A new matrix for matrix-assisted laser desorption/ionization on magnetic sector instruments with point detectors

A new matrix consisting of a binary mixture of alpha-cyano-4-hydroxycinnamic acid and 3-amino-quinoline has been developed specifically for matrix-assisted laser desorption/ionization (MALDI) analysis on magnetic sector mass spectrometers with point detectors. The major benefit of this matrix is that it is a viscous liquid with a self-healing surface. These properties provide very long-lasting and reasonably constant ion currents from pmol quantities of analyte, allowing MALDI-magnetic sector spectra to be obtained even though a non-integrating point detector is used. The applicability of this matrix for biological samples is demonstrated by analyzing a mixture of complex N-linked oligosaccharides with the new liquid matrix and with several traditional solid MALDI matrices both on magnetic sector and time-of-flight instruments.