Metal and metalloid monitoring in water by passive sampling – A review

Abstract

Passive sampling methodologies offer a series of advantages, providing time-averaged contamination levels in the field, separating the analyte from complex matrices, lowering the limits of quantification, and offering the possibilities of chemical fractionation and speciation. This review surveys the recent developments in passive samplers (PSs) tools such as diffusive gradients in thin films, polymer inclusion membranes, stabilized liquid membrane devices, “octopus” samplers, and active PSs. This article also discusses some challenges in the on-site utilization of these techniques and presents the latest on-site application of PSs to assess metals and metalloids in aquatic systems. Passive sampling is becoming a recognized practice, confirmed by numerous articles published in this field. Advances were made to increase the robustness, accuracy, and precision of the method, and collaborative studies were used for on-site validation. Chemical fractionation, speciation, and bioavailability of elements received special attention in recent years. This review provides a comprehensive update on the latest progress in passive sampling techniques. It brings together for the first time the newest developments of the most used PSs for metal and metalloid monitoring, speciation, and fractionation in aquatic systems. The potential contribution of passive sampling for metal and metalloid determination in water samples in achieving the analytical chemistry green and white analytical concept is also discussed.