Premium
Sensitivity of Positive Ion Mode Electrospray Ionization Mass Spectrometry in the Analysis of Thiol Metabolites
Author(s) -
Mautjare Alpheus,
Looi Donq Wen,
Eyler John R.,
BrajterToth Anna
Publication year - 2010
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200900284
Subject(s) - adduct , thiol , chemistry , electrospray ionization , electrochemistry , mass spectrometry , cysteine , glutathione , quinone , electrospray , analytical chemistry (journal) , medicinal chemistry , stereochemistry , chromatography , organic chemistry , electrode , enzyme
High signal intensities of glutathione (GSH), [GSH+H] + ( m / z 308), cysteine (CySH), [CySH+H] + ( m / z 122), and homocysteine (hCySH), [hCySH+H] + ( m / z 136), are observed in ESI MS with on‐line electrochemistry (EC). Dimers formed by H‐bonding, which are not electrochemical products, are detected as [2GSH+H] + ( m / z 615), [2CySH+H] + ( m / z 243) and [2hCySH+H] + ( m / z 271) together with disulfide dimers GSSG, CySSCy and hCySSCyh, [GSSG+H] + ( m / z 613), [CySSCy+H] + ( m / z 241) and [hCySSCyh+H] + ( m / z 269). When dopamine is present a thiol/dopamine quinone (DAQ) adduct is observed. Formation of this adduct is proposed to occur by an electrochemical mechanism during ESI. Catalysis of thiol oxidation and analysis of thiol mixtures is addressed.