Passive Sampling Technologies

Applications for Passive Sampling of Hydrophobic Organic Contaminants in Water—A Review

“…This must be shorter than said variations in concentration. Environmentally significant concentrations of certain HOCs in aqueous media are often trace (ng L -1 to pg L -1 ) and relatively stable and in these circumstances, PSDs operating in the equilibrium regime are appropriate [16]. When PSDs are operated in the equilibrium regime equation (1) can be altered to equation (2):…”

Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays

“…36 An alternative approach for water extraction that has become increasingly popular during the past decade is using passive sampling, 9 which is typically performed in the kinetic rather than the equilibrium regime due to long equilibrium sampling times for hydrophobic organic chemicals of months to years. 37 Kinetic PS provides time-integrative measurements 11 and is particularly suited for chemicals with low and variable aqueous concentrations. For kinetic PS in bulk water, sampling rates (R s ) need to be calibrated for the chemicals and the system of interest.…”

Passive Sampling in Regulatory Chemical Monitoring of Nonpolar Organic Compounds in the Aquatic Environment

“…The capability of PSDs for measuring aqueous concentrations of most nonpolar compounds (log K ow > 4) that are listed by OSPAR, U.S., and EU has been demonstrated, with detection levels in the low picogram per liter range . While most studies have focused on PAHs and globally regulated contaminants such as hexachlorobenzene (HCB), PCBs, organochlorine pesticides, PCDD/Fs, and polybrominated diphenyl ethers (PBDEs), − a number of hydrophobic compounds of emerging concern have also been sampled by PSDs, including triclosan, , alkylphenols, pyrethroids, − cyclic methylsiloxanes, and organophosphates …”

“…During prolonged exposure, the compounds gradually attain their equilibrium concentrations. All samplers go through a kinetic sampling stage, but equilibrium is not always reached on practical time scales for compounds with high sampler-water partition coefficients ( K sw ), particularly for passive sampling in the water column, where the sampling rates ( R s ) are usually smaller than for passive sampling in pore waters or biota. − Equilibration times are generally shorter at higher water flow rates, lower K sw , and higher area/volume ratios of the sampler, , and typically range from days (e.g., endosulfan, log K ow = 4) to years (e.g., benzo­[ ghi ]­perylene, log K ow = 6.5) and beyond . Whether or not fast equilibration is desirable depends on the research question: long equilibration time scales may be desirable when a time-weighted average concentration is aimed for.…”

“…It should be noted that the main error source for C free is not in the chemical analysis of the PSD matrix, but in the K sw values used in the calculations thereafter (see above). Further, the uncertainty in C free remains fairly constant down to the level where the amounts in exposed PSDs approach the amounts that are present in the field control samplers (i.e., ∼ 10 pg L –1 or lower) . In addition, several water EQS values for nonpolar compounds are set at the pg L –1 level (e.g., cypermethrin) or below, and it is difficult to imagine how compliance with these EQS can be demonstrated without PSDs.…”