Background. A worker was diagnosed to have bladder cancer in Taiwan (2002). With a suspicion of exposure to 4,4’-Methylene bis(2-chloroaniline) (MOCA) at work as the cause of the disease, we are anxious to establish a sampling and analytical method to measure the chemical with adequate reliability and accuracy. Methods. We used glass fiber filters to collect MOCA particles followed by extraction with methanol and measurement with HPLC-UV detector. Results. We obtained an excellent calibration result with a relative linear correlation greater than 0.999, a detect limit of 16.74 ng, and an average correlation variation of 0.46% in reproducibility. The recovery rates obtained for three different levels of permissible exposure limit(PEL) ranged from 100.1 to 100.6% with the coefficients in variations of concentrations(CV%) and analyses(CVa%) to be 1.22 and 1.0%, respectively. Samples stored with glass fiber filters would sustain for 28 days with a coefficient of variation for quality control samples lower than 3.75%. The relative percent difference for the short-term duplication analyses was lower than 0.5%. This method can get good outcome at work place. Conclusion. Glass fiber filter is an adequate tool to collect MOCA samples with good outcome.Key words：4,4’-Methylene bis(2-chloroaniline),MOCA, bladder cancer, glass fiber, HPLC-UV.
