An Improved Impregnated-filter Method for Measuring Low-levelConcentrations of Toluene
An improved method was developed and validated for measuring low-level concentrations of toluene diisocyanates (TDls) in air. The method is based on OSHA Method 42 for industrial applications. Airborne TDls were trapped on a 25-mm glass-fiber filter impregnated with 50 pg of 1-(2-pyridy1)piperazine. A filter holder was constructed to minimize contamination and losses of the analytes. The derivatized TDls were extracted by immersion of the filter in a small volume of solvent. The analysis was performed with a high performance liquid chromatograph equipped with a fluorescence detector and a CIB base-deactivated silica column. The modified method has a lower limit of quantitation of 0.02 ppb in 15 L of air for both 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI), which is about a fifteen-fold enhancement over Method 42. The recovery efficiencies and 95% confidence intervals for vapor-spiked filters were 77 {+-} 6 percent for 2,4-TDI and 69 {+-} 10 percent for 2,6-TDI. The precision of replicate analyses was ten percent or better. The method was used to screen flexible polyurethane foam for emissions of unreacted TDls.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director, Office of Science
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 915405
- Report Number(s):
- LBL-36641; TRN: US200817%%336
- Country of Publication:
- United States
- Language:
- English
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