In-depth chromatographic analyses of illicit cocaine and its precursor, coca leaves.

Chromatographic methodology used for the in-depth alkaloid analyses of coca leaves and for the characterization of alkaloidal impurities and manufacturing by-products in illicit refined cocaine samples is reviewed. This includes liquid-liquid partition and liquid-solid adsorption column chromatography, packed- and capillary-column gas chromatography with flame-ionization, electron-capture, nitrogen-phosphorous and mass spectrometric detection, and high-performance liquid chromatography with ultraviolet detection. The rationale supporting the presence and determination of processing impurities/by-products in cocaine samples is discussed, and chromatographic methodology used for the development of drug impurity signature profiles is presented.

Determination and in-depth chromatographic analyses of alkaloids in South American and greenhouse-cultivated coca leaves.

Methodology is described for the detection and/or determination of cocaine and minor alkaloids in South American coca as well as in greenhouse- and tropical-cultivated field coca of known taxonomy. Coca leaf from Bolivia, Peru, Ecuador and Colombia were subjected to the determination of cocaine, cis- and trans-cinnamoylcocaine, tropacocaine, hygrine, cuscohygrine and the isomeric truxillines. The greenhouse samples were cocaine-bearing leaves of the genus Erythroxylum and included E. coca var. coca, E. novogranatense var. novogranatense and E. novogranatense var. truxillense, and the alkaloids determined were cocaine, ecgonine methyl ester, cuscohygrine, tropacocaine and the cinnamoylcocaines. The tropical-cultivated coca were E. novogranatense var. novogranatense and E. coca var. coca. Cocaine and minor alkaloids were isolated from basified powdered leaf samples using a toluene extractant, followed by acid-Celite column chromatography. The isolated alkaloids were determined by capillary gas chromatography with flame ionization or electron-capture detection. Methodology is also presented for the isolation and mass spectral analysis of numerous trace-level coca alkaloids of unknown structure.

Profiling of impurities in illicit methamphetamine by high-performance liquid chromatography and capillary electrochromatography.

High performance liquid chromatography (HPLC) with photodiode array (PDA) UV and fluorescence (FL) detection, and capillary electrochromatography (CEC) with laser-induced fluorescence (LIF) detection were investigated for the analysis of acidic extracts derived from illicit methamphetamine. These compounds include major impurities from the hydriodic acid/red phosphorous reduction method, i.e., 1,3-dimethyl-2-phenylnaphthalene and 1-benzyl-3-methylnaphthalene, and other trace-level, structurally related impurities. For certain of these solutes, HPLC with conventional FL detection gave at least a 60x increase in sensitivity over UV detection. In addition, other highly fluorescent impurities were detected in methamphetamine produced via four other synthetic routes. The use of a rapid scanning FL detector (with acquisition of "on the fly" excitation or emission) provided structural information and gave "optimum" excitation and emission detection wavelengths. CEC with LIF detection using UV laser excitation provided greatly improved chromatography over HPLC, with good detection limits in the low ng/ml range. Both methodologies provide good run-to-run repeatability, and have the capability to distinguish between samples.

An aqueous-organic extraction method for the isolation and identification of psilocin from hallucinogenic mushrooms.

A simple aqueous extraction method for the isolation and identification of psilocin from Psilocybe cubensis mushrooms is reported. This method employs a dephosphorylation of the phosphate ester to psilocin, which facilitates a greater product yield and simplifies identification. Psilocin extracted by this method is sufficiently concentrated and free of cocontaminants to allow identification by infrared spectroscopy and gas chromatography/mass spectrometry.

A computerized neural network method for pattern recognition of cocaine signatures.

This article describes a practical procedure for rapidly searching a large database of cocaine signatures to identify database entries that closely resemble a given reference cocaine exhibit using a personal computer (PC). The procedure takes advantage of the pattern recognition capability of the multilayer perceptron neural network to identify similar cocaine signatures. A PC-based software implementation is now being used on a daily basis at the North Carolina State Bureau of Investigation (NCSBI) to aid forensic experts in identifying signatures that originate from the same batch. Intelligence reports generated from database searches have been useful to undercover agents in the field who are striving to build drug related conspiracy cases. This software was developed as a collaborative effort between the NCSBI and the Center for Systems and Engineering of the Research Triangle Institute.

Detection and determination of pseudococaine in coca leaves and illicit cocaine samples.

Methodology is presented for the isolation, identification and determination of pseudococaine in coca leaves and illicit cocaine. Coca leaves, crude cocaine base (coca paste), refined cocaine base and refined cocaine hydrochloride, all derived from the same geographic location in Bolivia, were examined. Pseudococaine and other coca alkaloids were isolated from leaf samples using toluene extraction followed by acid/Celite trap and ion-pair column chromatography, and from crude and refined cocaine samples by acid/Celite column ion-pairing chromatography. Mass spectral analysis of coca leaf isolates confirmed the presence of pseudococaine. Pseudococaine was quantified by capillary gas chromatography with flame ionization detection at levels of 0.0001-0.035% (relative to cocaine) in refined illicit cocaine and coca leaves.

Novel chlorinated tropanes derived from the treatment of cocaine with sodium hypochlorite.

Several novel chlorinated tropanes were produced when cocaine was treated with aqueous sodium hypochlorite. Two of these, 2'- and 3'-chlorobenzoyloxy-2-carbomethoxypseudotropine (that is, ortho- and meta-chlorococaine), were characterized by synthesis and gas chromatography/mass spectrometry. Four other new chlorinated tropanes (endo-6- and 7-chlorococaine, exo-6- or 7-chlorococaine and N-chlorobenzoylnorecgonine methyl ester) were also tentatively identified via their gas chromatography retention data and mass spectra. The results are of potential use in cocaine signature and comparative analysis.

Illicit Production of Cocaine.

The predominant methods currently used for illicit production of cocaine are described. For illicit natural cocaine (i.e., from coca leaf), this includes production of coca paste from coca leaf via both the solvent and acid extraction techniques, purification of coca paste to cocaine base, and conversion of cocaine base to cocaine hydrochloride. For illicit synthetic cocaine (i.e., synthesized from precursor chemicals), the classic five-step synthetic route used in all clandestine laboratories seized to date is summarized. The origins of the most common alkaloidal impurities and processing/synthetic by-products typically identified in illicit natural, illicit synthetic, and pharmaceutical cocaine are discussed. Forensic differentiation of exhibits arising from the various production methods are addressed both in terms of overall product purity and the presence/absence of these impurities and by-products.

Cocaine Profiling Methodology - Recent Advancesk.

The rationale for developing cocaine profiling methodology is described. Current cocaine signature procedures in use at the U.S. Drug Enforcement Administration's Special Testing and Research Laboratory are reviewed. Newer selective and sensitive methodology, recently developed, is described. That methodology detects more alkaloidal impurities in refined illicit cocaine than heretofore reported. The alkaloidal impurities were isolated from the bulk cocaine matrix by alumina column chromatography and detected using capillary gas chromatography-mass selective detection in the selected ion mode. Fifty-one refined illicit cocaine samples were subjected to this methodology for the determination of 15 selected alkaloids. Reproducibility data are reported. Methodology for the isolation, detection, and characterization of coca alkaloids in South American coca leaf, a commercial coca-leaf extract, and a large seizure of refined illicit cocaine is reviewed.

Effects of various anionic chiral selectors on the capillary electrophoresis separation of chiral phenethylamines and achiral neutral impurities present in illicit methamphetamine.

In this study, various anionic chiral selectors were investigated for the capillary electrophoresis (CE) separation of six chiral phenethylamines and three achiral neutral impurities which are commonly identified in illicit methamphetamine. Analyses were carried out at pH 8 (high osmotic flow) with untreated capillaries using 25 mM chiral surfactant or 10 mM charged cyclodextrin. The chiral selectors included the micelle (R)-N-dodecoxycarbonylvaline (EnantioSelect (R)-Val-1) (ES) and the cyclodextrins sulfobutyl(IV)-ether-beta-cyclodextrin (SBE(IV)-beta-CD) (BSB4), SBE(VII)-beta-CD (BSB7), SBE(XII)-beta-CD (BSB 12), SBE(IV)-gamma-CD (GSB-4), SBE(VII)-gamma-CD (GSB-7), sulfated(XI)-alpha-cyclodextrin (SU(XI)-alpha-CD (AS11), SU(VII)-beta-CD (BS7), SU(XII)-beta-CD (BS12) and SU(XIII)-beta-CD (GS13). Enantiomeric and achiral selectivity strongly depends on the size of the CD, the average degree of substitution, and the type of substitution. ES exhibits good performance for the neutral solutes, but exhibits enantiomeric selectivity only for the alpha-hydroxyphenethylamines. GS13 provides the best overall enantiomeric selectivity. All fifteen solutes related to methamphetamine are simultaneously separated using BSB7.

Separation and detection of acidic and neutral impurities in illicit heroin via capillary electrophoresis.

The separation and detection of acidic and neutral impurities in illicit heroin using capillary electrophoresis (CE) is described. Separations were achieved using charged cyclodextrin modified micellar electrokinetic capillary chromatography. The use of the anionic beta-cyclodextrin sulfobutyl ether 1V in combination with sodium dodecyl sulfate significantly increased resolution. Improved selectivity and/or sensitivity in detection was obtained using photodiode array ultraviolet and laser-induced fluorescence detection. The phenanthrene-like heroin impurities exhibit high native fluorescence under krypton-fluoride laser excitation (248 nm). The limit of detection by laser-induced fluorescence detection for one of these solutes (acetylthebaol) is 1.8 ng/ml, 500 times more sensitive than UV. This methodology is applicable to analysis of both crude and refined heroin.

Capillary electrophoresis analysis of isomeric truxillines and other high molecular weight impurities in illicit cocaine.

The analysis of by-products and impurities in illicit cocaine, including the isomeric truxillines, is important for derivation of both strategic and tactical intelligence. In the present study, various capillary electrophoresis techniques were investigated for this purpose. The use of the anionic beta-cyclodextrin sulfobutyl ether IV as a run buffer additive at pH 8.6 gave a good separation of the truxillines and similar high molecular weight impurities in less than eight minutes. These impurities were first isolated from the bulk cocaine matrix using liquid-liquid extraction and size-exclusion high performance liquid chromatography. There was a red shift in the UV spectra obtained for the truxillines using photodiode array (PDA) UV detection during CE analysis. This anomalous behavior is attributed to photo-degradation of the truxillines during the PDA-UV irradiation process. Laser-induced fluorescence detection using a UV krypton/fluoride laser provided greater selectivity and sensitivity versus UV detection for certain uncharacterized high molecular weight impurities.