sodium-hypochlorite and ethyl-glucuronide

Ethyl glucuronide (EtG), a minor metabolite of alcohol, is used as a sensitive marker in hair to detect the retrospective consumption of alcohol. The proximal 0-3 cm hair segment is often used for analysis, providing information on alcohol consumption over the past 3 months. Using more distal segments would allow the detection of alcohol consumption over longer time periods, thereby addressing the chronicity of the consumption. In view of this, permanent coloring and bleaching were shown in vitro to alter EtG concentrations in hair, but no in vivo studies are available to prove or disprove this.. To investigate the influence of repeated bleaching and permanent coloring on EtG concentrations in vivo and to assess the stability of EtG concentrations in distal compared to proximal hair segments.. Hair samples from alcohol-dependent patients with uncolored/unbleached (N=4), permanent coloration (N=5) and bleached hair (N=5) were analyzed in two to six 3 cm long segments for EtG concentrations, and alcohol consumption and hair cosmetic treatments were assessed.. We observed that hair bleaching and permanent coloring reduces EtG concentrations by 82±11% and 65±24%, respectively, with correlations between the number of cosmetic treatments and the decrease in EtG concentrations. EtG remained stable in untreated hair samples up to 18 cm.. EtG is a sensitive marker to assess chronic alcohol consumption up to 18 months in alcohol-dependent patients with no cosmetic hair treatments. However, in alcohol-dependent patients who color or bleach their hair, care should be taken when interpreting EtG measurements.

Topics: Adult; Alcoholism; Biomarkers; Female; Forensic Toxicology; Gas Chromatography-Mass Spectrometry; Glucuronates; Hair; Hair Dyes; Humans; Male; Middle Aged; Sodium Hypochlorite

Ethyl glucuronide in hair (HEtG) has recently gained great attention, because of its high sensitivity and specificity in the diagnosis of chronic alcohol abuse. Due to its high polarity hydrophilicity, a strong hair treatment followed by a shampooing may lead to removal/degradation of this molecule from hair matrix.. To set up an in vitro study in order to evaluate the ability of bleaching of modifying HEtG test results.. Thirty hair samples from teetotalers (n=5), social drinkers (n=4) and heavy drinkers (n=21), after an informed written consent, were collected and divided longitudinally into four aliquots. The first aliquot was kept untreated and was processed following the method routinely used in our lab for the determination of HEtG (double washing with methanol/dichloromethane, overnight incubation in water, and LC-MS/MS analysis, LLOQ: 3pg/mg). To the other three aliquots a commercially available bleaching solution was applied, according to the manufacturer's instructions. One out of the three aliquots was submitted to the analysis by following the same procedure used for the untreated sample. The other two were submitted to a purification step before LC-MS/MS analysis, by using two different SPE cartridges (aminopropyl and dimethyl butylamine).. HEtG levels in the untreated samples from social drinkers and heavy drinkers ranged from 7.7 to 149.0pg/mg. All the samples from teetotalers tested negative. The treated samples processed without any SPE extraction and with aminopropyl cartridges showed a relevant ion suppression for both EtG and D(5)-EtG (IS) signals. Samples treated with the bleaching solution and extracted with dimethyl butylamine cartridge allowed to sensitively reduce ion suppression (less than 35%) and to verify that EtG, after a strong treatment like bleaching, completely disappears.. This in vitro study showed that HEtG disappears from hair matrix after a strong hair treatment. It is not clear whether the mechanism involved is chemical degradation or physical removal from the damaged keratinic matrix. However, owing to the highly hydrophilic character of the compound, the second mechanism seems more likely to occur. Finally, bleaching solutions could lead to a heavy ion suppression of this metabolite that may be avoided by using an SPE purification before instrumental analysis.

Topics: Alcohol Drinking; Chromatography, Liquid; Disinfectants; Forensic Toxicology; Glucuronates; Hair; Humans; In Vitro Techniques; Mass Spectrometry; Sodium Hypochlorite