Stability of phosphatidylethanol 16:0/18:1 in authentic and spiked whole blood

Phosphatidylethanol 16:0/18:1 (PEth) is the most abundant homologue of the phosphatidylethanol group of phospholipids. Formed only in the presence of ethanol, PEth is used as a biomarker in whole blood to provide information about the consumption of alcohol. As information on the storage life of PEth is essential for its beneficial use as a biomarker, this study investigated the stability of PEth in spiked and authentic whole blood samples stored at 4°C. Human whole blood samples (n = 23) and spiked whole blood samples (n = 7) with a concentration range between 5 and 2000 ng/ml were analysed at specific time intervals, up to 90 days. Differences were evident between the stability of authentic and spiked samples. PEth was stable at 4°C for 60 days (concentrations within 15% of initial concentration) in authentic samples, whereas spiked samples were stable for up to 30 days. This study emphasizes the importance of including authentic samples in stability experiments. Phosphatidylethanol 16:0/18:1 (PEth) stability at 4°C was investigated in both spiked and authentic whole blood samples. Human whole blood samples (n = 23) and spiked whole blood samples (n = 7) with a concentration range between 5 and 2000 ng/ml were analysed at specific time intervals, up to 90 days. Differences were evident between the stability of authentic and spiked samples, and PEth was stable for up to 30 days in spiked samples and for up to 60 days in authentic samples.