Page:NIOSH Manual of Analytical Methods - 8302.pdf/2

 MBOCA in urine: METHOD 8302, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS:

EQUIPMENT:

1. 4,4'-Methylenebis(2-chloroaniline) (MBOCA) calibration stock solution, 200 mg/mL.* Accurately weigh 50 mg MBOCA. Dissolve in a small volume of methanol. Dilute to 250 mL with methanol. Stable five days at 25 °C. 2. 4,4'-Methylenedianiline (MDA), internal standard, 10 µg/mL in methanol. 3. Hexane.* 4. Diethyl ether.* 5. Triethylamine (TEA), 0.05 M stock solution in hexane. 6. Heptafluorobutyric anhydride (HFBA). 7. Florisil, 60 to 100 mesh, activated by the manufacturer at 650 °C, heated to 130 °C for 24 h, then deactivated by adding 10% (w/w) water and mixing 2 h on a rotary mixer at 50 rpm. Stable one week. 8. Benzene.* 9. NaOH. 10. KH 2PO 4 buffer, 0.1 M, adjusted to pH 6 with conc. HCl. 11. Sodium sulfate, granular, anhydrous. 12. Methanol. 13. Citric acid, monohydrate, granular. 14. Pooled urine sample or Hycel urine control (Hycel Co., Houston, TX). 15. HCl, conc. 16. P-5 carrier gas, 5% methane in argon.

1. Bottles, polyethylene, screw-top, 125-mL. 2. Gas chromatograph with 63Ni electron capture detector, integrator and capillary column (page 8302-1). 3. Pipets, Pasteur. 4. Centrifuge tubes, 15-mL, graduated, glass-stoppered. 5. Mixer, rotary, 50 to 60 rpm, for 20-mm culture tubes. 6. Culture tubes, 20 x 150-mm, screw cap, PTFE-lined. 7. Mixer, vibration. 8. Chromatography column, 7-mm ID x 20 cm, with a 25-mL reservoir and PTFE stopcock. 9. pH paper, wide range. 10. Nitrogen manifold for evaporating organic solutions. 11. Pipets, 10-mL. 12. Centrifuge, table top, clinical. 13. Syringes, glass, 10- and 50-µL. 14. Waterbath, 50 °C. 15. Volumetric flasks, 100- and 250-mL. 16. Glass wool.

See SPECIAL PRECAUTIONS.

SPECIAL PRECAUTIONS: Samples of urine collected from humans pose a real health risk to laboratory workers who collect and handle these samples. These risks are primarily due to personal contact with infective biological samples and can have serious health consequences, such as infectious hepatitis, and other diseases. There is also some risk from the chemical content of these samples, but this is much less. Those who handle urine specimens should wear protective gloves, and avoid aerosolization of the samples. Mouth pipetting, of course, must be avoided. MBOCA, MDA, and benzene are suspect carcinogens; handle either in a glove box or a well-ventilated hood. Handle ethyl ether and hexane with care; both are highly flammable and should be used in a hood.

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