Analysis of Urinary Markers for Toluene Exposure by LC-MS/MS with a New Liquid-Liquid-Liquid Extraction (LLLE) Device

• Main Authors: Li-Jun Huang, 黃豊鈞
• Other Authors: 沈振峯
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/rf5j2j

碩士 === 國立虎尾科技大學 === 光電與材料科技研究所 === 98 === Toluene is a widely used solvent in industry. It is a human central nervous system depressant. Long-term exposure of toluene is associated with liver and kidney damage in humans. Bio-monitoring of low level toluene exposure is commonly performed by determination of urinary benzylmercapturic acid (BMA) and o-cresol. In this study, a new three phase liquid-liquid-liquid extraction (LLLE) device was developed and applied in the analysis of the urinary markers of toluene exposure. The new device was simply constructed with centrifuge tube and sample vials, and it is very easily to operate. Because of the higher buffer contents of the acceptor phase, the APCI mode was chosen for the LC-MS/MS analysis. The mainly applied parameters were urine sample mixed with phosphorate buffer (pH~2, donor layer), 1.5 mL toluene and diethyl ether (1:1, organic layer) and 400μL 0.1 M NaOH(aq) (pH~13, acceptor). After extraction and back-extraction, the urinary markers were cleaned up and enriched in the donor phase. In comparing with unprocess urine sample, after LLLE, the ion signals were increased about 100 times for BMA and about 8 times for o-cresol. Good linearity (r2 > 0.99) was also obtained in the range of 10-1000 ng/mL for both urinary BMA and o-cresol. To reduce the relative matrix effect, 10-fold dilution was needed before LLLE. The obtained RSD values of the markers of 7 lots urine samples were all less than 15% .