A novel derivatization approach for determination of ketamine in urine and plasma by gas chromatography–mass spectrometry

A new method was developed for determination of ketamine (KT) in urine and plasma samples by derivatization and gas chromatography–mass spectrometry. In this article, KT was first derivatized with sodium nitrite to volatile N-nitrosamines under acidic condition. Then the derivative had been identified by the mass spectra. The derivatization conditions including the amount of hydrochloric acid, the amount of sodium nitrite, reaction temperature, reaction time and the extraction reagents were optimized. Calibration curves were linear in the range of 0.04–20 μg mL−1 for KT, and the limit of detection (LOD) and limit of quantitation (LOQ) were 0.01 μg mL−1 and 0.04 μg mL−1, respectively. The results of recovery indicated that the method had good precision and reproducibility. Compared with existing derivatization methods, this method provided a rapid, convenient, effective and low-cost way for gas chromatography method of KT quantification.