Patrick A. Hays

Use of dynamically coated capillaries with added cyclodextrins for the analysis of opium using capillary electrophoresis.

A rapid, precise, accurate, and robust method using capillary electrophoresis (CE) with dynamically coated capillaries for the analysis of the major opium alkaloids in opium is presented. Dynamic coating of the capillary surface is accomplished using a commercially available reagent kit (polycation coating followed by polyanion coating). The addition of dual cyclodextrins (hydroxypropyl-beta-cyclodextrin and dimethyl-beta-cyclodextrin) to the run buffer imparts excellent selectivity for the opium alkaloids. For the determination of morphine, papaverine, codeine, noscapine and thebaine in opium gum and opium latex samples (using tetracaine as an internal standard) good agreement with values obtained by gradient high-performance liquid chromatography is obtained. Compared to the latter technique, CE affords better resolution with significantly faster analysis time (12 min versus 29 min). Dynamically coated capillaries, which give rise to a relatively high and robust electroosmotic flow (EOF) at the background electrolyte pH of 2.5, allow for rapid analysis and excellent migration time and peak area precision (RSDs < or = 0.12% and < or = 1.2%, respectively). Reproducible separations (relative migration times) for over 500 samples have been obtained on a single capillary. The nature of the injection solvent, the injection time and the contents of the waste vials have a profound effect on the pressure injection precision of the relatively hydrophobic solutes. The CE conditions reported in this study are also applicable to the analysis of lysergic acid diethylamide (LSD) exhibits.

Proton Nuclear Magnetic Resonance Spectroscopy (NMR) Methods for Determining the Purity of Reference Drug Standards and Illicit Forensic Drug Seizures

A rapid, sensitive, accurate, precise, reproducible, and versatile method for determining the purity of reference drug standards and the routine analysis of illicit drugs and adulterants using proton (1H) Nuclear Magnetic Resonance (NMR) Spectroscopy is presented. The methodology uses a weighed sample dissolved in a deuterated solvent or solvent mixture containing a high purity internal standard. The NMR experiment employs 8 scans using a 45 second delay and 90 degrees pulse. In the determination of purity of reference standards, the number of quantitative determinations available is equal to the number of peak groups that are baseline resolved. The relative standard deviation (RSD) of these signals is usually < 1% for pure standards, and the results agree well with other purity determining methods. This method can also aid in the determination of correct molecular weight for standards containing an unknown number of waters of hydration or an unknown number of acids per drug in salts. Because the molar response for the hydrogen nucleus is 1 for all compounds, and since no separation media are used, only one linearity study is required to test a probe. In the presented study, the linearity of the NMR probe was determined using methamphetamine HCl dissolved in deuterium oxide (D2O) with maleic acid as the internal standard (5 mg) for a range of concentrations from 0.033 to 69.18 mg/ml with a resulting correlation coefficient of >0.9999 for all 6 methamphetamine peak groups. The spectra of complex illicit heroin, methamphetamine, MDMA, and cocaine samples are presented, as well as an extensive list of compounds, their solubilities and the solvent(s) and internal standard used.

Use of Dynamically Coated Capillaries for the Routine Analysis of Methamphetamine, Amphetamine, MDA, MDMA, MDEA, and Cocaine using Capillary Electrophoresis

A rapid, accurate, precise, reproducible, economical, and environmentally gentle method using capillary electrophoresis (CE) is presented for the routine analysis of methamphetamine, amphetamine, MDA, MDMA, MDEA, and cocaine in seized drugs. The methodology uses a 32 cm by 50 microm capillary (length to detector 23.5 cm) with a commercially available buffer kit and diode array UV detection. Dynamic coating of the capillary surface is accomplished by flushing with base for 1 min, a proprietary polycation for 1 min, and then a proprietary polyanion for 2 min. This approach provides a relatively high and stable electroosmotic flow (EOF), even at low pHs. The background electrolyte (BGE) contains 75 mM phosphate buffer (pH 2.5) with the same polyanion as above. Using this methodology, amphetamine, methamphetamine, MDA, MDMA, MDEA, and an internal standard (n-butylamphetamine) are baseline resolved in less than 5 min. The run-to-run migration time %RSDs and peak area %RSDs are typically <0.3% and <2.1%, respectively. The day-to-day and capillary-to-capillary migration time %RSDs are <1.5% and <2.1%, respectively. The %RSDs of the relative migration times compared with the internal standard on a day-to-day and capillary-to-capillary basis are <0.2% and <0.06%, respectively. The linear dynamic range using peak areas range from 0.003 to 0.10 mg/mL. The correlation coefficients are >0.9998, with all calibration curves passing at or near the origin. Similar data are obtained for cocaine and its internal standard henyltoloxamine. None of the compounds usually encountered in illicit samples interfere with the target compound (e.g., methamphetamine and cocaine) or the internal standard. Quantitative results for synthetic mixtures and seized exhibits are in good agreement with actual values, and also with results obtained from other techniques. The relatively high EOF for the dynamically coated capillary system allows for the screening of basic, acidic, and neutral adulterants in drug seizures; identification is facilitated by the use of automated UV library searches.

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.

A processing method enabling the use of peak height for accurate and precise proton NMR quantitation

In NMR, peak area quantitation is the most common method used because the area under a peak or peak group is proportional to the number of nuclei at those frequencies. Peak height quantitation has not enjoyed as much utility because of poor precision and linearity as a result of inconsistent shapes and peak widths (measured at half height). By using a post‐acquisition processing method employing a Gaussian or line‐broadening (exponential decay) apodization (i.e. weighting function) to normalize the shape and width of the internal standard (ISTD) peak, the heights of an analyte calibration spectrum can be compared to the analyte peaks in a sample spectrum resulting in accurate and precise quantitative results. Peak height results compared favorably with ‘clean’ peak area results for several hundred illicit samples of methamphetamine HCl, cocaine HCl, and heroin HCl, of varying composition and purity. Using peak height and peak area results together can enhance the confidence in the reported purity value; a major advantage in high throughput, automated quantitative analyses. Published in 2009 by John Wiley & Sons, Ltd.

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.

Isolation and characterization of a newly identified impurity in methamphetamine synthesized via reductive amination of 1‐phenyl‐2‐propanone (P2P) made from phenylacetic acid/lead (II) acetate

A trace processing impurity found in certain methamphetamine exhibits was isolated and identified as trans-N-methyl-4-methyl-5-phenyl-4-penten-2-amine hydrochloride (1). It was determined that this impurity was produced via reductive amination of trans-4-methyl-5-phenyl-4-penten-2-one (4), which was one of a cluster of related ketones generated during the synthesis of 1-phenyl-2-propanone (P2P) from phenylacetic acid and lead (II) acetate. This two-step sequence resulted in methamphetamine containing elevated levels of 1. In contrast, methamphetamine produced from P2P made by other methods produced insignificant (ultra-trace or undetectable) amounts of 1. These results confirm that 1 is a synthetic marker compound for the phenylacetic acid and lead (II) acetate method. Analytical data for 1 and 4, and a postulated mechanism for the production of 4, are presented. Copyright

Hygrine, bona fide alkaloid or artifact: its chemical reduction, novel di-heptafluorobutyrylation and sensitive detection in South American coca leaves using capillary gas chromatography-electron capture detection

Methodology is described for the isolation of hygrine, along with the related compound-cuscohygrine, from South Americancoca leaf and its major tropane alkaloids. The isolated hygrine was reduced with lithium aluminum hydride to yield diastereomeric alcohols, which were subsequently derivatized with heptafluorobutyric anhydride in the presence of 4-dimethylaminopyridine. The resultant diastereomeric di-heptafluorobutyryl derivatives could be detected on-column at femtogram levels when using a polar fused-silica capillary column interfaced with 63Ni electron-capture detector. The artifactual formation of hygrine, resulting from the degradation of cuscohygrine, is discussed. Quantitative data are provided for hygrine and cuscohygrine levels in South American coca.