Electrodeposition step, stripping analysis

Stripping analysis is a two-step technique. The first or deposition step commonly involves the electrolytic deposition of a small portion of the metal ions in solution into the mercury electrode to preconcentrate the metals. Non-electrolytic (adsorptive) accumulation schemes have also been developed for expanding the scope of stripping analysis to trace metals that cannot be electrodeposited. The preconcentration step is followed by the stripping (measurement) step, which involves the dissolution (stripping) of the deposit. Different versions of stripping analysis can be employed, depending upon the nature of the deposition and measurement steps. 

Stripping methods are of prime importance in trace analysis because the electrodeposition step concentrates the analyte and allows minute amounts to be determined with reasonable accuracy. Thus, analytes in the 10 to 10 M range can be determined with stripping methods that use simple and rapid procedures. 

What is the purpose of the electrodeposition step in stripping analysis ... 

Because of its remarkable sensitivity (down to 10-11 M) stripping analysis is the most widely used voltammetric technique for trace metal determination in clinical samples (Wang, 1982A). Stripping analysis can be considered as a two-step technique. In the first step, metals in solution are effectively preconcentrated onto the working electrode by electrodeposition ... 

The purpose of the electrodeposition step in stripping analysis is to preconcentrate the analyte on the surface of the working electrode and to separate it from many interfering species. 

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