Recent Developments in Electrochemistry–Mass Spectrometry

Abstract

Hyphenation of electrochemistry and mass spectrometry is an attractive method to investigate oxidation and reduction processes. By using mass spectrometry, electrochemically generated products can be identified. In this Review, different approaches to electrochemistry–mass spectrometry will be summarized, including hyphenation of electrochemical flow cells to mass spectrometry as well as integration of separation steps between electrochemical reactions and detection of products. Fields of application range from bioanalytical studies to studies regarding corrosion, electrosynthesis and energy carriers. Important historical developments will be highlighted, followed by an overview of terminology and instrumental setups and discussion of developments within recent years (2017–2020).

Nanoscale electrochemistry in a copper/aqueous/oil three-phase system: surface structure–activity-corrosion potential relationships

“…and d (extracted fromMovie S2 and S3) can give an insight on the relationship between the two half reactions contributing to Cu corrosion [i.e., Cu oxidation and ORR, Eqs. (1) and(4)]. The variation in τ within a single grain is generally relatively high, for example, comparing the τ distributions of grains γ, δ and ε (inset inFigure 5d), differences in the maximum value of the three distributions are evident (e.g., β has the longest transition time), but the distributions overlap more than in the equivalent E surf distributions (inset inFigure 5d).…”

“…1,2 For metals, in particular, electrochemical techniques, allied to complementary analytical and microscopy methods, play a central role in unveiling corrosion and corrosion protection mechanisms. [3][4][5][6][7] However, a limitation of many experimental approaches is that the electrochemical perturbation (and measurement) is applied globally at a macroscopic electrode immersed in a bulk solution, 8 but most corrosion processes are initiated and perpetuated at (sub)microscopic surface sites (e.g., grain boundaries, inclusions, microscratches etc.). [9][10][11][12][13][14] Mismatch between the scale of key corrosion phenomena and conventional electrochemical methods makes it difficult to unambiguously identify the key anodic/cathodic sites driving corrosion.…”

Recent Advances of In‐Source Electrochemical Mass Spectrometry

“…The combination of electrochemistry (EC) and mass spectrometry (MS) has become a powerful and versatile strategy that allows one to characterize a broad range of electrochemical and biological reactions, and extends the scope of analytes for mass spectrometric analysis. [1][2][3][4][5][6][7][8][9][10][11][12] In this hyphenation, MS has often been used due to its high sensitivity and specificity for determination of electrochemical reactions, providing structural information unavailable from EC methods. Electrochemical reactions can be used to oxidize or reduce analytes so as to improve the ionization of analytes for mass spectrometric analysis.…”

“…In addition, on-/off-line coupling of EC flow cells to mass spectrometers, as well as hyphenation of chromatography/ electrophoresis and MS for EC reaction mixture analysis have been well reviewed by Herl and Matysik. [4] Although the upstream electrochemical cells are often decoupled from the ionization process for MS detection, [20][21][22][23] the electrochemical properties of ion sources such as electrospray ionization (ESI) have long been recognized. It was underestimated partly due to the identity of analytes in a mass spectrum seldom reflecting the electrochemical phenomena occurring in ESI under frequently utilized conditions.…”

“…Important developments of these applications have been highlighted in a special issue of TrAC‐Trends in Analytical Chemistry in 2015. In addition, on‐/off‐line coupling of EC flow cells to mass spectrometers, as well as hyphenation of chromatography/electrophoresis and MS for EC reaction mixture analysis have been well reviewed by Herl and Matysik [4] …”