title: Application of Polar Organic Chemical Integrative Sampler (POCIS) to monitor emerging contaminants in tropical waters.
abstract: Tools specifically validated for tropical environments are needed to accurately describe the behavior of chemical contaminants in tropical ecosystems. In the present study, sampling rates (Rs) were determined for the commercial pharmaceutical-type Polar Organic Chemical Integrative Sampler (POCIS) with a 45.8cm(2) exposure surface for 35 Pharmaceutically Active Compounds (PhACs) and Endocrine Disrupting Compounds (EDCs), of which eight compounds (albuterol, atorvastatin, diltiazem, dilantin, enalapril, norfluoxetine, risperidone and warfarin) were reported for the first time. These sampling rates were measured in an outdoor laboratory calibration setup to best capture diurnal tropical temperature variations (29±3°C). The effect of stirring and salinity was investigated. For all compounds, the sampling rates were higher under stirred conditions as compared to quiescent conditions. Calibration results in the presence of 30g sodium chloride support that the effects of salinity on POCIS sampling rates are compound-specific. Comparisons between Time-Weight Average (TWA) water concentrations using POCIS and spot sample levels in the field (2 lake and 1 mangrove estuary sites) are presented. Results showed that POCIS TWA concentrations were in agreement with spot sample concentrations for these aquatic systems. Results indicate that POCIS can be used to effectively measure the TWA concentration for a range of PhACs and EDCs in tropical waters. However, based on the results from mass balance and field deployments, POCIS did not appear suitable for compounds with a low mass balance recovery during calibration (e.g. triclosan and linuron in this study).
authors.affiliation: Singapore-Delft Water Alliance, National University of Singapore, Singapore. Electronic address: sbayen@nus.edu.sg.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bayen
authors.affiliation: Singapore-Delft Water Alliance, National University of Singapore, Singapore.
authors.forename: Elvagris
authors.initials: E
authors.lastname: Segovia
authors.affiliation: Singapore-Delft Water Alliance, National University of Singapore, Singapore.
authors.forename: Lay Leng
authors.initials: LL
authors.lastname: Loh
authors.affiliation: Singapore-Delft Water Alliance, National University of Singapore, Singapore.
authors.forename: David F
authors.initials: DF
authors.lastname: Burger
authors.affiliation: Public Board Utilities of Singapore, Singapore.
authors.forename: Hans S
authors.initials: HS
authors.lastname: Eikaas
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore.
authors.forename: Barry C
authors.initials: BC
authors.lastname: Kelly
mesh_terms: D002138:Calibration; D052244:Endocrine Disruptors / Q000032:analysis; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D009930:Organic Chemicals / Q000032:analysis*; D014329:Tropical Climate; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D052244:Endocrine Disruptors; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical
keywords: Emerging contaminant; Liquid chromatography–electrospray ionization tandem mass spectrometry; Polar Organic Chemical Integrative Sampler; Risk assessment; Solid-phase extraction; Tropical ecosystem