There are many types of passive samplers used that specialize in absorbing different classes of aquatic contaminants found in the environment. Chemcatcher and SMPD are two types of passive samplers that are also commonly used. Monitoring programs use SMPDs to measure to hydrophobic organic contaminants. SPMDs are designed to mimic the bioconcentration of contaminants in fatty tissues (ITRC, 2006). Contaminants applicable to the use of an SPMD include, but are not limited to, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, dioxins, and furans.
The SPMD consist of a thin-walled, nonporous, polyethylene membrane tube that is filled with high molecular weight lipid. These tubes are approximately 90 cm long and wrap around the inside of a stainless steel deployment canister. SMPDs are efficient at absorbing pollutants with a log Kow of 4-8. This slightly overlaps with the range of contaminants absorbed by POCIS. Because of this, SMPDs and POCIS devices are often used together in monitoring studies to achieve a more representative understanding of contamination.