Đang tải... (xem toàn văn)
A Modified Phenylfluorone Method for Determining Organotin Compounds in the ppb and Subppb Range All reagents used were of the highest available purity and no pretreatment was required. Sodium Hydroxide (50%). 50 g of NaOH pellets were dissolved in distilled water and diluted to 100 mL after cooling. OTC Stock Solution. 44.5 mg of bis(trinbutyltin) oxide (TBTO) (MT Chemical Co., Rahway, NJ (C.A. registry number 56359) Assay (9) 98.9%) was dissolved in 95% ethanol, quantitatively transferred to a 500 mL volumetric flask and diluted to volume in the same solvent to yield 35.5 ~g of tin per mL. TBTO Standard Solution. 3.0 mL of OTC stock solution was diluted to 100 mL with 95% ethanol to prepare a 1.068 ~gmL tin solution. This standard was prepared fresh as needed. Phenylfluorone. I0 mg of phenylflluorone (Eastman Kodak Co., Rochester, NY) 2,6,7trihydroxy9phenylisoxanthane3 one, was dissolved in 25 mL of ethanol containing 0.2 mL of concentrated sulfuric acid, and dilute to 100 mL with ethanol. This solution is stored in the dark and further diluted to a 10 4 M solution when used.
Journal of Analytical Toxicology, Vol. 4, January/February 1980 A Modified Phenylfluorone Method for Determining Organotin Compounds in the ppb and Sub-ppb Range L.R. Sherman* and T.L. Carlson Department of Chemistry, The University of Akron, Akron, OH 44325 This research was supported by Edna McConnel Clark Foundation, New York, NY. *Author to whom correspondence should be sent. Methods and Materials Reagents Introduction Yrialkyl organotin compounds (OTC) are used as biocidal agents in controlled-release antifouling preparations (1), molluscicides (2) and mosquito larvicides (3). In order to determine organotin emission rates from dispensing pellets, and monitor residual toxicant levels in the hydrosphere, absorbing solid and biological specimens, it is imperative that analytical methods be developed that will accurately assess ultra-low concentrations. The method must be specific for organotin species and overcome interference from the ubiquitous inorganic tin background. The phenylfluorone method has been proven to be a superior analytical method having sensitivity in the tzg range when the colored material is subjected to chloroform extraction (4). The use of sensitizers, cetyltrimethylammonium bromide (CTAB), and cetylpyridinium bromide (CPB), enhances tin IV -catechol violet complex color formation, but gives a bathocromic shift (5,6,7). The use of C T A B with phenylfluorone at pH 1.2 yields an intense k,,o~ at 530 nm and has been successfully utilized in the range of 0.1 to 4 ppm tin (8). The technique reported herein is a modification of the latter method keyed to the specific determination of O T C in the sub part-per-billion range. All reagents used were of the highest available purity and no pretreatment was required. Sodium Hydroxide (50%). 50 g of NaOH pellets were dissolved in distilled water and diluted to 100 mL after cooling. OTC Stock Solution. 44.5 mg of bis(tri-n-butyltin) oxide (TBTO) ( M & T Chemical Co., Rahway, NJ (C.A. registry number 56-35-9) Assay (9) 98.9%) was dissolved in 95% ethanol, quantitatively transferred to a 500 mL volumetric flask and diluted to volume in the same solvent to yield 35.5 /~g of tin per mL. TBTO Standard Solution. 3.0 mL of OTC stock solution was diluted to 100 mL with 95% ethanol to prepare a 1.068 ~ g / m L tin solution. This standard was prepared fresh as needed. Phenylfluorone. I0 mg of phenylflluorone (Eastman Kodak Co., Rochester, NY) 2,6,7-tri-hydroxy-9-phenylisoxanthane-3one, was dissolved in 25 mL of ethanol containing 0.2 m L of concentrated sulfuric acid, and dilute to 100 mL with ethanol. This solution is stored in the dark and further diluted to a 10-4 M solution when used. CTAB. 0.10 g of cetyltrimethylammonium bromide (Eastman Kodak Co., Rochester, NY) was dissolved in warm distilled water and diluted to 100 mL; 1.0 mL was further diluted to 25 mL when used. Preparation of Calibration Curve Standard T B T O solution, 0-4.0 ug (0,1,2,3, & 4 mL), was added to 200 mL of distilled water and extracted with two 20 mL aliquots of hexane. Extracts were then added to 1 mL of cone. H2SO4 in a 30 mL beaker and the hexane slowly evaporated under reflux conditions. When HzSO4 reflux initiated, 30% hydrogen peroxide was added one drop at a time to the sample to destroy the organic material and oxidize the tin. Heating continued until the colorless refluxing acid filled approximately 2/3 of the beaker. About 15 mL of distilled water and 2.2 mL of CTAB were added to the cooled samples, 50% N a O H was used to adjust pH to 1.2, and materials were quantitatively transferred to 25 mL flasks. 1 mL of phenylfluorone and distilled water, previously adjusted to pH 1.2 with H2SO4, was added to dilute the samples to volume. After 40 minutes at Reproduction(photocopying)of editorialcontentof thisjournalis prohibitedwithoutpublisher'spermission. 31 Journal of Analytical Toxicology, Vol. 4, January/February 1980 room temperature, the samples were measured on a Bechman 25 U.V.-Vis. spectrophotometer at the ,X.m~near 535 nm using water as the blank. Table I. Effect of Hexane Extraction Upon the Analysis of TBTO Fleld Samples Sample A number of controlled release monolithic molluscides containing T B T O have been field tested on St. Lucia Island in the Caribbean. Environmental samples of water, soil, plants, fish, and other aquatic life have been collected and have been qualitatively tested for OTC as follows: Water Samples: 200 mL of water was extracted with hexane as described above for the TBTO curve. Solid Samples: The soils were extracted with hexane and the hexane removed as described above. 2 mL of H2SO4 was used. Plants, Fish, and Other Aquatic' Specimens: These were totally dissolved in 2-4 mL sulfuric acid and analyzed as described previously. 1. Extraction 2. Extraction 3. Extraction 4. Extraction Extractions A set of standard T B T O samples were prepared as outlined in the experimental section under TBTO Standards and were extracted with 1,2,3, and 4 -10 mL samples of hexane and determined as described under Preparation of Calibration Curve. The results, given in Table I, indicate that two bexane extractions will quantitatively remove T B T O from an aqueous sample. The results for all the samples were within the experimental limitations of the method; however, because the single extraction was less than quantitative, a second extraction is recommended to avoid errors. Addition of Inorganic Tin To each of five standard T B T O samples was added 3.156 #g of inorganic tin. The samples were extracted and processed as field samples. The results are tabulated in Table 11. Although the percent of recovered tin varied randomly from one sample to the next, the average for the two sets of samples indicates that inorganic tin is not extracted with the organotin and that there is negligible suppression or enhancement of the color development. The Slope of the Lines The slope of the line, calculated by the method of least squares, for the inorganic tin standards was 0.0346 and the intercept was 0.0144. The slope of the TBTO curve was 0.0344, and intercept was 0.0580 with an average correlation coefficient of 0.975. Three different technicians have been using this method; their first sample usually produced a slope of tess than 0.030 and a correlation coefficient of approximately 0.94. As their technique improved, the slope was enhanced. After three or four attempts, the correlation coefficient was better than 0.99 with a standard deviation of 0.0133 or less. The slope o f t h e O T C and inorganic tin is definitely within experimental values; however, when corrected for the different procedure they are about 20% greater than the published values(8) and reflect an improvement in the analytical method. The large difference in the inter- 32 Analysis % Recovered 21.6 21.6 21.6 21.6 20.5 21.6 22.3 21.6 94.9 100.0 103.2 100.0 Table II. Effect of Inorganic Tin Upon Analysis of TBTO Samples Results ppb Sn 0 1. 2. 3. 4. Micrograms* Sn as TB TO Added to 200 mL of H20 0.00 1.08 2.16 3.24 4.32 Micrograms Recovered % Recovered Set l Set2 Set1 Set2 0.00 0.94 2.03 3.26 5.10 0.00 0.00 1.05 87.0 2 . 3 1 94.0 2.77 100.8 4.29 118.0 Average 99.9 0.00 97.2 108.9 85.5 99.3 97.2 "Each sample contained 5.710,ug of tin sulfate. cepts is due to either colored impurities in the hexane, sulfuric acid and hydrogen peroxide, or due to the fact that different spectrophotometers and cells were used in preparing the two curves. Furthermore, only unmatched 1 X 1 cmcells wereavailable in preparing the O T C curve whereas matched 1 X 10 mm cells were available in preparing the inorganic curve. Field Samples A large number of environmental samples (approximately 400) consisting of water, soil, plants, fish, and other aquatic life were recovered from the test area on St. Lucia Island in the Caribbean and have been analyzed for residual OTC. The environmental samples were treated as described above and the organotin assayed as tin varies from non-detectable to 44 ppb, which corresponds to 8.8 ~ug of tin. Most of the samples contained between .250 and 1.00 ug of tin (10). Although the data is readable to three significant figures, reproducibility of replicated environmental samples was about + I in the second significant figure. Conclusions The modified phenylfluorone method for analyzing tin can be used for the specific analysis of organotins in the ppb range. The method can be used for very reliable analysis of water, soil, or aquatic life, in the range of 500 ppt (100 ng) to 25 ppb (5 ,ug). Above 25 ppb the samples no longer fit a Beers Law plot and need to be diluted before developing the color. Journal of Analytical Toxicology, Vol. 4, January/February 1980 References 1. N.F. Cardarelli. Controlled Release Pesticide Formulations CRC Press, Cleveland, OH 1976, p. 210. 2. N.F. Cardarelli. Controlled Release Molluscicides, monogr. The University of Akron, Akron, OH 1977, p. 136. 3. N.F. Cardarelli. Controlled release organotins as mosquito larvicides. Mosq. News 3:328-33 (1978). 4. A. Sh. Shakhabudinov and O.A. Tataen. Reaction between tin (IV) and trihydroxyfluorones in the presence of antipyrene. J. Anal Chem. USSR 27:2163-66 (1972). 5. H. Corbin. Rapid and selective pyrocatechol violet method for tin. Anal. Chem. 45:534-37 (1973)o 6. R.M. Dagnall, T.J. West, and P. Young. The catechol violet colour reaction for tin (IV) sensitized by cetyltrimethylam- monium bromide. Analyst (London) 92:27-30 (1967). 7. V. Svoboda and V. Chromy. Reactions of metallochromic indicators on micelles-III. Talanta 13:237-44 (1966). 8. V.H. Kulkarnl and M.L. Good. Phenylfluorone method for the determination of tin in submicrogram levels with cetyltrimethylammonium bromide. Anal Chem. 50:973-75 (1978). 9. N.H. Furman. Standard Methods of Chemical Analysis. D. Van Nostrand Co., Inc., Princeton, NJ 1962, pp. 1078-79. 10. J.D. Christie, T.L Carlson, L.R. Sherman, and N.F. Cardarelli. Laboratory and field trials of a slow release organotin molluscicide in St. Lucia. In production. University of Texas, Galveston, TX 77550 (1980). Manuscript received July 23, 1979 Quantitative Determination of 2-Hydroxy-3-Methoxy6/3-Naltrexol (HMN), Naltrexone, and 6/3-Naltrexol in Human Plasma, Red Blood Cells, Saliva, and Urine by Gas Liquid Chromatography K. Verebey, A. De Pace, D. Jukofsky, J.V. Volavka, and S.J. MuI(~ New York State Division of Substance Abuse Services, Bureau of Laboratories and Testing, 80 Hanson Place, Brooklyn, NY 11217 Introduction 2-Hydroxy-3-methoxy-6/3-naltrexol (HMN) is a minor metabolite of naltrexone in man (!-4) (Figure 1). It was isolated from human red blood cells and urine of subjects taking naltrexone (1). A methylated 2,3-catechol type metabolite of naltrexone with the same mass unit as HMN was also reported (2). The assignment of the methyl group in the -3- position was initially based on the fact that this metabolite is excreted only in the free form. Naltrexone, 6/3-naltrexol and various similar molecules are being glucuronidated in the 3 position and large percentages of such molecules are excreted into the urine in the conjugated form. If the 3 position is blocked by methylation, no glucuronide can form, as it was observed with HMN (1). More recently, the structure of HMN was proven by synthesis (3) and by studies utilizing nuclear magnetic resonance spectra (4). In an earlier pharmacokinetic study, HMN was quantitated in urine and expressed as 6/3-naltrexol equivalents (5). The recent availability of synthetic HMN allowed development of new and specific quantitative methodology. In this communication we report on clinically applicable methods for the determination of HMN, naltrexone and its major metabolite 6/3-naltrexol in plasma (or serum), RBC, saliva, and urine. Reprint requests to: Dr. K. Verebey, New York State Division of Substance Abuse Services, Bureau of Laboratories and Testing, 80 Hanson Place, Brooklyn, NY 11217 Reproduction(photocopying)of editorialcontentof this journalis prohibitedwithoutpublisher'spermission. 33 ... from the test area on St Lucia Island in the Caribbean and have been analyzed for residual OTC The environmental samples were treated as described above and the organotin assayed as tin varies... enhancement of the color development The Slope of the Lines The slope of the line, calculated by the method of least squares, for the inorganic tin standards was 0.0346 and the intercept was... of recovered tin varied randomly from one sample to the next, the average for the two sets of samples indicates that inorganic tin is not extracted with the organotin and that there is negligible