Improvements to matrix assisted laser desorption ionisation mass spectrometry imaging (maldi-msi)

摘要

A method for preparing a matrix assisted laser desorption ionisation mass spectrometry imaging (MALDI-MSI) sample comprises: dusting a sample with a MALDI-MSI matrix powder; removing excess powder from the sample, and spraying the dusted sample with a solvent in which both the matrix powder and the sample are soluble. Preferably, the sample is a fingermark, and the sample is lifted from a surface upon which the sample is deposited using an adhesive backed strip, pad or tape. The prepared sample may be introduced into a MALDI imaging mass spectrometer, a laser beam delivered to the sample and an image generated. A fluorescent or UV image of the prepared sample may be obtained. The MALDI-MSI matrix may be 4-hydroxycinnamic acid. The solvent may comprise a mixture of trifluoroacetic acid and acetonitrile.