O15: Determination of EtG in body hair samples for monitoring of teetotalism: A suitable alternative to scalp hair locks?

Abstract

Introduction The quantitative determination of ethyl glucuronide (EtG) in scalp hair has become established in both clinical and forensic toxicology as a direct marker for alcohol intake. It is a useful tool in the retrospective assessment of alcohol consumption, providing a specific window of detection that depends on the length of the hair sample. However, scalp hair is not always available, e.g. due to cosmetic reasons or bodily changes like alopecia. The main focus of this study was on statistical evaluation of our routine cases and the practicability of non-head hair in the context of the recommended interpretation threshold of 7 pg/mg EtG in hair. Additionally, a comparison of hair from different alternative anatomical sites (chest, axilla, arm, leg, and beard) was made. Pubic hair samples were not investigated. Methods Two different analytical methods to analyze EtG in hair samples were used. One was a GC-NCI-MS/MS method with SPE clean up (OASIS Max) and PFPA-derivatisation and the other one a LC-MS/MS method; both were validated. Our routine work, e.g. during the assessment for re-granting the driver's license, includes several 1,000 cases per annum . Thereof, 9% were body hair samples, mainly chest and leg hair, and could be analyzed. In a recent paper, an intra-individual comparison of EtG quantified in scalp and nonhead hair was presented (A. Pianta, B Liniger, M. R. Baumgartner, Alcohol and Alcoholism, 48 ( 2013 ). 295 – 302). Additionally, we compared hair samples of one type (e.g. leg hair) collected from different regions (e.g. left and right leg, front and back side). Results and Discussion EtG concentration could be determined in arm hair samples (in 0.5% of all routine cases), in leg hair samples (4.4%), in chest hair samples (3.9%), and in beard hair samples (0.1%), respectively. The gender distribution of our overall case work is 87% men and 13% women. As far as body hair samples are concerned, only four arm hair samples from women (less than 0.1%) were tested during the last few years. From all the subjects that were tested for long term teetotalism (no alcohol intake during more than 6 months), the percentage of negative cases for head hair was 83%, for leg and chest hair 75%, for arm and beard hair 67% and 64%, respectively. Repeated analysis of body hair revealed no larger inhomogeneity than for head hair. Conclusion Chest, arm, leg, and beard hair samples may represent a suitable alternative to monitor alcohol intake, especially for assessment of long term teetotalism. Admittedly, due to today's beau ideal, body hair can usually be collected only from men.