Fatty acid ethyl esters in hair as markers of alcohol consumption. Segmental hair analysis of alcoholics, social drinkers, and teetotalers

Background: Fatty acid ethyl esters (FAEEs) are products of nonoxidative et hanol metabolism. After incorporation in hair, they should be suitable long -term markers of alcohol abuse. Methods: Hair samples from 19 alcoholics in a treatment program, 10 fatalit ies with verified excessive alcohol consumption, 13 moderate social drinker s who consumed up to 20 g ethanol/day, and 5 strict teetotalers were analyz ed in 1-12 segments for four FAEEs (ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate) by external degreasing with n-heptane, extract ion with a dimethyl sulfoxide-n-heptane mixture, headspace solid-phase micr oextraction of the extracts, and gas chromatography-mass spectrometry with deuterated internal standards. The n-heptane washings were analyzed in the same way for FAEEs from the hair surface. Results: The sum of the four ester concentrations in hair calculated for th e proximal 0-6 cm segment was 2.5-13.5 ng/mg (mean, 6.8 ng/mg) for the fata lities, 0.92-11.6 ng/mg (mean, 4.0 ng/mg) for 17 of the alcoholics in treat ment, 0.20-0.85 ng/mg (mean, 0.41 ng/mg) for the moderate social drinkers, and 0.06-0.37 ng/mg (mean, 0.16 ng/mg) for the teetotalers. In almost all c ases the segmental concentrations increased from proximal to distal. There was no agreement between the self-reported drinking histories of the partic ipants and the FAEE concentrations along the hair length. Ethyl oleate was the dominant ester in all samples. Conclusions: FAEEs are deposited in hair mainly from sebum. Despite large i ndividual differences, FAEE hair concentrations can be used as markers for excessive alcohol consumption with relatively high accuracy. (C) 2001 Ameri can Association for Clinical Chemistry.