Electrochemistry combined on-line with atomic mass spectrometry and related techniques for trace-metal analysis and electrode-reaction studies

Abstract

Electrochemistry (EC) combined on-line with atomic mass spectrometry (MS) and related techniques (e.g., inductively coupled plasma atomic emission spectrometry, ICP–AES) affords an avenue for analysis of metals present at ultratrace levels and the effective elimination of matrix effects detrimental to atomic MS and spectrometric techniques. In addition, electrode reactions involving inorganic species can be conveniently studied, and analyte accumulated and released from adsorbates or electroactive thin films can be accurately quantified. This review summarizes recent advances based on EC coupled with atomic MS and related techniques for trace-metal analysis and studies of electrode processes. Particular emphasis is placed on EC combined with ICP–MS (EC–ICP–MS) and electrospray–MS (EC–ES–MS). I describe criteria for selecting the suitable EC flow-cell designs and the MS sample-introduction systems or interfaces. The versatility of this hyphenated technique is well reflected in the different systems studied and the possibility of electrolytic and non-electrolytic accumulation of trace analytes for subsequent sensitive MS detections.