In-Sample Stability of 52 Performance- and Image-Enhancing Drug Biomarkers in Wastewater

Abstract

Wastewater analysis shows promise in tracking community use of performance- and image-enhancing drugs, yet their post-sampling stability remains unknown. To understand and minimize post-sampling analyte degradation, knowledge of stability and optimal preservation methods is essential. A selection of 52 performance-enhancing substance biomarkers relevant to sports doping and image enhancement were subjected to a series of stability experiments in wastewater, testing several conditions including two pretreatments, filtered and unfiltered, and three sample preservation methods, unpreserved, sodium metabisulfite addition, and hydrochloric acid addition to pH 2, and were assessed at three temperatures, 22, 4, and −20 °C, for up to 200 days. Results indicated that the optimum preservation techniques were filtration, with or without preservatives, and acidification to pH 2 without filtration, with the times to 50% transformation indicating that the majority had medium (40–160%) to high (80–120%) stability at 4 °C for up to 92 days and at −20 °C for up to 200 days. A typical sample collection and archiving scenario was assumed and evaluated for each biomarker using an interactive calculator made available online from this study. This study provides, for the first time, post-sampling/archiving stability assessments for 52 biomarkers of performance- and image-enhancing drugs in wastewater for six pretreatment methods.