Forensic application of chiral separation of amphetamine-type stimulants to impurity analysis of seized methamphetamine by capillary electrophoresis

The applicability of capillary electrophoresis (CE) with a UV detector using highly sulfated gamma-cyclodextrin as a chiral selector was examined for analysis of impurities in seized methamphetamine. Samples of methamphetamine-hydrochloride dissolved in water at a high concentration (20 mg/mL) were analyzed. Electrokinetic injection has an advantage over hydrodynamic injection for improving the detection of trace impurities. Small peaks of the precursor impurities, such as (1R,2S)-(-)-ephedrine and (1S,2S)-(+)-pseudoephedrine, were detected and quantified without extraction. The seized drugs could be classified into three groups based on the contents of the two impurities.     

Optimization of a simple method for the chiral separation of methamphetamine and related compounds in clandestine tablets and urine samples by beta-cyclodextrine modified capillary electrophoresis: a complementary method to GC-MS

The chiral separation of (+/-)-methamphetamine, (+/-)-methcathinone, (+/-)-ephedrine and (+/-)-pseudoephedrine by means of beta-cyclodextrine modified capillary electrophoresis is described. The distribution of enantiomers in clandestine tablets and urine samples were identified. Several electrophoretic parameters such as the concentration of beta-cyclodextrin, temperature, the applied voltage and the amount of organic solvent required for successful separation were optimized. The method, as described herein, represents a good complementary method to GC-MS for use in forensic and clinical analysis.     

Formation of Trifluoroacetylated Ephedrine During the Analysis of a Pseudoephedrine-Formaldehyde Adduct by TFAA Derivatization Followed by GC-MS

Abstract:  (+)-Pseudoephedrine reacts with formaldehyde to form (4 S ,5 S )-3,4-dimethyl-5-phenyloxazolidine. Gas chromatography–mass spectrometry (GC-MS) analysis after the reaction of this oxazolidine with excess trifluoroacetic acid anhydride (TFAA) shows predominantly N , O- bis(trifluoroacetyl)pseudoephedrine with some of the monotrifluoroacetylated derivative. In addition, variable amounts of N , O- bis(trifluoroacetyl)ephedrine were detected by GC-MS. N , O- bis(trifluoroacetyl)ephedrine was not detected upon trifluoroacetylation of the source (+)-pseudoephedrine, and nuclear magnetic resonance analysis of the (4 S ,5 S )-3,4-dimethyl-5-phenyloxazolidine showed no evidence of the (4 R ,5 S ) isomer. This suggests that the N ,O-bis(trifluoroacetyl)ephedrine is formed by epimerization during the TFAA derivatization and GC-MS analysis of the pseudoephedrine-formaldehyde adduct.     

N-cyanomethyl-N-methyl-1-(3',4'-methylenedioxyphenyl)-2-propylamine: an MDMA manufacturing by-product

This paper describes the structural elucidation of a compound produced during the synthesis of 3,4-methylenedioxymethylamphetamine (MDMA) via the reductive amination of 3,4-methylenedioxyphenyl-2-propanone (3,4-MDP-2-P) with methylamine and sodium cyanoborohydride. The compound was isolated from MDMA by column chromatography, proton and carbon nuclear magnetic resonance spectroscopy, LC/mass spectrometry, and total synthesis were used to identify the compound as N-cyanomethyl-N-methyl-1-(3',4'-methylenedioxyphenyl)-2-propylamine. This compound has been identified as a potential synthetic route marker for the reductive amination of 3,4-MDP-2-P with methylamine and sodium cyanoborohydride and as such it should prove valuable to forensic scientists engaged in profiling illicit drugs. Profiling MDMA can provide useful information to law enforcement agencies relating to synthetic route, precursor chemicals and reagents employed and may be used for comparative analyses of different drug seizures. This paper also describes the structural elucidation of the analogous methylamphetamine synthetic route marker compound, N-cyanomethyl-N-methyl-1-phenyl-2-propylamine, produced during the reductive amination of phenyl-2-propanone using methylamine and sodium cyanoborohydride.     

Determination of synthesis method of ecstasy based on the basic impurities

MDMA was prepared by five different synthesis routes, i.e. by dissolving metal reduction (Al/Hg), cyanoborohydride reduction (NaBH(3)CN), borohydride reduction in low temperature (NaBH(4)), Leuckart reaction and safrole bromination. MDP-2-P was prepared by two different synthesis methods, i.e. by isosafrole oxidation and MDP-2-nitropropene reduction. Each of the synthesis routes was repeated three times in order to establish variation in qualitative composition of route specific impurities between different batches. The analysis of impurities in MDP-2-nitropropene, MDP-2-P, bromosafrole and MDMA was performed with GC-MS. GC/MS was used also in the analysis of impurities in starting materials: safrole, isosafrole and piperonal. As a result of our study the way of determination of MDMA synthesis route determination based on qualitative composition of impurities is proposed.     

Identification of common impurities present in the synthetic routes leading to 4-methylthioamphetamine (4-MTA). Part II: Reductive amination and nitropropene route

In this paper the by-products arising during the synthesis of 4-methylthioamphetamine (4-MTA) by LiAlH(4) reduction of 1-(4-methylthiophenyl)-2-nitropropene (nitropropene route) and reductive amination of 4-methylthiophenyl-2-propanone in the presence of NaCNBH(4) are investigated. The identification of 4-methylthio derivatives of N-(β-phenylisopropyl)benzaldimine, 4-methylthio derivative of N-(β-phenylisopropyl)benzyl methyl ketimine, 1-(4-methylthiophenyl)-N-(4-methylthiobenzyl)-2-propanamine, (RS) and (SS/RR)-N,N-di-[β-(4-methylthiophenyl)isopropyl]amine, 4-methylthiobenzyl ether and methylthiobenzoic acid methyl ester as most prominent impurities in crude 4-MTA synthesised by reductive amination of 4-methylthiophenyl-2-propanone, is reported. Methylthio derivatives of 2-methyl-3-phenylaziridine, 2-benzylaziridine, and 4-methylthio derivative of BMK oxime as route-specific markers of nitropropene route leading to 4-MTA, were also characterized. The identity of these compounds was confirmed by their independent synthesis.     

Four new illicit cocaine impurities from the oxidation of crude cocaine base: formation and characterization of the diastereomeric 2,3-dihydroxy-3-phenylpropionylecgonine methyl esters from cis- and trans-cinnamoylcocaine

Four new impurities have recently been detected in the gas chromatographic signature profiles of many illicit cocaine hydrochloride exhibits. These impurities are only seen in exhibits that have been oxidized and are most prominent in samples that have been highly oxidized. Exhibits containing these compounds were subjected to gas and liquid chromatographic-mass spectrometric analyses to determine the identity of the impurities. These impurities were subsequently synthesized to verify their structures. Four diastereomeric diols formed from the oxidation of cis- and trans-cinnamoylcocaine were characterized by nuclear magnetic resonance spectrometry, mass spectrometry, and synthesis. Oxidation of cis-cinnamoylcocaine in neutral conditions yielded (2R,3R)-dihydroxy-3-phenylpropionylecgonine methyl ester and (2S,3S)-dihydroxy-3-phenylpropionylecgonine methyl ester, while trans-cinnamoylcocaine produced (2R,3S)-dihydroxy-3-phenylpropionylecgonine methyl ester and (2S,3R)-dihydroxy-3-phenylpropionylecgonine methyl ester. The recent appearance of these new impurities suggests that some illicit cocaine processors have modified their oxidation procedures of crude cocaine base for transformation into illicit refined cocaine hydrochloride.     

Determination of synthesis route of 1-(3,4-methylenedioxyphenyl)-2-propanone (MDP-2-P) based on impurity profiles of MDMA

In our study 1-(3,4-methylenedioxyphenyl)-2-propanone (MDP-2-P or PMK) was prepared by two different routes, i.e. by oxidizing isosafrole in an acid medium and by 1-(3,4-methylenedioxyphenyl)-2-nitropropene reduction. The final product-MDP-2-P was subjected to GC/MS analysis. The intermediates and reaction by-products were identified and the 'route specific' impurities were established. The following impurities are the markers of the greatest importance: 1-(3,4-methylenedioxyphenyl)-1-propanone (compound 10, Table 2), 1-methoxy-1-(3,4-methylenedioxyphenyl)-2-propanone (compound 11, Table 2) and 2,2,4-trimethyl-5-(3,4-methylenedioxyphenyl)-[1,3]dioxolane (compound 13, Table 2) (the 'oxidising isosafrole route') and N-cyclohexylacetamide (compound 3, Table 1), 3-methyl-6,7-methylenedioxyisoquinoline-1,4-dione (compound 15, Table 1) (the 'MDP-2-nitropropene reduction route'). Subsequently, MDMA was prepared by reductive amination of MDP-2-P using NaBH4 as reducing agent (so-called 'cool method'). Impurities were extracted with n-heptane under alkaline conditions. The impurity profiles were obtained by means of GC/MS, some reaction by-products were identified by means of the EI mass spectra including low energy EI mass spectra and 'route specific' impurities were established. 4-Methyl-5-(3,4-methylenedioxyphenyl)-[1,3]dioxolan-2-one (compound 22, Table 2), N-methyl-2-methoxy-1-methyl-2-(3,4-methylenedioxyphenyl)-ethaneamine (compound 18, Table 2), 3-methyl-6,7-methylenedioxyisoquinoline-1,4-dione (compound 15, Table 1) and N-cyclohexyloacetamide (compound 3, Table 1) were found to be the synthesis markers of greatest importance.     

鞘胺醇1-磷酸2/3受体对心肌缺血再灌注损伤的影响

目的观察鞘胺醇1-磷酸2/3受体(S1PR2/3)在大鼠心肌缺血再灌注的在体实验中对心脏的影响。方法健康SD雄性大鼠,随机分为7组:正常对照组、假手术组、IR组、IR+DMSO组、IR+Cym5541(S1P3受体激动剂)组、IR+Cay10444(S1P3受体阻断剂)组、IR+Cay10444/Jte-013(S1P2/3受体阻断剂)组。制作大鼠缺血再灌注模型,并记录心功能、心肌梗死面积、死亡率。结果给予S1PR3抑制剂组和S1PR2/3抑制剂组与IR组相比在心肌缺血再灌过程中,心率下降(P0.05),左室舒张末期压力(LVEDP)上升(P0.05),心肌梗死面积增大(55.7%:28.8%,51.6%:28.8%),给予S1PR3激动剂组心肌梗死面积显著减小(18.6%:28.8%)。给予S1P2/3抑制剂组死亡率明显高于IR组(53%:22%,P0.05)。结论 S1P2和S1P3受体对缺血再灌注心肌起保护作用,抑制S1P2/3受体参与了IR后心源性猝死(SCD)。     

GC／MS检验1-苯基-1-丙酮和1-苯基-2-丙酮

目的阐明1-苯基-1-丙酮和1-苯基-2-丙酮在色谱行为、用途和受管制程度等方面的差异。方法使用GC／MS对1-苯基一1-丙酮和1-苯基-2-丙酮进行定性分析。结果1-苯基-1-丙酮和1-苯基-2-丙酮的保留时间相差约1min，特征离子显著不同。结论1-苯基-1-丙酮和1-苯基-2-丙酮虽然为同分异构体，且多数时中文名称都简称为苯丙酮，也都是制备毒品的原料，但其实二者在色谱行为、用途、管制程度上却有着巨大的差别。     

International Conference on Harmonisation; guidance on S2(R1) Genotoxicity Testing and Data Interpretation for Pharmaceuticals intended for Human Use; availability. Notice

The Food and Drug Administration (FDA) is announcing the availability of a guidance entitled ``S2(R1) Genotoxicity Testing and Data Interpretation for Pharmaceuticals Intended for Human Use' (ICH S2(R1)). This guidance was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The ICH S2(R1) combines and replaces two ICH guidances, "S2A Specific Aspects for Regulatory Genotoxicity Tests for Pharmaceuticals' and "S2B Genotoxicity: A Standard Battery for Genotoxicity Testing of Pharmaceuticals.' ICH S2(R1) provides guidance to drug sponsors on which tests should be performed to assess potential genotoxicity of pharmaceuticals. It also provides guidance on testing conditions, data interpretation, and followup strategies if a positive response is seen in in vitro assays. This guidance is intended to provide drug sponsors with recommendations to ensure that drugs are appropriately tested for potential to cause genetic damage and to ensure efficient development of new drugs.     

Cleavage of 2-phenylpropan-1-ol and 2-phenylpropan-2-ol-glucuronide, 2 metabolites of isopropylbenzol (Cumol)

The behaviour of 2-phenyl-1-propanol (I) and 2-phenyl-2-propanol (II) and their glucuronides with HCl has been investigated. While I shows a high acidic constancy, II undergoes a partial conversion into 2-phenylpropane (III) which itself yields numerous products. The glucosidic bond of glucuronide I is quantitatively split by 10.0% HCl, whereby an aglucone yield of nearly 100% is obtained. The second glucuronide behaves otherwise: the recovery of II is very low (only 40% to 45%) with HCl concentrations of 1.0%-20.0%, although with 1.0% HCl 100% of the glucuronide is hydrolysed.     

Distribution of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) stereoisomers in a fatal poisoning

This communication presents the quantitation and differential distribution of the enantiomers of 3,4-methylenedioxymethamphetamine (MDMA) and its physiologically active metabolite 3,4-methylenedioxyamphetamine (MDA) in a fatal poisoning following insufflation of MDMA, cocaine and heroin. Animal studies have demonstrated the stereoselective pharmacokinetics and neurotoxicity of these compounds; however, enantiomeric distributions have not been reported in humans. Quantitation of MDMA and MDA enantiomer was by gas chromatography/mass spectrometry (GC/MS) following chiral derivatization with N-trifluoroacetyl-l-triproyl chloride (LTPC). The decedents' blood concentration of S(+)-MDMA was slightly less than that of R(−)-MDMA (1.3 vs. 1.6 mg/l, respectively), while the S(+)- and R(−)-MDA blood concentrations were identical (0.8 mg/l). Both primary routes of excretion, bile and urine, had greater concentrations of R(−)-MDMA than the S(+) isomer. These fluids also contained twice the concentration of S(+)-MDA than the R(−)-isomer. These data indicate that S(+)-MDMA is metabolized and eliminated faster than R(−)-MDMA. The results appear to support the findings in animals regarding stereoselective metabolism of MDMA.     

LC-MS/MS analysis of pholedrine in a fatal intoxication case

Pholedrine (4'-hydroxymethamphetamine) is a cardiovascular agent exerting hypertensive and adrenergic effects. High doses may cause a drop in the peripheral circulation blood flow and increase blood pressure, heart rate and body temperature up to a state of central respiratory paralysis. A 15-year-old girl who suffered from heavy agitation and hallucinations was admitted to the intensive care unit in a comatose state. The clinical findings included a maximum heart rate of 170 bpm and a body temperature of 43.8 degrees C. Resuscitation measures were in vain and abandoned after approximately 2h. A toxicological emergency analysis using GC/MS revealed a considerable amount of pholedrine in blood and urine. A method for determining pholedrine in human body fluids utilizing high-performance liquid chromatography (HPLC)/tandem mass spectrometry (LC-MS/MS) with a turbo ion-spray source was developed, using D11-methamphetamine and D5-methylenedioxymethamphetamine as internal standards. Samples were prepared by SPE extraction using SPEC-C18AR/MP3((R)) columns, which yielded the best extraction recovery (67%). Chromatographic separation was achieved at pH 5 on an RP-18 stationary phase applying gradient elution from 50 to 70% of B (methanol/acetonitrile 3/1 (v/v), 0.02% acetic acid) in A (5mM ammonium acetate/acetonitrile 95/5 (v/v), 0.02% acetic acid). Supra-pure acetic acid was added to the post-column effluent with a flow rate of 0.2 microl/min to optimize ionization. Detection was carried out in the positive ionization, multiple reaction monitoring (MRM) mode. The chromatograms showed no interference from other substances. The limit of detection (LOD, S/N=3) of pholedrine was 0.8 ng/ml and its lower limit of quantification (LLOQ, S/N=10) 3ng/ml. The calibration curve was linear (r=0.999) in the range 1-100 ng/ml. Samples with higher concentrations were diluted to suit the working range. The intra-day R.S.D. between 5 and 80 ng/ml were 3.8-8.7% and the inter-day R.S.D. between 5 and 100 ng/ml were 6.7-10.7%. The pholedrine concentrations in blood and urine collected when the girl was still alive were 16.1 microg/ml (R.S.D. 10.5%) and 1120 microg/ml (R.S.D. 8%), respectively. In post-mortem samples, they were 23.0 microg/ml (R.S.D. 5.1%) in heart blood and 27.3 microg/g (R.S.D. 6.6%) in the liver.     

Formation of an interfering substance, 3,4-dimethyl-5-phenyl-1,3-oxazolidine, during a pseudoephedrine urinalysis

During fatal aviation accident investigations, biosamples from the victims are submitted to the FAA Civil Aeromedical Institute (CAMI) for drug analysis. In the process of one such analysis by CAMI, an unknown substance was found in a urine sample. Simultaneous screening by thin layer chromatography (TLC) and gas chromatography/FID (GC/FID) suggested the presence of pseudoephedrine. A subsequent routine confirmation analysis of a separate urine aliquot by GC Fourier transform infrared (GC/FTIR) and GC mass spectrometry (GC/MS) indicated that the retention times of the unknown substance matched with those of pseudoephedrine. However, its infrared and mass spectra were different--the -OH and -NH groups were missing, a C-O-C group was present, and the molar mass was 12 atomic mass units (amu) more than that of pseudoephedrine. A subsequent literature search suggested that ephedrine-like amines react with aldehydes to form oxazolidines. Therefore, the 12-amu increase could be accounted for by condensation of pseudoephedrine with formaldehyde. Since this aldehyde is present in various grades of methanol and ethyl acetate, and these solvents were used during the solid-phase extraction, 3,4-dimethyl-5-phenyl-1,3-oxazolidine was synthesized by using (+)-pseudoephedrine HCl and formaldehyde. The analytical findings of the synthesized compound were consistent with those of the unknown interfering substance, confirming that it was the oxazolidine. Aldehyde contaminants in solvents or specimens can transform drugs of interest and may result in misidentification of a compound originally present in specimens. Therefore, chemicals used in analyses should be of the highest available purity, and a multi-analytical approach should be adopted to maintain a high degree of quality assurance.     

Positive- and negative-ion mass spectrometry and rapid clean-up of 19 phenothiazines

Positive-ion electron impact (PIEI), positive-ion chemical ionization (PICI) and negative-ion chemical ionization (NICI) mass spectra of 19 phenothiazines are presented. In the PIEI mode, peaks due to M, M minus side chain (M - R1), M - R1 + H, and side chain itself (R1) appeared for most compounds. The M - R1 and R1 ions were very useful for drug screening. In the PICI mode, most spectra showed base or intense peaks due to M + H, and small peaks due to M + C2H5; peaks due to M - R1 + 2H and R1 also appeared in many compounds. In the NICI mode, fragmentation modes were different in different compound groups; molecular or [M - H]- quasi-molecular anions appeared in many compounds with aliphatic side chains. Anions at m/z 98 and 115 were characteristic for compounds with (N-methylpiperazinyl)propyl side chains. Selected ion monitoring in the PIEI mode generally gave much higher sensitivity than in the PICI and NICI modes. Phenothiazines present in urine or plasma could be rapidly isolated by use of Sep-Pak C18 cartridges. Thirteen of 19 phenothiazines could be detected by HP-17 wide-bore capillary gas chromatography with satisfactory separation from impurities in their underivatized forms.     

Australian Federal Police seizures of illicit crystalline methamphetamine ('ice') 1998-2002: impurity analysis

Nineteen crystalline methamphetamine ('ice') seizures captured by the Australian Federal Police (AFP) at the Australian border between 1998 and 2002 were analysed. Using a modified gas chromatograph-mass spectrometry (GC-MS) impurity profiling approach of these samples we have identified >30 compounds associated with methamphetamine and/or its synthetic route. Major impurities detected include 1,2-dimethyl-3-phenylaziridine 8, dimethylamphetamine 14, N-formylmethamphetamine 24, N-acetylmethamphetamine 25, 1,3-dimethyl-2-phenylnaphthalene 32, 1-benzyl-3-methylnaphthalene 33 and methamphetamine dimer 34. These data are suggestive of ephedrine/pseudoephedrine as the main precursor of the 'ice' samples seized during 1998-2002. Additionally the two naphthalenes 32 and 33 further identified that 15 items in 9 seizures were produced via the more specific ephedrine/hydriodic acid/red phosphorus method. One sample comprised 75% dimethylamphetamine and 9.7% methamphetamine, representing the first Australian seizure of imported dimethylamphetamine reported.     

Basic and neutral route specific impurities in MDMA prepared by different synthesis methods. Comparison of impurity profiles

In this work, the neutral and basic impurities found in the precipitate of MDMA(*)HCl are presented. MDMA.HCl was prepared by the most popular synthesis methods used in clandestine manufacture, i.e. safrole bromination, Leuckart method and reductive amination with various reducing agents: Al/Hg, NaBH(4), NaBH(3)CN. 3,4-Methylenedioxyphenyl-2-propanone (MDP-2-P), the starting material in Leuckart reaction and reductive amination, was prepared by two different synthesis methods, i.e. by isosafrole oxidation and MDP-2-nitropropene reduction. The extraction of impurities was performed under alkaline and neutral conditions. Impurity profiles were obtained using GC/MS. Each synthesis method is characterised by its own route specific impurities. The influence of pH on the extraction of synthesis markers from 3,4-methylenedioxymethamphetamine (MDMA) samples is discussed and comparison of the profiles of basic and neutral impurities is presented.     

Cross-examination of liquid-liquid extraction (LLE) and solid-phase microextraction (SPME) methods for impurity profiling of methamphetamine

Impurities in 48 methamphetamine (MA) samples were analyzed by liquid-liquid extraction (LLE) and headspace solid-phase microextraction (HS-SPME) methods. MPS-2 autosampler was used to improve reproducibility of SPME method, and nonadecane (C(19)) diluted with potassium bromide (KBr) powder was used as an internal standard for standardizing retention time. Impurities identified by SPME method showed different patterns compared with LLE method. Non-volatile impurities like methamphetamine dimer were not identified by SPME method, but some volatile impurities like diphenylketone, caprolactam and lots of unknowns were identified only by SPME method. 1-Phenyl-2-propanone (P2P), 1-phenyl-2-propanol and benzylcyanide peaks could be discriminated clearly by SPME method without interference of amphetamine, an artifact originates from MA degradation. Differences in the impurity patterns resulted in different clustering results. When 48 MA samples were classified into 5 LLE and 5 SPME clusters, cross-matching of the clusters resulted in 8 sub-clusters. It shows that combination of the different extraction methods can distinguish the differences which cannot be distinguished by LLE or SPME method alone, and can improve reliability of the profiling results.     

Distribution of D1S80 alleles in the Bahrainian population

This study demonstrates that the locus D1S80 is highly polymorphic in the Bahrainian population. There were 24 different D1S80 alleles and 51 distinct genotypes observed in 198 Bahrainians. There was one allele observed that was smaller than the 14 repeat allele. This data set meets the Hardy-Weinberg expectations (HWE) and could be a useful marker for parentage testing and forensic applications.