title: Solvent-enhanced microwave-assisted derivatization following solid-phase extraction combined with gas chromatography-mass spectrometry for determination of amphetamines in urine.
abstract: An approach using microwave-assisted derivatization (MAD) following solid-phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) was developed to determine amphetamines in urine samples. The parameters affecting the derivatization efficiency - including microwave power and irradiation time - were investigated. Besides, solvent is thought critically important to MAD. Derivatization performance was studied using various solvents and compared with the performance obtained without solvent. Derivatization efficiency was clearly found to be enhanced by the presence of solvent. The highest derivatization efficiencies were obtained in ethyl acetate (EA) under microwave power of 250W for 1min. Calibration curves for all amphetamines were linear over a range from 1 to 1000ng/mL, with correlation coefficients above 0.9992. The intra-day and inter-day precision were less than 15%. The applicability of the method was tested by analyzing amphetamine-abusing subjects urine samples. Accordingly, the solvent-enhanced MAD-GC-MS method appears to be adequate for determining amphetamines in urine.
authors.affiliation: Department of Chemistry, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan, ROC.
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Chung
authors.forename: Geng-Jhih
authors.initials: GJ
authors.lastname: Liu
authors.forename: Zu-Guang
authors.initials: ZG
authors.lastname: Li
authors.forename: Yan-Zin
authors.initials: YZ
authors.lastname: Chang
authors.forename: Maw-Rong
authors.initials: MR
authors.lastname: Lee
mesh_terms: D019969:Amphetamine-Related Disorders / Q000175:diagnosis / Q000652:urine; D000662:Amphetamines / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D015813:Substance Abuse Detection / Q000379:methods
chemical_list: D000662:Amphetamines