Sorption methods of concentrating trace elements before their determination in natural waters

A review systematizing the published data over the last 5 years on application of sorption methods to concentrate microelements for their determination in natural (sea, river, ground, rain etc.) waters is given. The methods of coprecipitation, sorption on inorganic and organic sorbents, on activated charcoal, and others are considered. Special attention is paid to chelating sorbents, rather promising for concentrating microelements from natural waters with a high saline background. It is nated that, in concentrating microelements, it is important to preliminarily treat natural waters and select concentrating conditions. To choose conditions for concentrating from large water volumes, it is perspective to use calculation methods