Passive sampling offers several advantages over conventional sampling. The sampler is in place for a longer period of time (often days or weeks), accumulating the analytes. The result is an average of the concentration during this time, which eliminates the risk of non-detection of, for example, occasional peaks in emitted pollutants.

PS Polar is our sampling system for polar organic compounds in water. Many hydrophilic pesticides and drug substances, among others, belong to this category. The sampler consists of a solid sorbent (a powder) enclosed between two membrane layers that are mounted between a pair of stainless steel washers. Up to three PS Polar samplers can be mounted in one steel canister (the same type of canister as for PS Organic), that can be hired or purchased from ALS. Polar compounds diffuse through the membranes and are accumulated by the sorbent. Following extraction, the analysis is carried out by standard methods, and the concentrations in the sampled water can be calculated.