Sample treatments improved by electric fields

Sample treatment is one of the most important stages in the analytical process. In the past few years, there have been many advances in preconcentration techniques and extraction of analytes from complex samples. Well-known sample treatments based on extractions (e.g., solid-phase extraction, liquid-liquid extraction, solid-phase microextraction and pressurized liquid extraction) or membranes (e.g., electromicrodialysis) can be improved by using electric fields. This has led to a new trend in analytical chemistry. We present a comprehensive, illustrated review of sample treatments using electric fields.