Stability of pharmaceuticals and other polar organic compounds stored on polar organic chemical integrative samplers and solid‐phase extraction cartridges

Abstract

Abstract-The stability of 24 chemicals, including pharmaceuticals and personal care products, and some agrochemicals on extraction media was evaluated by preloading them onto Oasis hydrophilic lipophilic balanced solid-phase extraction (SPE) cartridges and polar organic chemical integrative samplers (POCIS) followed by storage at -208C over time. After 20 months, the average loss was 11% on POCIS, with only 2,4-dichlorophenoxyacetic acid, atrazine, chlorpyrifos, and gemfibrozil showing a statistically significant decline compared with initial concentrations. Losses on SPE cartridges were below 19%, with an average loss of 9%. In addition to laboratory spiked samples, multiple POCIS deployed in wastewater-impacted surface waters and SPE extracts of these waters were stored in their original coextracted matrix for nearly two years with minimal observed losses. Errors from typical sampling, handling, and concentration estimates from POCIS sampling rates were typically AE 15 to 30% relative standard deviation, so observed storage losses are minimal for most POCIS applications. While losses during storage on SPE cartridges for 20 months were small but statistically significant for many compounds, addition of labeled internal standards prior to freezing should correct for such losses. Thus, storage of processed water samples for analysis of polar organic pollutants is viable for archival purposes or studies for which samples cannot be analyzed in the short term. Environ. Toxicol. Chem. 2013;32:337-344. # 2012 SETAC

Performance of a constructed wetland in Grand Marais, Manitoba, Canada: Removal of nutrients, pharmaceuticals, and antibiotic resistance genes from municipal wastewater

“…Following collection, samples were stored at 4°C for up to 24 h for ARG samples and for 24-48 h prior to analysis of nutrients or extraction by solid phase extraction (SPE) prior to further analytical analysis for PPCPs. Extracted samples were stored at -20°C for no more than 6 weeks prior to analysis by LC/MS [61]. …”

“…For extracted SPE samples and collected POCIS samples, minimal losses have been previously observed for the compounds of interest during frozen storage for 2-3 months (<7%) and up to 20 months (<20%) [61]. Therefore, any losses incurred during the storage period were deemed to be negligible and thus, no corrections were required to account for sample losses between collection and analysis.…”

Analysis of drugs of abuse in wastewater from two Canadian cities

“…Each disk was stored in a plastic re-sealable bag and stored on ice during transportation back to the laboratory. To ensure that analytes were retained on the POCIS, samplers were stored in a freezer at − 20°C (Carlson et al, 2013), and extraction was performed was within one month of retrieval.…”

Passive sampling of pharmaceuticals and personal care products in aquatic environments

“…POCIS are also deployed in agricultural watersheds (Jairnes-Correa et al 2015), areas of pharmaceutical industrial activity or hospital effluents (Bailly et al 2013), to investigate the degree of contamination by particular pollutants. Spiked water samples and laboratory tests are commonly used in studies on the kinetics of uptake of new micropollutants and evaluation of various physical effects on the sampler or the characterization of the innovative features of future POCIS (Li et al 2011;Carlson et al 2013;Morin et al 2013;Belles et al 2014;Kaserzon et al 2014). These approaches often include a range of analytes with different physical-chemical properties (basic, acidic, phenolic and neutral) which provide a better insight into the new samplers' efficiency for monitoring various analytes.…”

“…POCIS containing MCX and MAX sorbents can be eluted using MeOH with an addition of 5% ammonium hydroxide and 2% formic acid, respectively (Li et al 2011). A study dealing with the stability of pharmaceuticals and other polar organic compounds stored in POCIS and solid phase cartridges indicates they remain relatively stable and suitable for expost analysis for 20 months when stored at -20 °C (Carlson et al 2013).…”