The use of osazones as matrices for the matrix-assisted laser desorption/ionization mass spectrometry of carbohydrates.

Fifteen sugar osazones were synthesized and evaluated for their use as matrix-assisted laser desorption/ ionization matrices. Various carbohydrate samples were analyzed, indicating that D- or L-arabinosazone, prepared from D- or L-arabinose and phenylhydrazine, gave the overall best performance. The arabinosazones facilitated superior analyses in providing a highly uniform distribution of sample molecules within the matrix microcrystals, and a possibility of using low laser energy for irradiation, leading to high spectral resolution and low matrix background. The arabinosazones with a moderate content of sodium ions promoted specific fragmentation for certain carbohydrates tested. The 50 fmol amounts of maltohexaose and maltoheptaose (present in 0.1 microliter of sample/matrix solution) were detected at a signal-to-background ratio of 3:1.