DETERMINATION OF PHOSPHATIDYLETANOL IN DRIED BLOOD SPOT BY UHPLC-MS/MS: EVALUATION OF ALCOHOL CONSUMPTION IN CHEMICAL DEPENDENTS

We developed and validated an UHPLC-MS/MS method for the quantification of phosphatidylethanol (PEth) in dried blood spots (DBS). Sample preparation was a liquid extraction and chromatographic separation was performed in an Acquity C8 column. The mobile phases were 4 mM ammonium acetate in water (A) and acetonitrile (B) at 24:76 (v/v). The total analytical run time was 6 minutes, with retention time of 3.36 min for PEth and 4.13 min for phosphatidylpropanol. The method was linear from 10 to 3000 ng mL-1, specific, with, precise and accurate. The analyte was stable in DBS stored from -20 to 45 °C for 21 days. Matrix effect was compensated with the internal standard (-5.21% to + 6.09%). The method was applied in the evaluation of alcohol consumption in DBS from 25 chemical dependents. The PEth concentrations ranged from 14.5 to 2380.8 ng mL-1, with significant correlation with the self-report alcohol consumption AUDIT scores (r=0.41).