A DESALTING APPROACH FOR MALDI-MS USING ON-PROBE HYDROPHOBIC SELF-ASSEMBLED MONOLAYERS

One of the problems encountered in preparing samples for matrix-assist ed laser desorption/ionization (MALDI) analysis is the presence of non volatile salts in the sample, This difficulty is often exacerbated by the necessity to prepare the sample in the appropriate sample-to-matri x ratio, This paper reports a probe surface derivatization method that greatly simplifies this sample preparation process, By constructing s elf-assembled monolayers of octadecyl mercaptan (C18) on the MALDI pro be surface, we were able to generate a surface capable of reversibly b inding polypeptides via hydrophobic interactions, which in turn, permi ts the analyte to be easily concentrated and desalted directly on the probe tip.