John F. Casale

Tracing the geographical origin of cocaine

Here we show that cocaine originating from different geographic regions in South America can be identified by its isotope-ratio signature. The distinct carbon (δ13C) and nitrogen (δ15N) isotope-ratio combinations allow the country of origin to be determined for the principal coca-growing regions along the Andean Ridge. By combining this information with detectable differences in the patterns of the trace alkaloids truxilline and trimethoxycocaine, we correctly identified the source of 96% of 200 cocaine samples.

A Chromatographic Impurity Signature Profile Analysis for Cocaine Using Capillary Gas Chromatography

The signature patterns of cocaine samples were examined by capillary gas chromatography using 14 impurities commonly found in illicit cocaine samples. The procedure is based on acidic, basic, and neutral impurities introduced from the coca plant and from the processing of cocaine in clandestine laboratories. Impurities containing either alcoholic, N- nor, or carboxylic acid functional groups were analyzed as their silyl derivatives. The reported procedure provides a simple one-step assay for obtaining chromatographic impurity signature profile analyses (CISPA) of illicit cocaine samples using flame ionization detection (FID).

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.

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.

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.

Isotopic fractionation of carbon and nitrogen during the illicit processing of cocaine and heroin in South America.

The forensic application of stable isotope analysis to cocaine and heroin for geolocation of exhibits must take into account the possible enrichment and/or depletion of 13C and 15N during the illicit manufacturing process. Continuous-flow elemental analysis-isotope ratio mass spectrometry was utilized to measure changes in the stable isotope ratios of carbon and nitrogen for both cocaine (N = 92) and heroin/morphine (N = 81) exhibits derived from illicit manufacturing processes utilized by South American clandestine chemists. In controlled settings in South America, there was no siginficiant carbon isotope fractionation during the conversion of cocaine base to cocaine HCI using current illict methodologies. In contrast, nitrogen isotope fractionation for this conversion was 1 per thousand. There was a kinetic carbon isotope ratio fractionation during the acetylation of Colombian morphine to heroin and as a result heroin exhibits will almost always have more negative delta13C values than the original morphine. There was an isotopic fractionation against 15N during the acetylation of morphine base to heroin base, but this effect was not expressed since all of the heroin base was precipitated during the manufacturing process. However, the clandestine process of converting a single batch of heroin base usually involved two consecutive crops of heroin HCl and the latter crop was isotopically depleted as expected from a Rayleigh distillation process. When heroin was deacetylated to morphine, the morphine produced resulted in delta13C values that were indistinguishable from the original morphine. The kinetic carbon isotope fractionation factor for the South American process of morphine acetylation was -1.8 per thousand, allowing calculation of the delta13C values of the acetic anhydride from deacetylated heroin delta13C values.

3′,4′,5′-Trimethoxy-Substituted Analogs of Cocaine, Cis-/Trans -Cinnamoylcocaine and Tropacocaine: Characterization and Quantitation of New Alkaloids in Coca Leaf, Coca Paste and Refined Illicit Cocaine

Four new alkaloids have been detected in South American coca leaf, coca paste and refined illicit cocaine. The compounds 3′,4′,5′-trimethoxycocaine (TMC), 3′,4′,5′-trimethoxytropacocaine (TMT), 3′,4′,5′-trimethoxy-cis-cinnamoylcocaine (cTMCC) and 3′,4′,5′-trimethoxy-trans-cinnamoylcocaine (tTMCC) were isolated from the coca leaf matrix and other alkaloids by toluene extraction followed by trap and ion-pair column chromatography. The identity of each alkaloid was verified via comparison of its mass spectrum with a synthesized standard. All four alkaloids were quantitated in leaf, paste and refined samples at levels of less than 0.1% relative to cocaine via capillary gas chromatography—flame ionization detection (cGC-FID).

Comparative determination of total isomeric truxillines in illicit, refined, South American cocaine hydrochloride using capillary gas chromatography-electron capture detection

Abstract The isomeric truxillines and their hydrolysis products are present as manufacturing impurities in most illicit, refined cocaine samples. Methodology is described for the comparative gas chromatographic determination of total isomeric truxilline manufacturing impurities/by-products, i.e., intact truxillines and their hydrolysis products, in illicit, refined cocaine samples seized in South America. These isomers, namely, alpha-, beta-, delta-, epsilon-, gamma-, omega-, zeta-, peri-+neo- and epi-truxilline, were all quantified relative to mu-truxillic acid, a structurally-related internal standard. In this method, the cocaine samples were first subjected to treatment with boron trifluoride-methanol, followed by lithium aluminum hydride reduction and then acylation with heptafluorobutyric anhydride. The resultant di-heptafluorobutyryl derivatives of the truxillyl and truxinyl diols exhibited excellent chromatography and low-picogram on-column detection when using a moderately polar fused-silica capillary column interfaced with an electron-capture detector. This methodology demonstrated good reproducibility, as determined by the repetitive analysis of a selected illicit cocaine exhibit. The analysis of 117 unadulterated, illicit, refined cocaine samples revealed that total truxilline levels ranged from 0.2–12.3% (w/w relative to cocaine), with the two most abundant truxillines being the alpha- and beta- isomers. Truxilline data for the total individual truxilline isomers in cocaine hydrochloride exhibits from five South American countries are presented.

Synthesis and Characterization of the 2,3-Methylenedioxyamphetamines

Synthetic methods and spectroscopic and chromatographic data are provided for four 2,3-methylenedioxyamphetamines (2,3-MDA, N-methyl-2,3-MDA, N-ethyl-2,3-MDA and N,N-dimethyl-2,3-MDA). These compounds are aromatic positional isomers of the corresponding 3,4-methylenedioxyamphetamines, which are well known, widely abused central nervous system stimulants with euphoric properties. Direct spectroscopic and chromatographic comparisons of the two isomeric series indicate that the 2,3-MDAs may be easily and unambiguously differentiated from the corresponding 3,4-MDAs via standard analytical methodologies.

1-Hydroxytropacocaine: An abundant alkaloid of Erythroxylum novogranatense var. Novogranatense and var. Truxillense

A new alkaloid, 1-hydroxytropacocaine, was isolated from leaves of greenhouse-cultivated Erythroxylum novogranatense var. novogranatense and identified. Quantitative levels of this alkaloid in dry leaf were similar to those for cocaine, i.e. 0.3–0.5% w/w. 1-Hydroxytropacocaine was also detected at 0.04–0.07% w/w (relative to dry coca leaf) in greenhouse-cultivated Erythroxylum novogranatense var. truxillense and at similar levels in Erythroxylum novogranatense var. novogranatense, grown at a tropical site other than in South America. The presence of 1-hydroxytropacocaine was <0.01% w/w (relative to dry coca leaf) in suspected Erythroxylum novogranatense var. novogranatense and Erythroxylum coca var. coca, field-cultivated in Colombia and Bolivia, respectively.