Segmental analysis of amphetamines in hair using a sensitive UHPLC-MS/MS method

Area of Science:

• * Forensic Toxicology
• * Analytical Chemistry
• * Pharmacology

Background:

• * Accurate quantification of amphetamines in biological matrices is essential for forensic investigations and clinical toxicology.
• * Existing methods may lack the sensitivity, robustness, or speed required for routine forensic analysis.
• * Hair analysis offers a long detection window for drug use, making it valuable in various legal and clinical contexts.

Purpose of the Study:

• * To develop and validate a sensitive and robust ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for quantifying amphetamine, methamphetamine, and their analogs in hair.
• * To assess the method's suitability for forensic casework, including drug testing and investigations of drug-facilitated crimes.
• * To explore the potential of segmented hair analysis for estimating the timing of drug intake.

Main Methods:

• * Quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, and 3,4-methylenedioxy methamphetamine using UHPLC-MS/MS.
• * Sample preparation involved alkaline hydrolysis of segmented hair (10 mg) followed by liquid-liquid extraction.
• * Method validation encompassed selectivity, matrix effects, recovery, calibration, lower limit of quantification, precision, and bias.

Main Results:

• * The validated UHPLC-MS/MS method demonstrated high sensitivity and robustness with a calibration range of 0.02 to 12.5 ng/mg.
• * Recovery ranged from 62-83%, with validation bias < ±7% and imprecision < 5%.
• * Routine analysis showed imprecision < 13% for fortified controls and < 26% for authentic hair controls.

Conclusions:

• * The developed UHPLC-MS/MS method is suitable for the reliable quantification of target amphetamines in hair for forensic applications.
• * The method's ability to analyze segmented hair allows for the estimation of drug intake timing, aiding in investigations of drug-facilitated crimes.
• * This validated assay provides a valuable tool for various forensic casework scenarios, including violent crimes, autopsy, and drug testing.