Electrospray Mass Spectra of Arsenic Compounds

Positive ion electrospray mass spectra of arsenobetaine, AB, arsenocholine, AK, monomethylarsonic acid, MMA, dimethylarsinic acid, DMA, tetramethylarsonium TMAs, arsenate, AsV, and arsenite, AsIII, have been obtained. When appropriate, negative ion electrospray mass spectra have been performed. In order to clarify fragmentation pathways MS/MS spectra have also been recorded. Positive ion electrospray mass spectra have been found to be more useful for the identification of the organoarsenic compounds AB, AK, MMA, DMA and TMAs, whereas negative ion electrospray mass spectra is more suitable for the identification of the inorganic compounds AsV and AsIII.