Advances in on-site analytical sample preparation for analysis of environmental waters: A review

The collection, storage, and transportation of water samples from far-off places to the labs is a pretty challenging task. It can cause contamination, degradation, or losses of the analytes, leading to errors in the analysis. On-site sample preparation provides an opportunity to extract the analytes into suitable extraction media that preserves the analytes and is easy to handle in terms of storage and transportation. However, the required equipment for on-site sample preparation should be simple, portable, and energy-efficient. Solvent- and sorbent-based microextraction approaches and the modern variants of solid-phase extraction have shown great potential for on-site sample preparation because of reduced consumption of solvents and low energy requirement. This review provides an overview of the application of different extraction techniques in on-site sample preparation, their advantages, and their limitations. The recent advances combining on-site extraction and analysis have also been critically discussed.