title: Quantifying PPCP interaction with dissolved organic matter in aqueous solution: combined use of fluorescence quenching and tandem mass spectrometry.
abstract: The documented presence of pharmaceuticals and personal care products (PPCPs) in water sources has prompted a global interest in understanding their environmental fate. Dissolved organic matter (DOM) can potentially alter the fate of these contaminants in aqueous systems by forming contaminant-DOM complexes. In-situ measurements were made to assess the interactions between three common PPCP contaminants and two distinct DOM sources: a wastewater treatment plant (WWOM) and the Suwannee River, GA (SROM). Aqueous DOM solutions (8.0 mg L(-1) C, pH 7.4) were spiked with a range of concentrations of bisphenol-A, carbamazepine and ibuprofen to assess the DOM fluorophores quenched by PPCP interaction in excitation-emission matrices (EEM). Interaction effects on target analyte (PPCP) concentrations were also quantified using direct aqueous injection ultra high performance liquid chromatography tandem mass spectrometry (LC-MS/MS). At low bisphenol-A concentration, WWOM fluorescence was quenched in an EEM region attributed to microbial byproduct-like and humic acid-like DOM components, whereas carbamazepine and ibuprofen quenched fulvic acid-like fluorophores. Fluorescence quenching of SROM by bisphenol-A and carbamazepine was centered on humic acid-like components, whereas ibuprofen quenched the fulvic acid-like fluorophores. Nearly complete LC-MS/MS recovery of all three contaminants was obtained, irrespective of analyte structure and DOM source, indicating relatively weak PPCP-DOM bonding interactions. The results suggest that presence of DOM at environmentally-relevant concentration can give rise to PPCP interactions that could potentially affect their environmental transport, but these DOM-contaminant interactions do not suppress the accurate assessment of target analyte concentrations by aqueous injection LC-MS/MSMS.
authors.affiliation: Department of Soil, Water and Environmental Science, University of Arizona, 1177 E 4th St, Tucson, AZ 85721, USA. selene.hernandez27@gmail.com
authors.forename: Selene
authors.initials: S
authors.lastname: Hernandez-Ruiz
authors.forename: Leif
authors.initials: L
authors.lastname: Abrell
authors.forename: Samanthi
authors.initials: S
authors.lastname: Wickramasekara
authors.forename: Benny
authors.initials: B
authors.lastname: Chefetz
authors.forename: Jon
authors.initials: J
authors.lastname: Chorover
mesh_terms: D002220:Carbamazepine / Q000302:isolation & purification; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003358:Cosmetics / Q000032:analysis* / Q000737:chemistry; D005845:Georgia; D007052:Ibuprofen / Q000302:isolation & purification; D009930:Organic Chemicals / Q000032:analysis*; D004364:Pharmaceutical Preparations / Q000032:analysis*; D045483:Rivers / Q000737:chemistry; D012995:Solubility; D012996:Solutions; D013050:Spectrometry, Fluorescence / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
chemical_list: D003358:Cosmetics; D009930:Organic Chemicals; D004364:Pharmaceutical Preparations; D012996:Solutions; D014874:Water Pollutants, Chemical; D002220:Carbamazepine; D007052:Ibuprofen