title: Use of mixed-mode ion exchange sorbent for the passive sampling of organic acids by polar organic chemical integrative sampler (POCIS).
abstract: Acidic herbicides are increasingly monitored in freshwater, since their high solubility favors their rapid transfer to the water phase. Therefore, contaminant levels in the water can vary rapidly and passive sampling would be preferred over spot sampling to integrate all pollution events over a given exposure time. In this work, we propose to compare the conventional pharmaceutical polar organic chemical integrative sampler (POCIS) with modified POCISs containing two different receiving phases: a standard polystyrene divinylbenzene polymer with a higher specific surface area (Chromabond HR-X) and a mixed-mode anion exchange sorbent providing additional strong anion exchange interaction sites (Oasis MAX). Due to its hydrophobic character, Chromabond HR-X had little interaction with water (no sampling of acidic herbicides); whereas Oasis MAX provided acceptable sampling parameters (longer kinetic regime together with higher sampling rates). Additional experiments with POCIS-MAX showed no influence of nitrates on analyte uptakes, and linear isotherms reaching 10 μg L⁻¹, supporting the applicability of this device for the sampling of organic acids in continental water. The performance and reference compound (PRC) approach would be then applicable for POCIS-MAX if no competition is observed with other anions, especially organic acids (e.g., humic acids).
authors.affiliation: Irstea, UR REBX, F-33612 Cestas Cedex, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Fauvelle
authors.forename: Nicolas
authors.initials: N
authors.lastname: Mazzella
authors.forename: François
authors.initials: F
authors.lastname: Delmas
authors.forename: Karine
authors.initials: K
authors.lastname: Madarassou
authors.forename: Mélissa
authors.initials: M
authors.lastname: Eon
authors.forename: Hélène
authors.initials: H
authors.lastname: Budzinski
mesh_terms: D000327:Adsorption; D002264:Carboxylic Acids / Q000032:analysis*; D060766:Drinking Water / Q000737:chemistry; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods*; D007475:Ion Exchange Resins / Q000737:chemistry*; D009566:Nitrates / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis*; D012015:Reference Standards; D045483:Rivers / Q000737:chemistry; D052616:Solid Phase Extraction; D013696:Temperature
chemical_list: D002264:Carboxylic Acids; D060766:Drinking Water; D007475:Ion Exchange Resins; D009566:Nitrates; D009930:Organic Chemicals