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Quantitative and isomeric determination of amphetamine and methamphetamine from urine using a nonprotic elution solvent and R(-)-alpha-methoxy-alpha-trifluoromethylphenylacetic acid chloride derivatization.
J Anal Toxicol. 2005 Oct; 29(7):652-7.JA

Abstract

Forensic Urine Drug Testing Laboratories often requires two confirmatory methods for a methamphetamine positive screen. First, methamphetamine is identified and quantitated using gas chromatography-mass spectrometry. If the total methamphetamine concentration is above the administrative cutoff level, the isomeric composition must be determined. This eliminates a possible contribution by over-the-counter cold medications that contain l-methamphetamine (Vick's inhalers). Products that contain only the l-isomer of methamphetamine must be distinguishable from prescription or illicitly manufactured methamphetamine, which consists mainly of the d-isomer. Optically impure derivatizing reagents will produce an impure mixture from a pure isomeric compound. Therefore, methods utilizing impure reagents can prove problematic when interpreting results. Use of an optically pure chiral derivatizing reagent, such as R(-)-alpha-methoxy-alpha-trifluoromethylphenylacetic acid chloride, allows for the creation and measurement of chromatographically separable isomeric compounds. The novel method described here utilizes a polymer-based solid-phase column adapted to a positive pressure manifold extraction system and a one-step derivatization process that occurs directly in the elution solvent. This methodology eliminates an elution solvent dry-down step that may adversely affect recovery of volatile amphetamine compounds. Although the method was designed for the quantitative analysis of the isomers of amphetamine and methamphetamine, it can be adapted for use with a wide range of phenethylamines including methylenedioxyamphetamine, N-methylenedioxymethamphetamine, and possibly N-methylenedioxyethylamphetamine. The linear range for quantitation was 25-10,000 ng/mL for d,l-methamphetamine and d,l-amphetamine, and correlation coefficients were 0.997 or better. The coefficient of variation for all four analytes did not exceed 2.8%. Concentrations analyzed ranged from 500 to 4000 ng/mL (n=40). The method allows for a simple and accurate quantitation and isomeric determination of amphetamine and methamphetamine using a process that eliminates extraction and derivatization complications common in current methods.

Authors+Show Affiliations

Office of the Armed Forces Medical Examiner, Division of Forensic Toxicology, Armed Forces Institute of Pathology, 1413 Research Boulevard, Building 102, Rockville, Maryland 20850-3125, USA. justin.holler@afip.osd.milNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16419395

Citation

Holler, Justin M., et al. "Quantitative and Isomeric Determination of Amphetamine and Methamphetamine From Urine Using a Nonprotic Elution Solvent and R(-)-alpha-methoxy-alpha-trifluoromethylphenylacetic Acid Chloride Derivatization." Journal of Analytical Toxicology, vol. 29, no. 7, 2005, pp. 652-7.
Holler JM, Vorce SP, Bosy TZ, et al. Quantitative and isomeric determination of amphetamine and methamphetamine from urine using a nonprotic elution solvent and R(-)-alpha-methoxy-alpha-trifluoromethylphenylacetic acid chloride derivatization. J Anal Toxicol. 2005;29(7):652-7.
Holler, J. M., Vorce, S. P., Bosy, T. Z., & Jacobs, A. (2005). Quantitative and isomeric determination of amphetamine and methamphetamine from urine using a nonprotic elution solvent and R(-)-alpha-methoxy-alpha-trifluoromethylphenylacetic acid chloride derivatization. Journal of Analytical Toxicology, 29(7), 652-7.
Holler JM, et al. Quantitative and Isomeric Determination of Amphetamine and Methamphetamine From Urine Using a Nonprotic Elution Solvent and R(-)-alpha-methoxy-alpha-trifluoromethylphenylacetic Acid Chloride Derivatization. J Anal Toxicol. 2005;29(7):652-7. PubMed PMID: 16419395.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Quantitative and isomeric determination of amphetamine and methamphetamine from urine using a nonprotic elution solvent and R(-)-alpha-methoxy-alpha-trifluoromethylphenylacetic acid chloride derivatization. AU - Holler,Justin M, AU - Vorce,Shawn P, AU - Bosy,Thomas Z, AU - Jacobs,Aaron, PY - 2006/1/20/pubmed PY - 2006/2/4/medline PY - 2006/1/20/entrez SP - 652 EP - 7 JF - Journal of analytical toxicology JO - J Anal Toxicol VL - 29 IS - 7 N2 - Forensic Urine Drug Testing Laboratories often requires two confirmatory methods for a methamphetamine positive screen. First, methamphetamine is identified and quantitated using gas chromatography-mass spectrometry. If the total methamphetamine concentration is above the administrative cutoff level, the isomeric composition must be determined. This eliminates a possible contribution by over-the-counter cold medications that contain l-methamphetamine (Vick's inhalers). Products that contain only the l-isomer of methamphetamine must be distinguishable from prescription or illicitly manufactured methamphetamine, which consists mainly of the d-isomer. Optically impure derivatizing reagents will produce an impure mixture from a pure isomeric compound. Therefore, methods utilizing impure reagents can prove problematic when interpreting results. Use of an optically pure chiral derivatizing reagent, such as R(-)-alpha-methoxy-alpha-trifluoromethylphenylacetic acid chloride, allows for the creation and measurement of chromatographically separable isomeric compounds. The novel method described here utilizes a polymer-based solid-phase column adapted to a positive pressure manifold extraction system and a one-step derivatization process that occurs directly in the elution solvent. This methodology eliminates an elution solvent dry-down step that may adversely affect recovery of volatile amphetamine compounds. Although the method was designed for the quantitative analysis of the isomers of amphetamine and methamphetamine, it can be adapted for use with a wide range of phenethylamines including methylenedioxyamphetamine, N-methylenedioxymethamphetamine, and possibly N-methylenedioxyethylamphetamine. The linear range for quantitation was 25-10,000 ng/mL for d,l-methamphetamine and d,l-amphetamine, and correlation coefficients were 0.997 or better. The coefficient of variation for all four analytes did not exceed 2.8%. Concentrations analyzed ranged from 500 to 4000 ng/mL (n=40). The method allows for a simple and accurate quantitation and isomeric determination of amphetamine and methamphetamine using a process that eliminates extraction and derivatization complications common in current methods. SN - 0146-4760 UR - https://www.unboundmedicine.com/medline/citation/16419395/Quantitative_and_isomeric_determination_of_amphetamine_and_methamphetamine_from_urine_using_a_nonprotic_elution_solvent_and_R____alpha_methoxy_alpha_trifluoromethylphenylacetic_acid_chloride_derivatization_ L2 - https://academic.oup.com/jat/article-lookup/doi/10.1093/jat/29.7.652 DB - PRIME DP - Unbound Medicine ER -