Validation of a novel method to identify in utero ethanol exposure: simultaneous meconium extraction of fatty acid ethyl esters, ethyl glucuronide, and ethyl sulfate followed by LC-MS/MS quantification

Discrimination between the Triglyceride Form and the Ethyl Ester Form of Fish Oil Using Chromatography-Mass Spectrometry

Although the triglyceride form is the natural form of fish oil found in fish, the ethyl ester form of fish oil, which is used during processing to save costs, is also present on the market. In this study, fatty acids and lipids were determined using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-linear ion trap mass spectrometry (LC-LIT/MS), respectively, according to developed methods. The identification of fatty acids was based on the mass spectral characteristics and equivalent chain lengths. However, the fatty acid contents of both forms of fish oils are quite similar. The application of the LC-LIT/MS method for the structural characterization of triacylglycerols (TAGs) and the mechanism of LIT/MS fragmentation are also discussed. Neutral losses of CH2=CH2 (m/z 28) and CH3CH2OH (m/z 46), which are LIT/MS characteristics of ethyl ester from fish oil, were found for the first time. The triglyceride form of fish oils was easily and accurately identified using fingerprint chromatography. In conclusion, lipid analysis combined with LC-LIT/MS showed an improved capability to distinguish between types of fish oil.

High-resolution imaging in studies of alcohol effect on prenatal development

Fetal alcohol syndrome represents the leading known preventable cause of mental retardation. FAS is on the most severe side of fetal alcohol spectrum disorders that stem from the deleterious effects of prenatal alcohol exposure. Affecting as many as 1 to 5 out of 100 children, FASD most often results in brain abnormalities that extend to structure, function, and cerebral hemodynamics. The present review provides an analysis of high-resolution imaging techniques that are used in animals and human subjects to characterize PAE-driven changes in the developing brain. Variants of magnetic resonance imaging such as magnetic resonance microscopy, magnetic resonance spectroscopy, diffusion tensor imaging, along with positron emission tomography, single-photon emission computed tomography, and photoacoustic imaging, are modalities that are used to study the influence of PAE on brain structure and function. This review briefly describes the aforementioned imaging modalities, the main findings that were obtained using each modality, and touches upon the advantages/disadvantages of each imaging approach.

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

Alcohol 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.

High concentrations of urinary ethanol metabolites in neonatal intensive care unit infants

BACKGROUND

Infants in the neonatal intensive care unit may be exposed to ethanol via medications that contain ethanol as an excipient and through inhalation of ethanol vapor from hand sanitizers. We hypothesized that both pathways of exposure would result in elevated urinary biomarkers of ethanol.

METHODS

Urine samples were collected from infants in incubators and in open cribs. Two ethanol metabolites, ethyl sulfate (EtS) and ethyl glucuronide (EtG), were quantified in infants' urine.

RESULTS

A subset of infants both in incubators and open cribs had ethanol biomarkers greater than the cutoff concentration that identifies adult alcohol consumption. These concentrations were associated with the infant having received an ethanol-containing medication on the day of urine collection. When infants who received an ethanol-containing medication were excluded from analysis, there was no difference in ethanol biomarker concentrations between the incubator and crib groups.

CONCLUSIONS

Some infants who received ethanol-containing medications had concentrations of ethanol biomarkers that are indicative of adult alcohol consumption, suggesting potential exposure via ethanol excipients.

IMPACT

Infants and newborns in the neonatal intensive care unit are exposed to concerning amounts of ethanol. No one has shown exposure to ethanol in these infants before this study. The impact is that better understanding of the excipients in medications given to patients in the NICU is needed. When physicians order medications in the NICU, the amount of excipient needs to be indicated.

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

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.

Quantifying fetal alcohol exposure by meconium fatty acid ethyl esters (FAEE); association with adverse fetal outcomes and population estimates of fetal alcohol exposure

Fetal Alcohol Spectrum Disorder (FASD) describes the wide range of adverse physical, behavioral and cognitive effects resulting from ethanol exposure during embryonic and fetal development. Identification of children suffering from FASD is often difficult, as abuse of ethanol during pregnancy is a heavily stigmatized behavior that receives little prenatal screening attention in routine care. Over the last 3 decades, measurement of the ethanol metabolites fatty acid ethyl esters (FAEE) has emerged as a useful tool to detect in the neonatal period fetal alcohol exposure starting from mid gestation. This review aims at updating clinicians and researchers on the validity and utility of this biological marker in two aspects: The association with adverse fetal outcomes and in generating population estimates of fetal alcohol exposure.

Sensitive and reliable gas chromatography tandem mass spectrometry assay for ethyl glucuronide in neonatal meconium

Prenatal exposure to maternal ethanol leads to serious physical and mental irreversible disabilities. Ethyl glucuronide (EtG) is a direct metabolite of alcohol and its measurement in neonatal meconium has been established as the best biomarker to assess prenatal exposure to social and excessive gestational ethanol. We developed and validated the first gas chromatography tandem mass spectrometry method to quantify EtG extracted from meconium by a simple solid phase extraction pretreatment. The method was linear from limit of quantification (2 ng/g) to 200 ng/g matrix with good determination coefficient (r² = 0.99). Recovery of EtG from meconium was always higher than 70% and intra-assay and inter-assay precision and accuracy were always better than 10%. Robustness of the developed GC-MS/MS method was tested by analysing 150 real samples coming from a previous national epidemiological project pre-screened through an ultra-chromatography tandem mass spectrometry assay obtaining a good comparability of results obtained by the two methods.

Prenatal alcohol exposure prevalence as measured by direct ethanol metabolites in meconium in a Native American tribe of the southwest

BACKGROUND

Although fetal alcohol spectrum disorders represent a significant public health problem, Native Americans are underrepresented in population and targeted screening programs. Prior reports suggest that Native American tribal communities may have a higher prevalence of alcohol use during pregnancy; however, systematic examination using ethanol biomarkers is lacking.

METHODS

This study utilized data collected through the Navajo Birth Cohort Study (NBCS)-a birth cohort study of a Southwestern tribal community. Prevalence of prenatal alcohol exposure (PAE) was assessed by a battery of meconium biomarkers among 333 NBCS participants. Meconium samples were analyzed for nine individual fatty acid ethyl ester (FAEE) species, ethyl glucuronide (EtG), and ethyl sulfate (EtS) by LC-MS/MS.

RESULTS

Participants were recruited from five hospitals at the Navajo Nation located in Arizona (Chinle, Tséhootsooí, Tuba City) and New Mexico (Gallup, Shiprock). All participants identified as Native American; most reported a personal income of <$20,000 per year (71.3%), and ≤high school education (55.3%). The most prevalent biomarker was EtS (7.8%) followed by ethyl oleate (6.9%); 5.4% of the sample were positive for at least two biomarkers.

CONCLUSIONS

Results of this study on the prevalence of PAE in the Navajo Nation, obtained for the first time with an objective comprehensive panel of meconium biomarkers, indicate that the rates in the NBCS may be comparable to the general U.S. population and are in accord with recent U.S. national survey estimates. Our findings emphasize that drinking behaviors among Native American communities in the United States can vary, and generalization across all Native American populations is not warranted.

Drug exposure during pregnancy: analytical methods and toxicological findings

Drug use during pregnancy constitutes a major preventable worldwide public health issue. Birth defects, growth retardation and neurodevelopmental disorders are associated with tobacco, alcohol or drugs of abuse exposure during pregnancy. Besides these adverse health effects, drug use during pregnancy also raises legal and social concerns. Identification and quantification of drug markers in maternal and newborn biological samples offers objective evidence of exposure and complements maternal questionnaires. We reviewed the most recent analytical methods for quantifying drugs of abuse, tobacco, alcohol and psychotropic drugs in maternal, newborn and maternal-fetal unit biological samples by gas and liquid chromatography coupled to mass spectrometry. In addition, manuscripts comparing the usefulness of different biological samples to detect drug exposure during pregnancy were reviewed.

Simultaneous determination of ethanol's four types of non-oxidative metabolites in human whole blood by liquid chromatography tandem mass spectrometry

The importance of ethanol non-oxidative metabolites as the specific biomarkers of alcohol consumption in clinical and forensic settings is increasingly acknowledged. Simultaneous determination of these metabolites can provide a wealth of information like drinking habit and history, but it was difficult to achieve because of their wide range of polarity. This work describes development and validation of a simple liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for 4 types of ethanol non-oxidative metabolites (ethyl glucuronide, ethyl sulfate, fatty acid ethyl esters and phosphatidylethanols) in 50 μL of human whole blood. Pretreatment method, column and MS conditions were optimized. For the first time, the four types of ethanol non-oxidative metabolites with enormous discrepancies of property were simultaneously extracted and analyzed in one run within 40 min. The limits of detections (LODs) were among 0.1-10 ng/mL, and good linearity was obtained. Deviations in precision and accuracy were all lower than 15% at three QC levels. This method was then applied to two forensic samples, resulting in information on drinking habits and drinking time which were very useful for the interpretation of the blood alcohol results.

Biomarkers for the Detection of Prenatal Alcohol Exposure: A Review

Alcohol exposure during pregnancy can cause adverse effects to the fetus, because it interferes with fetal development, leading to later physical and mental impairment. The most common clinical tool to determine fetal alcohol exposure is maternal self-reporting. However, a more objective and useful method is based on the use of biomarkers in biological specimens alone or in combination with maternal self-reporting. This review reports on clinically relevant biomarkers for detection of prenatal alcohol exposure (PAE). A systematic search was performed to ensure a proper overview in existing literature. Studies were selected to give an overview on clinically relevant neonatal and maternal biomarkers. The direct biomarkers fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG), ethyl sulfate, and phosphatidylethanol (PEth) were found to be the most appropriate biomarkers in relation to detection of PAE. To review each biomarker in a clinical context, we have compared the advantages and disadvantages of each biomarker, in relation to its window of detectability, ease of collection, and the ease and cost of analysis of each biomarker. The biomarkers PEth, FAEEs, and EtG were found to be applicable for detection of even low levels of alcohol exposure. Meconium is an accessible matrix for determination of FAEEs and EtG, and blood an accessible matrix for determination of PEth.

Influence of P-glycoprotein on the disposition of fexofenadine and its enantiomers

OBJECTIVES

P-glycoprotein (P-gp) is responsible for the efflux of a broad variety of human and veterinary drugs. Canine P-gp polymorphisms alter drug disposition and toxicity, but their impact on the disposition of enantiomeric drugs is unknown. Using fexofenadine as a model compound, we developed and validated HPLC-fluorescence methods to determine the effect of P-gp on the disposition of fexofenadine and its enantiomers.

METHODS

A chiral CD-Ph column was used for the separation of (R) and (S)-fexofenadine. Determination of racemic fexofenadine was achieved on an XDB-CN column. Fexofenadine and its enantiomers were detected by fluorescence at the excitation wavelength of 220 nm and emission wavelength of 300 nm. These methods were used to measure concentrations of fexofenadine and its enantiomers in Collie plasma after oral administration.

KEY FINDINGS

This study demonstrates that P-gp prefers to transport (S)-fexofenadine, and P-gp deficiency causes the increase in both (R)-fexofenadine and (S)-fexofenadine in plasma. Racemic fexofenadine, (R)-fexofenadine and (S)-fexofenadine were increased in ABCB1-1Δ Collies (118.7, 72.0 and 48.3 ng/ml) compared to wild-type Collies (25.0, 16.5 and 7.7 ng/ml) at 1 h postadministration. The results demonstrate that the stereoselectivity of P-gp plays a key role in the disposition of fexofenadine enantiomers.

CONCLUSIONS

The information derived from this drug model will be used to determine whether additional safety or efficacy requirements are necessary for enantiomeric drugs that would be used in dogs or humans.

Alcohol Consumption during Pregnancy: Analysis of Two Direct Metabolites of Ethanol in Meconium

Alcohol consumption in young women is a widespread habit that may continue during pregnancy and induce alterations in the fetus. We aimed to characterize prevalence of alcohol consumption in parturient women and to assess fetal ethanol exposure in their newborns by analyzing two direct metabolites of ethanol in meconium. This is a cross-sectional study performed in September 2011 and March 2012 in a series of women admitted to an obstetric unit following childbirth. During admission, socio-demographic and substance use (alcohol, tobacco, cannabis, cocaine, and opiates) during pregnancy were assessed using a structured questionnaire and clinical charts. We also recorded the characteristics of pregnancy, childbirth, and neonates. The meconium analysis was performed by liquid chromatography—tandem mass spectrometry (LC-MS/MS) to detect the presence of ethyl glucuronide (EtG) and ethyl sulfate (EtS). Fifty-one parturient and 52 neonates were included and 48 meconium samples were suitable for EtG and EtS detection. The median age of women was 30 years (interquartile range (IQR): 26–34 years); EtG was present in all meconium samples and median concentration of EtG was 67.9 ng/g (IQR: 36.0–110.6 ng/g). With respect to EtS, it was undetectable (<0.01 ng/g) in the majority of samples (79.1%). Only three (6%) women reported alcohol consumption during pregnancy in face-to-face interviews. However, prevalence of fetal exposure to alcohol through the detection of EtG and EtS was 4.2% and 16.7%, respectively. Prevention of alcohol consumption during pregnancy and the detection of substance use with markers of fetal exposure are essential components of maternal and child health.

Determination of fatty acid ethyl esters in dried blood spots by LC-MS/MS as markers for ethanol intake: application in a drinking study

The forensic utility of fatty acid ethyl esters (FAEEs) in dried blood spots (DBS) as short-term confirmatory markers for ethanol intake was examined. An LC-MS/MS method for the determination of FAEEs in DBS was developed and validated to investigate FAEE formation and elimination in a drinking study, whereby eight subjects ingested 0.66-0.84 g/kg alcohol to reach blood alcohol concentrations (BAC) of 0.8 g/kg. Blood was taken every 1.5-2 h, BAC was determined, and dried blood spots were prepared, with 50 μL of blood, for the determination of FAEEs. Lower limits of quantitation (LLOQ) were between 15 and 37 ng/mL for the four major FAEEs. Validation data are presented in detail. In the drinking study, ethyl palmitate and ethyl oleate proved to be the two most suitable markers for FAEE determination. Maximum FAEE concentrations were reached in samples taken 2 or 4 h after the start of drinking. The following mean peak concentrations (c̅(max)) were reached: ethyl myristate 14 ± 4 ng/mL, ethyl palmitate 144 ± 35 ng/mL, ethyl oleate 125 ± 55 ng/mL, ethyl stearate 71 ± 21 ng/mL, total FAEEs 344 ± 91 ng/mL. Detectability of FAEEs was found to be on the same time scale as BAC. In liquid blood samples containing ethanol, FAEE concentrations increase post-sampling. This study shows that the use of DBS fixation prevents additional FAEE formation in blood samples containing ethanol. Positive FAEE results obtained by DBS analysis can be used as evidence for the presence of ethanol in the original blood sample.

A novel, simultaneous extraction of FAEE and EtG from meconium and analysis by LC-MS/MS

Fatty acid ethyl esters (FAEEs) and ethyl-glucuronide (EtG) in meconium have been widely studied as biomarkers of maternal alcohol consumption during pregnancy. Many analytical approaches have been proposed for their analysis, mostly consisting of separated extraction procedures requiring the use of two meconium aliquots. This study aimed to validate a new analytical procedure for the simultaneous extraction of FAEEs and EtG from a meconium aliquot through a single solid-phase extraction (SPE) applied to 242 anonymized samples of meconium. Targeted FAEEs were: ethyl-myristate (Myr), ethyl-palmitate (Pal), ethyl-oleate (Ole) and ethyl-stearate (Ste). Two hundred milligrams of meconium was sonicated with acetonitrile, and a single SPE performed by means of aminopropyl columns. FAEEs were eluted with hexane, followed by EtG elution with water. Both the mixtures were dried, recovered, and analyzed by liquid chromatography-tandem mass spectrometry using C8 (FAEEs) and C18 (EtG) columns. Transitions were: m/z 257 → 57,88, Myr; m/z 262 → 57,88, Myr-d5; m/z 285 → 57, 72, Pal; m/z 290 → 57,258, Pal-d5; m/z 311 → 72,114, Ole; m/z 316 → 72,265, Ole-d5; m/z 257 → 57,72 Ste; m/z 318 → 57,286, Ste-d5; m/z 221 → 75,85, EtG; m/z 226 → 75,85, EtG-d5. Lower limit of quantification range was 10-15 ng/g for FAEEs and 10 ng/g for EtG. Linearity was evaluated for different concentration ranges; the mean coefficients of determination (R (2)) were above 0.9961. Precision and accuracy for FAEEs and EtG were consistently ≤20 % and ±20 %, respectively. Ion suppression was observed for all the analytes. Matrix effect did not significantly affect the analyses. Recovery efficiency was 93 % for EtG and 75-85 % for FAEEs.

Bioanalytical procedures and developments in the determination of alcohol biomarkers in biological specimens

Excessive alcohol consumption is a global problem, and consequently its evaluation is of great clinical and forensic interest. Alcohol biomarkers have been the focus of several research works in the past decades, with new compounds being studied in more recent years. The main objective of this review is to discuss topics for an analyst to consider when evaluating alcohol consumption through the analysis of alcohol biomarkers in biological specimens. For this, existing alcohol biomarkers will be reviewed, including carbohydrate-deficient transferrin, 5-hydroxytryptophol, ethanol, hemoglobin-associated acetaldehyde, fatty acid ethyl esters, ethyl glucuronide, ethyl sulfate and phosphatidylethanol. Additionally, their potential will be discussed, as well as analytical considerations, main challenges, limitations, data interpretation and existing methodologies for their determination in biological specimens.

Bioanalysis during pregnancy: recent advances and novel sampling strategies

Consumption of drugs of abuse, tobacco and alcohol throughout pregnancy is a serious public health problem and results in an important economic cost to the health system. Drug and/or metabolites determination in biological matrices from mother and newborn is an objective measure of in utero drug exposure. We reviewed methods published for the determination of in utero drug exposure from 2007 to 2014, with special focus on meconium, placenta, umbilical cord and newborn hair. Accurate bioanalytical procedures are essential to obtain high-quality data to perform interventions and to establish correlations between analytical measures and clinical outcomes. We included a brief overview of clinical implications of in utero drug exposure to better understand the importance of this serious health issue.

Antiretroviral Drugs in Meconium: Detection for Different Gestational Periods of Exposure

OBJECTIVES

To determine whether antiretroviral (ARV) medications can be detected in meconium from second or third trimester, labor and delivery (L&D), or postnatal exposures.

STUDY DESIGN

Twenty ARV medications were quantified by liquid chromatography-tandem mass spectrometry in 598 meconium samples from uninfected infants born to pregnant women with HIV enrolled in the Pediatric HIV/AIDS Cohort Study.

RESULTS

ARV detection in meconium following third trimester exposure was 85.7%-94.4% for all ARVs except stavudine (0%, n = 2), likely because of low doses and a high limit for quantification. Of 107 samples with some second trimester only ARV exposures, meconium was positive for only lopinavir, tenofovir, or efavirenz in 11.8%-14.3% of exposed neonates; administration of these ARVs occurred between gestational weeks 25-28 in the positive samples. Days without lopinavir or tenofovir before delivery significantly correlated with decreasing concentrations of lopinavir and tenofovir in meconium. Tenofovir and lamivudine concentrations significantly correlated with increasing gestational age among infants with continuous second and third trimester exposure. Zidovudine given during L&D or for neonatal prophylaxis was detected in 95.1% and 94.6% of meconium samples, respectively.

CONCLUSIONS

Changes in ARV treatments during pregnancy offered a unique opportunity to investigate ARV detection in meconium. ARVs in meconium primarily reflect third trimester ARV exposures, although 6 of 107 second trimester only exposures were detected. Zidovudine administration during L&D was detected in meconium indicating potential urine contamination or rapid incorporation into meconium. These data will improve interpretation of meconium drug test results.

Clinical sensitivity and specificity of meconium fatty acid ethyl ester, ethyl glucuronide, and ethyl sulfate for detecting maternal drinking during pregnancy

BACKGROUND

We investigated agreement between self-reported prenatal alcohol exposure (PAE) and objective meconium alcohol markers to determine the optimal meconium marker and threshold for identifying PAE.

METHODS

Meconium fatty acid ethyl esters (FAEE), ethyl glucuronide (EtG), and ethyl sulfate (EtS) were quantified by LC-MS/MS in 0.1 g meconium from infants of Safe Passage Study participants. Detailed PAE information was collected from women with a validated timeline follow-back interview. Because meconium formation begins during weeks 12-20, maternal self-reported drinking at or beyond 19 weeks was our exposure variable.

RESULTS

Of 107 women, 33 reported no alcohol consumption in pregnancy, 16 stopped drinking by week 19, and 58 drank beyond 19 weeks (including 45 third-trimester drinkers). There was moderate to substantial agreement between self-reported PAE at ≥19 weeks and meconium EtG ≥30 ng/g (κ = 0.57, 95% CI 0.41-0.73). This biomarker and associated cutoff was superior to a 7 FAEE sum ≥2 nmol/g and all other individual and combination marker cutoffs. With meconium EtG ≥30 ng/g as the gold standard condition and maternal self-report at ≥19 weeks' gestation as the test condition, 82% clinical sensitivity (95% CI 71.6-92.0) and 75% specificity (95% CI 63.2-86.8) were observed. A significant dose-concentration relationship between self-reported drinks per drinking day and meconium EtG ≥30 ng/g also was observed (all P < 0.01).

CONCLUSIONS

Maternal alcohol consumption at ≥19 weeks was better represented by meconium EtG ≥30 ng/g than currently used FAEE cutoffs.

Electromigrative separation techniques in forensic science: combining selectivity, sensitivity, and robustness

In this review we introduce the advantages and limitations of electromigrative separation techniques in forensic toxicology. We thus present a summary of illustrative studies and our own experience in the field together with established methods from the German Federal Criminal Police Office rather than a complete survey. We focus on the analytical aspects of analytes' physicochemical characteristics (e.g. polarity, stereoisomers) and analytical challenges including matrix tolerance, separation from compounds present in large excess, sample volumes, and orthogonality. For these aspects we want to reveal the specific advantages over more traditional methods. Both detailed studies and profiling and screening studies are taken into account. Care was taken to nearly exclusively document well-validated methods outstanding for the analytical challenge discussed. Special attention was paid to aspects exclusive to electromigrative separation techniques, including the use of the mobility axis, the potential for on-site instrumentation, and the capillary format for immunoassays. The review concludes with an introductory guide to method development for different separation modes, presenting typical buffer systems as starting points for different analyte classes. The objective of this review is to provide an orientation for users in separation science considering using capillary electrophoresis in their laboratory in the future.

Ethyl glucuronide and ethyl sulfate

Alcohol misuse is associated with significant morbidity and mortality. Although clinical history, examination, and the use of self-report questionnaires may identify subjects with harmful patterns of alcohol use, denial or under-reporting of alcohol intake is common. Existing biomarkers for detecting alcohol misuse include measurement of blood or urine ethanol for acute alcohol consumption, and carbohydrate-deficient transferrin and gamma-glutamyl transferase for chronic alcohol misuse. There is a need for a biomarker that can detect excessive alcohol consumption in the timeframe between 1 day and several weeks. Ethyl glucuronide (EtG) is a direct metabolite of ethanol detectable in urine for up to 90 h and longer in hair. Because EtG has high specificity for excess alcohol intake, it has great potential for use in detecting "binge" drinking. Using urine or hair, this noninvasive marker has a role in a variety of clinical and forensic settings.