Luginbühl Marc, Schröck Alexandra, König Stefan, Schürch Stefan, Weinmann Wolfgang
Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, 3012, Bern, Switzerland.
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland.
Anal Bioanal Chem. 2016 May;408(13):3503-9. doi: 10.1007/s00216-016-9426-y. Epub 2016 Mar 11.
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.
研究了脂肪酸乙酯（FAEEs）在干血斑（DBS）中作为乙醇摄入短期确证标志物的法医学效用。开发并验证了一种用于测定DBS中FAEEs的液相色谱-串联质谱（LC-MS/MS）方法，以研究饮酒研究中FAEEs的形成和消除情况，在该研究中，8名受试者摄入0.66 - 0.84 g/kg酒精，使血液酒精浓度（BAC）达到0.8 g/kg。每1.5 - 2小时采集一次血液，测定BAC，并制备含50 μL血液的干血斑用于测定FAEEs。四种主要FAEEs的定量下限（LLOQ）在15至37 ng/mL之间。详细列出了验证数据。在饮酒研究中，棕榈酸乙酯和油酸乙酯被证明是用于测定FAEEs的两种最合适的标志物。饮酒开始后2或4小时采集的样本中FAEEs浓度达到最高。达到的以下平均峰值浓度（c̅(max)）为：肉豆蔻酸乙酯14 ± 4 ng/mL，棕榈酸乙酯144 ± 35 ng/mL，油酸乙酯125 ± 55 ng/mL，硬脂酸乙酯71 ± 21 ng/mL，总FAEEs 344 ± 91 ng/mL。发现FAEEs的可检测时间尺度与BAC相同。在含有乙醇的液态血液样本中，采样后FAEEs浓度会增加。本研究表明，使用DBS固定可防止含乙醇血液样本中额外的FAEEs形成。通过DBS分析获得的FAEEs阳性结果可作为原始血液样本中存在乙醇的证据。
