Determination Method for Nitromethane in Workplace Air

Determination Method for Nitromethane in Workplace Air: Akito T akeuchi , et al . Osaka Occupational Health Service Center, Japan Industrial Safety and Health AssociationObjectives The purpose of this research was to develop a determination method for nitromethane (NM) in workplace air for risk assessment. Methods A suitable sampler and appropriate desorption condition were selected by a recovery test in which a spiked sampler was used. The characteristics of the proposed method, such as recovery, detection limit, and reproducibility, and the storage stability of the sample were examined. Results A sampling tube containing bead‐shaped activated carbon was chosen as the sampler. NM in the sampler was desorbed with acetone and analyzed by a gas chromatograph equipped with a flame ionization detector. The recoveries of NM from the spiked sampler were 81–97% and 80–98% for personal exposure monitoring and working environment measurement, respectively. On the first day of storage in a refrigerator, the recovery from the spiked samplers exceeded 90%; however, it decreased dramatically with increasing storage time. In particular, the decrease was more remarkable for the smaller spiked amounts. The overall LOQ was 2 µg/sample. The relative standard deviation, which represents the overall reproducibility, was 1.1–4.0%. Conclusions The proposed method enables 4‐hour personal exposure monitoring of NM at concentrations equaling 0.001–2 times the threshold limit value‐time‐weighted average (TLV‐TWA: 20 ppm) proposed by the American Conference of Governmental Industrial Hygienists, as well as 10‐minute working environment measurement at concentrations equaling 0.02–2 times TLV‐TWA. Thus, the proposed method will be useful for estimating worker exposure to NM.