[Determination of cotinine, phenylglyoxylic acid and mandelic acid in human urine by GC/MS].

To establish a GC/MS method for analysis of cotinine (COT), phenylglyoxylic acid (PA) and mandelic acid (MA) in human urine. Human urine samples were extracted by CCl(3) and derivatized with MSTFA after dried completely. The contents of COT, PA and MA were measured by GC/MS method with DB-5MS capillary column and EI ion-source. The calibration curves for COT in urine samples were linear over the concentration ranges of 0.0002 approximately 3.5 microg ml(-1), while PA and MA were both of 1.25 approximately 160 microg ml(-1). The limits of quantification were 0.0002 microg ml(-1), 1.25 microg ml(-1) and 1.25 microg ml(-1) for COT, PA and MA, respectively. The assay recoveries for COT, PA and MA ranged from 89.53% approximately 102.4%, 84.88% approximately 91.46% and 83.46% approximately 13.6%, respectively. The established method can detect cotinine, phenylglyoxylic acid and mandelic acid simultaneously, which would be used in routine assessment and monitoring of the internal exposure to nicotine and styrene in human body.