1 research outputs found
Effect of Biofilm on Passive Sampling of Dissolved Orthophosphate Using the Diffusive Gradients in Thin Films Technique
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