurements, for a given error, 85 Mixed potential, 412 Modified methyl orange, 298, E15 Mohr method, 378 Molal, 155 Molality, 155 Molar, 152 Molar absorptivity, 496 Molar concentration, 226 Molar mass, 150 Molarity, 152 Molarity calculations, useful rules, 170 Mole, 150 Molecular absorption background in AAS, 549 Molecular activity, 774 Molecular diffusion, 610 Molecular ion, 742 Molecular sieve, 626 Molecular weight, 150 (see also Formula weight) Molecular weight distribution of polymers, 653 Molybenum blue, E49 Monochromator, 504 Monoclonal antibody, C10 Monohydrogen phosphate pH, 257 Monolithic columns, 661 Mother liquor, 345 MSDS, see Material safety data sheets MS/MS, 765 Muffle furnace, 44 Mull technique, 510 Multichannel analyzers, 788 Multiplex advantage, 524 Multiplicity, 530 Multiwalled carbon nanotubes, 471 Mutarotation, 777 MW, 150 MWCNTs, 471 N Nano LC, 670 Nanogram, 159 Nanoliter, 159 V1 - 08/21/2013 12:29 A.M Page 822 Near-infrared (see also NIR), 492 Near-infrared spectrometry, calibration, 492 nondestructive testing, 491 uses of, 492 Near-IR region, 480 Near-IR spectrometer, 525 Near-UV region, 480 Neat sample, 492, 509 Negative pH, 229 Nernst equation, 390 Nernst-Einstein equation, 679 Nersnt glower, 505 Neutral solution, 229 at elevated temperatures, 231 Neutralization reaction, 282 Newton, Isaac, 478 NHE, 386 Nickel, gravimetric determination, E11 Nikolsky equation, 429 limitations of, 430 NIR (see also Near infrared), 492 NIR region, 492 Nitrate, spectrophotometric determination, E46 standard solution, E46 Nitric acid NO2 -free, E21 Nitrogen dioxide determination, EN8 Nitrogen rule, 740 Nitrogen-phosphorus GC detector, 633 Nitrous oxide-acetylene flame, 566 Nominal wavelength, 517 Nondestructive testing by NIR, 491 Normal, 154, text websiteChp5 Normal distribution, 64 Normal error curve experiment, volumetric measurement, E4 Normal hydrogen electrode, 386 Normal phase chromatography, 652 aqueous, 653 Normality, 154, text website Chp5 Normality calculations, text website Chp5 Normal-phase chromatography, 605 Notch filter, 508 Nuclease enzyme, G5 Nucleation, 344 Nucleotide, G3 Nujol, 510 Numerical aperture, 511 O Occlusion in precipitates, 347 Offset of pH electrode, 421 Ohm’s law, 467, 468 Oligonucleotide, G3 Open tubular liquid chromatography, 702 Open-tubular columns, 624 Optical filter, 508 Optical rotary dispersion, 685 Orthophosphate buffers, 245 Ostwald ripening, 345 Ostwald, Wilhelm, Overtone absorption, 491 Oxidation, 383 Oxidizing agent, 384 Oxine, 349 Oxygen electrode, 472 Oxygen removal, 471 Ozone determination, EN8 P PAGE, 709 2-D PAGE, G15 Paired t-test, 93 Parabola mass spectrograph, 755 Parallax error, 35 Parent ion, 742 Partition chromatography, 605 Parts per billion, 160 Parts per million, 160 Parts per thousand, 160 Parts per thousand, 71 Parts per trillion, 160 PBMS, EN13 PCR, see Polymerase chain reaction p-Diphenylamine sulfonate solution, E27 Pearson correlation coefficient, 104 Pentane, GC determination, E69 Peptide, G14 Peptization, 346, 348 Perchloric acid, precautions with, 54 Performance-based measurement system, EN13 Periodic tables on the Web, P1 Permeation tube, EN9 Peroxide, iodometric titration, E30 Pesticide determination, EN13 PFF, see Protein-free filtrate pH calculator for mixtures, 269 pH calculators, 269 pH electrode, see Glass pH electrode pH indicators, inside back cover pH measurement, accuracy, 420 of blood, 422 in nonaqueous solvents, 423 temperature compensation, 422 of unbuffered solution, 422 pH meter, 409 digital, 421 high resolution, 422 operation of, 421 pH scale, 227 pH titration, 457 pH, blood, 231 definition, 228 determination in shampoo, E24 at elevated temperatures, 231 negative, 229 operational definitions, 418 of phosphoric acid, 246 salts of weak acids and bases, 234 of seawater, 272 weak acids, 232 weak bases, 232 pH-stat, 785 pH using Goal Seek, 253 Phenacetin, UV determination, E54 Phenol red solution, E18 Phenoldisulfonic acid solution, E46 Christian7e bindex.tex V1 - 08/21/2013 12:29 A.M Page 823 INDEX Phenolphthalein, 289 Phenolphthalein solution, E13, E39 Phenolsulfonphthalein solution, E18 Phosphate buffers, 245, 263 Phosphate pH, 257 Phosphate, FIA determination, E80 spectrophotometric determination, E80 Phosphorescence, 532 gated measurements, 537 Phosphoric acid, alpha values, 248 ionization of, 245 pH, 246 Phosphorus, GC detector, 633 standard solution, 49 Phosphorous in serum, spectrophotometric determination, E48 Photoionization detector, 635 Photomultiplier tube, 513 Photon detector, 517 Photon energy, 480 Phototube, 513 Phrap, G11 Phred, G11 Physiological buffers, 261 pI, 691 Pico, 159 Pipet, 31 calibration of, 40 graduated, 31 measuring, 31 syringe, 32 transfer, 31 use of, E2 volumetric, 31 Pipetting procedure, E3 Pipettor calibration, E4 Pirkle phases, 663 Planar gel electrophoresis, quantitation, 710 Planck’s constant, 480 Plasma, 10 Plasmids, G7 Plate height, 607 effective, 609 for HPLC column, 613 reduced, 612 Plate number, 607 (see also Theoretical plate) effective, 608, 614 for skewed peaks, 608 Platelets, C1 Platinum black, 386, 403 PLOT columns, 625 Plotting in Excel, video, 102, 118 pOH, 228 Point-of-care analysis, C6 Poising capacity, 412 Poisson distribution, 109 Polarography, 473 Polyacrylamide gel electrophoresis (PAGE), 709 Polyacrylamide gel electrophoresis (see 2-D PAGE) Polymerase chain reaction, G6 Polynomial equation, Goal Seek solution, 198 Polyprotic acids, 823 buffer calculations, 245 salts of, 255 species distribution, 248 titration, 300 Pooled standard deviation, 89 Portable GCs, 643 Post-column reaction detection in HPLC, 689 Postprecipitation, 348 Potassium dichromate, primary standard, 453 standard solution, E28 Potassium iodate standard solution, E30 Potassium ion, standard activity solutions, 430 Potassium permanganate solution, E36 standardization, E37 Potassium thiocyanate standardization, E22 Potassium-selective electrode, 426 Potential measurement cell, 410 Potential, complexation dependence, 395 at equivalence point, 440 measurement of, 409 mixed, 412 pH dependence, 395 Potentiometric electrodes, 399 inert metal, 402 metal-metal cation, 400 metal-metal salt, 401 Potentiometric measurement, accuracy, 412 Potentiometric titration, 456 characteristics, 458 pH, 457 precipitation, 457 Potentiometry, 399 Potentiostat, 467 Power analysis, 110 Precipitates, drying, 349 filtering, 348 igniting of, 48, 349 impurities in, 347 organic, 353 washing, 348 Precipitation titrations, 374 potentiometric, 457 Precipitation, potentiometric, 457 minimum solubility, 357 Precision of the mean, 74 Precision, 63, 72 in validation, 138 Preparing the solution, for redox titrations, 454 Primary standard, 167 requirements, 168 Primary standard chemicals, 23 Primer, G6 Principle of electroneutrality, 205 Prism, 506 Probability, 84 Process analysis, 785 instrument requirements, 787 Proficiency testing, 143 Proficiency testing experiment, E84 Propagation of errors, 75 addition and subtraction, 76 multiplication and division, 77 and significant figures, 81 Propagation of uncertainty, 67 Protein identification, G16 Protein-free filtrate, 11, 57 Ba(OH)2 -ZnSO4 , C3 Folin-Wu, C4 trichloroacetic acid, C4 tungstic acid, C4 Proteins, G1 desalting of, 653 Kjeldahl determination, 310 percent nitrogen, 311 Proteome, G13 Proteomics, G13 Pseudo first-order reaction, 771 Pseudo zero-order reaction, enzymatic, 773 Pulsed discharge detector, 634 Pulsed field gel electrophoresis, 710 Purge-and-trap, 642 for indoor/outdoor air monitoring, 642 Purnell equation, 615 Pyrolysis GC, 642 Q Q test, 95 Q values table, 96 QA, see Quality assurance QUA, see Quality assurance unit Quadratic equation, Goal Seek solution of, 198 program for, 199, 258 Quadratic formula, 799 Quadrupole mass analyzer, 756 Qualitative analysis, Quality assurance unit, 134 Quality assurance, 143 Quality control, 143, 785 Quality control chart, 15, 83 Quality control experiment, E82 Quantitative analysis, Quantum yield, 534 R r2 , 105 video, 119 Radiation, absorption of, 480 Radioimmunoassay, C6, C8 Random error, 15, 75 (see also Indeterminate error) Range, efficiency of, 99 in validation, 139 Rate constant, 188, 770 Rate expression, 770 Rate law, 770 Reacting units, acid-base, text website Chp5 reduction-oxidation, text website Chp5 Reaction completion time, first order reaction, 770, 771 second order reaction, 771 Reaction mechanism, 769 Reaction order, 769 Christian7e bindex.tex INDEX 824 Reaction rate, 769 Reaction time, 771 Reagent blank, 64 (see also Blank) Reagent-grade chemicals, 23 Redox indicators, 446 transition range, 446 Redox mediator, 473 Redox reactions, 384 balancing, 437 reacting species, 387 Redox titrants, cerium(IV), 453 iodine, 447 potassium dichromate, 453 potassium permanganate, 452 sodium thiosulfate, 449 Redox titration, potential change required, 442 potentiometric end point detection, 456 preparing the sample, 475 visual end point detection, 445 Redox titration curve, calculation, 441 equivalence point, 441 Reduced velocity, 612 Reducing agent, 384 Reduction potential, 386 Reduction, 383 Reduction-oxidation reactions, see Redox reactions Reference electrode, 400, 404 double junction, 408 SCE, 407 Reference materials, 15 in validation, 138 Reference method, 135 Refractory compound formation, 566 Refractory elements, 560 Regression analysis Excel, 120, 502, 640, 775, 778 Rejection of a result, 95 Relative accuracy, 71 Relative error, 71 Relative method, 13 Relative uncertainty, 67 Reliability, 140 Repeatability, 140 Representative sample, in environmental analysis, EN1 Reproducibility, 140 Residual liquid-junction potential, 411 Response factor, 137 Retention factor, 609, 630 and resolution, 614 Retention time, 607, 621 adjusted, 608 Retention volume, 607 Reversed-phase chromatography, 605, 652 Rf value, 703 RF, see Response factor Riboflavin, fluorescence determination, E57 Robustness, 140 Rohrshneider constant,629 Rotameter, EN4 Rotational transition, 481 Rounding off, 71 V1 - 08/21/2013 12:29 A.M Page 824 Rubber policeman, 47 Ruggedness, 140 S Safety in the laboratory, 57, S1 Safety rules, S1 Salt bridge, 385 Salting out, 217 Sample preparation, solid-phase extraction, 579 solvent extraction, 579 Sample, 49 analysis, 9, 50 dissolution of, 52 drying of, 51 grab, 9, 50 gross, 9, 49 laboratory, minimum size, 112 preparing for analysis, 10 representative, Samples, handling and storing, 10 minimum number of, 108 Sampling, 49 of gases, 50 of liquids, 50 of solids, 50 statistics of, 107 Sandell-Kolthoff reaction, 772 Saturated calomel electrode, 407 Saturated solution, 356 SciFinder Scholar, 794 SCOT columns, 625 SDS-PAGE, 709, G15 Seawater, pH determination, 272 SEC, see Size exclusion chromatography Secondary ion mass spectrometry, 752 Secondary standard, 43, 197, E16 Second-order reaction, 770 Sediment sampling, EN11 Selective, Selectivity coefficient of ISE, fixed interference method, 430 matched potential method, 430 separate solution method, 430 Selectivity, in validation, 136 Semiautomatic instruments, 788 Semimicrobalance, 26 Sensitivity, in validation, 139 Sensor, electrochemical, 472 Separation factor, 615 Separatory funnel, 580 Sephadex, 653 Sequential injection analysis, 791 Serum electrolytes, C4 Serum, SHE, 386 Shotgun genome sequencing, G7, G10 SIA, see Sequential injection analysis Significant figures, 65 addition and subtraction, 67 least-squares line, 120 logarithms, 70 multiplication and division, 67 and propagation of errors, 81 Silver, Volhard determination, E21 Silver nitrate, standard solution, E23 Simultaneous equations, program for, 258 Single-nucleotide polymorphism, G11 (see also SNPs) Single-pan balance, use of, E1 Singlet state, 530 Single-walled carbon nanotubes, 471 Size exclusion chromatography, 605, 653 Slab gel electrophoresis, 708 Slightly soluble substances, 194 Slit width, mechanical, 518 spectral, 518 Slope, spreadsheet calculation, 118 standard deviation of, 102 Snell’s law, 674 SNP analysis, G12 SNPs, G12 Soda ash, determination of, E14 (see also Sodium carbonate) Sodium, flame emission determination, E60 standard solution, E60 Sodium carbonate, primary standard, E15 potentiometric titration, E38 titration, 296 Sodium D-line, 549 Sodium hydroxide , solution preparation, E13 standard solution of, 42 standardization, E13 Sodium ion, activity coefficient in blood, 430 standard activity solutions, 430 Sodium thiosulfate solution, E31 Sodium thiosulfate standardization, 451, E31, E33 Soil sampling, EN11 Solid-phase extraction (see also SPE), 586 dual phases, 590 polymer based, 590 procedure optimization, 589 silica based, 586 sorbents for, 589 of trace organics in water, EN12 universal sorbent, 589 Solid-phase extraction experiment, E61 Solid-phase microextraction, 591 Solid-phase nanoextraction, 593 Solubility product constants, 803 Solubility product, 355 conditional, 367,372 Solubility, acidity effect, 366 calculation of, 356 common ion effect, 356 complexation effect, 372 diverse ion effect, 361 stoichiometry effect, 357 Solvent extraction, accelerated, 585 efficiency, 581 Christian7e bindex.tex INDEX of ion-association complexes, 583 metal chelates, 336 of metal complexes, 584 of metals, 583 microwave-assisted, 585 Solver, buffer calculation, 264 charge balance method titration curve, 285, 293 multiple pH calculations, 258 for spectrophotometric mixture, 500 video, 87 SOPs, see Standard operating procedures Sørenson, Søren, 228 Soxhlet extractor, EN12 SPE (see also solid-phase extraction), 586 SPE, procedure optimization, 589 SPE cartridges, 587 SPE disks, 588 SPE microtiter plates, 589 SPE pipet tips, 587 Specific activity, 774 Specific conductance, 677 Specific gravity, 155 Specific rate constant, 770 Specific resistivity, 679 Specific rotation, 685 Specific, Spectral databases, 493 Spectral slit width, 518 Spectrofluorometer, 535, 536 Spectrometer, visible/UV/IR cells, 509 Spectrometer components, diffraction grating, 506 prism, 506 Spectrometer detectors, IR, 516 UV-vis, 513 Spectrometer sources, 504 infrared, 505 visible, 504 ultraviolet, 505 Spectrometer, 504 absorbance calibration, 518 array, 522 double-beam, 521 IR, 523 near-IR, 548 single-beam, 519 wavelength calibration, 518 Spectrometric error, 526 Spectrometry, 548 of mixtures, 498 quantitative calculations, 494 solvents for, 493 Spectrophotometer, 504 Spectrophotometry, mixture determination, E50 Spectroscopy, 548 Spike, 138 Spike recovery, 138 Spontaneous process, 191 Spreadsheet, calculation of unknown from calibration curve, 502 coefficient of determination calculation, 118 internal standard calibration, 640 V1 - 08/21/2013 12:29 A.M Page 825 825 logarithm concentration diagram, 267 for mixture calculations, 500 for rate calculation, 778 weak acid titration curve, 293 Spreadsheets, 112 absolute cell references, 114 filling cell contents, 112 for graphing, 112 plotting calibration curves, 117 printing, 113 relative cell references, 114 saving, 113 strong acid titration curve, 283 useful syntaxes, 116 web tutorial on use, 112 SRMs, 15 Stability constant, 323 Standard acid, 290 Standard acid solution, preparation of, 42 Standard addition, 14, 461 in atomic spectrometry, 567 in atomic absorption, E59 in gas chromatography, 639 Standard addition calculations, 568 Standard addition experiment, E61 Standard base solution, preparation of, 42 Standard base, 290 Standard buffers, accuracy, 415 temperature dependence, 419 Standard deviation, 72 estimated, 72 of intercept, 102 relative, 74 pooled, 89 of slope, 102 of unknown concentration, 102, 503 video, 116 Standard deviation of regression, 103, 120 Standard electrode potentials, 806 Standard error, 74 Standard error of the estimate, 124 Standard hydrogen electrode, 386 Standard operating procedures, 134 Standard potential, 390 Standard reference materials, 15 in validation, 138 Standard solution, 166, 167 Standard state of solids, 211 Standard state of water, 211 Standardization, 167, 176 calculations, 173 Starch indicator, 446 Starch solution, E30 Stationary phases, see GC, HPLC Stationary phases, in HPLC, 654 Statistical programs, Excel LINEST, 123 Statistics for small data sets, 98 Statistics of sampling, 107 Stern layer, 717 STM, see Sub-two micron phase Stoichiometric calculations, 166 Stoichiometric, 167 Stoichiometry, 149 Stokes-Einstein equation, 677 Stray light, 530 Student t-test, 88 (see also t-test) Sub-two micron phase, 665 Successive approximations, 196 Sulfate, barium titration, 381 gravimetric determination, E9 Sulfur and nitrogen chemiluminescence detectors, 635 Sulfur dioxide determination, EN8 Sulfur GC detector,633 Supersaturation, 344 Supporting electrolyte, 470 Suppressor column, 693 Surface adsorption on precipitates, 347 SWCNTs, 471 Synge, Richard L M , 598 Syntaxes, useful, 116 Syringe pipets, 32 System point, 7.16.2 website Systematic approach to equilibrium calculations, 204 multiple equilibria, 368 steps, 207 Systematic error, 15, 63, 75 (see also Determinate error) Sytematic approach, hints for applying, 208 T Tandem mass spectrometry, 765 TC, 30 TD, 31 Temperature programming, 638 and analyte volatility, 630 Tenax A, 642 Theoretical plate, 607 (see also Plate number) Theory of solvent systems, acid, 224 base, 224 Thermal conductivity detector, 630 Thermal desorption, 641 Thermal noise, 526 Thermal precipitator, EN6 Thermistor, 517 Thermocouple, 516 Thermodynamic equilibrium constant, 217 acid, 226 autoprotolysis, 226 solubility product, 361 Thermopile, 517 Thin-layer chromatography, 702 high performance, 703 mobile phases, 704 sample application, 704 spot detection, 707 stationary phases, 703 quantitative, 707 two-dimensional, 707 Thiocyanate standardization, E22 Thymine, G3 Thymol blue solution, E47 Time domain spectrum, 523 Time-of-flight analyzer, 758 TISAB, 425 TISAB solution preparation, E26 Titer, 179 Christian7e bindex.tex V1 - 08/21/2013 12:29 A.M Page 826 INDEX 826 Titrant, 167 Titrating, tips for, 36 Titration calculations, 173 Titration curve, 282 precipitation, 374 program for, supplement 8.11b website spreadsheet construction for HCl, 283 spreadsheet construction for weak acid, 293 weak acid, 290 weak base, 295 Titration curve of weak base, strong acid, 282 Titration error, 288 Titration methods, kinds of, 168 Titration, 12 requirements, 166 Titrimetric analysis, 12 Titrimetry, origin of, TLC, see Thin-layer chromatography Total hydrocarbon determination, EN8 Total ionic strength buffer, 425 (see also TISAB) Trace organic environmental sampling, EN12 Transcription, G14 Transducer, 472 Transferability, 140 Transmittance, 495 Triplet state, 530 Tris buffers, 264 Tswett, Mikhail, 597 ttest for paired samples, video, 94 t-test, types of situations, 88 t-test, paired, 93 Turnover number, 773 t-values table, 84 Two-dimensional gas chromatography, 645 Two-dimensional GC, 619, 645 (see also GC x GC) Two-dimensional PAGE, G15 U UHPLC, 651, 701 Ultracentifuge, 46 Ultra-high pressure liquid chromatography, 651, 701 Ultramicroelectrode, 474 Uncertainty of unknown, 102, 502 Uncertainty, propagation of, 67 Urea determination, 311, 780 Uric acid determination, 780, C4 V Vacutainer, 43 Vacuum ultraviolet GC detector, 637 Vacuum-UV region, 480 Validation of analytical method, 15, 134 Validation process, 135 minimum number of measurements, 138 Valinomycin, 426 van Deemter, J J., 609 van Deemter equation, 609 reduced form, 612 van Deemter plot, HPLC, 652, 702 Variance, 75, 86, G7 of an analysis, 107 Vectors, G7 Vibrational overtone, 491 Vibrational relaxation, 531 Vibrational transition, 481, 482 Videos, absolute cell reference, 115 average, 116 data analysis regression, 87 equilibrium calculation, 201 error bars, 107 Example 9.6, 339 F-test, 88 Goal Seek equilibrium, 219 Goal Seek pH NH4 F, 238 intercept, 119 introduction to Excel, 113 LINEST, 120 paired t-test from Excel, 94 plotting in Excel, 102, 118 slope, 119 Solver, 87 spreadsheet tutorial basic functions, 112 spreadsheet tutorial graphing, 112 standard deviation, 116 ttest for paired samples, 94 Visible region, 480 Vitamin B2, fluorescence determination, E57 Vitamin C, HPLC determination, E71 Void volume, 608, 614 Volatile organic compound (VOC) sampling, EN6 Volatile organic compounds, GC determination, 643 Volhard determination, E21 Volhard titration, 379 Voltage drop, 467 Voltaic cell, 384 (see also Electrochemical cell) cell convention, 388 with liquid junction, 405 without liquid junction, 404 Voltammetry, 467 potential range, 471 potential required, 468 solid electrode, 471 Voltammogram, 467 Volume/volume basis, 164 Volume/volume gas concentrations, EN2 Volumetric analysis, 12 Volumetric calculations, molarity, 169 normality, text website Chp5 Volumetric flasks, 30 calibration of, 39 Volumetric glassware, calibration of, 37 care of, 35 NIST tolerances, inside back cover precision of, 37 selection of, 41 to contain, 32 to deliver, 31 tolerances of, 37, back cover Volumetric measurements, microplate reader, E4 Von Liebig, Justus, 223 von Wiemarn ratio, 344 W Walsh, Alan, 556 Wash bottle, 45 Water hardness, 166, 334 EDTA determination, E19 microscale titration, E36 Water sample analysis, EN11 Water sampling, EN9 Water, standard state, 211 Wavelength calibration, 518 Wavelength, 479 nominal, 517 Wavenumber, 479 WCOT columns, 624 Web of Knowledge, Web of Science, Weighing boat, 29 Weighing by difference, E2, E15 Weighing dish, 29 Weighing, accurate, 29 by difference, 29 direct, 29 of liquids, 29 of solids, 29 rough, 29 rules for, 28 Weight relationships, 180 Weight, 24 Weight/volume basis, 162 Wet digestion, 11, 52, 53 Wet-test meter, EN4 Wheatstone bridge circuit, 630 Whole genome sequencing, G11 Working electrode, 467 minimum potential for reduction, 468 X Xylene isomers, IR determination, E56 Y Yalow, Roslyn, C7 Z z score, 143 z score experiment, E84 Zero integrated field electrophoresis, 711 Zero point, determination of, E2 Zero point drift, 26 Zeta potential, 717 ZIFE, 711 Zimmermann-Reinhardt reagent, 453 Zwitterion, 309, 691 ... Ksp 0.05916 log aHg2 2+ (3) 0.05916 0.05916 log Ksp − log 2 aHg2 2+ (4) E = 0.789 − For Hg2 Cl2 + 2e− 2Hg + 2Cl− , E = 0 .26 8 − Since Ksp = aHg2 2+ · (aCl− )2 , E = 0 .26 8 − E = 0 .26 8 − From (1) and... electrode is 0 .26 8 V and that of the Hg/Hg2 2+ electrode is 0.789 V, calculate Ksp for calomel (Hg2 Cl2 ), for 29 8K Solution For Hg2 2+ + 2e− Hg, 0.05916 log aHg2 2+ (1) 0.05916 log(aCl− )2 (2) Ksp 0.05916... 7.4 72 7.448 7. 429 7.413 7.400 7.389 7.384 7.380 7.373 7.367 — — — — — — 9.464 9.395 9.3 32 9 .27 6 9 .22 5 9.180 9.139 9.1 02 9.081 9.068 9.038 9.011 8.985 8.9 62 8. 921 8.885 8.850 8.833 13. 423 13 .20 7