Has anyone ever tried using sulfamic acid as an additive in LC-MS (say 15 mM)? I have an analyte with pKa 2.7 so I would like to acidify the mobile phase to pH ~ 2 to get some retention in RP-HPLC. It doesn have a good chromofore so I guess the only way to go is MS (MS/MS).
So does anyone have any suggestions/experience regarding sulfamic acid and MS?