Page:NIOSH Manual of Analytical Methods - 5516.pdf/2

This page has been proofread, but needs to be validated.

2,4- and 2,6-TOLUENEDIAMINE: METHOD 5516, Issue 2, dated 15 August 1994 - Page 2 of 5

REAGENTS:

  1. Toluene, reagent grade.
  2. 1-(2-Methoxyphenyl)piperazine, purified (see
    APPENDIX A).
  3. Sampling medium: 43 μg/mL 1-(2-methoxy-
    phenyl)piperazine in toluene.
  4. 2,4-Toluenediamine*, reagent grade.
  5. 2,6-Toluenediamine*, reagent grade.
  6. Acetic anhydride, reagent grade.
  7. Methanol, reagent grade.
  8. Mobile phase A: Dissolve 60 mg anhydrous
    sodium acetate in 1 L of 12% acetonitrile in
    distilled water. Add 17% (V/V) aqueous acetic
    acid. Bring pH to 6.0.
  9. Mobile phase B: Acetonitrile, chromatographic
    quality.
  10. Water, distilled deionized.
  11. Sodium acetate, anhydrous.
  12. 2,4-Bisacetamidotoluene, (see APPENDIX B).
  13. 2,6-Bisacetamidotoluene, (see APPENDIX B).
  14. Calibration stock solution, 0.5 μg/μL. Dissolve 5
    mg each of 2,4- and 2,6-bisacetamidotoluene
    in methanol. Dilute to 10 mL.
  15. Nitrogen, prepurified.
  16. Pentane*, purified.

EQUIPMENT:

  1. Sampler: midget impinger, 25-mL.
  2. Personal sampling pump, 1 L/min, with flexible
    connecting tubing.
  3. Liquid chromatograph (HPLC) with 229-nm
    UV detector, recorder, integrator, and column
    (page 5516-1).
  4. Vials, 4-mL and 20-mL, glass, with PTFE-lined
    caps.
  5. Pipets, pasteur, 14.6-cm, glass disposable.
  6. Volumetric flasks, 10-mL.
  7. Syringes, 10- and 100-μL.
  8. Pipets, 2-mL (graduated) and 15-mL, glass,
    with pipet bulb.
  9. Water bath.
  10. Hotplate, spark-free, 35 to 50 °C.
  11. Evaporator, Mini-Vap, six-port, or equivalent.
  12. pH meter.
  13. Beakers, 250-mL.
  14. Flask, filtration, 500-mL.
  15. Funnel, Buchner, fritted glass, 100-mL.
  16. Vacuum pump.
  17. Vacuum desiccator.
  18. Watchglass.

*See SPECIAL PRECAUTIONS

SPECIAL PRECAUTIONS: 2,4-Toluenediamine is a cancer suspect agent [13]; 2,6-toluenediamine may be mutagenic [14]. Handle these chemicals carefully in a hood or glove box, and avoid working-surface contamination which might occur by spillage or by dissipation of fine powder from opening of containers or making transfers. Pentane is highly volatile and flammable. Take adequate precautions while handling pentane.

SAMPLING:

  1. Calibrate each personal sampling pump with a representative sampler in line.
  1. Transfer 15.0 mL sampling medium to an impinger.
  1. Connect the assembled impinger to a sampling pump.
  1. Sample 30 to 500 L of air at an accurately measured sampling rate of
    1 L/min. When it is necessary to
    add solvent for proper impinger operation during sampling, add only toluene.
    NOTE: The reagent in the sampling medium reacts with isocyanates present to form ureas, thus
    preventing reaction of the isocyanate with the toluenediamines.
CH3OC6H4N(CH2CH2)2NH + R-NCO → CH3OC6H4N(CH2CH2)2NCONHR
1-(2-methoxyphenyl)piperazine + isocyanates → ureas

5. Transfer sample solution, including condensed water, to a 20-mL vial for shipment. Rinse impinger
with 1 to 2 mL toluene. Add rinsings to sample solution.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition

This article is issued from Wikisource. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.