Chemical Pollutants in Air, Water, Soil, and Solid Wastes Phần 7 pdf

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Chemical Pollutants in Air, Water, Soil, and Solid Wastes Phần 7 pdf

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ETHYLBENZENE Synonym: phenylethane; Formula C 8 H 10 ; Structure: MW 106.18; CAS [100-41-4]; used as a solvent and an intermediate to produce styrene monomer; colorless liquid; characteristic aromatic odor; boils at 136°C; vapor pressure 7.1 torr at 21°C; freezes at –95°C; density 0.86 g/mL at 20°C; solubility in water 0.015 g/100 g; readily miscible with organic solvents. ANALYSIS OF AQUEOUS AND NONAQUEOUS SAMPLES Purge and trap method; ethylbenzene transferred from aqueous to vapor phase under helium purge; analyte adsorbed on a sorbent trap; thermally desorbed out from the sorbent trap backflushed with He onto a GC column for separation from other volatile compounds; determined by PID, FID or a mass spectrometer. Solid samples mixed with methanol; a portion of methanol extract spiked into a measured volume of water (25 mL) in the purging vessel; subjected to purge and trap concentration and analyzed as above. Alternatively, ethylbenzene thermally desorbed from the solid sample under He purge (without any solvent treatment) onto the GC column and analyzed on a suitable detector or by a mass spectrometer as above. • Characteristic masses for GC/MS identification: 106 and 91. • Limit of detection: in the range 0.5 mg/L for a 5 mL sample volume, when detected by PID. • GC column: a nonpolar fused silica capillary column, such as DB-5, SPB- 5, VOCOL, DB-624, or equivalent; packed column: 1% SP-1000 on Car- bopack B (60/80 mesh) or equivalent. CH 2 CH 3 3.33 © 1997 by CRC Press LLC © 1997 by CRC Press LLC 350 HANDBOOK OF ENVIRONMENTAL ANALYSIS • Recommended surrogate/IS: ethylbenzene-d 5 (m/z 111) and 1,4-difluo- robenzene (m/z 114, 63,88). • Samples collected in glass containers without headspace, refrigerated, and analyzed within 7 days. Samples preserved with 1:1 HCl (0.2 mL acid/40 mL sample) may be analyzed in 14 days. AIR ANALYSIS Air drawn through a sorbent tube packed with coconut shell charcoal (100 mg/50 mg); analyte desorbed into CS 2 (more than 30 min standing); CS 2 extract analyzed by GC-FID (NIOSH Method 1501, 1984); recommended air flow rate 100 mL/min; sample volume 20 L. • GC column: packed column 10% OV-275 on 100/120 mesh Chromosorb W-AW, Porapak P (50/80 mesh), or equivalent. Alternatively, air collected in a SUMMA passivated stainless steel canister either by pressurizing the canister using a sample pump or by preevacuating; canister then connected to an analytical system; air transferred to a cryogenically cooled trap; cryogen removed and temperature raised; analyte revolatilized; separated on a GC column; determined by PID, FID, or a mass spectrometer (U.S. EPA Method TO-14, 1988). Alternatively, air drawn through a cartridge packed with either Tenax (1 g) or carbon molecular sieve (0.5 g); cartridge heated at 350°C under helium purge; analyte transported to the front of a precooled GC column, temperature pro- grammed; ethylbenzene determined on a PID, FID, or a mass spectrometer; recommended air flow rate 0.5 L/min; sample volume 50 L. • No precision and accuracy data available for this method. (1 ppm ethylbenzene in air = 4.34 mg/m 3 at NTP) © 1997 by CRC Press LLC © 1997 by CRC Press LLC 350 ETHYL CHLORIDE Synonym: chloroethane; Formula: C 2 H 5 Cl; MW 64.52; CAS [75-00-3]; colorless gas at room temperature with ether-like odor; liquefies at 12.5°C; slightly soluble in water, miscible with organic solvents. ANALYSIS OF AQUEOUS SAMPLES Aqueous samples subjected to purge and trap extraction; volatile analyte thermally desorbed out from the trap on heating and swept onto a GC column for sepa- ration; detected by HECD, ECD, or MDS; low retention time. • Characteristic masses for GC/MS identification: 64 and 66. • Limit of detection: in the range 0.1 µg/L when detected by HECD for a 5-mL sample aliquot (subject to matrix interference). • Recommended surrogate/IS: bromochloromethane and 1,2-dichloro- ethane-d 4 . • Samples collected in glass/plastic containers without headspace, refriger- ated, and analyzed within 14 days. See Halogenated Hydrocarbons, Chapter 2.9, for GC columns and conditions and a detailed discussion. AIR ANALYSIS The following methods are recommended: Adsorbed over carbon molecular sieve (~400 mg); desorbed at 350°C into a cryogenically cooled trap; flash evaporated onto a capillary column GC/MS system; recommended sample volume 10 L; flow rate 100 mL/min. Collected in SUMMA passivated canister or a liquid argon trap; transferred onto a precooled GC column; determined by ECD or MSD. The precision and accuracy of the above methods for this compound are not established. (1 ppm ethyl chloride in air = ~2.2 mg/m 3 at NTP) 3.34 © 1997 by CRC Press LLC ETHYLENE CHLOROHYDRIN Synonyms: 2-chloroethanol, 2-chloroethyl alcohol; Formula: C 2 H 5 OCI; Structure: Cl–CH 2 –CH 2 –OH; MW 80.52; CAS [107-07-3]; used as a solvent for cellulose esters and in making ethylene glycol and ethylene oxide; colorless liquid with a faint ether odor; boils at 129°C; freezes at –67°C; density 1.197 g/mL at 20°C; soluble in water, alcohol, and ether; highly toxic. ANALYSIS OF AQUEOUS SAMPLE Purge and trap concentration; sample purged with He under heating; analyte desorbed from the trap by heating and backflushing with He; transferred onto a GC column for separation; determined by GC-FID or a mass spectrometer. • No precision and accuracy data are available. • Purging efficiency is low because of high solubility of the analyte in water. Purging vessel should be heated under He purge. AIR ANALYSIS Air drawn through a solid sorbent tube containing petroleum charcoal (100 mg/50 mg); analyte desorbed with 1 mL 5% 2-propanol in CS 2 (more than 30 min standing) and analyzed by GC-FID (NIOSH Method 2513, 1985); recommended flow rate 0.1 L/min; sample volume 20 L. • GC column: 10% FFAP on 80/100 mesh Chromosorb WHP or equivalent. •Working range: 0.5 to 15 ppm for a 20 L air sample. (1 ppm ethylene chlorohydrin in air = 3.29 mg/m 3 at NTP) 3.35 © 1997 by CRC Press LLC © 1997 by CRC Press LLC ETHYLENE DIBROMIDE Synonyms: 1,2-dibromoethane, EDB; Formula: BrCH 2 CH 2 Br; MW 187.88; CAS [106-93-4]; used in fumigant and antiknock gasolines; colorless heavy liquid; chloroform odor; boils at 131°C; freezes at 10°C; vapor pressure 11 torr at 20°C; density 2.7 g/mL at 25°C; slightly soluble in water (0.4%); miscible with alcohol and ether; irritant and toxic. ANALYSIS OF AQUEOUS AND NONAQUEOUS SAMPLES Purge and trap method; aqueous samples purged with He; EDB thermally desorbed from the sorbent trap and swept by an inert gas onto a GC column for separation from other volatile compounds; analyzed by a halogen-specific detector or a mass spectrometer. Solid samples mixed with methanol; methanol extract spiked into water; aqueous solution subjected to purge and trap extraction and analyzed as above. • Characteristic masses for GC/MS identification: 107, 109, and 188. • GC column: a fused silica capillary column such as DB-5, SPB-5, Rtx-5, or equivalent. • Limit of detection: the range 0.1 µ g/L for a 5-mL sample aliquot purged. • Samples collected in glass containers without headspace, refrigerated, and analyzed within 7 days. AIR ANALYSIS Air drawn through a sorbent tube containing coconut shell charcoal (100 mg/50 mg); EDB desorbed from the charcoal by treatment with 10 mL 99:1 benzene-methanol (allowed to stand for 1 h); the solvent extract analyzed by GC-ECD (NIOSH Method 1008, 1987); recommended flow rate 100 mL/min; sample volume 10 L. • GC column: 3% OV 210 on Gas Chrom Q (80/100 mesh). • IS: 1,2-dibromopropane or 1,1,2,2-tetrachloroethane. 3.36 © 1997 by CRC Press LLC © 1997 by CRC Press LLC Air collected in a SUMMA passivated canister under pressure using an additional pump or at subatmospheric pressure by initially evacuating the canister; sample transferred into a cryogenically cooled trap attached to a GC column; the trap heated; EDB separated on the GC column and determined by a mass spectrometer (U.S. EPA Method TO-14). (1 ppm EDB in air = 7.68 mg/m 3 at NTP) © 1997 by CRC Press LLC © 1997 by CRC Press LLC 356 ETHYLENE GLYCOL Synonym: 1,2-ethanediol; Formula: HOCH 2 CH 2 OH; MW 62.07; CAS [107- 21-1]; used as antifreeze in cooling and heating systems and in hydraulic brake fluids; colorless liquid; sweet taste; hygroscopic; density 1.11 g/mL; boils at 197.5°C; freezes at –13°C; highly soluble in water, lower alcohols, acetone, and pyridine; toxic. ANALYSIS OF AQUEOUS AND NONAQUEOUS SAMPLES (SUGGESTED METHOD) Aqueous samples directly injected onto a GC column and determined by an FID. • GC column: a polar column (polar PEG type phase), such as Supelcowax 10, Nukol, or equivalent. • No precision or accuracy data are available. 10 g soil, sediment, or solid wastes sonicated with 50 mL 2% isopropanol in water; extract injected onto GC column; determined on FID. • No precision or accuracy data are available. • Detection level: in the range 50 mg/kg. AIR ANALYSIS Air drawn through a glass fiber filter and then through a sorbent tube containing silica gel (520 mg/260 mg), ethylene glycol desorbed out from silica gel with 2% isopropanol in water (on 5-min standing); the analyte in eluant determined by GC-FID (NIOSH Method 5500, 1984); recommended air flow rate 0.2 L/min; sample volume 30 L. • GC column: packed glass column 3% Carbowax 20M on 80/100 mesh Chromosorb 101. Any appropriate polar column may be used. • The working range for a 3 L air sample was found to be 7 to 330 mg/m 3 . 3.37 © 1997 by CRC Press LLC © 1997 by CRC Press LLC . esters and in making ethylene glycol and ethylene oxide; colorless liquid with a faint ether odor; boils at 129°C; freezes at – 67 C; density 1.1 97 g/mL at 20°C; soluble in water, alcohol, and ether;. OH; MW 62. 07; CAS [1 07- 21-1]; used as antifreeze in cooling and heating systems and in hydraulic brake fluids; colorless liquid; sweet taste; hygroscopic; density 1.11 g/mL; boils at 1 97. 5°C; freezes. [123-31-9]; crystalline solid; melts at 170 °C; boils at 286°C; low solubility in water (7% ); dissolves readily in alcohol and ether; oxidizes slowly in air. ANALYSIS OF AQUEOUS AND NONAQUEOUS SAMPLES

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