MALDI-MS is popularly utilized as an analytical tool for identifying synthetic polymer samples. However, minor components in complicated mixtures may not be recognized because of ion suppression by components that are more abundant. Gel Permeation Chromatography (GPC)-MALDI is a method to analyze these samples in detail. In GPC-MALDI, complex samples are separated by GPC before MALDI-MS analysis is done. Samples for MALDI-MS analysis should be mixed with MALDI matrix as well as salt before they are loaded to the MALDI target. Salt promotes the cationization of the sample to be analyzed. The process can be automated through the organic solvent-resistant fraction collector or the MALDI spotting robot (AccuSpot) that we have created. They mix the GPC eluent with the MALDI matrix solution before the resulting solution is automatically deposited to the MALDI sample target.