Rapid Analysis of Amphetamine, Methamphetamine, MDA, and MDMA in Urine Using Solid-Phase Microextraction, Direct On-Fiber Derivatization, and Analysis by GC-MS

Abstract

A rapid, sensitive, and solvent-free procedure for the simultaneous determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), and 3,4-methylenedioxymethamphetamine (MDMA) in urine was developed using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode. A headspace vial containing the urine sample, NaOH, NaCl, and amphetamine-d3 as the internal standard was heated at 100 degrees C for 20 min. A polydimethylsiloxane fiber was maintained in the vial headspace for 10 min in order to adsorb the amphetaminic compounds, which were subsequently derivatized by exposing the fiber to trifluoroacetic anhydride for 20 min in the headspace of another vial maintained at 60 degrees C for 20 min. The trifluoroacetyl derivatives were desorbed in the GC injection port for 5 min. Several parameters were considered during the method optimization process. These included a comparison of SPME with or without headspace, the required derivatization procedure, and the influence of temperature on the headspace extraction and derivatization methods. The optimized method was validated for the four compounds tested. Calibration curves showed linearity in the range 50-1000 ng/mL (r = 0.9946-0.9999). Recovery data were 71.89-103.24%. The quantitation limits were 10 ng/mL for amphetamine and methamphetamine and 20 ng/mL for MDA and MDMA. All of these data recommend the applicability of the method for use in the analytical routine of a forensic laboratory.

Separation of Sympathomimetic Amines of Abuse and Related Compounds by Micellar Electrokinetic Chromatography.

“…The detection limits calculated were in a range from 4 to 97 fmol/injection at a signal-tonoise ratio (S/N) of 3. This sensitivity is almost comparable to that for an HPLC-UV method employing sodium naphthoquinone-4-sulphonate as a derivatizing reagent 13) and a GC method with a nitrogen-phosphorus detector, 3) but lower than that of GC-MS 7,8) and HPLC-FL methods.…”

“…For the analysis of some of these drugs, gas chromatography (GC), [2][3][4] GC-mass spectrometry (GC-MS) [5][6][7][8][9] and high-performance liquid chromatography (HPLC) [10][11][12][13][14] are exclusively employed. GC-MS methods are generally highly sensitive but require a derivatization procedure prior to the analysis.…”

“…GC-MS methods are generally highly sensitive but require a derivatization procedure prior to the analysis. [5][6][7][8][9] HPLC methods with fluorescence (FL), 11,14) chemiluminescence (CL) 12) and UV-Vis 10,13) detections also require derivatization to increase the sensitivity and a rather long time to separate analytes. As an analytical technique to meet the requirements for the applicability to diverse analytes, capillary electrophoresis (CE) has been developed.…”

The development of selective and biocompatible coatings for solid phase microextraction

“…In general, it can provide selectivity in the analysis via quantitative labeling of only those compounds that react with the derivatizing reagent. Derivatization has been applied to SPME with great success and can also have the added advantage of improving the volatility of the sample for better headspace extraction, and increasing the chromatographic separation [28] and/or detector response [29].…”

Simultaneous Separation and Detection of 18 Phenethylamine/Tryptamine Derivatives by Liquid Chromatography–UV Absorption and –Electrospray Ionization Mass Spectrometry

“…[7][8][9][10][11][12][13][14][15][16][17] However, the major ionization source used in GC/MS Loved) and TiHKAL (Tryptamines i Have Known and Loved), is electron impact (EI) and, in many cases, acquiring parent ions respectively. 1,2 Unfortunately, these compounds have been abused of the analytes is a difficult task.…”