Determination method for p-Phenylazoaniline and 2-methyl-4-(2-tolylazo)aniline in workplace air by high-performance liquid chromatography.

OBJECTIVES The purpose of this research was to develop a method for the simultaneous determination of p-Phenylazoaniline (also called 4-aminoazobenzene, AAB) and 2-methyl-4-(2-tolylazo)aniline (also called o-aminoazotoluene, AAT) in workplace air for risk assessment. METHODS The characteristics of the proposed method, such as recovery, limit of quantitation, reproducibility and storage stability of the samples were examined. RESULTS An air sampling cassette containing two sulfuric acid-treated glass fiber filters was chosen as the sampler. The AAB and AAT were extracted from the sampler filters by methanol and then analyzed by a high-performance liquid chromatograph equipped with a photo-diode array detector. The overall recoveries from spiked samplers were 77-98 and 85-98% for AAB and AAT, respectively. The recovery after 5 days of storage in a refrigerator exceeded 96%. The overall limits of quantitation were 5.00 and 2.50 μg/sample for AAB and AAT, respectively. The relative standard deviations, which represent the overall reproducibility defined as precision, were 0.6-1.8 and 0.5-2.2% for AAB and AAT, respectively. CONCLUSIONS The proposed method enables 4-h personal exposure monitoring of AAB and AAT at concentrations of 21 to 2,000 μg/m3 for AAB and 10 to 2,000 μg/m3 for AAT, respectively. The proposed method is useful for estimating worker exposure to AAB and AAT.