Identification of impurities and statistical classification of methamphetamine tablets (Ya-Ba) seized in Thailand

Impurity profiles of methamphetamine tablets seized in Thailand have been investigated. The samples are extracted with small amounts of ethyl acetate under alkaline condition and the extracts are analyzed by capillary gas chromatography. Nine compounds (1,2-dimethyl-3-phenylaziridine, ephedrine, methylephedrine, N-formylmethamphetamine, N-acetylmethamphetamine, N-formylephedrine, N-acetylephedrine, N,O-diacetylephedrie, methamphetamine dimer) are identified as impurities in methamphetamine tablet. Caffeine and ethyl vanillin are also detected as diluents and/or adulterants, and acetylcodeine monoacetylmorphine and diacetylmorphine are contained in many samples. In addition, trans-3,4-dimethyl-5-phenyl-2-oxazolidone is newly found as an impurity. For characterization and comparison of methamphetamine tablet exhibits, intensely and commonly detectable nine peaks are selected as the factor for multivariate analysis. The procedures reported here permit classification of 250 analyzed exhibits into five groups and characterization of classified groups.     

Optimum methamphetamine profiling with sample preparation by solid-phase microextraction

Solid-phase microextraction (SPME) is a relatively new technique in which a small, polymer-coated fiber is employed to extract volatile and semivolatile organic compounds from the sealed headspace above a questioned sample. SPME, coupled with gas chromatography/mass spectrometry (GC/MS), was used to characterize impurities in illicit methamphetamine samples. Trace impurities present in a specimen were tentatively identified using mass-spectral databases and included 1,2-dimethyl-3-phenyl-aziridine (indicating synthesis via a halogenated ephedrine intermediate), ethyl vanillin (a flavoring compound), and caffeine (a stimulant used as cutting agent). The types and numbers of organic compounds sampled by SPME were compared with those collected by various solvent extraction protocols. In addition to unambiguously confirming the presence of methamphetamine, SPME-GC/MS analyses detected approximately 30 more organic analytes than were found by GC/MS following the ethyl acetate extraction method adopted by the United Nations International Drug Control Programme. SPME-GC/MS is a superior method for generating material "fingerprint" profiles in methamphetamine samples. The detection and characterization of increased points of comparison in drug samples provide more detailed chemical signatures for both intelligence and operational information.     

Abuse of smoking methamphetamine mixed with tobacco: I. Inhalation efficiency and pyrolysis products of methamphetamine

Experiments of smoking methamphetamine in tobacco have been investigated. Inhalation efficiencies of methamphetamine into tar were 6 to 17% according to the additive amounts, suction volume, and intervals of smoking. Major pyrolysis products of methamphetamine in tar were identified as methamphetamine, amphetamine, phenylacetone, dimethylamphetamine, N-formyl-, N-acetyl-, N-propionyl-, and N-cyanomethyl-methamphetamine by the spectral analysis of infrared spectra (IR), mass spectra (MS), and proton magnetic resonance spectra (PMR), and comparison with the samples synthesized from authentic samples by one step. The largest pyrolysis product was N-cyanomethylmethamphetamine which is a new compound and easily metabolized to methamphetamine in the body. Methamphetamine itself transferred into tar was not so large, but the total active compounds in tar which would be metabolized to methamphetamine in the body were considerably larger.     

Determination of impurities in illicit methamphetamine samples seized in Iran

In this study fifty samples of crystalline methamphetamine obtained from antinarcotics police of Iran seized during the year 2010 were analyzed. In order to determine the chemical characteristics of these samples, anion test, Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS) were carried out on the samples. All of the samples containing methamphetamine tested positive for chloride anion. The range of methamphetamine hydrochloride content in these samples was 33-95%. One sample out of 50 contained no methamphetamine. The fact that 1,2-dimethyl-3-phenylaziridine was the most frequently found impurity in the analyzed samples, indicates that most of the methamphetamine samples seized in Iran have been synthesized from pseudoephedrine as starting material.     

Analysis of dimethylamphetamine and its metabolites in human urine by liquid chromatography-electrospray ionization-mass spectrometry with direct sample injection

An analytical method to identify and determine dimethylamphetamine (DMA) and its metabolites in human urine was developed with liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) involving the direct injection of a urine sample. The urine samples were directly injected by using a gel permeation column, whose stationary phase was polyvinyl alcohol with a small amount of a carboxyl group, so DMA and its metabolites were analyzed rapidly and simply without pretreatment such as extraction, concentration and derivatization. DMA and its metabolites were identified in drug-free human urine spiked with 1 microg of DMA, dimethylamphetamine N-oxide (DMANO) and methamphetamine (MA), and 3 microg of amphetamine (AM) in 1 ml of urine under the full-scan mode. Under the selected ion monitoring (SIM) mode, the limits of detection (signal-to-noise ratio=5) for DMA, DMANO, MA and AM were 20, 20, 20 and 60 ng in 1 ml of urine, respectively. This method was applied to the identification and determination of DMA and its metabolites in urine samples of 10 DMA abusers. The concentrations of DMANO were higher than those of unchanged DMA in all urine samples; thus, DMANO is considered to be a useful metabolite as an indicator to prove DMA intake.     

Abuse of smoking methamphetamine mixed with tobacco: II. The formation mechanism of pyrolysis products

The pyrolysis products of smoking methamphetamine mixed with tobacco were determined by gas chromatography (GC) and GC/mass spectrometry (GC/MS) methods. The mainstream smoke contained methamphetamine (14.5% of the initial methamphetamine), phenylacetone (3.1%). N-cyanomethylmethamphetamine (1.9%), trans-beta-methylstyrene (1.7%), N-formylmethamphetamine (1.5%), and other products (each less than 1%). The amount of each pyrolysis product in the sidestream smoke was less than that in the mainstream smoke by a factor of over 5, except for methamphetamine (10.5%) and N-formylmethamphetamine (1.4%). The formation mechanism of these products was investigated, by use of a pyrolyzer, from the standpoint of the material, pyrolysis temperature, and pyrolysis atmosphere. Although several products (for example, dimethylamphetamine and trans-beta-methylstyrene) were formed by thermal self-decomposition of methamphetamine alone, most of the products, except N-cyanomethylmethamphetamine, were formed chiefly by the thermal reaction of methamphetamine with cigarette components. The formation of N-cyanomethylmethamphetamine required air and a high pyrolysis temperature. Air and a high pyrolysis temperature generally accelerated the formation of the pyrolysis products.     

SPME/GC-MS characterization of volatiles associated with methamphetamine: toward the development of a pseudomethamphetamine training material

The headspace profiles of eleven methamphetamine (MA) samples have been analyzed using solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS). Nine of the eleven are illicit MA seizures from the Southwest U.S. border. One sample is methamphetamine base synthesized in the Drug Enforcement Administration (DEA) Southwest Laboratory, and the remaining sample is pharmaceutical-grade methamphetamine hydrochloride that is used to make training aids for drug detecting canines. In addition. volatiles associated with 1-phenyl-2-propanone (P2P), a methamphetamine precursor, have been identified for comparison with those found in methamphetamine seizure and the two reference samples. Eighty-seven different compounds were identified from all the samples, not including simple hydrocarbons and aldehydes. Only seven occur consistently in all seizure samples, and these are: acetic acid, benzaldehyde, acetophenone, P2P, 1-phenyl-1,2-propanedione (P12P), 3-phenyl-3-buten-2-one, 1-chloro-1-phenyl-2-propanone. Dimethyl sulfone, a common cutting agent in methamphetamine. was found in six of the nine seizure materials. When the reference methamphetamine and P2P samples are included, only two compounds are common to all twelve samples, and these are benzaldehyde and P2P. As such, these two compounds are likely candidates for use in a pseudomethamphetamine (PM) formulation, and their effectiveness in eliciting a canine response is being evaluated before actual deployment.     

Identification of impurities and the statistical classification of methamphetamine using headspace solid phase microextraction and gas chromatography-mass spectrometry

The profiling of impurities in methamphetamine (MA) using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) is described. The extraction of the impurities with an SPME fiber was examined under varying conditions. Optimal chromatograms were obtained when a 50 mg MA sample at 85 degrees C for 30 min was extracted using a fiber coated with divinylbenzene/carboxen/polydimethylsiloxane. MA samples from nine different origins were analyzed under optimized extraction conditions. Compounds related to MA such as benzaldehyde, benzyl alcohol, amphetamine, benzyl methyl ketone, cis- and trans-1,2-dimethyl-3-phenylaziridine, dimethylamphetamine, N-acetylamphetamine, N-acetylmethamphetamine and N-formylmethamphetamine were detected in the chromatograms. Trace amounts of ethanol, diethyl ether and acetic acid were also detected in some of the chromatograms. The numbers and intensities of the peaks detected were different, depending on the sample. After the areas of the eight principal peaks were converted to their square root and logarithm, similarities among the samples were evaluated by Euclidian distance, cosine distance and correlation coefficient. The results showed that a combination of logarithmic conversion and cosine distance was the most suitable for discriminating and classifying the samples. HS-SPME/GC-MS is a simple and effective method for the extraction and identification of impurities. The present method, in combination with an appropriate statistical analysis, would be useful for developing a profile of impurities in MA.     

Carbon and Nitrogen Stable Isotope Analyses of Ephedra Plant and Ephedrine Samples and Their Application For Methamphetamine Profiling

In this study, stable isotope ratio analysis was used to track the precursor information of methamphetamine. The δ¹³C and δ¹⁵N values of 30 nature ephedra plants, 12 synthetic ephedrine/pseudoephedrine (ephedrine), 14 natural ephedrine, and 987 seized methamphetamine samples were measured and compared. Due to different weather and earth conditions, the δ¹³C and δ¹⁵N values of ephedra plants grown in the east and the west of Inner Mongolia showed great difference. The δ¹⁵N values of ephedra plants were consistent with related ephedrine extracted from them. Moreover, the criteria to infer the synthetic origin of ephedrine were set up after the analysis of natural and synthetic ephedrine samples. Finally, the precursor origins of 949 seized methamphetamine samples synthesized by Emde and Nagai method were tentatively inferred. Influenced by different preprecursors, the δ¹³C values of seized methamphetamine samples that synthesized from P2P also showed great difference, and this result is consistent with the reported data.     

Capillary gas-liquid chromatography separation of phenethylamines in amphetamine-positive urine samples

Good gas chromatography (GC) separation of molecules is essential for clean gas chromatography/mass spectrometry (GC/MS) confirmation of compounds. The trifluoro derivatives of ephedrine (E) and methamphetamine (MA) coelute on dimethyl silicone capillary columns, such as DB-1, which are most commonly used by chromatographers. Methods are described to separate E and MA to aid GC/MS confirmations of methamphetamine, ephedrine, or both E and MA together, whichever may be present in Enzyme Immunoassay (EIA)-analyzed amphetamine-positive urine samples. The use of the heptafluoro derivatives of E and MA on a DB-1 column, or the trifluoro derivatives of E and MA on a DB-17 column, is suggested for good gas chromatographic separation.     

Abuse of "pheticol" and its interference to the analysis of methamphetamine

The study was to eliminate interference from ephedrine in the analysis of methamphetamine. The extraction procedure for methamphetamine was modified to include an oxidation step (2 ml urine specimen was treated with 0.5 ml of 1 mol/L phosphate buffer (pH 6.8) and 0.5 ml 0.3 mol/L sodium periodate). Results showed that ephedrine could be oxidized in the presence of periodate ions into smaller fragments while leaving methamphetamine intact. It is recommended that specimens be treated with sodium periodate prior to extraction in order to eliminate any interference caused by ephedrine.     

Contribution of thermal desorption and liquid-liquid extraction for identification and profiling of impurities in methamphetamine by gas chromatography-mass spectrometry

Impurity profiling of methamphetamine (MA) using thermal desorption (TD) and gas chromatography-mass spectrometry (GC-MS) was examined. Using TD/GC-MS, impurities were extracted and separated under various conditions. Optimal chromatograms were obtained when a 20 mg MA sample was extracted at 120 degrees C for 3 min using a TD instrument, followed by separation of the extracts using a non-polar capillary column coated with (5%phenyl)-methylpolysiloxane. MA samples from nine different batches were analyzed under optimized conditions. Compounds related to the structure of MA, such as benzaldehyde, benzyl alcohol, amphetamine, cis- and trans-1,2-dimethyl-3-phenylaziridine, dimethylamphetamine, and N-acetylephedrine, were detected in the chromatograms without any laborious extraction procedure. Compounds such as ethanol, diethyl ether, and acetic acid, which are considered reagents and solvents for MA synthesis, were also detected in some of the chromatograms. The numbers and intensities of the peaks detected were different among the samples. Impurity profiling of MA using TD was compared with that using liquid-liquid extraction (LLE). Better reproducibility of peak areas was obtained using LLE, whereas higher intensities and numbers of peaks were detected using TD. Solvents were extracted more effectively using TD. The nine batches of MA were classified using both extraction procedures. The nine batches were divided roughly into two groups using data from LLE. Subsequently, the groups were classified in detail using data from TD. TD can be used to provide supplemental information for LLE, and the combination of these extraction methods can be helpful for impurity profiling of MA.     

Population data on the 11 STR loci in the Upper Silesia (Poland)

Smuggling of methamphetamine is affected by enforced regulation and international situation, resulting in changes of precursors and synthetic methods used. Enantiomer ratio of methamphetamine can provide information concerning its precursor and synthetic method. This information is useful for the prevention of smuggling methamphetamine and its precursor, and resultant reduction of methamphetamine abuse. In the present study, we investigated on the enantiomer ratios of 433 crystalline methamphetamine samples seized in Korea from 1994 to 2005. Excluding 17 samples of low purity, 416 samples were used for enantiomer profiling. The methamphetamine samples were derivatized with (S)-(+)-alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride ((S)-(+)-MTPACl), and the derivatives were analyzed by GCMS in selected ion monitoring (SIM) mode. The enantiomer ratios of the samples were calculated from the standard calibration curves of each enantiomer, both of which showed good linearity in the range of 0-1.2 microg. Most of the seizures were pure S(+)-enantiomer, but 21% (95 of 416 samples) contained R(-)-enantiomer above 1%. They began to appear from 1997, and increased continuously up to 50% in the year 2005 (55 of 111 samples). From this study, we could find out that alternative precursors have been used recently for the illicit manufacture of methamphetamine seized in Korea.     

超高效液相色谱法（UPLC）同时筛选检测吗啡等7种常见毒品

目的建立快速筛选检测中毒者血液、尿液中吗啡、甲基苯丙胺、苯丙胺、麻黄碱、3，4-亚甲基双氧甲基苯丙胺（MDMA）、3，4-亚甲基双氧苯丙胺（MDA）、氯胺酮并定量分析的方法；方法采用超高效液相色谱（UP—LC）-二极管阵列检测器（PAD）；结果峰面积和质量浓度的线性关系良好，分离效果好、速度快、灵敏度提高；结论该方法与传统的HPLC相比能够更好满足实际办案中吗啡、甲基苯丙胺、苯丙胺、麻黄碱、MDMA、MDA、氯胺酮等中毒者血液、尿液的筛选检测并定量分析。     

Structural determination of the principal byproduct of the lithium-ammonia reduction method of methamphetamine manufacture

One common method of illicit methamphetamine manufacture utilizes an alkali metal, typically lithium, and liquid ammonia to chemically reduce ephedrine or pseudoephedrine to form methamphetamine. This method is often referred to as the lithium-ammonia reduction method or the Birch reduction method. While the hydroxyl group of ephedrine is more reactive than the aromatic ring, excess alkali metal and the presence of a proton source allow the formation of a cyclohexadiene byproduct not found in samples of methamphetamine produced from other manufacturing methods. A sample enriched in this byproduct was generated and characterized using nuclear magnetic resonance (NMR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), infrared (IR) spectrophotometry, and ultraviolet (UV) spectrophotometry. The chemical structure of this byproduct was determined to be 1-(1',4'-cyclohexadienyl)-2-methylaminopropane (CMP).     

Methamphetamine impurity profiling using a 0.32 mm i.d. nonpolar capillary column

Classification of seized methamphetamine by impurity profiling can provide very useful information in criminal investigations of drug traffic routes, sources of supply and relationships between seizures. The aim of this study is to improve and develop an analytical method for detecting impurities such as starting materials and by-products in illegally prepared methamphetamine.HCl samples. A 50mg sample of methamphetamine.HCl was dissolved in 1 ml of buffer solution (four parts 0.1M phosphate buffer pH 7.0 and one part 10% Na2CO3). Impurities were extracted with 0.5 ml of ethyl acetate containing four internal standards (ISs) (n-decane, n-pentadecane, n-nonadecane and n-hexacosane) and analyzed by gas chromatography (GC) using a flame ionization detector (FID) on a DB-5 capillary column (0.32 mmi.d. x 30 m, film thickness 1.0 microm). The use of a middle-bore column offered better separation of the impurity peaks. The correction of the retention times of impurity peaks with four ISs made peak identification very accurate for subsequent data processing. Twenty-four characteristic peaks were selected for comparison and similarity and/or dissimilarity between samples, and the data were evaluated by the Euclidean distance of the relative peak areas after logarithmic transformation. The results indicate that the present method would be useful for methamphetamine impurity profiling.     

Impurity profiling of ecstasy tablets seized in Hong Kong by gas chromatography-mass spectrometry

In Hong Kong, ecstasy tablets are more commonly known as "Fing Tau Yuen", literally meaning "Shake Head Pills". The tablets contain mainly amphetamine-type stimulants (ATS) including 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), methamphetamine (MA) and/or ketamine. Adulterant such as caffeine was also detected in the tablets. This paper reports a study on the impurity profiles of ecstasy tablets from 89 seizures in Hong Kong from 2002 to early 2004. Tablet samples were extracted by diethyl ether under alkaline condition and then analyzed by gas GC-MS. The chromatograms obtained were compared. A total of 19 identified impurities were selected as markers for impurity profiling. They are different precursors, intermediates and by-products. The data matrices were examined by hierarchical cluster analysis (HCA), and then the ecstasy tablets were classified into different groups. Cluster analysis of ecstasy tablets is shown to be capable of providing intelligence on clandestine laboratory networks.     

Evaluation of ephedrine, pseudoephedrine and phenylpropanolamine concentrations in human urine samples and a comparison of the specificity of DRI amphetamines and Abuscreen online (KIMS) amphetamines screening immunoassays

The purpose of this study was to evaluate the ability of two amphetamine class screening reagents to exclude ephedrine (EPH), pseudoephedrine (PSEPH), and phenylpropanolamine (PPA) from falsely producing positive immunoassay screening results. The study also sought to characterize the prevalence and concentration distributions of EPH, PSEPH, and PPA in samples that produced positive amphetamine screening results. Approximately 27,400 randomly collected human urine samples from Navy and Marine Corps members were simultaneously screened for amphetamines using the DRI and Abuscreen online immunoassays at a cutoff concentration of 500 ng/mL. All samples that screened positive were confirmed for amphetamine (AMP), methamphetamine (MTH), 3,4-Methylenedioxyamphetamine (MDA), 3,4-Methylenedioxymethamphetamine (MDMA), EPH, PSEPH, and PPA by gas chromatography/mass spectrometry (GC/MS). The DRI AMP immunoassay identified 1,104 presumptive amphetamine positive samples, of which only 1.99% confirmed positive for the presence of AMP, MTH, MDA, or MDMA. In contrast, the online AMP reagent identified 317 presumptive amphetamine positives with a confirmation rate for AMP, MTH, MDA, or MDMA of 7.94%. The presence of EPH, PSEPH, or PPA was confirmed in 833 of the 1,104 samples that failed to confirm positive for AMP, MTH, MDA, or MDMA; all of the 833 samples contained PSEPH. When compared to the entire screened sample set, PSEPH was present in approximately 3%, EPH in 0.9%, and PPA in 0.8% of the samples. The results indicate that cross reactivities for EPH, PSEPH, and PPA are greater than reported by the manufacturer of these reagents. The distribution of concentrations indicates that very large concentrations of EPH, PSEPH, and PPA are common.     

Analysis of the impurities in the methamphetamine synthesized by three different methods from ephedrine and pseudoephedrine

Organic impurities of methamphetamine may show different patterns by synthesis. In the present study, we tried to find the impurities reflecting the conditions of synthesis by comparing impurity patterns of the methamphetamine samples synthesized by different methods. Sixteen methamphetamine samples were synthesized from ephedrine and pseudoephedrine by the three different manufacturing methods of Emde, Nagai and Moscow. The synthesized samples were extracted with ethyl acetate containing four internal standards, and the patterns of the organic impurities were investigated by GC-MS and GC-FID . Through the investigation, we found 10 peaks appearing in the latter part of GC chromatograms are characteristic to synthesis. The areas of the selected peaks were converted to the variables suitable for the statistical calculation, and the synthesized samples could be classified into four groups through the resultant cluster analysis.     

Drug intelligence based on organic impurities in illicit MA samples

One major objective of the European project "Collaborative Harmonisation of Methods for Profiling of Amphetamine Type Stimulants" (CHAMP), funded by the sixth framework programme of the European Commission, consisted of the harmonisation of a gas chromatography/mass spectrometry (GC/MS) method for the analysis of organic impurities found in illicit methamphetamine (MA) samples in a drug intelligence perspective. Statistical analysis provided a selection of pertinent variables among the 43 organic impurities identified in the chromatograms. As for the 3,4-MethyleneDioxyMethAmphetamine (MDMA) study, correlation coefficients were used as a discrimination tool between populations of linked samples (from the same seizure) and unlinked samples (from different seizures). It was also shown that correlation measurements based on Pearson and cosine functions applied to the data pre-treated by normalisation to the sum of peak responses followed by the square root provided excellent discrimination between the two populations. The organic impurities profiling method was proved to be relevant for the characterization of samples from different seizures and their synthesis route patterns.