Premium
Electrochemical sample pretreatment coupled on‐line with electrospray mass spectrometry for enhanced elemental analysis
Author(s) -
Pretty Jack R.,
Berkel Gary J. Van
Publication year - 1998
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/(sici)1097-0231(19981115)12:21<1644::aid-rcm377>3.0.co;2-7
Subject(s) - chemistry , electrochemistry , supporting electrolyte , electrospray , mass spectrometry , electrolyte , acetic acid , aqueous solution , analytical chemistry (journal) , chromatography , analyte , detection limit , stripping (fiber) , electrode , biochemistry , electrical engineering , engineering
The successful coupling of a thin‐layer, flow‐by electrochemical cell on‐line with electrospray mass spectrometry (ES‐MS) for electrochemically modulated sample preconcentration and clean up, using copper(II) as the targeted analyte, is demonstrated. Particular requirements for the interfacing of this electrochemical system with ES‐MS, the choice of cell and electrode materials, and the solvent and electrolyte requirements are addressed. The transfer of Cu 2+ at low μg/L levels from matrices that cannot be analyzed directly by ES‐MS, including 100% aqueous solutions containing up to 1% (v/v) HNO 3 and 1% (w/w) NaCl, to a more suitable medium (i.e. CH 3 OH/H 2 O (95/5 v/v) with 5.0 m M ammonium acetate and 0.75% (v/v) acetic acid) via electrochemically controlled reduction (deposition) and oxidation (stripping) of the Cu 2+ is demonstrated. Acidic samples and samples containing significant levels of dissolved solids required cell washout times of up to 4.0 min following electrochemical extraction. Nonetheless, analysis time was still less than 8 min per sample. Quantification of 20–50 μg/L Cu 2+ in various matrices using standard additions with this electrochemical/ES‐MS combination is evaluated. The limitations of this combination in its present state of development and possible future directions are summarized. © 1998 John Wiley & Sons, Ltd.