Imaging Matrix assisted laser desorption ionisation mass spectrometry: A new technique for drug distribution studies

A new technique for the study of drug distribution, imaging matrix assisted laser desorption mass spectrometry is described. In this technique a tissue sample is imaged by moving it by set increments under a stationary laser. At each position the laser is fired for a pre-selected time or number of shots and a mass spectrum is acquired. Images are obtained by plotting the spatial coordinates of x and y versus the abundance of a selected ion or ions, which is represented as a grey or colour scale. Examples from recent work on studying the absorption of drugs in skin are given and the use of principal component analysis for the interpretation of such data described.