The influence of pH on sampler uptake for an improved configuration of the organic-diffusive gradients in thin films passive sampler

Trends in the use of passive sampling for monitoring polar pesticides in water

“…Speciation of ionisable pesticides is pH dependant. pH was found to effect uptake of acid herbicides in o-DGT containing Oasis™ HLB or Oasis™ MAX [110] and Oasis™ HLB or Sepra™ ZT [101].…”

“…Changes in transport distance or resistance to mass transfer can be caused by variation in the thickness of the external WBL or the formation of fouling films [99]. Whilst temperature and matrix composition may also influence solute diffusion [79], speciation [100], or interaction with surfaces of DM and sorbent [101]. Additionally, amenable metabolic pathways or sorption sites present in fouling films may attenuate mass flux, suppressing accumulation in the sorbent [99].…”

“…Stroski et al [101] attributed this to differential proclivity of species for solute-sorbent interactions leading to sorption as uptake of neutral pesticides was unaffected by pH. The effect of pH on solutesorbent interactions for ionizable pesticides has also been highlighted in Chemcatcher ® [58,72] and POCIS [111], with ion-exchange sorbents displaying superior performance for ionised species.…”

Effects of biofouling on the uptake of perfluorinated alkyl acids by organic-diffusive gradients in thin films passive samplers

“…Reagents for making gels and the o-DGT assembly and extraction are discussed elsewhere. 27 The previously developed polyacrylamide-WAX (weak anion exchange) o-DGT was used and no obvious sorption of target PFAS to the polyacrylamide diffusive gels was found. 28…”

Rapid direct analysis of river water and machine learning assisted suspect screening of emerging contaminants in passive sampler extracts

“…The range of log D values for all compounds sequestered onto these HLB sorbents during both campaigns was À1.16 to 6.09 at the mean river pH and similar to previous works. [44][45][46][47][48][49] The log D of all 18 compounds unique to water samples covered a range of À0.3 to 4.21. Despite methanol being a recognised solvent for passive sampler sorbent elution, 28 incomplete elution or ion suppression for some compounds may have occurred.…”