Ma. Aramendia et al., DETERMINATION OF ISOFLAVONES USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ATMOSPHERIC-PRESSURE CHEMICAL-IONIZATION MASS-SPECTROMETRY, Rapid communications in mass spectrometry, 9(6), 1995, pp. 503-508
High-performance liquid chromatography in combination with mass spectr
ometric detection (atmospheric-pressure chemical ionization, APCI) was
used to determine various isoflavones. Negative-ion APCI ionization h
as proved to be a suitable technique for determining this class of nat
ural. compound, as it provides quality mass spectra which give not onl
y the molecular weight of the isoflavones, but also their molecular st
ructures; consistent collision-induced dissociation pathways were eluc
idated and fragments are reported. Deuterium oxide was used to induce
peak shifts in the mass spectra in order to determine the number of ex
changeable hydrogen atoms in each molecule.