Ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) are alcohol metabolites measured in hair and
are after a decade of research thoughtto be the best markers in hair to indicate alcoholism and abstinence
Forensic Sci. Int. 218 (2012) 2. A great body of work concerning EtG and FAEEs detection in hair has been
performed. However, no recent extensive comparison has been made concerning washing and extraction
procedures. This work shows that the washing procedure of dichloromethane followed by a methanol
rinse of the hair sample removes more than 16% of the FAEEs and 50% of the total EtG that is present
in and on the hair. A review of ten washing protocols (where the removal is categorised: high, medium
or low) showed that a relatively high percentage of FAEEs was removed and “medium” amount of EtG
compared to the other washing protocols. This work shows promising results for the extraction of the
FAEEs and the combined extraction of FAEEs and EtG by using 30 min of sonication with methanol. More
FAEEs were recovered from hair with methanol than with any other extraction solvent including the
commonly used dimethyl sulfoxide/heptane mixture. When the sonication time was increased a higher
percentage of transesterification of the FAEEs was observed, the extraction was “dirtier” as solids and
a colour change was observed whereas the extraction efficiency did not increase. Therefore, washing
the hair sample with dichloromethane and methanol followed by an addition of 1 ml of methanol and
sonication for 30 min to extract the FAEEs and EtG from hair is recommended for FAEEs as well as for the
combined analysis of EtG and FAEEs. A linear calibration curve (r2 > 0.99) was obtained for all analyte