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Identification of Methamphetamines and Over-the-Counter Sympathometic Amines by Full-Scan GC-Ion Trap MS with Electron Impact and Chemical Ionization
- Source :
- Journal of Analytical Toxicology. 16:137-141
- Publication Year :
- 1992
- Publisher :
- Oxford University Press (OUP), 1992.
-
Abstract
- An underivatized methane chemical ionization (CI) assay for measuring amphetamines in urine was evaluated against derivatized electron impact (EI) assays using a gas chromatograph-ion trap mass spectrometer. The full-scan CI mass spectra of methamphetamine, ephedrine/pseudoephedrine, and phentermine were compared with the full scan and three-ion EI mass spectra of heptafluorobutyric anhydride (HFBA) and 4-carbethoxyhexafluorobutyryl chloride (CB) derivatives. The fragmentation patterns for these compounds were nearly identical for the three major high molecular weight ions (m/z 254, 210, and 169 for EI-HFBA derivatives, and m/z 308, 262, and 280 for EI-CB derivatives). The CI mass spectra of the underivatized drugs contained more discernible differences at the higher molecular weights, including m/z 119, 148, and 150 for methamphetamine, 148, 166, and 176 for ephedrine/pseudoephedrine, and 91, 133, and 150 for phentermine. The within-run precision ranged from 7-9% for CI versus 5-6% for EI with HFBA derivatization (mean 500 ng/mL, n = 5). The limits of detection (LOD) for amphetamine and methamphetamine were 2.4 and 8.6 ng/mL, respectively, for CI versus 0.7 and 1.4 ng/mL for EI. The limits of quantitation (LOQ) were 4.5 and 19.1 ng/mL for CI versus 1.4 and 5.7 ng/mL for EI. The use of full-scan mass spectral analysis with either electron impact or chemical ionization provides additional qualitative data that may be helpful for measuring methamphetamine in the presence of other sympathomimetic amines.
- Subjects :
- Ephedrine
Phentermine
Chemical ionization
Chemical Health and Safety
Chromatography
Chemistry
Health, Toxicology and Mutagenesis
Nonprescription Drugs
Toxicology
Mass spectrometry
Pseudoephedrine
Gas Chromatography-Mass Spectrometry
Methamphetamine
Analytical Chemistry
Amphetamine
medicine
Mass spectrum
Environmental Chemistry
Ion trap
Gas chromatography–mass spectrometry
Electron ionization
medicine.drug
Subjects
Details
- ISSN :
- 19452403 and 01464760
- Volume :
- 16
- Database :
- OpenAIRE
- Journal :
- Journal of Analytical Toxicology
- Accession number :
- edsair.doi.dedup.....afabdbfda664783da6cae8568ffbd07c