On-rod standardization technique for time-weighted average water sampling with a polydimethylsiloxane rod

In this study, a polydimethylsiloxane (PDMS) rod was developed as a passive sampler, based on the solid-phase microextraction (SPME) technique. The on-rod standardization technique was applied to the PDMS rod passive sampler. Using the desorption of the pre-loaded standard on the PDMS rod to calibrate the absorption of the target analytes allows for the determination of the time-weighted average (TWA) concentrations of pollutants in the aqueous media. The PDMS rod passive sampler with the on-rod standardization technique was tested in the laboratory with a flow-through system and was subsequently applied to measure TWA concentrations of polycyclic aromatic hydrocarbons (PAHs) in the field (Hamilton Harbour, Hamilton, Ont., Canada). Both the laboratory and field experiments demonstrated that, with the on-rod standardization technique, the PDMS rod can be successfully used as a passive sampler for TWA water sampling in the field. The PDMS rod passive sampler benefits from the inherent advantages of the SPME approach: it incorporates sampling, isolation and enrichment into one step. The design of this system also addressed the additional needs for passive sampling techniques, providing an economical approach to field sampling that is also easy to deploy. Rather, with this approach, TWA concentrations of target analytes can be obtained by one sampler, and can be analyzed directly, with no further sample preparation treatment required.