Stability studies of amphetamine and ephedrine derivatives in urine (original) (raw)
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2009
Neste trabalho foi desenvolvido e validado um método quantitativo para a análise de anfetaminas e efedrinas em urina, utilizando-se anidrido acético e piridina, ambos em grau analítico, como derivatizantes. As amostras foram extraídas por extração em fase sólida (EFS), derivatizadas e em seguida analisadas por CG-EM. O método apresentou ampla faixa linear (25-1000 ng mL-1 com R 2 > 0,99), alta sensibilidade (LODs variando de 0,0140 a 15,33 ng mL-1 e LOQs variando de 0,0466 a 51,10 ng mL-1), bons índices de precisão (CV < 6% para intra-e inter-ensaios) e excelentes índices de recuperação (87-96%) para todos os compostos estudados. Após a validação, o método foi aplicado em análises de amostras reais de urina humana nas quais ao menos um dos analitos em estudo foi identificado previamente. Em todas as amostras, anfetaminas e efedrinas foram facilmente quantificadas mostrando que a associação de anidrido acético e piridina é uma boa opção como agente derivatizante. A GC/MS method for the simultaneous analyses of different amphetamines and ephedrines in urine employing analytical-grade acetic anhydride/pyridine as derivatizing reagents was developed and validated. Solid-phase extraction was performed on the samples, which were then derivatizated and analyzed by GC/MS. The method showed a broad linear dynamic range (25-1000 ng mL-1 with R 2 > 0.99), high sensitivity (LODs of 0.0140 to 15.33 ng mL-1 and LOQs of 0.0466 to 51.10 ng mL-1), good precision (CV < 6% for intra-and inter-assays), and excellent extraction recovery (87 to 96%) for all the compounds studied. After validation, the method was applied in the analyses of real samples of human urine which were previously determined to contain at least one of such drugs. In all the samples, the amphetamines and ephedrines were promptly quantified, showing that the association of acetic anhydride and pyridine can be conveniently employed as a derivatizing agent.
2005
The use of fast gas chromatography-mass spectrometry (FGC-MS) was investigated to improve the efficiency of analysis of urine specimens that previously screened presumptively positive for amphetamine (AMP), methamphetamine (MAMP), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and/or 3,4 methylenedioxyethylamphetamine (MDEA) by immunoassay testing. Specimens were pretreated with basic sodium periodate, extracted using a positive-pressure manifold/cation-exchange solidphase cartridge methodology, and derivatized using 4-carbethoxyhexafluorobutyryl chloride (4-CB). The analytical method was compared to traditional GC-MS analysis and evaluated with respect to assay chromatography, linearity, sensitivity, precision, accuracy, and reproducibility. The limits of detection were 62.5 ng/mL for MDA and 31.25 ng/mL for AMP, MAMP, MDMA, and MDEA. All of the target analytes were linear to 12,000 ng/mL with the exception of MAMP which was linear to 10,000 ng/mL. The intra-assay precision of a 500 ng/m/multiconstituent control (n-15) ranged from 522.6 to 575.9 ng/mL with a coefficient of variation of less than 3.8%. Authentic human urine specimens (n-187) previously determined to contain the target analytes were re-extracted and analyzed by both FGC-MS and the currently utilized GC-MS method. No significant differences in specimen concentration were observed between these analytical methods. No interferences were seen when the performance of the FGC-MS method was challenged with ephedrine, pseudoephedrine, phenylpropanolamine, and
The stability of ephedrine in compound ephedrine spray N. F
Journal of the American Pharmaceutical Association, 1955
PARTITION CHROMATOGRAM OF BENZOCAINE 5 ML. FRACTIONS Fig. 5.-Partition chromatogram of benzocaine as eluted with diisopropyl ether from an aqueous solution of benzocaine and caffeine. The benzocaine was eluted from aqueous solution by the "slurry method" referred to in the text. During the removal of a sample from a reaction flask, nitrogen gas was run over the mouth of the flask to prevent any carbon dioxide from the atmosphere from entering the flask and reacting with the barium hydroxide solution. The 20-cc. sample removed from the reaction flask was placed into a 25-cc. volumetric flask to which was added 0.5 N acetic acid in 10% excess. The acetic acid neutralized any barium hydroxide remaining unreacted. The solution was then brought up to 25 cc. with distilled water. Exactly 5 cc. of the aqueous solution was placed on 5 Gm. of silicic acid in a 50-cc. beaker and mixed thoroughly. A slurry was made by adding 30 cc. of Skellysolvea-C. The slurry was then quantitatively transferred to the column, the beaker rinsed with 10 cc. of Skellysolve@-C, and the rinsings were added to the column. When removing the plunger, care was exercised not to remove any adhering slurry. When approximately all the supernatant liquid had passed into the column, 1 cc. of diisopropyl ether was added and allowed to drain until almost all the supernatant liquid had again passed into the column. Then 1 cc. of diisopropyl ether was again added and allowed to drain as above. Following this step a 40-cc. portion of diisopropyl ether was added and the first 10 cc. was collected in a 10-cc. graduate and discarded. The next 25 cc. was collected in a 25-cc. volumetric flask for spectrophotometric analysis for benzocaine.
Fast Ephedrine Quantification by Gas Chromatography Mass Spectrometry
Journal of the Brazilian Chemical Society, 2018
Ephedrines are widely used in therapy. Because of their stimulant properties, these substances are relevant in different forensic fields. At present, the state of the art for ephedrines quantification relay based on a liquid chromatography mass spectrometry, mainly because of the dilute-andshoot approach. Notwithstanding, several gas chromatography based methods have already been described, all of them include cleanup steps, with the potential disadvantage of incurring errors and increasing the workload. In this paper, a straightforward method for ephedrine quantification based on gas chromatographic mass spectrometry, without cleanup and based on Doehlert matrix optimization is presented. Only 10 µL of a urine sample is necessary and for N-methyl-N-(trimethylsilyl)trifluoroacetamide/N-methyl-bis-trifluoracetamide derivatives, the intermediate precision was 2.77% for ephedrine, 9.20% for cathine, 8.29% for norephedrine and 4.27% for pseudoephedrine. The limit of detection was 20 ng mL-1 for ephedrine, 30 ng mL-1 for cathine and 40 ng mL-1 for norephedrine and pseudoephedrine.
Determination of amphetamines in Urine_application note.pdf
A capillary electrophoresis tandem mass spectrometry (CE-MS/MS) method was developed for the simultaneous determination of amphetamine (AM), methamphetamine (MAM), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA), and phentermine (PTM) in urine. The urine samples were submitted to a modified QuEChERS extraction procedure followed by electrophoretic separation in 0.1 M formic acid electrolyte (pH 2.4) using a polyvinyl alcohol (PVA)-coated capillary. The correlation coefficients of the calibration curves in the range of 1.0 to 500 ng/mL were up to 0.997. Limits of detection were in the range of 0.01 to 0.02 ng/mL. Precision and accuracy were verified through recovery for spiked urine blank samples at three concentration levels (10, 20, and 50 ng/mL), in triplicate measurements. The recovery values ranged between 90 to 115 %, with a relative standard deviation (RSD) lower than 5.4 %. 2
JPC – Journal of Planar Chromatography – Modern TLC, 2020
Drug abuse is a global menace in the society. Strict measures are planned and effectuated to dismantle this crime yet a large number of cases of narcotics drugs are seized and referred to forensic science laboratories for analysis. Over the past few years, the misuse of precursor chemicals has increased substantially. Examination of these precursor chemicals, especially ephedrine and its analogues, is a major task for forensic analysts. Though gas chromatography-mass spectrometry (GC-MS) is a well-established technique, it dwindles in the identification of the analogues of ephedrine as they have similarity in molecular weight and structure. The analysis involves timeconsuming extraction and derivatization process in sample preparation when used for the identification of isomers. The present paper describes a use of high-performance thin-layer chromatography coupled with mass spectrometry (HPTLC-MS) for the purpose. This technique requires minimum sample preparation; it is a quick and easy methodology with no derivatization and gives a conclusive result for the separation and identification of ephedrine analogues. The drug samples were dissolved in methanol and spotted on Si 60 F 254 thin-layer chromatography (TLC) plate. Good separation of ephedrine from a mixture of ephedrine, pseudoephedrine, and phenylpropanolamine was achieved using the solvent system n-butyl acetate-acetone-n-butanol-5 M ammonia-methanol (4:2:2:1:1, v/v). The separated spot on the TLC was subjected to MS, which identified ephedrine with confirmation.
Determination of ephedrines in urine by gas chromatography–mass spectrometry
Journal of Chromatography B: Biomedical Sciences and Applications, 2001
A selective gas-liquid chromatographic method with mass spectrometry (GC-MS) for the simultaneous confirmation and quantification of ephedrine, pseudo-ephedrine, nor-ephedrine, nor-pseudoephedrine, which are pairs of diastereoisomeric sympathomimetic amines, and methyl-ephedrine was developed for doping control analysis in urine samples. O-Trimethylsilylated and N-mono-trifluoroacetylated derivatives of ephedrines -one derivative was formed for each ephedrine -were prepared and analyzed by GC-MS, after alkaline extraction of urine and evaporation of the organic phase, using 2 d -ephedrine as internal standard. Calibration curves, with r .0.98, ranged from 3.0 to 50 mg / ml depending on the analyte. Validation data (specificity, % RSD, accuracy, and recovery) are also presented.
Journal of Chromatography A, 2000
Different reversed-phase columns for basic analytes were compared for the simultaneous determination of ephedrines in urine, such as LiChrospher 60 RP-Select B, LiChrospher 100 RP18, Hypersil BDS-C18, Inertsil ODS-2, Spherisorb ODS-B and Symmetry Shield RP8. Symmetry Shield was the only column which did not require the use of high concentrations of buffer and triethylamine. With this column, a good separation of the six ephedrines and the internal standard was achieved using 50 mM phosphate buffer-25 mM triethylamine as a mobile phase. Linearity, precision and accuracy were satisfactory for the levels usually found in urine. Due to these all parameters the developed analytical method was found to be suitable for the application in the doping field.
Clinical …, 2000
Background: The popular designer drugs 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyethylamphetamine (MDEA) can be determined in serum, whole blood, and urine, but also in vitreous humor. The latter matrix is interesting when dealing with decomposed bodies in a toxicological setting. Methods: After extraction, chromatographic separation was achieved on a narrow-bore C 18 column by gradient elution with fluorometric detection; results were confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: The method was linear over the range of 2-1000 g/L for whole blood, serum, and vitreous humor, and 0.1-5 mg/L for urine. Extraction recoveries were >70%, imprecision (CV) was 2.5-19%, and analytical recoveries were 95.5-104.4%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.8 and 2 g/L, respectively, for whole blood, serum, and vitreous humor, and 2.5 g/L and 0.1 mg/L, respectively, for urine. Excellent correlations between the quantitative LC-fluorescence and LC-MS/MS results were obtained. We found the following concentrations in a thanatochemical distribution study in rabbits: in serum, 5.3-685 g/L for MDMA and from the LOQ to 14.5 g/L for 3,4-methylenedioxyamphetamine (MDA); in whole blood, 19.7-710 g/L for MDMA and from the LOQ to 17.8 g/L for MDA; in vitreous humor, 12.1-97.8 g/L for MDMA and from the LOQ to 3.86 g/L for MDA. In routine toxicological urine samples, concentrations ranged from LOQ to 14.62 mg/L for MDA, from LOQ to 157 mg/L for MDMA, and from LOQ to 32.54 mg/L for MDEA. Conclusions: The HPLC method described is sensitive, specific, and suitable for the determination of MDMA, MDEA, and MDA in whole blood, serum, vitreous humor, and urine.
Journal of Chromatography B, 2003
Solid-phase microextraction (SPME) is under investigation for its usefulness in the determination of a widening variety of volatile and semivolatile analytes in biological fluids and materials. Semivolatiles are increasingly under study as analytical targets, and difficulties with small partition coefficients and long equilibration times have been identified. Amphetamines were selected as semivolatiles exhibiting these limitations and methods to optimize their determination were investigated. A 100-mm polydimethylsiloxane (PDMS)-coated SPME fiber was used for the extraction of the amphetamines from human urine. Amphetamine determination was made using gas chromatography (GC) with flame-ionization detection (FID). Temperature, time and salt saturation were optimized to obtain consistent extraction. A simple procedure for the analysis of amphetamine (AMP) and methamphetamine (MA) in urine was developed and another for 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-methamphetamine (MDMA) and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) using headspace solid-phase microextraction (HS-SPME) and GC-FID. Higher recoveries were obtained for amphetamine (19.5-47%) and methamphetamine (20-38.1%) than MDA (5.1-6.6%), MDMA (7-9.6%) and MDEA (5.4-9.6%).