Determination of ecstasy components in human urine by gas chromatography using a dispersive liquid-liquid microextraction procedure

Abstract

Um método novo foi desenvolvido para pré-concentração e determinação de compostos de ecstasy, 3,4-metilenodioxiamfetamina (MDA), 3,4-metilenodioximetilamfetamina (MDMA), 3,4-metilenodioxietilamfetamina (MDEA) e 3,4-metilenodioxipropilamfetamina (MDPA), em amostras de urina utilizando microextração líquido-líquido dispersiva (DLLME) e cromatografia gasosa com detector por ionização em chama (GC-FID). O método foi baseado na formação de gotículas de um extratante orgânico em soluções preparadas utilizando água, solvente orgânico imiscível (CS 2 ) dissolvido em solvente dispersor miscível em água (acetona). A fase orgânica, que extraiu MDA, MDEA, MDMA e MDPA da solução da amostra preparada, foi separada por centrifugação. Parâmetros que afetam a eficiência da extração foram investigados e otimizados. Sob condições ideais, as linearidades do método foram 1,0-500 µg L -1 para MDEA e MDPA e 2,5-500 µg L -1 para MDA e MDMA. . O método foi aplicado com sucesso na determinação de analitos em amostras de urina.A new method was developed for preconcentration and determination of ecstasy compounds, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethylamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA) and 3,4-methylenedioxypropylamphetamine (MDPA), in urine samples using dispersive liquid-liquid microextraction (DLLME) and gas chromatography (GC) with flame ionization detection (GC-FID). The method was based on the formation of tiny droplets of an organic extractant in prepared sample solution using water, immiscible organic solvent (CS 2 ) dissolved in water-miscible organic disperser solvent (acetone). The organic phase, which extracted MDA, MDEA, MDMA and MDPA from the prepared sample solution, was separated by centrifugation. Parameters affecting extraction efficiency were investigated and optimized. Under the optimum conditions, linearities of the method were 1.0-500 µg L -1 for MDEA and MDPA and 2.5-500 µg L -1 for MDA and MDMA. The limits of detection (LODs, S/N = 3, signal-to-noise ratio) were in the range from 0.3 to 0.8 µg L -1 . The method was successfully applied to the determination of analytes in urine samples.

Solid-phase extraction followed by dispersive liquid-liquid microextraction for the sensitive determination of ecstasy compounds and amphetamines in biological samples

“…The comparison of extraction time of the proposed method with solid-phase microextraction (SPME) [25] and microwave-assisted extraction (MAE) [36] for the extraction of the target analytes indicates that this novel method has a short extraction time of only one minute, which results in better quantitative results than the SPME and MAE methods. The LODs and RSDs of the proposed method are better than that of the DLLME [30]. DLLME alone needs extra steps in sample preparation for the extraction of the analytes in plasma in comparison with SPE-DLLME.…”

“…The sample solution must be adjusted to a desired pH where the analytes were uncharged, thus the uncharged molecular forms of the analytes were extracted into CS 2 droplets effectively [30]. The pH of the samples was adjusted with 1 M NaOH to ensure that the neutral molecular forms of the analytes are present prior to performing the microextraction step.…”

“…Also, in urine sample, DLLME method needs more dilution with compare to SPE-DLLME method. We reported the application of DLLME method for the determination of ecstasy and amphetamines compounds in human urine samples [30].…”

Mixed-Hemimicelle Solid Phase Extraction Followed by Dispersive Liquid-Liquid Microextraction of Amphetamines from Biological Samples

“…The quantitative results of the proposed method are better than those of for solid-phase microextraction (SPME) 46 and microwave-assisted extraction (MAE) 47 techniques in urine sample. The LOD and RSD values of the proposed method are also better than those of for DLLME 48 method in urine sample. DLLME alone needs extra steps in sample preparation for the extraction of the analytes in plasma sample comparing with SPE-DLLME method 49 and MHSPE-DLLME method.…”

Development of a Method Based on DLLME and UFLC-DAD for the Determination of Antibiotics in Honey Samples and the Study of Their Degradation Kinetics

“…In the selection of the extractant solvent, the maximum desirability was observed for the level (+1) ( Table S2 and Figure S1, SI section), which means chloroform as the extractant solvent. According to Mashayekhi and Rezaee, 54 the extractant solvent should be slightly miscible with water and denser than it, besides presenting the ability to extract the analytes. On the other hand, for selection of the dispersant solvent the overall desirability should be maximum for the level (-1) (Table S2 and Figure S1, SI section), meaning acetonitrile as the dispersant solvent.…”