Microdialysis-derived Sampling of Benzene and Phenol for Workplace Monitoring

• Main Authors: Hai-Ying, 錢海瑛
• Other Authors: 顏慶堂
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/27005678950582391824

碩士 === 中山醫學大學 === 公共衛生學系碩士班 === 96 === Benzene and phenol are widely applied in industrial and agriculture aspects. The workplace monitoring of benzene and phenol is an important issue to understand the harmful risks of workers due to exposure to these chemicals. Conventionally, benzene was sampled in charcoal tube and desorbed by using carbon disulfide (CS2) at room temperature prior to gas chromatography-flame ionization detection during workplace monitoring. However, carbon disulfide is a highly toxic solvent with highly volatile and highly flammable, operator of analysis might exposure to CS2 and suffer the toxicity easily. Therefore, a safety sampling and pretreatment protocol for monitoring benzene in workplace is worthy to investigate. The aim of this study is to develop a new sampling technique for workplace monitoring of benzene and phenol based on microdialysis- derived technique before high performance liquid chromatography (HPLC) analysis. A polyethersulfone (PES) hollow fiber dialysis modules filled with ethylene glycol in the shell-side as absorption solvent was applied as the sampling tube to collect benzene and phenol from gas stream in tube-side of hollow fiber dialysis modules through the equilibrium between absorption solvent and gas stream. The generation of standard gas stream was also designed and evaluated. Factors that influence the sampling such as the flow rate of gas stream, sampling time and sampling flow rate were studied thoroughly. Results indicated that for the flow rate of gas stream at 790 mL/min, sampling flow rate at 37.3 mL/min for 30 min offered the best sampling conditions. The concentration of phenol in air appropriated to sampling was in 0.7 to 9.9 ppm with recovery between 91.2 to 94.2%, and benzene was in 0.7 to 10.5 ppm with recovery between 89.8 to 94.9%. The proposed method was identified as an alternative to conventional sampling method for workplace monitoring of benzene and phenol prior to HPLC-UV analysis, with advantages of convenience, rapidity, less-toxic solvent, lower detection limit in chemical analysis.