Miniature mass spectrometer-based point-of-care assay for measuring phosphatidylethanol in blood

We demonstrate proof-of-concept for point-of-care assessment of long-term alcohol consumption by measuring phosphatidylethanol in blood/dried blood spots with nano-electrospray ionization and MS/MS using a miniature mass spectrometer. ‘Abstinence’, ‘moderate’, and ‘chronic’ consumption could be distinguished rapidly for both sample types, and quantitative performance was obtained with blood (LoQ-100 ng mL^-1).

We have demonstrated proof-of-principle evidence for an objective, convenient and reliable method to monitor alcohol consumption by measuring concentrations of 16:0–18:1 PEth in whole blood as well as DBS. Good quantitative performance was obtained with blood samples in the 100–800 ng mL^-1 range, and the analysis of DBS samples allows for distinction between ‘alcohol consumption’ and ‘chronic excessive alcohol consumption’ with spiked as well as patient samples in the 45–850 ng mL^-1 range. These results demonstrate the feasibility of on-site analysis for long-term alcohol monitoring with minimal sample pre-treatment using miniature MS systems. It has potential applications in abstinence monitoring, in the study of alcohol-drug interactions, and in POC monitoring of alcohol consumption in a doctor’s office, as opposed to relying on self-reports which may be incorrect. Furthermore, these on-site results should enable healthcare practitioners to stage interventions immediately after the blood sample is taken. As the importance of screening and behavioral counseling interventions is being increasingly recognized, results from such measurements would place physicians and primary care providers in an ideal position to stage such interventions and reduce the morbidity associated with risky alcohol use to prevent poor outcomes. In the long term, we project that making these results more accessible should empower patients as well as clinicians, and alleviate the problems of sample backlog, high costs and complex logistics associated with sample testing in traditional analytical laboratories.