Abstract

Analytical scientists have long sought accurate and sensitive methods for the determination of molecular masses for heavy biomolecules such as proteins and peptides. These molecules are extremely difficult to convert from the condensed to the vapour phase because of their extremely small vapour pressures, and hence traditional methods of mass analysis proved to be of little use. One of the exciting new technologies that has been developed in the last few years to solve this problem is matrix-assisted laser de-sorption/ionisation (MALDI).¹ This is a technique in which the analyte of interest is dissolved in a matrix that has absorption properties matched to the desorbing laser. Although MALDI has found considerable acceptance in the study of large biological molecules and polymers as an ionisation source, the processes involved that lead to the formation of the ions are less well understood.

© 1994 IEEE