04-22-03 21:44
No 428726
Optimization of extraction parameters for the chemical profiling of 3,4-methylenedioxymethamphetamine (MDMA) tablets
P Gimeno et al. J Forensic Sci 132 (2003) 182-194
DOI:10.1016/S0379-0738(03)00019-7
Abstract - The extraction of impurities from illegally produced 3,4-methylenedioxymethamphetamine (MDMA) has been studied in order to optimize the parameters. Two different MDMA samples were used. Particular attention was paid to the influence of the pH, the evaporation step, and the sample storage. The method used was an extraction of impurities by diethyl ether from a buffer solution at pH 11.5, followed by gas chromatography (GC) mass spectrometric (MS) analyses after a dryness concentration under monitored conditions of the ethereal extract. Repeat extractions of the same sample gave an average relative standard deviation (RSD) of less than 8.5% within day and less than 10.5% between days.
Introduction - 3,4-Methylenedioxymethamphetamine (MDMA) is an illicit synthetic, psychoactive substance possessing stimulant and mild hallucinogenic properties. According to Europol, in 2000, 17.4 millions of ecstasy tablets were seized in the member states of the European Union, corresponding to an increase of almost 50% compared with 1999. Significant increases were observed in Austria (420%), Finland (394%), Greece (1803%), Ireland (163%), Italy (86%), The Netherlands (50%), Spain (64%) and Sweden (152%) [1]. In order to know synthesis schemes used by clandestine laboratories, an analytical method has been developed in order to identify by gas chromatography–mass spectrometry (GC–MS) the various impurities present in ecstasy samples [2]. Nevertheless, several extraction parameters needed to be optimized in order to improve the reproducibility of the method suggested.
As a matter of fact, if many publications deal with a detailed impurity extraction process for the profiling of MDMA [4–7]. More authors prefer to focus on the identification of impurities in freshly prepared MDMA samples via different synthesis routes and give us analytical data of precursors, intermediates and reaction by products [8–18]. Among published extraction processes, one consists in dissolving 5 mg of crushed MDMA tablets into 1 ml of redistilled diethyl ether [4]. The supernatant is then taken off and evaporated to dryness before adding 0.1 ml of methyl alcohol for GC–MS analyses. Another paper presents the impurities found in MDMA and MDEA street samples [5]. The extraction method used consists in dissolving 150–300 mg of each sample into 5 ml of phosphate buffer (pH ¼ 7), in order to have about 80 mg of active substance, the extraction being carried out with 1 ml of diethyl ether containing heneicosane (C21) as internal standard. Other authors also use a phosphate buffer (pH ¼ 6 [6] or pH ¼ 9 [7]) to dissolve MDMA powders whereas organic impurities are extracted, respectively by dichloromethane [6] and ethyl acetate [7]. In that last study, comparison between liquid–liquid extraction (LLE) and solid phase extraction (SPE) for the profiling of ecstasy tablets is also discussed.
The rest of the article is rather graphical... If there is general interest, I can try to put it online somewhere.
The faster you run, the quicker you die.
(Stranger)
04-24-03 11:53
No 429113
There's certainly interest here if it's not too much trouble
(Hive Bee)
04-28-03 21:51
No 430040
In the article they say that PMMA is present as an impurity in the two samples of MDMA they investigated. Is the p-methoxy compound present in sassafras oil or does it originate from cleavage of the methylenedioxy ring? Furthermore, I think the GC chromatograms they present are rather lousy. As an analytical chemist I think they should have done a better job
In the beginner´s mind there are many possibilities, but in the expert´s mind there are few.
(Chief Bee)
07-18-03 03:03
No 448141
Optimization of extraction parameters for the chemical profiling of 3,4-methylenedioxymethamphetamine (MDMA) tablets
Pascal Gimeno, Fabrice Besacier
Forensic Science International, 132(3), Issue 3, 182-194 (2003) (../rhodium/pdf /mdma.impurit
DOI:doi:10.1016/S0379-0738(03)00019-7
Abstract
The extraction of impurities from illegally produced 3,4-methylenedioxymethamphetamine (MDMA) has been studied in order to optimize the parameters. Two different MDMA samples were used. Particular attention was paid to the influence of the pH, the evaporation step, and the sample storage. The method used was an extraction of impurities by diethyl ether from a buffer solution at pH 11.5, followed by gas chromatography (GC) mass spectrometric (MS) analyses after a dryness concentration under monitored conditions of the ethereal extract. Repeat extractions of the same sample gave an average relative standard deviation (RSD) of less than 8.5% within day and less than 10.5% between days.