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Separation and identification of isoflavones with on‐line liquid chromatography‐electrochemistry‐thermospray mass spectrometry
Author(s) -
Dewald Howard D.,
Worst Sue Anne,
Butcher Jared A.,
Saulinskas Elaine F.
Publication year - 1991
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.1140030810
Subject(s) - thermospray , chromatography , chemistry , biochanin a , mass spectrometry , detection limit , ammonium acetate , formononetin , analytical chemistry (journal) , working electrode , high performance liquid chromatography , electrochemistry , electrode , selected reaction monitoring , genistein , tandem mass spectrometry , medicine , daidzein
Abstract The on‐line high‐performance liquid chromatography‐electrochemistry‐thermospray mass spectrometry (LCEC‐LC/MS) for separation and identification of the phenolic isoflavones genistein, formononetin, and Biochanin A is described. The isoflavones are separated on a C‐18 reversed phase column with methanol: 0.1 M ammonium acetate pH (70:30 v/v) as eluent, which is compatible for both LCEC and LC/MS detection. Low ng detection is achieved with a conventional glassy carbon thin‐layer electrochemical cell at 1.3 V vs. Ag/AgCl. Selected ion monitoring (SIM) mode LCMS results in detection levels at the 20–50 ng range, and the compounds are positively identified. In the on‐line detection, the electrochemical cell is connected to the thermospray and the column effluent flows from the working electrode into the heated thermospray capillary tube. The results show that on‐line coupling between a thin‐layer LCEC and a thermospray‐LC/MS can be used to characterize analytical systems.