Storage stability of phosphatidylethanol homologues in whole blood and dried blood spots of nonalcoholics at different temperatures over 60  days

This study gained further information on the long-term stability of five PEth homologues (16:0/18:1, 16:0/18:2, 16:0/20:4, 18:0/18:1, 18:0/18:2) in whole blood (WB) and dried blood spots (DBS) stored at −80°C, 4°C, and room temperature (18°C) over a period of 60 days. All homologues, except PEth 16:0/20:4, were stable at −80°C in DBS and WB for 60 days. The initial PEth 16:0/18:1 concentrations remained stable in both DBS and WB in all but one volunteers' specimen at 4 and 18°C. AbstractPhosphatidylethanol (PEth) has recently become a popular direct alcohol marker for evaluating drinking behavior. This study aimed at gaining further information on the long-term stability of five PEth homologues (16:0/18:1, 16:0/18:2, 16:0/20:4, 18:0/18:1, 18:0/18:2) in whole blood (WB) and dried blood spots (DBS) stored at −80°C, 4°C, and room temperature (18°C) over a period of 60 days. Venous blood was taken from 10 volunteers (five females and five males, aged 21–40 years) with a moderate drinking behavior and a negative breath alcohol test at the time of collection. 100 μL aliquots of WB were prepared in addition to 20 μL DBS samples. The initial PEth concentrations were determined on the day of the blood collection. On days 1, 3, 5, 7, 11, 17, 40, and 60, DBS were analyzed in triplicate by means of LC–MS/MS. On these days, WB aliquots having been stored until that time were used to create fur ther DBS in triplicate, which were subsequently stored at 18°C and ...
Source: Drug Testing and Analysis - Category: Drugs & Pharmacology Authors: Tags: RESEARCH ARTICLE Source Type: research