Ester Del Bravo

University of Florence, Florens, Tuscany, Italy

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Publications (2)5.49 Total impact

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    ABSTRACT: Fatty acid ethyl esters (FAEEs) are minor ethanol metabolites that can accumulate in hair. The performance of hair FAEEs as a biomarker that can discriminate null or moderate drinking from risky, excessive drinking was verified by evaluating the relationship between self-reported daily alcohol intake and FAEE concentration in hair. The study subjects were 160 healthy volunteers (52% female) that included teetotallers, moderate/social drinkers (< 60 g of ethanol per day), and heavy drinkers (≥ 60 g/day).The estimated daily alcohol intake (EDAI) was assessed by a specific written questionnaire aimed at estimating the measure and the frequency of alcohol drinking and at excluding confounding factors. FAEEs (ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate) were extracted from the hair matrix by overnight incubation in n-hexane/dimethylsulphoxide, purified by solid-phase extraction (SPE) and analyzed by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring and Electron ionization (EI) mode, using pentadeuterated internal standards. Hair samples exhibited FAEE concentrations (expressed as the sum of the four esters, CFAEE ) ranging from 0.01 to 10.78 ng/mg (average 1.16 and median 0.60 ng/mg). The EDAI was from 0 to 246 g of ethanol per day, average 28 g/day and median 15 g/day. A cut-off of 0.5 ng/mg in 3 cm of a proximal hair segment was adopted to discriminate social drinking from excessive ethanol consumption. False positive samples were identified in subjects using ethanol-containing hair lotions and women on estroprogestin therapy. Specificity of 87% was reached when the identified false positives were excluded from data elaboration. CFAEE in hair at a predetermined cut-off can be used to discriminate between moderate and excessive drinking only when confounding factors are meticulously removed. Copyright © 2014 John Wiley & Sons, Ltd.
    Full-text · Article · Sep 2014 · Drug Testing and Analysis
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    ABSTRACT: A gas chromatography-mass spectrometry method for the determination of ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate in hair samples was developed, validated and applied to real samples. Ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate are fatty acid ethyl esters (FAEE) which are known to be direct biotransformation products of ethanol. Their presence in the body fluids and tissue is therefore indicative of alcohol intake and, in particular, FAEE concentration in hair higher than 0.5 ng/mg is indicative of excessive chronic alcohol consumption. The method was applied to 80 hair samples formerly found positive for cocaine and FAEE analytical results were compared with the presence of cocaethylene, a cocaine metabolite formed only when alcohol and cocaine are used together. According to our data the two biomarkers (FAEE and cocaethylene in hair) are tools of great value in the assessment of the diagnosis of use of cocaine and ethanol. In fact, discrepancies were noted and might be related to various factors including differences in consumption habits and thus permitting to distinguish the use of both substances non-concurrently or concurrently. Also, the determination of both markers may, in some cases, discriminate the use of moderate or heavy alcohol amounts when associated with cocaine. Finally, in a population of non-cocaine-users our results support FAEE as valuable means in the assessment of excessive alcohol chronic use.
    No preview · Article · Apr 2011 · Journal of pharmaceutical and biomedical analysis