Analysis of Pharmaceuticals and Personal Care Products (PPCPs) in Drinking Water at Low Part Per Trillion Levels by Online SPE-UHPLC-MS/MS

Topics in Drinking Water
Poster Presentation

Prepared by J. Foss
PerkinElmer, 710 Bridgeport Ave, Shelton, Connecticut, 06484, United States


Contact Information: [email protected]; 203-447-9324


ABSTRACT

Pharmaceuticals and Personal Care Products (PPCPs) comprise a wide range of chemicals, including: prescription medications, over-the-counter medications, sunscreens, lotions, soaps, and insect repellant. They are an emerging environmental concern due to their physiological activity, potential adverse impacts to aquatic life, and unknown impact to human health associated with low-level, long-term exposure. PPCPs encompass a wide variety of chemical classes and are typically present at parts per trillion (pg/mL) concentrations in drinking water. Therefore, developing an optimal analytical method, one that provides effective chromatographic separation, as well as optimal analyte sensitivity, is challenging. This method utilizes online solid phase extraction (SPE) coupled to a UHPLC-MS/MS for the enrichment, separation, and quantitation of the EPA Method 542 panel of PPCPs.

Analytes of interest include: trimethoprim, enalapril, erythromycin, sulfamethoxazole, fluoxetine, phenytoin, carbamazepine, naproxen, diazepam, diclofenac, gemfibrozil, and triclosan. Drinking water samples were collected from several sources, including tap water and different brands of bottled water. Samples were filtered using 0.2Ám filters and formic acid was added to each sample to a final concentration of 0.1%. Samples were allowed to sit at room temperature for 1 hour prior to analysis. Analyte enrichment, separation, and quantitation was done using a PerkinElmer QSight SP50 Online SPE-UHPLC-MS/MS instrument. The integrated online SPE module performs the solid phase extraction of a 3-mL sample load of drinking water on a proprietary SPE cartridge prior to analysis by UHPLC-MS/MS.

Sample preconcentration was accomplished through loading 3 mL of filtered drinking water onto the SPE cartridge prior to elution. Exceptional linearity (r2>0.995) was achieved for all analytes across the calibration range of 0.5-500 ppt. The 3-mL stacked loading process resulted in greater than 65% efficiency with RSDs below 10% for each analyte. Analyte LOQs were below 2 ppt, with most analytes below 1 ppt. This resulted in a 7 to 200-fold improvement in sensitivity compared to a 50uL direct injection, depending on the analyte.