Determination of Amphetamine and Methamphetamine in Blood by Derivatization with Perfluorooctanoyl Chloride and Gas Chromatography/Mass Spectrometry

A relatively simple method for quantitaUon of amphetamine and methamphetamlne in blood was developed. Blood samples were extracted with cyclohexane, and the extracts were derlvatized with perfluorooctanoyl chloride prior to gas chromatography/mass spectrometry. Selected ions were monitored at m/z 118 and 440 for amphetamine, m/z 118 and 454 for methamphetamine, end m/z 121 and 443 for the internal standard amphetamine-d 3. The imprecision was less than 5 % for amphetamine and less than 9 % for methemphetamine. Limits of detection were 11 #g/L for amphetamine and 13 lig/L for methamphetamine, while limits of quentltation were 22 and 34 I~g/I-, respectively. Calibration curves were linear in the ranges 14-2700 i~g/L and 15-3000 p.g/L, respectively. Some drugs that were known or suspected to interfere with immunological or chromatographic methods for amphetamine and methamphetamine were tested for interference. None of the drugs tested interfered, except for a substance in putrefied blood samples, which was found to interfere with one Ion (m/z 118) for amphetamine but not with the second ion. Introduct ion Amphetamine and methamphetamine ar among the most commonly abused rugs in many countries. Amphetamines are used to a lesser extent for medical purposes, primarily for the treatment of narcolepsy and childhood hyperkinesia, andin some countries for appetite suppression (1). The medical use of am-phetamines is strictly regulated inmany countries. Amphetamine and methamphetamine are abused for their cen-tral stimulant effects, which include euphoria and increased self-esteem. In some cases these drugs are abused intravenously, with injections of up to 5000 mg/day (1-3). In drug abuse cases, amphetamine and methamphetamine are most commonly analyzed in urine samples by immunological screening methods (4--6). Confirmation ismostly accomplished by gas chromatography (GC) or gas chromatography/mass spec