Solid-phase micro-extraction-gas chromatography-mass spectrometry and headspace-gas chromatography of tetrahydrocannabinol, amphetamine, methamphetamine, cocaine and ethanol in saliva samples.
In the present work, a method was developed aiming at the serial detection of tetrahydrocannabinol (THC), amphetamine, methamphetamine, cocaine and ethanol in saliva. Saliva samples were submitted to an initial headspace procedure for ethanol determination by gas chromatography/flame ionization detector (GC-FID). After this step, two consecutive solid-phase micro-extractions (SPME) were carried out: THC was extracted by submersing a polydimethylsiloxane fiber (100 micro m) in the vial for 20 min; amphetamine, methamphetamine and cocaine were subsequently extracted after alkalinization. Derivatization of the amphetamines was carried out directly in the solution by adding 2 micro l of butylchloroformate. Gas chromatography-mass spectrometry (GC-MS) was used to identify the analytes in selected ion monitoring (SIM) mode. Confidence parameters of validation of the method were: recovery, linearity, intra- and inter-assay precision as well as limits of detection and quantification of the analytes. The limits of quantification (LOQ) obtained were: ethanol (0.010 g/l); amphetamine (5.0 ng/ml); methamphetamine (0.5 ng/ml); cocaine (5 ng/ml) and THC (5 ng/ml). The method proved to be highly precise (coefficient of variation<8%) for all detected substances.
College of Pharmaceutical Sciences, Toxicology, University of S. Paulo, USP, Av. Professor Lineu Prestes, 580 B13B CEP, 05508-900, SP, São Paulo, Brazil. yonamine@usp.br
Mauricio
M
Yonamine
Nadia
N
Tawil
Regina Lucia de Moraes
RL
Moreau
Ovandir Alves
OA
Silva
D000661:Amphetamine / Q000032:analysis*; D002849:Chromatography, Gas / Q000379:methods*; D003042:Cocaine / Q000032:analysis*; D013759:Dronabinol / Q000032:analysis*; D000431:Ethanol / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008694:Methamphetamine / Q000032:analysis*; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry*; D012680:Sensitivity and Specificity
D000431:Ethanol; D008694:Methamphetamine; D013759:Dronabinol; D000661:Amphetamine; D003042:Cocaine