A method, device, and kit for chemical species separation, such as of arsenic compounds, are provided. Using the kit in the field, a sample is provided, part of which is preserved for total chemical species analysis. The remainder of the sample is introduced into a solid phase that is disposed, for example, in a column (1) and that has been prepared for a chemical species of interest. At least one eluant that is appropriate for separating off the chemical species of interest is then introduced to the solid phase. The sample and eluant effluent are then collected for a mass balance calculation.
