Application Of Passive Sampling Technique With Low-density Polyethylene (LDPE) As Sorbent Phase For Determining Of LDPE-water Partition Coefficients For Novel Halogenated Flame Retardants

In this study,the coefficients of partitioning between low-density polyethylene?LDPE?film?25?m thickness?and water(K_pew)for 9 novel halogenated flame retardants?NHFRs?were firstly determined by an optimized method,that is,large device and standard solution generated by dialysis.Concentrations of PBDEs and NHFRs were obtained by the sheets and the open water passive samplers with LDPE as sorbent phase in typical polluted areas,comparing those from active method,and analysing advantages and disadvantages of both sampling method.The main results are summarized as follows:First,the K_pew values for 13 polycyclic aromatic hydrocarbon?PAHs?and 13polychlorinated biphenyls?PCBs?were determined using the optimized method,and the results were good agreement with those reported in the literatures.Thus,it is verified that the optimized method can be used to determine K_pew for hydrophobic organic contaminants.Second,the K_pew valued for 9 NHFRs were determined using optimized method based on a regression analysis of sorption kinetics over experimental period.A linear relationship between log K_pew and log K_ow was obtained for the 9 NHFRs,13 PAHs,and 13 PCBs when about log K_ow<7.2,while a nonlinear relationship between log K_pew and log K_ow was found with the turning point occurring at about log K_ow=7.2.This may be because different structure between octanol and LDPE film,and large-size molecules must overcome more energy barrier when it attempts to diffuse into the LDPE structure,indicating that it can't use the K_ow to estimate its K_pewfor NHFRs.In addition,K_pew values for BDE-209 determined by optimized method was higher two orders of magnitude than that reported in other literature,indicating that standard solution generated by dialysis is superior to directly spiked target compounds.Based on the measured K_pew of 9 NHFRs and reported K_pew of PBDEs from the literatures,the sheets and the open water passive samplers with LDPE as sorbent phase were deployed in two typical polluted areas of South China to quantify freely dissolved halogenated flame retardants.BDE-28 and BDE-47 were detected in all samples,and the sum concentration of both of them accounted for more than 80%of the total PBDE concentrations.Moreover,syn-DP and anti-DP were detected from recycled four sheets water samplers at site L2,indicating the result obtained by passive sampling techniques were consistant and stable.While the result obtained by active sampling techniques were affected by particle phase and generated randomly for PBDEs and NHFRs.Thus,passive sampling method is a good choice for monitoring very hydrophobic organic chemicals in water.