Phentermine Interference and High l-Methamphetamine Concentration Problems in GC–EI-MS SIM Analyses of R-(−)-α-Methoxy-α-(Trifluoromethyl)Phenylacetyl Chloride-Derivatized Amphetamines and Methamphetamines†
| Autor: | Theron J. Hamilton, Katherine V. R. Dozier, Zachary J. Fuller, Harry Z. Qui |
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| Rok vydání: | 2014 |
| Předmět: |
Phentermine
Analyte Phenethylamine Resolution (mass spectrometry) Health Toxicology and Mutagenesis Stereoisomerism Toxicology Mass spectrometry Sensitivity and Specificity Chloride Gas Chromatography-Mass Spectrometry Methamphetamine Analytical Chemistry chemistry.chemical_compound medicine Humans Environmental Chemistry Phenylacetates Chemical Health and Safety Chromatography Trifluoromethyl Amphetamines Reproducibility of Results Reference Standards Substance Abuse Detection Military Personnel chemistry medicine.drug |
| Zdroj: | Journal of Analytical Toxicology. 38:456-461 |
| ISSN: | 1945-2403 0146-4760 |
| DOI: | 10.1093/jat/bku069 |
| Popis: | In order to achieve chromatographic separation, urine samples shown to be initially positive for amphetamines and methamphetamines in US Department of Defense immunoassays are derivatized with R-(-)-α-methoxy-α-(trifluoromethyl)phenylacetyl chloride (R-(-)-MTPA) prior to gas chromatography-electron impact-mass spectrometry (GC-EI-MS) analysis. Phentermine, a member of the phenethylamine class of drugs and a common appetite suppressant, interferes with GC-EI-MS assays of R-(-)-MTPA-derivatized d-amphetamine, degrading the chromatography of the internal standard and analyte ions and skewing concentration calculations. Additionally, when specimens with high concentrations of l-methamphetamine are derivatized with R-(-)-MTPA, signal peaks have the potential to be misidentified by integration software as d-methamphetamine. We have found that replacing R-(-) MTPA with (S)-(+)-α-methoxy-α-(trifluoromethyl)phenylacetyl chloride reduces phentermine interference problems related to internal standard chromatography, reduces the possibility of concentrated l-methamphetamine peaks being misidentified by integration software, improves resolution of d-methamphetamine in the presence of high l-methamphetamine concentrations, and is a cost-neutral change that can be applied to current amphetamines GC-EI-MS methods without the need for method modification. |
| Databáze: | OpenAIRE |
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