Adapting current model with field data of related performance reference compounds in passive samplers to accurately monitor hydrophobic organic compounds in aqueous media

Performance reference compounds (PRCs) are neutral organic compounds, introduced in a passive sampler prior deployment for the assessment of in situ sampling rate. In this study, evaluation of in situ sampling rates of 16 ¹³C-PAH-PRCs with moderate and high hydrophobicity was established to provide an overall correction factor for variations in virtual organism (VO) uptake rates of the analytes of interest. In situ sampling rate was compared to an empirical model during sampling campaign in 2011 with VO in 12 different sites along the Three Gorges Reservoir (TGR) in China. A discrepancy was observed for high hydrophobic compounds with log K_ow ranging from 5.18 to 6.63 where ΣPAH concentration in TGR from Huckins model (305,624 pg/L) was resulted to be roughly 2-fold higher than the alternative procedure (182,292 pg/L). A relationship between in situ sampling rates of the 16 ¹³C-PAH-PRCs (Rs,_PRC) and log K_ow was set up to allow then calculation of analyte sampling rate Rs_analyte(N) of various organic pollutants with log K_ow ≤ 6.63.