title: Effect of Biofilm on Passive Sampling of Dissolved Orthophosphate Using the Diffusive Gradients in Thin Films Technique.
abstract: We evaluated the possibility of sampling dissolved orthophosphate using the diffusive gradient in thin films (DGT) technique with a phosphate ion-imprinted polymer (PIP)-based adsorbent and assessed the effect of biofilm on the DGT measurement. The composition of biofilm formed on the DGT surface was analyzed, and the effect of biofouling on the diffusion coefficient of the analyte was investigated. The corrected diffusion coefficient for the biofouled DGT was estimated and used for the calculation of the DGT equation. PIP-binding gels had a higher adsorption affinity for orthophosphate than for the other anions, indicating its selectivity for orthophosphate. The concentrations predicted via DGT agreed well with the concentrations determined in the bulk solutions. Sampling of orthophosphate using PIP-DGT was consistent over a pH range of 3-9 and ionic strength range of 0.01-10 000 μM. Other P compounds cannot be measured using the PIP-DGT technique. The diffusion coefficient of the orthophosphate linearly decreased with increasing thickness of the biofilm. This sampling method performed predictably in freshwater when the biofilm was not formed or when value for the biofilm interference was reduced by using the corrected diffusion coefficient.
authors.affiliation: College of Sciences, Northeastern University , Shenyang, Liaoning 110819, China.
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Feng
authors.affiliation: School of Material Science and Engineering, South China University of Technology , Guangzhou, Guangdong 510006, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhu
authors.affiliation: College of Applied Chemistry, Shenyang University of Chemical Technology , Shenyang, Liaoning 110142, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Fan
authors.affiliation: Chongqing Branch of Beijing Hyundai Motor Company, Chongqing, 401133, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Piao
authors.affiliation: College of Pharmacy, Liaoning University , Shenyang, Liaoning 110036, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.affiliation: College of Sciences, Northeastern University , Shenyang, Liaoning 110819, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Sun