Concentration Ratios of Methamphetamine to Amphetamine in Blood Can Help to Distinguish Use of Methamphetamine from Various Mixtures of the Two Stimulants

• Published in: Journal of analytical toxicology 2012-11, Vol.36 (9), p.634-637
• Main Authors: Jones, A.W., Holmgren, A.
• Format: Article
• Language: English
• Subjects: amines; Amphetamine; Amphetamine - blood; Automobile Driving; Biological and medical sciences; Contamination; Drug abuse; Drug addictions; Female; Forensic science; Forensic Toxicology; Gas chromatography; Gas Chromatography-Mass Spectrometry; Humans; Liquid-Liquid Extraction; Male; Mass spectroscopy; Medical sciences; MEDICIN; MEDICINE; Methamphetamine; Methamphetamine - blood; Quantitation; Stimulants; Substance Abuse Detection - methods; Sweden; Toxicology
• ISSN: 0146-4760; 1945-2403; 1945-2403
• DOI: 10.1093/jat/bks075

Using a forensic toxicology database, the authors investigated cases of driving under the influence of drugs (DUID) if methamphetamine (MA) was identified in the blood samples (N = 9,310). The concentrations of MA and amphetamine (AM) in blood were determined after liquid-liquid extraction by gas chromatography-mass spectrometry at limits of quantitation of 0.03 mg/L for both stimulants. In 814 cases, AM was negative in blood and MA was positive at mean (median) and highest concentrations of 0.19 mg/L (0.11 mg/L) and 3.4 mg/L, respectively. Both amines were present in blood in 8,496 cases at concentrations of 0.54 mg/L (0.35 mg/L) and 10.4 mg/L for AM and 0.41 mg/L (0.22 mg/L) and 5.6 mg/L for MA. However, the correlation between AM and MA was low and insignificant (r = −0.13) in the whole material. The coefficient of correlation increased to r = 0.41 (P < 0.001) when the MA/AM concentration ratio was >1. When MA/AM ratios were selected at intervals of 1.0 (e.g., >3.0 and 9.0 and