Development of Underwater Ambient ESI-MS

Conventional ambient mass spectrometry employs an ionization source and samples placed in an open environment under atmospheric pressure. Attempts were made in our laboratories to develop an underwater ambient mass spectrometry using remote sampling ESI. To mass analyze the chemical compounds originating from samples in an aqueous environment, ethyl acetate, which is immiscible in water was used for liquid extraction at the tip of the sampling probe. This brief report presents the preliminary result using a modified remote sampling ESI prototype for the analysis of raw aqueous solution.