Imaging with Mass Spectrometry
In imaging mass spectrometry, molecules present on the surface of a solid sample are desorbed from the surface and transported to the mass spectrometer for analysis. One critical feature of the method is that the spatial information of the chemicals is preserved. A 2D image of the distribution of the chemicals can therefore be reconstructed.
For example, in the simple experiment shown to the left, the symbol M* was drawn with two different colored markers and then imaged using DESI-MS. The actual drawing is shown in the upper left, and the 2D ion image is shown in the lower right. The ion image is actually an overlay of two images. The intensity of the blue color reflects the intensity of the blue dye, while the intensity of the red color reflects the intensity of the red dye.