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Thermospray liquid chromatographic/mass spectrometric studies with inositol phosphates
Author(s) -
Hsu FongFu,
Duane Goldman H.,
Sherman William R.
Publication year - 1990
Publication title -
biomedical and environmental mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0887-6134
DOI - 10.1002/bms.1200191004
Subject(s) - thermospray , chemistry , inositol , chromatography , mass spectrometry , ion chromatography , chemical ionization , ion exchange , phosphate , inositol phosphate , ion , detection limit , mass spectrum , ionization , organic chemistry , tandem mass spectrometry , biochemistry , selected reaction monitoring , receptor
Thermospray mass spectrometry of inositol mono‐ and polyphosphates, separated by ion‐exchange chromatography, was evaluated for its potential as a general method for quantitative analysis of these substances. The only ions of significant abundance that are produced by the thermospray ionization process result from the total loss of phosphate from inositol. Thus inositol mono‐, tris‐ and hexakisphosphate each gave mass spectra consisting solely of [MH] + and [MNH 4 ] + of inositol. When the chromatographic eluates are passed through a heated reactor prior to the thermospray source maximal yields of these ions are obtained. The sensitivity of the technique falls short of that needed for a general method for biological applications, because the lower limit of detection is about 100 pmol μl −1 . Inositol phosphates peracetylated on C‐hydroxyls were also studied, with separation by ion‐exchange chromatography. Again, thermospray ionization produces totally dephosphorylated species, with the highest‐mass ions retaining all of the acetyl groups, even when using the thermal reactor. Losses of acetate were also observed. Sensitivity with the acetyl derivative was comparable to that with the underivatized inositol phosphates.