The influence of ethanol containing cosmetics on ethyl glucuronide concentration in hair

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Abstract

Ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE), non-volatile, direct metabolites of ethanol have been shown to be suitable markers for the evaluation of social and chronic excessive alcohol consumption. Previous investigations have shown that the regular use of hair-care products with high alcohol content lead to an increase of FAEE concentration and consequently gave false-positive results for the determination of FAEE in hair. In this study we investigated the influence of a long-term hair treatment with EtOH containing lotion, on the EtG concentrations in hair.

In this study 7 volunteer subjects (classified as either rare, social or heavy drinkers) treated the right side of their scalp every day during a one or two month period with a commercial hair tonic (Seborin), which contains 44.0% ethanol (vol%). Collection of hair specimens from both sides of the scalp was done one day before hair treatment, one week and one month after treatment (for 5 subjects also after two months of treatment). A hair segment of 3 centimeters (cm) was cut and then washed with water and acetone, and then pulverized. EtG was quantified by GC/MS after pulverization and 2 h of ultrasonication in water, extraction by solid phase extraction using Oasis MAX columns and derivatization with HFBA. Measurements were done in negative chemical ionization mode using EtG-D5 as internal standard. Comparison of EtG concentration in the treated and in the non-treated hair specimens did not show any increase at the different dates of collection for the 7 subjects.

In conclusion, these results show that there is no indication for an increase of EtG after use of ethanol containing hair cosmetics.

Introduction

Alcoholism is one of the most frequent addictions and is of great interest to forensic and clinical medicine. Consequently, the research in forensic toxicology has focused on the identification of biochemical markers of ethanol consumption to diagnose chronic heavy alcohol use, dependence or abstinence and to analyze the alcohol rate in cases, where alcohol abuse can be dangerous (e.g. driving, pregnancy, work place and child custody).

Alcohol itself cannot be used as an analyte for this purpose because of its high volatility. However, there are several suitable minor metabolites of ethanol from which fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) had been thoroughly investigated.

The determination of FAEE and EtG allows a discrimination between excessive repeated alcohol consumption (above 60 g EtOH daily, social drinking (10–40 g EtOH per day) and rare drinking) [1], [2], [3], [4]. In these studies a cut-off of 0.5 ng/mg for FAEE and 7.0 pg/mg for EtG was proposed to discriminate between rare drinkers and moderate drinkers. In a recent consensus of the Society of Hair Testing a concentration of FAEE above 1.0 ng/mg (6 cm hair length) and/or a EtG concentration above 30 pg/mg (hair length between 3 and 6 cm) strongly suggests repeated and excessive alcohol drinking (SoHT consensus) [5].

It is known that cosmetic treatment must be taken into consideration for the correct interpretation of hair results [6], [7]. Regarding alcohol markers, special attention should be considered to ethanol containing hair lotions. Beside EtOH these lotions mostly contain natural plant ingredients like essential oils and are sometimes composed of an organic and an aqueous phase. They are supposed to re-moisturise and to stimulate the scalp, to reinforce hair growth, to eliminate dandruff and/or to prevent hair loss.

Only a few studies have been published so far regarding ethanol containing hair care products and the alcohol marker. In a study by Hartwig et al. three volunteer moderate social drinkers treated one side of their scalp daily with a commercial hair lotion (Florena Birken Haarwasser), which contains 62.6 vol% ethanol [8]. The other side of the scalp was left untreated. In the samples from the treated side, FAEE concentrations above 1.0 ng/mg were found, whereas the untreated side presented concentrations below 0.5 ng/mg. These results indicate that for FAEE analysis there is a risk of false positive results when using hair lotions containing high levels of ethanol. In a more recent study by Gareri et al. 12 hair samples of 9 patients using hair-care products were analyzed [9]. The hair-care products presented EtOH contents varying between 10 and 95 vol%. The results for FAEE analysis varied between 0.496 and 4.984 ng/mg hair, whereas the EtG results varied between 1.9 and 23.5 pg/mg hair. The authors concluded that the regular use of products with an ethanol content as low as 10% can impact FAEE results using a cut-off of 0.5 ng/mg. EtG findings were below the used cut-off of 30 pg/mg and thus this alcohol marker seems to be unaffected by these EtOH containing hair lotions.

The aim of this study was to investigate the influence of long-term treatment of hair with EtOH containing hair lotion, on EtG concentration.

Section snippets

Chemicals and reagents

All chemicals and reagents were analytical grade. Ethyl glucuronide and ethyl glucuronide-D5, used as internal standard, were purchased from Medichem (Stuttgart Germany) and heptafluorobutyric anhydride (HFBA) was purchased from Sigma Aldrich (Bornem, Belgium). EtOH content in 100 times diluted hair lotions was determined by Headspace/MS.

Hair samples and treatment

Seven volunteer subjects (rare, social and heavy drinker) treated the right side of the scalp every day during a 1 or 2 month period with a commercial hair

Results and discussion

To test the influence of EtOH containing hair lotions on the EtG concentration in hair, one hair lotion with a high EtOH concentration was selected.

In total 9 different commercial hair lotions (bought in February 2010) were analyzed (Table 1). Seborin, which was determined to contain the highest vol% of EtOH (44.0%) was chosen for this study. To avoid false positive results the lotions were also tested for EtG. It was confirmed that all were EtG free.

The EtG concentrations in the non-treated

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This paper is part of the special issue entitled: Selected papers from the Chamonix 2011 Society of Hair Testing Meeting, Guest-edited by Pascal Kintz.

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