Analysis Of Amphetamine In Urine Research Articles

Enantiomer-specific analysis of amphetamine in urine, oral fluid and blood.

Illegal amphetamine is usually composed of a racemic mixture of the two enantiomers (S)- and (R)-amphetamine. However, when amphetamine is used in medical treatment, the more potent (S)-amphetamine enantiomer is used. Enantiomer-specific analysis of (S)- and (R)-amphetamine is therefore used to separate legal medical use from illegal recreational use. The aim of the present study was to describe our experience with enantiomer-specific analysis of amphetamine in urine and oral fluid, as well as blood, and examine whether the distribution of the two enantiomers seems to be the same in different matrices. We investigated 1,722 urine samples and 1,977 oral fluid samples from prison inmates, and 652 blood samples from suspected drugged drivers, where prescription of amphetamine was reported. Analyses were performed using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS). The enantiomer separation was achieved by using a chiral column, and results from the method validation are reported. Samples containing <60% (S)-amphetamine were interpreted as representing illegal use of amphetamine. The distribution of the two enantiomers was compared between different matrices. In urine and oral fluid, the mean amount of (S)-amphetamine was 45.2 and 43.7%, respectively, while in blood, the mean amount of (S)-amphetamine was 45.8%. There was no statistically significant difference in the amount of (S)-amphetamine between urine and oral fluid samples and between urine and blood samples, but the difference was significant in blood compared to oral fluid samples (P < 0.001). Comparison of urine and oral fluid between similar populations indicated that enantiomers of amphetamine can be interpreted in the same way, although marginally higher amounts of (R)-amphetamine may occur in oral fluid. Oral fluid, having several advantages, especially during collection, could be a preferred matrix in testing for illegal amphetamine intake in users of medical amphetamine.

GC/MS analysis of amphetamine in urine with amphetamine-d5(side chain) as an internal standard

This study examined the accessibility of using amphetamine-d5 (side chain) as an internal standard in quantitative analysis of the trichloroacetyl derivative of urinary amphetamine by gas chromatography / mass spectrometry (GC/MS). In GC/MS analysis , fragments with minimal interference between the assay protocol and the internal standard were selected for quantitation. In the full-scan mode, no interference from TCA-amphetamine-d5, the trichloroacetyl derivative of amphetamine-d5, was observed for the fragments of trichloroacetylamphetamine (TCA-amphetamine) with m/z 190, 188, 118 and 91. On the other hand, no interference from TCA-amphetamine was indicated in fragments of m/z 196 and 123 of TCA-amphetamine-d5. In the selective ion monitoring mode (SIM), the interference between m/z 190, 188, 118 and 91 of TCA-amphetamine and m/z 196, 194 and 123 of TCA-amphetamine-d5 was minimal. The fragments of m/z 190 from TCA-amphetamine and m/z 194 from TCA-amphetamine-d5 were thus selected for quantitation of urinary amphetamine by SIM. Calibration graph derived from the ratio of relative intensity of m/z 190 to m/z 194 versus the concentration of urinary amphetamine was linear over the concentration range of 31.25 - 2000 ng/mL (n=7, SD=0.0357, r=0.9987). Amphetamine-d5 was demonstrated to be a suitable internal standard in quantitative analysis of the trichloroacetyl derived urinary amphetamine by SIM analysis with GC/MS.

Analysis of amphetamines in urine with liquid–liquid extraction by capillary electrophoresis with simultaneous electrochemical and electrochemiluminescence detection

Amphetamines including methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine were separated and detected by CE using simultaneous electrochemical (EC) and electrochemiluminescence (ECL) detection (CE-EC/ECL). Factors that influenced the separation and detection performance, such as the detection potential, the pH value and concentration of the running buffer, the separation voltage and the pH of the detection buffer, were investigated. LODs of 3.3x10(-8) mol/L (0.16 fmol), 1.6x10(-7) mol/L (0.78 fmol) and 3.3x10(-8) mol/L (0.16 fmol) were obtained for methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine, respectively. For practical application, a liquid-liquid extraction with ethyl acetate procedure was developed for urine sample pretreatment and extraction efficiencies higher than 90% were obtained. The established simultaneous CE-EC/ECL was successfully applied for urine sample analysis.

Simultaneous analysis of some amphetamine derivatives in urine by nonaqueous capillary electrophoresis coupled to electrospray ionization mass spectrometry

A nonaqueous capillary electrophoresis method, coupled to UV and electrospray mass spectrometry (ESI-MS), is described for the simultaneous analysis of Ecstasy and other related derivatives. Several electrophoretic and ESI-MS parameters were systematically investigated, such as electrolyte nature and concentration, organic solvent and sheath liquid compositions, nebulization gas pressure and drying gas flow-rate. The best results were achieved with an acetonitrile–methanol (80:20, v/v) mixture containing 25 m M ammonium formate and 1 M formic acid, an applied voltage of 30 kV and a separation temperature of 15°C. Under optimized CE–ESI-MS conditions, separation of the investigated drugs was performed in less than 6 min, with a high efficiency. Method precision based on migration time and peak area was determined and the limits of detection, which depend on the tested compound, were established between 20 and 70 ng ml −1 in the selected ion monitoring mode. Finally, the described method was successfully applied to the analysis of amphetamines in urine after a liquid–liquid extraction.

Routine analysis of amphetamine class drugs as their naphthaquinone derivatives in human urine by high-performance liquid chromatography

We describe a simple HPLC method which is suitable for the routine confirmation of immunoassay positive amphetamine urine samples. The precolumn derivisation method employing sodium naphthaquinone-4-sulphonate was found to have adequate sensitivity, selectivity and precision for the measurement of amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), and 3,4-methylenedioxyethylamphetamine (MDEA) at 500 μg/l cutoff level for confirmatory analysis of amphetamines in urine. The specificity of the method is enhanced by detecting the peaks at two different wavelengths. The ratios of the peak heights measured at the two wavelengths were different for each of the 5 amphetamines analysed. There was no interference from other phenylethylamine analogues that are commonly found in “over the counter” preparations. The HPLC method is compared to a commercial TLC system for detecting amphetamines in urine of drug abusers attending drug rehabilitation programmes. The HPLC confirmatory method described is a viable alternative to GC or to the more complex and costly GC–MS techniques for confirming amphetamine, methamphetamine, MDMA, MDA and MDEA in urine of drug abusers especially when used in a clinical care setting

Method optimization for the analysis of amphetamines in urine by solid-phase microextraction.

Solid-phase microextraction is under investigation in many laboratories for its usefulness in the analysis of an ever widening variety of compounds. As new classes of compounds are investigated and new challenges arise, the methods are adapted to accommodate them. Polar semivolatiles are increasingly under study as analytical targets, and difficulties with small partition coefficients and long equilibration times have been identified. Amphetamine and methamphetamine were selected as semivolatiles exhibiting these limitations, and methods to optimize their analyses were investigated. Amphetamines are frequently monitored in very complex matrixes. Headspace methods minimize interactions between the sample and the fiber and have proven useful for these analyses. Several areas of experimental design were considered in the process of method optimization. These included matrix modification by heating, stirring, methanol content, addition of salt, and pH buffering. It was found that these amphetamines could be reliably analyzed using modified sample conditions, with excellent sensitivity, limits of detection, and method linearity. Clinical urine samples were successfully analyzed and gave clean chromatograms with no interfering peaks. Finally, the method developed was found to be useful for the analysis of narcotic analgesics. In the future, it is hoped that the method can be used to develop a general screen for a wide range of drugs of abuse.

Analysis of amphetamine in urine using TLC and interference refractometry

Urinary excretion of amphetamine has been examined in a number of male albino rats of the Wistar strain after intraperitoneal administration of d-amphetamine-HCl. The collected urine was rendered alkaline, extracted with chloroform, washed with water, dried with anhydrous magnesium sulfate, and evaporated down to 10 ml; the excretion of unchanged drug was determined using (a) silica-gel thin-layer chromatography and a number of solvents and (b) interference refractometry. The effect on the excretion of the amine when urine was acidic or alkaline was also measured. Quantities smaller than 1 mg were measured with these techniques.