Effects of suspended sediment on POCIS sampling rates

• Published in: Chemosphere (Oxford) Vol. 241; p. 124972
• Main Authors: Djomte, Valerie Toteu, Chen, Sunmao, Chambliss, C. Kevin
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2020
• Subjects: Environmental Monitoring - methods; Geologic Sediments - chemistry; Membranes, Artificial; Organic Chemicals - analysis; Organic Chemicals - chemistry; Organic contaminant; Passive sampler; PES membrane; Pesticides; Pesticides - analysis; Polymers; Sampling rate; Sediment; Sulfones; Water - chemistry; Water Pollutants, Chemical - analysis; PES membrane; Passive sampler; Sediment; Sampling rate; Organic contaminant; Pesticides
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2019.124972

Effects of chemical uptake onto polar organic chemical integrative samplers (POCIS) exposed to total suspended solid (TSS) sediment concentrations of 0 and 3600 ppm were investigated for 12 pesticides at constant concentration, temperature, and flow velocity. The effects of sediment exposure on POCIS uptake were negligible for compounds with polyethersulfone-water partition coefficients greater than three (i.e., log KPESW > 3). However, significant effects were observed for 3 of 12 compounds tested, and the maximum effect was an approximate 4-fold increase in sampling rate for the sediment experiment relative to the control. Effects of sediment on the pesticide distribution between polyethersulfone (PES) membranes and Oasis HLB sorbent were also investigated. The fraction of pesticide accumulated on PES membranes was relatively low for most compounds and ranged from 0 to 33%. In contrast, four compounds with higher affinity for PES accumulated preferentially on the membranes (fraction ranging from 64 to 96%), suggesting that a sampling rate derived from the additive contribution of membrane extraction and the more typical extraction of analytes from HLB sorbent would improve the sensitivity of sampling rate estimations for these compounds. However, for these same compounds, the combined sampling rate, Rs (HLB + PES), was considerably more susceptible to a sediment effect than the traditional sampling rate determination, relying solely on extraction from HLB sorbent. •Sediment has a negligible effect on POCIS Rs for compounds with log KPESW > 3.•POCIS Rs increases by a factor of up to 4-fold for POCIS exposed to sediment.•Compounds with log KPESW ≤ 3.31 primarily accumulate on POCIS sorbent (Oasis HLB).•Compounds with log KPESW ≥ 3.91 primarily accumulate on POCIS membranes (PES).