Simultaneous determination of the tobacco smoke uptake parameters nicotine,cotinine and thiocyanate in urine,saliva and hair,using gas chromatography-mass spectrometry for characterisation of smoking status of recently exposed subjects

摘要

A method using gas chromatography(GC)-mass spectrometry(MS)for the simultaneous determination of the smoke uptake parameters thiocyanate,nicotine and cotinine in human tissues is reported.Nicotine,cotinine and thiocyanate,in combination with a phase-transfer catalyst,were extracted from urine,saliva and hair into dichloromethane(DCM).Thiocyanate was alkylated in the DCM-layer to form a pentafluorobenzyl derivative.The biochemical markers in DCM were directly injected into the GC system and separated on a DB-1MS column using a 9.4 min temperature program.The method was validated in urine and saliva between the limits of quantitation(1.0-15 mug ml~(-1)thiocyanate,0.010-3.0 ug ml~(-1)nicotine and cotinine in urine,0.010-1.0 ug ml~(-1)nicotine and cotinine in saliva).The calibration curves were found to be linear(r>0.996),the within- and between-day accuracy's were 83-120%,the repeatability coefficients of variation were 3-20% and the limits of detection were 0.060 ng ml~(-1)thiocyanate and 0.60 ng ml~(-1)nicotine and cotinine.The results of the analysis of the biomarkers in the urine of 44 volunteers were used to develop a predictive model for smoking status,using discriminant analysis.The classification model correctly classified 93.2% of cross-validated grouped cases.Saliva samples were used to confirm the results of the classification method.