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;41:2658-2666. © 2022 SETAC.

Ultratrace analysis of per- and polyfluoroalkyl substances in drinking water using ice concentration linked with extractive stirrer and high performance liquid chromatography - tandem mass spectrometry.

Detection of drinking water contaminants is vital to the protection of human health. One group of contaminants that have recently generated serious concerns over health risks are per- and polyfluoroalkyl substances (PFAS). These compounds are very bio-persistent, leading to their detection in all types of water sources, including drinking water. While analysis of drinking water for PFAS is important, it is currently arduous to detect ultratrace levels of these contaminants. Specifically, current ultratrace PFAS analysis methods are difficult, costly, require large sample volumes, and consume relatively large volumes of organic solvent. In the present work, an analytical method using Ice Concentration Linked with Extractive Stirrer (ICECLES) and high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS/MS), was developed and validated to provide simple and ultratrace analysis of drinking water for 14 PFAS. The method featured a relatively low sample volume requirement (10 mL), automated extraction, minimal matrix effects, and minimal organic solvent use (i.e., the method requires only 50 µL of methanol per sample). The method produced a wide linear range of 0.5 to 500 ng/L, ultratrace limits of detection (0.05 to 0.3 ng/L), and good accuracy and precision (i.e., 87 to 108% accuracy and ≤19% relative standard deviation as a measure of precision). This method was tested on drinking water samples from across the United States and detected at least one PFAS compound in 52 of the 53 drinking water samples tested. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), and perfluoroheptanoic acid (PFHpA) were detected in 89, 96, and 77% of the samples tested with maximum concentrations of 268 ng/L for PFHxA, 213 ng/L for PFOA, and 75.7 ng/L for PFHpA. Additionally, perfluorononanoic acid, perfluorodecanoic acid, and perfluoroheptanoic acid were each detected in at least one drinking water sample at concentrations > 20 ng/L. The availability of the method presented here allows ultratrace detection of PFAS while circumventing many of the disadvantages of current methods.

Ultratrace analysis of atrazine in soil using Ice Concentration Linked with Extractive Stirrer and High Performance Liquid Chromatography-Tandem Mass Spectrometry.

Atrazine is a widely-used pesticide with a relatively long half-life in the environment. This leads to persistent soil contamination with the potential of migration to ground and surface waters. Analysis of atrazine in soil is difficult due to the inherent complexity of soil as a sample matrix. Moreover, the moderate hydrophobicity of atrazine makes it difficult to extract into typical sorbent phases during sample preparation. Therefore, a method for the ultratrace determination of atrazine in soil using Ice Concentration Linked with Extractive Stirrer (ICECLES) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed to address these issues. For the method, soil samples (10 g) were initially extracted with methanol:water (8:2, v:v), followed by solvent exchange to 100% water. The samples then underwent ICECLES with back-extraction into 100% methanol prior to HPLC-MS/MS analysis. The ICECLES-HPLC-MS/MS method produced a wide linear range of 10 to 1000 ng/kg, featured excellent limits of quantification and detection of 10 and 5 ng/kg, respectively, and good accuracy (100 ± 12%) and precision (≤9.6% relative standard deviation). This method was tested on field soil samples and provided ultratrace detection of atrazine. With this method, previously unachievable low parts per trillion (ppt) detection of atrazine in soil is now possible.

Comparison of the extraction efficiency of ice concentration linked with extractive stirrer, stir bar sorptive extraction, and solid-phase microextraction for pesticides from drinking water.

With the advent of highly selective analysis techniques (e.g., liquid chromatography-tandem mass spectrometry), and lower limits of detection requirements, extraction efficiency is arguably the most important property of modern sample preparation techniques. In this study, the extraction efficiency of Ice Concentration Linked with Extractive Stirrer (ICECLES) was compared to Stir Bar Sorptive Extraction (SBSE) and Solid-Phase Microextraction (SPME). A direct comparison of these sample preparation techniques was carried out with analysis via both Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS) and Thermal Desorption Gas Chromatography - Mass Spectrometry (TD-GC-MS). ICECLES produced 2x and 7x greater TD-GC-MS signals than SBSE and SPME, respectively. When comparing extraction techniques for a suite of 60 pesticides in drinking water, 32, 25, and 13 pesticides were detected via LC-MS/MS at 0.1 ng/mL by ICECLES, SBSE, and SPME, respectively. Overall, ICECLES consistently produced better extraction efficiencies than the other extraction techniques evaluated.