Page:NIOSH Manual of Analytical Methods - 2002.pdf/2

 AMINES, AROMATIC: METHOD 2002, Issue 2, dated 15 August 1994 - Page 2 of 6 REAGENTS:

EQUIPMENT:

1. Ethanol, 95%, non-denatured, chromatographic quality. 2. n-Hexane. 3. Benzene.* 4. Analytes, reagent grade.* 5. Aniline calibration stock solution, 102.2 mg/mL.* Dissolve 1 mL aniline in 2 mL benzene; dilute to 10 mL with hexane. NOTE: Benzene possibly could be replaced with toluene, alcohol, or acetone to minimize the analyst's exposure to suspect carcinogens. Effects of this substitution are not known and should be tested. 6. o-Toluidine calibration stock solution, 100.6 mg/mL.* Dilute 1 mL o-toluidine to 10 mL with n-hexane. 7. 2,4-Xylidine calibration stock solution, 97.8 mg/mL.* Dilute 1 mL 2,4-xylidine to 10 mL with n-hexane. 8. N,N-Dimethyl- p-toluidine calibration stock solution, 93.5 mg/mL.* Dilute 1 mL N,N-dimethyl- p-toluidine to 10 mL with n-hexane. 9. N,N-Dimethylaniline calibration stock solution, 95.6 mg/mL.* Dilute 1 mL N,N-dimethylaniline to 10 mL with hexane. 10. Hydrogen, prepurified. 11. Helium, purified. 12. Nitrogen, purified. 13. Air, filtered, compressed.

1. Sampler: glass tube, 7 cm long, 6-mm OD, 4-mm ID; with plastic caps; containing two sections of 20/40 mesh silica gel separated by a 2-mm portion of urethane foam (front = 150 mg; back = 75 mg). For N,N-dimethyl- p-toluidine, a front section of 100 mg and back section of 50 mg may be used. A silylated glass wool plug precedes the front section and a 3-mm urethane foam plug follows the back section. Pressure drop across the tube at 1 L/min airflow must be less than 3.4 kPa. Tubes are commercially available. 2. Personal sampling pump, 0.02 to 1 L/min, with flexible connecting tubing. 3. Gas chromatograph, FID, integrator and column (page 2002-1). 4. Vials, glass, 2-mL, PTFE-lined crimp caps. 5. Syringes, 10-, 25-, 50- and 100-µL. 6. Pipets, 1- and 2-mL. 7. Ultrasonic bath. 8. File. 9. Tweezers. 10. Flasks, volumetric, 10-mL.

See SPECIAL PRECAUTIONS.

SPECIAL PRECAUTIONS: n-Hexane and ethanol are flammable. Aniline, o-toluidine, 2,4-xylidine, and benzene are suspect carcinogens [7,8]. Absorption through skin is a potential hazard. All work with these chemicals should be performed in a hood. Use proper protective clothing including gloves. Analytes (1), (2), (3), and (5) are severe poisons.

SAMPLING: 1. 2. 3. 4.

Calibrate each personal sampling pump with a representative sampler in line. Break the ends of the sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate for a total sample size according to Table 3. Cap the samplers. Pack securely for shipment.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94