The Effect of Prolonged Storage Time on the Stability of Fatty Acid Ethyl Esters in Hair Samples

Abstract The advantages of analysis of drugs in hair samples are recognized for the long window of detection, alongside easy sampling and long stability after sample collection. Alcohol markers, ethyl glucuronide (EtG) and total fatty acid ethyl esters (FAEEs) in hair, are widely used for monitoring alcohol consumption for clinical and forensic purposes. Although stability of drugs and EtG in hair samples is documented to a certain extent, stability of FAEEs in hair samples after collection has not been reported. This study covered hair samples that had been tested for FAEEs on the day of arrival at the laboratory and retested between 4 and 80 months later. The statistical analysis of the data set reveals significant lower FAEEs levels including ethyl palmitate (EtPa) ester levels when samples were retested for the second time after 6 days of storage under ideal conditions. Specifically, the results suggest that when measuring total FAEEs or solely EtPa in hair samples, the elapsed time between sample collection and analysis of the sample needs to be considered when interpreting the results. The recommendation is that whenever hair samples need to be tested for total FAEEs or EtPa, the analytical procedure needs to be performed within 1 week after collection in order to obtain meaningful results. The study results substantiate the case for the use of hair samples solely for the analysis of EtG, in conjunction with other measurements such as full blood count, carbohydrate-deficient transferrin test, liver function test or phosphatidylethanol alongside clinical assessment for a more effective evaluation of alcohol consumption.

Download Full-text

Fatty Acid Ethyl Esters in Hair as Markers of Alcohol Consumption. Segmental Hair Analysis of Alcoholics, Social Drinkers, and Teetotalers

Clinical Chemistry ◽

10.1093/clinchem/47.12.2114 ◽

2001 ◽

Vol 47 (12) ◽

pp. 2114-2123 ◽

Cited By ~ 114

Author(s):

Volker Auwärter ◽

Frank Sporkert ◽

Sven Hartwig ◽

Fritz Pragst ◽

Hannelore Vater ◽

...

Keyword(s):

Fatty Acid ◽

Alcohol Consumption ◽

Ethyl Oleate ◽

Fatty Acid Ethyl Esters ◽

Ethyl Esters ◽

Excessive Alcohol Consumption ◽

Ethyl Stearate ◽

Social Drinkers ◽

Hair Samples ◽

Excessive Alcohol

Abstract Background: Fatty acid ethyl esters (FAEEs) are products of nonoxidative ethanol metabolism. After incorporation in hair, they should be suitable long-term markers of alcohol abuse. Methods: Hair samples from 19 alcoholics in a treatment program, 10 fatalities with verified excessive alcohol consumption, 13 moderate social drinkers who consumed up to 20 g ethanol/day, and 5 strict teetotalers were analyzed in 1–12 segments for four FAEEs (ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate) by external degreasing with n-heptane, extraction with a dimethyl sulfoxide-n-heptane mixture, headspace solid-phase microextraction of the extracts, and gas chromatography-mass spectrometry with deuterated internal standards. The n-heptane washings were analyzed in the same way for FAEEs from the hair surface. Results: The sum of the four ester concentrations in hair calculated for the proximal 0–6 cm segment was 2.5–13.5 ng/mg (mean, 6.8 ng/mg) for the fatalities, 0.92–11.6 ng/mg (mean, 4.0 ng/mg) for 17 of the alcoholics in treatment, 0.20–0.85 ng/mg (mean, 0.41 ng/mg) for the moderate social drinkers, and 0.06–0.37 ng/mg (mean, 0.16 ng/mg) for the teetotalers. In almost all cases the segmental concentrations increased from proximal to distal. There was no agreement between the self-reported drinking histories of the participants and the FAEE concentrations along the hair length. Ethyl oleate was the dominant ester in all samples. Conclusions: FAEEs are deposited in hair mainly from sebum. Despite large individual differences, FAEE hair concentrations can be used as markers for excessive alcohol consumption with relatively high accuracy.

Download Full-text

Development and validation of a method for the simultaneous analysis of fatty acid ethyl esters, ethyl sulfate and ethyl glucuronide in neonatal meconium: application in two cases of alcohol consumption during pregnancy

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-021-03248-0 ◽

2021 ◽

Vol 413 (11) ◽

pp. 3093-3105

Author(s):

Mateusz Kacper Woźniak ◽

Laura Banaszkiewicz ◽

Justyna Aszyk ◽

Marek Wiergowski ◽

Iwona Jańczewska ◽

...

Keyword(s):

Mass Spectrometry ◽

Fatty Acid ◽

Alcohol Consumption ◽

Solid Phase ◽

Fatty Acid Ethyl Esters ◽

Ethyl Esters ◽

Ethyl Glucuronide ◽

Published Data ◽

Ethyl Sulfate ◽

Analytical Approaches

AbstractAlcohol consumption during pregnancy constitutes one of the leading preventable causes of birth defects and neurodevelopmental disorders in the exposed children. Fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG) and ethyl sulfate (EtS) have been studied as potential biomarkers of alcohol consumption. However, most analytical approaches proposed for their analysis in meconium samples consist of separated extraction procedures requiring the use of two meconium aliquots, which is costly in terms of both time and materials. Therefore, the aim of this study was to develop and validate a method for the simultaneous extraction of 9 FAEEs, EtG and EtS from one meconium aliquot. The sample was homogenized using methanol, and then FAEEs were extracted with hexane while EtG and EtS were isolated using acetonitrile. Then, extracts were applied to solid-phase extraction columns and analysed by gas chromatography mass spectrometry (FAEEs) and liquid chromatography tandem mass spectrometry (EtG and EtS). Calibration curves were linear with r values greater than 0.99. The LODs ranged from 0.8 to 7.5 ng/g for FAEEs and were 0.2 ng/g and 0.8 ng/g for EtS and EtG, respectively. LOQs ranged from 5 to 25 ng/g for FAEEs and were 1 ng/g and 2.5 ng/g for EtS and EtG, respectively. Accuracies and precisions were between 93.8 and 107% and between 3.5 and 9.7%, respectively. The recovery values ranged from 89.1 to 109%. The method proved to be sensitive, specific, simple and fast and allowed for the reduction of the amount of organic solvent used for extraction compared to other published data while higher recoveries were obtained. The method was used for analysis of meconium samples in two cases of mothers who were consuming alcohol during pregnancy.

Download Full-text

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

Forensic Science International ◽

10.1016/s0379-0738(02)00412-7 ◽

2003 ◽

Vol 131 (2-3) ◽

pp. 90-97 ◽

Cited By ~ 71

Author(s):

Sven Hartwig ◽

Volker Auwärter ◽

Fritz Pragst

Keyword(s):

Fatty Acid ◽

Alcohol Consumption ◽

Fatty Acid Ethyl Esters ◽

Ethyl Esters ◽

Hair Care

Download Full-text

Fatty acid ethyl esters in meconium: A biomarker of fetal alcohol exposure and effect

Experimental Biology and Medicine ◽

10.1177/1535370220971562 ◽

2020 ◽

pp. 153537022097156

Author(s):

Charlie T Cheng ◽

Enrique M Ostrea Jr ◽

Joseph NB Alviedo ◽

Felix P Banadera ◽

Ronald L Thomas

Keyword(s):

Fatty Acid ◽

Alcohol Exposure ◽

The Body ◽

Fatty Acid Ethyl Esters ◽

Ethyl Esters ◽

Female Group ◽

Ethyl Stearate ◽

Ethyl Palmitate ◽

Treatment Groups ◽

Rat Pups

To determine if meconium fatty acid ethyl esters (FAEE) in rat pups is a good biomarker of prenatal exposure and effect to alcohol, three groups of pregnant rats were studied: one control (pair fed) and two treatment groups given 25% alcohol at 2.2 or 5.5 g−1 kg−1 d−1. The pups were delivered on day 20 and, for each dam, were separated into a male and female group. The body, brain, intestines, and placenta of the pups were obtained, weighed, and stored at −20°C. The pups’ intestines (as surrogate of meconium) from each group were pooled, and meconium was analyzed by gas chromatography/mass spectroscopy for FAEE. The meconium showed the following FAEE: ethyl palmitate, ethyl stearate, and ethyl linolenate and were only found in the alcohol-treated group and with high specificity but low sensitivity. Mean body weight of the pups was lower in the treatment groups compared to the control groups. Ethyl palmitate concentration correlated negatively to the pups’ mean body and brain weights. Therefore, ethyl palmitate, stearate, and linolenate, in meconium of rat pups prenatally exposed to alcohol, are useful biomarkers of prenatal alcohol exposure, with ethyl palmitate a good biomarker of adverse effect on the pups’ body and brain weight.

Download Full-text