TOLUENE-2,4-DIISOCYANATE: METHOD 2535, Issue 2, dated 15 August 1994 - Page 2 of 5 REAGENTS:
EQUIPMENT:
1. 2,4-TDI* (see APPENDIX A). 2. N-[(4-nitrophenyl)methyl]-propylamine hydrochloride. 3. 2,4-TDIU (see APPENDIX B). 4. Methanol, chromatographic quality. 5. Calibration stock solution, 10 mg/mL. Dissolve 50 mg 2,4-TDIU in methanol to make 5 mL solution. 6. Water, distilled. 7. NaOH, 1 M. 8. Toluene, reagent grade. 9. Dichloromethane, reagent grade. 10. Hexane, reagent grade.* 11. Nitrogen, purified, compressed. 12. Mobile phase. Mix 0.8 mL triethylamine and 1.6 mL H 3PO 4 with 1 L 55:45 CH 3CN:H 2O (v/v).* 13. Dibutylamine, 99% pure. 14. Tetrahydrofuran, reagent grade.* 15. Bromocresol purple indicator solution. 16. HCl, 0.05 M, standardized. 17. 2,4-TDI stock solution, 100 mg/mL. Dissolve 500 mg 2,4-TDI in dichloromethane to make 5 mL solution.
See SPECIAL PRECAUTIONS.
SAMPLING: 1. 2.
3. 4.
1. Sampler: glass tube, 4 cm x 6-mm ID, containing two sections of tightly compressed, reagent-coated glass wool (see Appendix C) (front = 7 mm; back = 5 mm), wrapped entirely with black tape; open ends with plastic caps. NOTE: Protect sampler from light. Store sampler in the dark at -21 °C up to 4 weeks, or at 25 °C up to 7 days. Pressure drop across the tube must be <3.4 kPa at 1 L/min air flow. Tubes available commercially by special order (SKC, Inc.). 2. Separatory funnels, 125-mL. 3. Beakers, 50- and 125-mL. 4. Aluminum foil. 5. Glass wool, silanized. 6. Glass rod, 15 cm x 4 mm. 7. Tweezers. 8. Rubber tubing, opaque 1.5 cm x ca. 8-mm ID. 9. Personal sampling pump, 0.2 to 1 L/min, with flexible connecting tubing. 10. High pressure liquid chromatograph, 254-nm UV detector, integrator, and column (page 2535-1). 11. Vials, glass, 2-mL, caps lined with PTFE. 12. Pipets, 2-, 15-, and 25-mL. 13. Ultrasonic bath. 14. Syringes, 100-µL, readable to 1 µL. 15. Syringes, 10-µL, readable to 0.1 µL. 16. Volumetric flasks, 5-mL. 17. Buret, 50-mL. 18. U-tube, glass, 25 cm x 15-mm ID, glass stopcocks. 19. Sorbent tube, glass, 7 cm x 6 mm, coconut shell charcoal, ca. 150 mg.
SPECIAL PRECAUTIONS: 2,4-TDI can irritate the eyes and skin, and can cause bronchial asthma and allergic eczema. Flash points of hexane, tetrahydrofuran and triethylamine are -26 °C, -17 °C, and -6 °C, respectively.
Calibrate each personal sampling pump with a representative sampler in line. Remove plastic caps from sampler. Attach sampler to personal sampling pump with flexible tubing. Sample 2 to 170 L of air at 0.2 to 1 L/min. Seal ends of sampler with plastic caps. Pack securely for shipment.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
