The Prevalence of Opioids in US Drinking Water Sources Detected Using Direct-Injection High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Active pharmaceutical ingredient (API) contamination of water sources, including opioid contamination, has become more common in recent years. Although drinking water-treatment plants help mitigate API infiltration, API contamination remains in some drinking water sources. Therefore, the ability to detect APIs at ultratrace concentrations is vital to ensure safe drinking water. A method for the ultratrace determination of fentanyl, hydrocodone, and codeine in drinking water via direct injection and high-performance liquid-chromatography tandem mass spectrometry (HPLC-MS/MS) was developed and validated. Drinking water samples (10 ml) are simply syringe-filtered and then analyzed by HPLC-MS/MS. A wide linear range (0.25-100 ng/L) and ultratrace limits of detection (80, 150, and 500 pg/L for fentanyl, hydrocodone, and codeine, respectively) were features of the method. The method produced excellent aggregate accuracies of 90%-115% and precisions of <= 11% for the three analytes tested. This method was used to test drinking water samples from 53 US locations, with hydrocodone and codeine detected in approximately 40% of the samples tested at concentrations between 0.3 and 20 ng/L. Codeine was detected at higher concentrations than hydrocodone (up to 7.3 times) for each sample containing these APIs. Fentanyl was not detected in any field drinking water sample. The detection of opioids in a large fraction of the US drinking water samples tested is cause for concern, and these levels should continue to be monitored to ensure that they do not become a threat to human health. Environ Toxicol Chem 2022;00:1-9. (c) 2022 SETAC

Automated summary

Contamination of water sources with active pharmaceutical ingredients (APIs), including opioids, has become more common in recent years. This study developed and validated a method for the ultratrace determination of fentanyl, hydrocodone, and codeine in drinking water using high-performance liquid-chromatography tandem mass spectrometry (HPLC-MS/MS). The method was used to test drinking water samples from 53 locations in the US, with hydrocodone and codeine detected in approximately 40% of the samples tested. Codeine was detected at higher concentrations than hydrocodone, while fentanyl was not detected in any samples. These findings raise concern and highlight the importance of continued monitoring of these drugs in drinking water.