Determination of direct alcohol markers: a review

Abstract

Alcohol is the most popular legal drug used in our society today, and its consumption by pregnant women remains an important public health problem. Gestational alcohol consumption can result in a continuum of adverse fetal outcomes known as fetal alcohol spectrum disorder (FASD). Effective strategies are needed to prevent the increasing adoption of risky drinking behaviors. Because ethanol itself is only measurable for a few hours after ethanol intake in conventional matrices including blood, urine, and sweat, these matrices are only useful to detect recent ethanol exposure. Since approximately early 2000, the non-oxidative ethanol metabolites have received increasing attention because of their specificity and, in some cases, wide time window of detection in non-conventional matrices including hair and meconium. In the attempt to update analytical methods for the determination of non-oxidative markers of alcohol, the objective of this study is to review published studies that measure fatty-acid ethyl esters (FAEE), ethyl glucuronide (EtG), and phosphatidylethanol (PEth) in alternative biological matrices, focusing on the extraction and detection methods and full analytical conditions used.

Quantification of phosphatidylethanol 16:0/18:1, 18:1/18:1, and 16:0/16:0 in venous blood and venous and capillary dried blood spots from patients in alcohol withdrawal and control volunteers

“…They are biomarkers of alcohol consumption [2] present in blood, mainly located in erythrocytes [3], and in different organs [4]. Up to forty-eight different PEths have been detected in blood collected in autopsy cases of heavy drinkers [5].…”

Direct biomarkers to determine alcohol consumption during pregnancy, which one to use?

“…Meconium formation begins at approximately 12 weeks of gestation (i.e. at the end of the first trimester), when fetal swallowing of amniotic fluid is initiated [2]. FAEE can be quantified in meconium by means of gas chromatography coupled with either flame ionization or mass spectrometry (GC-MS).…”

“…In addition, they are stable at neutral pH. FAEE do not cross the placenta into the fetal circulation, and because they can be detected in fetal matrices, must be produced in the fetus itself from the ethanol which crosses the placenta [2]. FAEE can be measured in blood for 24-44 hours, so it is still, such as ethanol in blood and breathing air, only a snapshot of the alcohol exposition to a child.…”

“…Several methods are described in literature to detect EtG, ranging from an immunoassay to LC-MS/MS [9,10,11]. Extraction techniques have not varied much over the years, ranging from ultrasonification, SPE, microwave-assisted extraction (MAE) and HS -SPME [2]. When combining FAEE and EtG analysis in meconium, both biomarkers are very specific and together can be used for confirmation.…”

“…Direct biomarkers are chemically derived from ethanol and are way more reliable to detect alcohol consumption during pregnancy. Three biomarkers can be used to detect alcohol in pregnant women: Fatty Acid Ethyl Esters (FAEE), ethyl glucuronide (EtG) / ethyl sulfate (EtS) and phosphatidylethanol (PEth) [2]. …”