Patent ID: 9490111
Filing Date: 2016-11-08
CPC Classification: H01J

Claim Text:
1. A method of detecting analyte by mass spectrometry, the method comprising: providing a composition comprising oil and an aqueous microdroplet comprising said analyte, said composition comprising surfactant to stabilise said aqueous microdroplet in said composition, wherein said surfactant comprises one of a polymeric surfactant or a small molecule surfactant, wherein said polymeric surfactant is less ionisable than said analyte, wherein said small molecule surfactant comprises a volatile small molecule surfactant that has a molecular weight that is less than 800 g/mol, wherein said oil is less ionisable than said analyte; injecting said composition comprising said oil, said aqueous microdroplet comprising said analyte, and said surfactant into a mass spectrometer from an emitter or orifice of a microfluidic device; and performing ionisation mass spectrometry analysis of said analyte, wherein, as a result of a higher ionisation potential of said surfactant and said oil compared to said analyte and during the step of performing said ionisation mass spectrometry analysis, a first portion of available charge to allow ionisation of said analyte is greater than a second portion of the available charge to allow ionisation of said surfactant and said oil.