A validated GC-MS method for the determination of DELTA~9-tetrahydrocannabinol and 11-nor-DELTA~9-tetrahydrocannabinol-9-carboxylic acid in bile samples

摘要

We present a validated gas chromatography-mass spectrometry method for the determination of DELTA~9-tet-rahydrocannabinol and 11-nor-DELTA~9-tetrahydrocannabinol-9-carboxylic acid in bile samples. The method includes protein precipitation with acetonitrile after enzymatic hydrolysis, and solid-phase extraction followed by silylation using N,O-bis(trimethylsilyl)trifluoroacetamide with 1% trirneth-ylchlorosilane. The limit of detection was 0.30 ng/ml and the limit of quantitation was 1.00 ng/ml. The calibration curves were linear within the dynamic range of 1.00-500 ng/ml (R~2 > =0.993) and the absolute recovery for both analytes was higher than 87.5%. Accuracy and precision were less than 8.8% and 8.2%, respectively. The developed method was applied for the analysis of bile samples obtained from 21 forensic cases.