Squalene in hair--a natural reference substance for the improved interpretation of fatty acid ethyl ester concentrations with respect to alcohol misuse

Fatty acid ethyl esters (FAEE) are incorporated into hair mainly from sebum. For this reason, the use of their concentration CFAEE as marker of excessive alcohol consumption is complicated by interindividual differences of the activity of the sebum glands and of elimination by hair care and hair cosmetics. Furthermore, an influence of the investigated hair length due to increasing accumulation from proximal to distal was found. Therefore, it was examined whether these sources of error can be avoided if in addition to CFAEE the relative FAEE concentrations CFAEE/CSQ related to squalene SQ as a natural reference compound were used for interpretation. Sebum contains about 10-20% SQ. A sensitive and reliable method for the determination of SQ in addition to FAEE from the same hair extracts by high performance liquid chromatography with photo diode array detector (HPLC-DAD) was developed. The concentrations of ethyl myristate, ethyl palmitate, ethyl oleate, ethyl stearate and squalene were determined and CFAEE/CSQ was calculated for 13 teetotallers, 16 social drinkers, 12 fatalities with excessive alcohol abuse at life time and 9 cases with unclear alcohol anamnesis. CSQ ranged from 0.02 to 1.97 microg/mg (mean 0.67 microg/mg). From the results follows that squalene enables a control of the lipid content of hair and a correction of CFAEE in cases with deviations from the usual lipid content in a similar way as creatinine in urine. Preliminary values of CFAEE/CSQ were suggested for the upper limit for teetotallers (< 0.6 ng/microg) and the lower limit for excessive alcohol abuse (> 1.5 ng/microg). However, the relative concentration CFAEE/CSQ cannot completely replace the absolute concentration CFAEE, and both should regularly be used for an improved interpretation with respect to alcohol abuse.     

Analysis of fatty acid ethyl esters in hair as possible markers of chronically elevated alcohol consumption by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS)

Fatty acid ethyl esters (FAEE) are products of the nonoxidative ethanol metabolism, which are known to be detectable in blood only about 24h after the last alcohol intake. After deposition in hair they should be suitable long-term markers of chronically elevated alcohol consumption. Therefore, a method for the analysis of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate from hair was developed based on the extraction of the hair sample by a dimethylsulphoxide (DMSO)/n-hexane mixture, separation and evaporation of the n-hexane phase and application of headspace solid-phase microextraction (HS-SPME) in combination with gas chromatography-mass spectrometry (GC-MS) to the extract. For use as internal standards, the corresponding D(5)-ethyl esters were prepared. The HS-SPME/GC-MS measurements were automatically performed using a multi-purpose sampler. The detection limits of the FAEE were between 0.01 and 0.04ng/mg and the reproducibility was between 3.5 and 16%. By application of the method to hair samples of 21 fatalities with known heavy alcohol abuse 0.045-2.4ng/mg ethyl myristate, 0.35-13.5ng/mg ethyl palmitate, 0.25-7.7ng/mg ethyl oleate and 0.05-3.85ng/mg ethyl stearate were measured. For social drinkers (30-60g ethanol per week), the concentrations were about one order of magnitude smaller. For 10 teetotalers negative results or traces of ethyl palmitate were found. It was shown by supplementary investigations in single cases that FAEE are also present in sebum, that there is no strong difference in their concentrations between pubic, chest and scalp hair, and that they are detectable in hair segments after a 2 months period of abstinence. From the results follows that the measurement of FAEE concentrations in hair is a useful way for a retrospective detection of alcohol abuse.     

Practical experiences in application of hair fatty acid ethyl esters and ethyl glucuronide for detection of chronic alcohol abuse in forensic cases

This article presents results from 1872 hair samples, which were analyzed for fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG). The results were evaluated in the context of self-reported drinking behavior, the use of hair cosmetics, the gender of the sample donors and hair sample length. For comparison, CDT and GGT in serum were available in 477 and 454 cases, respectively. A number of alcohol abstainers or low moderate drinkers and excessive drinkers were selected for assessment of cut-offs for FAEEs in the proximal 6cm hair segments and for EtG in the proximal 3cm hair segments. Cut-off values were assessed by ROC analysis. It was found that the cut-offs of 1.0ng/mg FAEE and 30pg/mg EtG presently used for excessive drinking lead to a low portion of false positives (4% and 3% respectively) but to a higher portion of false negatives (23% and 25% respectively). Comparison of the mean and medium concentrations in samples without any reported hair cosmetics (N=1079) and in samples with reported use of hair spray (N=79) showed an increase by the factor of about two for FAEE but no significant difference for EtG. Mean values of EtG were decreased by 80% in bleached samples (N=164) and by 63% in dyed samples (N=96). There was no significant effect of bleaching and dyeing on FAEE. Hair gel and hair wax, oil or grease showed no significant effect on both FAEE and EtG. With respect to gender and investigated hair length ambiguous results were obtained because of major differences in the compared subpopulations of male with higher alcohol consumption and mainly shorter hair, and less drinking female with longer hair. For excessive drinkers FAEEs in the 0-6cm hair segment and EtG in the 0-3cm segment decreased with increasing time of reported abstinence before sample collection. These drinkers attain the level of teetotalers only after more than 10 months of abstinence. In comparison to scalp hair, FAEEs recovered from armpit hair and leg hair were lower and from chest hair were higher. EtG in armpit hair was lower and in leg hair higher than in scalp hair. It is concluded that the combined use of FAEE and EtG essentially increases the accuracy of interpretation since both markers complement each other by a different sensitivity to sources of error.     

Wipe-test and patch-test for alcohol misuse based on the concentration ratio of fatty acid ethyl esters and squalene CFAEE/CSQ in skin surface lipids

Fatty acid ethyl esters (FAEE) are known to be formed in blood and almost all human tissues after alcohol consumption and to be incorporated from sebum into hair where they can be used as long-term markers for excessive alcohol consumption. In order to examine whether skin surface lipids which consist mainly of sebum are an equally useful matrix for measurement of FAEE as alcohol abuse markers, samples were collected by a wipe-test from the forehead of 13 teetotallers, 16 social drinkers, 10 death cases with known recent alcohol misuse and five death cases without indications of alcohol misuse. The samples were analysed by headspace solid-phase microextraction and gas chromatography-mass spectrometry for ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate and by high performance liquid chromatography with photodiode array detector for squalene, (SQ), as a natural reference substance which the FAEE concentrations were related to. The ratio mFAEE/mSQ ranged between 0.16 and 1.12 ng/microg (mean 0.34 ng/microg) for the teetotallers and between 0.08 and 0.94 ng/microg (mean 0.37 ng/microg) for the social drinkers with no significant difference between both groups. For the alcoholics 2.4-24.2 ng/microg (mean 13.1 ng/microg) were found. For two volunteers the course of mFAEE/mSQ 2 weeks before and 3 weeks after a single high alcohol dose was pursued by daily wipe tests. A strong increase of mFAEE/mSQ occurred between 7 and 12 days after the drinking event. This delay can be explained by the transition time of about 8 days between sebum production and its appearance on the skin surface known from literature. For seven social drinkers skin surface lipid samples were also collected using drug of abuse patches of the firm PharmCheck. The ratios mFAEE/mSQ in these samples were in the same range as from the wipe-test. The comparison with the self-reported ethanol amounts consumed the week before and during the test gave no good correlation (R2 = 0.42). It can be concluded from the results that FAEE in skin surface lipids can be used for medium-term retrospective detection of heavy drinking.     

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

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 2h 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.     

Effect of hair care and hair cosmetics on the concentrations of fatty acid ethyl esters in hair as markers of chronically elevated alcohol consumption

Fatty acid ethyl esters (FAEE) can be used as alcohol markers in hair. It was investigated in this study whether this diagnostic method is disturbed by hair care and hair cosmetics. Traces of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate were detected in all of 49 frequently applied hair care products by headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The highest concentration was 0.003% in a hair wax. From experiments with separated hair samples of alcoholics as well as from the evaluation of the FAEE concentrations and the data about hair care of 75 volunteers (alcoholics, social drinkers and teetotalers) follows that usual shampooing, permanent wave, dyeing, bleaching or shading are of minor importance as compared to the drinking amount and other individual features. However, false positive results were found after daily treatment with a hair lotion containing 62.5% ethanol, with a deodorant and with a hair spray. As an explanation, it is assumed that FAEE are formed in the sebum glands also after regular topical application of products with a higher ethanol content.     

Determination of ethyl glucuronide in human hair by SPE and LC-MS/MS

A method for the sensitive and selective determination of ethyl glucuronide (EtG) in hair has been developed using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Washed and cut hair segments were extracted by ultrasonication (3h, 50 degrees C) and the extracts were cleaned-up with aminopropyl SPE columns. LC-MS/MS analysis was performed using a polar-endcapped phenyl-hexyl-RP-phase with negative mode electrospray ionisation (ESI) using a triple quadrupole mass spectrometer (Sciex API 365) with a turboionspray source and post-column addition of acetonitrile for enhanced sensitivity. The MS/MS transitions monitored were m/z 221 -->75 for EtG and 226 -->75 for D(5)-EtG as an internal standard. The method was selective and sensitive, with a detection limit of 51 pg/mg hair at a signal-to-noise ratio of 3:1. The mean recovery was 96%, with an intra- and inter-day precision of less than 11.7% at a concentration of 200 pg/mg. The linearity was assessed in the range of 25-2000 pg/mg hair, with a correlation coefficient of 0.997. The method was successfully applied to 97 human hair samples which were taken at autopsies from persons with known alcoholism or were obtained from alcoholics who were hospitalized for ethanol withdrawal, from social drinkers and from children having not consumed any alcohol. Although, approximately two-third of the alcoholics showed EtG concentrations in hair of higher than 51 pg/mg (up to >4000 pg/mg), in one-third the EtG concentration was below the detection limit. However, only in one of five hair samples of "social drinkers", the EtG concentration was above the detection limit (51 pg/mg). No EtG has been detected in the hair of children. These investigations demonstrate that heavy alcohol consumption may be but not necessarily has to be detectable by EtG analysis in hair.     

Interpretation problems in a forensic case of abstinence determination using alcohol markers in hair

In a child custody case a mother with a longstanding history of alcohol misuse had to show absolute abstinence for one year. She entered a residential rehabilitation for six months and was tested two months later by way of a hair test for ethyl glucuronide (EtG) with the result of 22 pg/mg in the proximal 0-1cm segment and the segments 1-2 cm and 2-3 cm being negative. This was interpreted as a minimum alcohol intake of 20-50 units per week in the month before sampling. Since the mother denied any alcohol intake a second hair sample was collected seven weeks after the first and analyzed for fatty acid ethyl esters (FAEEs) by a second laboratory. A low concentration of 0.03 ng/mg was measured within the 0-6 cm segment of recently bleached hair and was interpreted as showing no evidence of alcohol use during the last six months. Three further hair samples were analyzed during the next nine months with low EtG values (<2.4-3.3 pg/mg, 0-3 cm segment) and low FAEE values (0.27-0.53 ng/mg, 0-6 cm segment). These findings were summarized as indicating continued low alcohol consumption over the past one year period. As a consequence of the conflicting results, the case was dealt with in a hearing before the Family Division of the High Court of London. It was concluded in the judgment that the evidence did not indicate that the mother had consumed alcohol in the period tested by the hair samples. It was stated that the evidence in this case highlighted the need for the exercise of considerable caution when hair tests for alcohol are being interpreted and relied upon, both generally and particularly in isolation, and that this case is a proper reminder of the need for expert evidence to be given in a manner according to the Practice Direction.     

Sexual abuse and anti-wrinkle cream: evidence from octocrylene

In a case of a driving ability assessment, hair analysis for ethyl glucuronide (EtG) was requested by the authorities. The person concerned denied alcohol consumption and did not present any clinical sign of alcoholism. However, EtG was found in concentrations of up to 910pg/mg in hair from different sampling dates suggesting an excessive drinking behavior. The person declared to use a hair lotion on a regularly base. To evaluate a possible effect of the hair lotion, prospective blood and urine controls as well as hair sampling of scalp and pubic hair were performed. The traditional clinical biomarkers of ethanol consumption, CDT and GGT, were inconspicuous in three blood samples taken. EtG was not detected in all collected urine samples. The hair lotion was transmitted to our laboratory. The ethanol concentration in this lotion was determined with 35g/L. The EtG immunoassay gave a positive result indicating EtG, which could be confirmed by GC-MS/MS-NCI. In a follow-up experiment the lotion was applied to the hair of a volunteer over a period of six weeks. After this treatment, EtG could be measured in the hair at a concentration of 72pg/mg suggesting chronic and excessive alcohol consumption. Overnight incubation of EtG free hair in the lotion yielded an EtG concentration of 140pg/mg. In the present case, the positive EtG hair findings could be interpreted as the result of an EtG containing hair care product. To our knowledge, the existence of such a product has not yet been reported, and it is exceptionally unusual to find EtG in cosmetics. Therefore, external sources for hair contamination should always be taken into account when unusual cosmetic treatment is mentioned. In those cases, it is recommended to analyze the hair product for a possible contamination with EtG. The analysis of body hair can help to reveal problems occurring from cosmetic treatment of head hair. As a consequence, the assessment of drinking behavior should be based on more than one diagnostic parameter.     

A study of distribution of ethyl glucuronide in different keratin matrices

Ethyl glucuronide (EtG) is a direct metabolite of ethanol, frequently used as a biomarker of alcohol abuse. To this purpose, EtG is preferentially determined in hair samples, using a cut-off value of 30pg/mg to discriminate between social and heavy drinkers, as recently fixed by an international consensus conference. Although this cut-off value is assumed for head hair, alternative matrices, such as pubic, axillary and chest hair, are often analyzed when head hair is not available. Previous studies suggested that determination of EtG in various keratin matrices may lead to different results; growth cycle and rate, urine contamination, distribution of sebum glands and other environmental factors are likely to contribute to these differences. We analyzed more than 2700 samples (head, pubic, chest and axillary hair) to evaluate the inter- and intra-individual distribution of the EtG concentration in the different keratin matrices. The data were interpreted on a statistical basis, on the assumption that large population data-sets will level off the average alcohol consumption of each group. From both inter- and intra-individual distribution data, significant differences were observed in EtG concentrations recorded in head, axillary and pubic hair samples. It is concluded that pubic hair cannot be utilized alternatively to head hair to prove chronic alcohol abuse, nor is axillary hair, since positive and negative biases respectively affect these determinations. In contrast, for chest hair, EtG distributions similar to head hair were found, although the large discrepancy between the examined population dimensions presently prevents any definitive conclusion. Thus, chest hair represents a promising alternative to head hair for EtG determinations, deserving further investigation on samples collected from the same individuals, in order to establish a clear correlation between their respective EtG concentrations.     

Segmental determination of ethyl glucuronide in hair: a pilot study

Ethyl glucuronide (EtG) is a minor metabolite of ethanol. Its detection in hair is more and more studied in both clinical and forensic context for the purpose of alcohol abuse monitoring. In this pilot study, hair specimens from 15 patients included in a treatment program after alcohol abuse cessation, were segmented and analyzed for EtG. The results were then compared to their self-reported past alcohol consumption and to their blood biomarkers values (GGT, MCV, ASAT, ALAT). EtG concentrations measured in hair varied from 8 to 261 pg/mg. The pattern of EtG concentration detected in the different hair segments matched with the drinking history of patients, displaying variations (increase and decrease) in alcohol consumption and also time of cessation. Results also demonstrated the existence of a significant correlation (r(p)=0.5357; p=0.0390) between EtG concentration in hair and the amount of alcohol intake. Variations in the EtG concentrations with respect to hair segments may provide an overview of the drinking history of patients. Moreover, EtG concentration in hair may help to estimate the daily alcohol intake.     

Do drug users use less alcohol than non-drug users? A comparison of ethyl glucuronide concentrations in hair between the two groups in medico-legal cases

Two groups were selected from the remainder of hair samples that had been tested for drugs at TrichoTech for medico-legal cases: samples that tested negative (drug-negative group; N=42, age 33.4+/-7.2 years) and samples that tested positive for drugs (drug-positive group; N=57, age 32.5+/-8.8 years). A rapid, simple method to detect the ethanol metabolite, ethyl glucuronide (EtG) in hair has been developed. The hair samples were sectioned, and then submitted to overnight sonication in water. Samples then underwent SPE using anion exchange cartridges, followed by derivatisation with N,O-bis[trimethylsilyl]trifluoroacetamide (BSTFA), before confirmation by GC-MS/MS. The assay produced excellent linearity and sensitivity over the calibration range 0.02-1.0 ng/mg, assuming a 10 mg hair sample. The mean age of the two groups was not statistically different (p=0.575, Student t-test), indicating a homogeneous group. Twelve of the 57 (21.0%) hair samples of the drug-positive group tested positive for EtG, and 17 of the 42 (40.5%) hair samples of the drug-negative group tested positive for EtG. The mean concentration of EtG in the drug-positive group was 0.011 ng/mg compared to 0.107 ng/mg in the drug-negative group. When the full results of this study were subjected to statistical analysis it was shown that EtG levels in the drug-negative group were statistically higher than those found in the drug-positive group (p<0.05). This preliminary finding may be of use in the study of addiction and adds valuable data to previous studies regarding the use of EtG as a valuable marker for alcohol levels in hair.     

Are there possibilities for the detection of chronically elevated alcohol consumption by hair analysis? A report about the state of investigation

The analysis of suitable ethanol markers in hair would be an advantageous tool for chronic alcohol abuse control because of the wide diagnostic window allowed by this specimen and the possibility of segmental investigation. Between the markers practically used or thoroughly investigated in blood or urine, ethylglucuronide, fatty acid ethylesters, phosphatidylethanol, acetaldehyde adducts to protein and 5-hydroxytryptophol can be regarded as possible candidates also in hair, but preliminary data were found in the literature only for ethylglucuronide and acetaldehyde modified proteins. By using headspace gas chromatography and headspace solid phase microextraction in combination with gas chromatography-mass spectrometry (SPME-GC/MS), in alkaline hydrolysates of hair it was possible to determine between 17 and 135 ng/mg of ethanol beside acetone and several other volatile compounds with slightly higher ethanol values for alcoholics than for social drinkers and teetotalers. A part of this is ethanol only absorbed in the hair matrix from the surrounding environment and consequently is not applicable as a diagnostic criterion. By extraction with aqueous buffer, methanol or a methanol/chloroform mixture and subsequent alkaline hydrolysis it was found that another part is generated from ethylesters, which are preferentially deposited in the lipid fraction of hair. In a specific search for ethylesters of 17 carboxylic acids by GC/MS-SIM in most cases ethyl 4-hydroxybenzoate (0.1 to 5.9 ng/mg, a preservative in hair cosmetics) and in four cases traces of indolylacetic acid ethylester were found. Furthermore, diethyl phthalate (a softening agent, present also in many cosmetic products) was identified in the hair of alcoholics as well as of children. As potential markers of alcohol intake, ethyl palmitate, ethyl stearate and ethyl oleate were detected in hair samples of alcoholics by headspace SPME-GC/MS of the chloroform/methanol extracts.     

Ethyl glucuronide in hair - A highly effective test for the monitoring of alcohol consumption

In Germany drink driving offenders lose their license and must prove abstinence for one year in order to regain it. In this paper we assess the newly introduced ethyl glucuronide (EtG) tests in urine and hair in this alcohol abstinence monitoring. 20% (80 out of 386) of the 3cm long hair samples were tested positive for EtG in hair, compared to only 2% (92 out of 4248 samples) in urine in the same time period. Additionally 50% of the samples positive for EtG in hair had EtG values greater than 30pg/mg hair, indicating chronic alcohol consumption in the last three months. This study shows that four EtG tests in 3cm hair lengths reveal a significantly higher percentage of drink driving offenders who fail to be sober in the rehabilitation period, than do six random EtG tests in urine. Presumably, the hair test is more adequate to monitor long term alcohol abstinence than the urine test as defined by the new driving license re-granting medical and psychological assessment (MPA) in Germany.     

Comparison of ethyl glucuronide in hair with phosphatidylethanol in whole blood as post-mortem markers of alcohol abuse

Ethyl glucuronide (EtG) is a direct metabolite of ethanol and has been used as a marker of alcohol abuse in both urine and hair. This study investigated the value of EtG testing in post-mortem hair for diagnostic improvement of alcohol abuse in forensic medicine. Material from 70 consecutive medico-legal autopsies was collected in accordance with the recommendations on ethics by the Swedish National Board of Forensic Medicine. A method for determination of EtG in hair samples was developed using ultra performance liquid chromatography/electrospray tandem mass spectrometry (UPLC/ESI-MS/MS; LOQ, 2.5 pg/mg). The result of the EtG analysis was compared with the findings of phosphatidylethanol (PEth) in femoral whole blood, as measured by high performance liquid chromatography with an evaporative light-scattering detector (HPLC-ELSD; LOQ, 0.22 micromol/l). Evaluation of liver histology and anamnestic evidence of alcohol abuse of the deceased were taken in consideration for the interpretation. Measurable levels of EtG were present in 49 of the 70 autopsy cases whereas PEth was present in 36. Thirty-nine cases had EtG levels above the cutoff limit (> or = 30 pg/mg) compared with 29 for PEth (> or = 0.7 micromol/l). Fifteen cases had EtG as exclusive indicator for alcohol abuse compared with four cases for PEth. These findings suggest that measurements of EtG in hair may provide improved diagnostic information on alcohol abuse, due to a long retrospective time-window for detection and stability of EtG in hair in the decaying cadaver. However, an EtG level below the cutoff does not completely exclude previous alcohol abuse.     

Ethyl glucuronide in human hair after daily consumption of 16 or 32 g of ethanol for 3 months

The overall objectives of the study were to develop a sensitive method for ethyl glucuronide (EtG) determination in hair and then investigate if a low or moderate intake of ethanol could be differentiated from total abstinence. Forty-four subjects were included in the study, 12 males (7 drinkers and 5 abstinent) and 32 females (14 drinkers and 18 abstinent). The study lasted 3 months and the female drinkers consumed one glass (16 g of ethanol) and the males consumed two glasses (32 g of ethanol) of wine (13.5-14%) daily. Hair samples were collected as close as possible above the skin and the proximal 2 cm were analyzed for EtG. Hair was cut into pieces of about 0.5 cm length and washed before incubation overnight in water and then extracted on Clean Screen EtG Carbon columns. The LC/MS/MS system consisted of a Waters ACQUITY UPLC connected to an API 4000 triple quadrupole instrument. Two transitions for EtG and one for the internal standard EtG-D(5) were measured. The method was linear from 60 to 10,000 pg/sample. Imprecision studies were performed at three levels as well as with an authentic sample. Total imprecision was 16% at 200 pg/sample, 8% at 1000 pg/sample, 6% at 8000 pg/sample and 13% at 29 pg/mg in the authentic sample. Of those who drank two glasses of wine every day, four had measurable amounts of EtG in their hair (5-11 pg/mg), and in only one of the females drinking one glass of wine EtG was quantified (3 pg/mg). Among the 23 abstinent subjects two had traces of EtG in the hair. We conclude that persons who ingested 16 or 32 g of ethanol daily for 3 months presented with low concentrations of EtG in hair, well below the proposed threshold for overconsumption set at 30 pg/mg. In addition, none of those who ingested 16 g/day had concentrations over the proposed abstinence threshold of 7 pg/mg.     

Markers of chronic alcohol use in hair: comparison of ethyl glucuronide and cocaethylene in cocaine users

Two direct ethanol metabolites, namely ethyl glucuronide (EtG) and cocaethylene (CE), in the hair of cocaine (COC) users were compared in this study. Hair samples (n=68) were submitted to the determination of EtG (by liquid chromatography-electrospray-tandem mass spectrometry) and of COC and metabolites, including CE (by gas chromatography-mass spectrometry). Quantitative and qualitative results were compared. No quantitative correlation was found between EtG and CE, as well as between EtG and the cocaethylene concentration divided by the concentration of COC and its metabolites (benzoylecgonine and ecgonine methylester, as COC equivalents). Nevertheless, many factors are supposed to affect the amount of the two substances incorporated in the hair matrix, such as the subject's habits in ethanol and COC use, genetic variability in the metabolism of both substances, and the different chemical and physical properties of EtG and CE. When establishing a cut-off of 4 pg/mg for EtG and of 200 pg/mg for CE, 47 samples tested positive for EtG and 41 samples tested positive for CE; 12 samples out of the 47 EtG-positives tested negative for CE (25%), whereas 6 samples out of the 41 CE-positives tested negative for EtG (15%). According to these data, EtG appears to be a more sensitive and specific marker of non-moderate alcohol users than CE.     

Ethyl glucuronide: unusual distribution between head hair and pubic hair

Ethyl glucuronide (EtG) is a minor metabolite of ethanol that can be detected in hair. In some specific situations, head hair can be missing, and therefore, alternative anatomical locations of hair are of interest. In this study, paired hair specimens (head hair and pubic hair) from eight social drinkers were analyzed for EtG. Each sample was decontaminated by two dichloromethane bathes (5 ml) for 2 min. After cutting into small pieces, about 50 mg of hair was incubated in 2 ml water in the presence of 10 ng of EtG-d5, used as internal standard and submitted to ultra-sonication for 2 h. The aqueous phase was extracted by SPE using Oasis MAX columns. The hair extract was separated on an ACQUITY BEH HILIC column using a gradient of acetonitrile and formate buffer. Detection was based on two daughter ions: transitions m/z 221-85 and 75 and m/z 226-75 for EtG and the IS, respectively. This laboratory is using a positive cut-off at 50 pg/mg. All eight head hair specimens were negative for EtG at a limit of quantitation fixed at 10 pg/mg. Surprisingly, EtG was identified at high concentrations in pubic hair, in the range 12-1370 pg/mg. It appears, therefore, that it is not possible to document the drinking status of a subject by simply switching from head hair to pubic hair.     

探究尸体血样中乙醇、乙基葡萄糖醛酸苷和硫酸乙酯的产生

目的探索尸体血样保存过程中乙醇的产生情况及乙基葡萄糖醛酸苷(EtG)和硫酸乙酯(EtS)的产生可能。方法对照组为7例阳性静脉血,而实验组则为7例阴性尸体血。每例血样分成3份并保存在室温(18~22℃),4℃及-20℃等3种不同的条件下,在保存天数为0、2、3、5、7、9、11、13、15、17、19、21等时间点取样。使用顶空气相色谱法(HS-GC)检测乙醇,采用固相萃取提取EtG和EtS,使用高效液相色谱-三重四级杆质谱(LCMS/MS)法检测EtG和EtS。结果保存期间,对照组各血样中的乙醇、EtG和EtS浓度均呈下降趋势;实验组中1、2、4、5、6、7号血样的室温及4℃的样本在保存第2~3天时检出乙醇,而7号-20℃的样本在第6天检出乙醇。其中,6号室温血样的乙醇峰值浓度为64.27mg/100mL。各血样中均未检出EtG,EtS。结论室温及4℃保存的尸体血可产生乙醇且产生速度较快,反复冻融可导致-20℃保存的尸体血产生乙醇,乙醇峰值浓度可超过法定酒驾标准,但实验组血样中均无EtG和EtS产生。因此,尸体血中的EtG,EtS可以作为乙醇生前入体的特异性标志物,区分乙醇生前入体和腐败产生乙醇的依据。实际工作中,乙醇原体检测的酒精认定应注意血样保存和运输条件造成的影响。为了避免假阳性结果,涉及死亡的案件进行酒精认定时有必要辅以EtG和EtS的检测。     

Detection of ethyl glucuronide in blood spotted on different surfaces

This study aims to show that sensitive detection of ethyl glucuronide in dried blood spotted onto various surfaces after a period of 24h is feasible. At present, there is insufficient information how tightly ethyl glucuronide (EtG) binds to various materials and how easily it can be eluted. 4ml aliquots of blood samples obtained from seven volunteers after consumption of alcoholic beverages were applied to six different surfaces. After drying and a 24h-storage at 20±2°C the samples were re-dissolved in water, and EtG was subsequently analyzed by a LC-MS Paul-type ion trap. A comparison was made between dried and corresponding fluid samples. EtG was detectable in all subjects' samples following consumption of alcohol. EtG was also detectable after a storage time of four weeks at 4°C in whole blood that had been preserved with EDTA. EtG was detectable in all samples dried on different surfaces and its concentration remained relatively constant irrespective of the particular condition of the material. Detection of EtG in blood spots from the scene may indicate recent alcohol consumption in cases where collection of blood remained undone or could not be performed.