Patent ID: 8604424

Claim:
A method for introducing a sample into a supersonic molecular beam for mass spectrometry analysis, said method comprising: directing sample compounds to be analyzed in a flowing liquid solvent towards a sample vaporization chamber located upstream of a supersonic nozzle; forming a spray from said sample compounds in a flowing liquid; heating said spray in the sample vaporization chamber to vaporize said sample compounds thereby simultaneously forming vaporized sample compounds and vaporized solvent prior to expansion of the sample compounds and vaporized solvent from said supersonic nozzle; expanding said vaporized sample compounds and vaporized solvent from said supersonic nozzle into a vacuum system, forming a supersonic molecular beam with both vibrationally cold sample molecules and vaporized solvent; ionizing with electrons said sample compounds while contained as vibrationally cold molecules in said supersonic molecular beam in a fly-through electron ionization ion source; mass analyzing the ions formed from said sample compounds; detecting said ions formed from said sample compounds after mass analysis and generating mass spectral information, processing the data obtained from the resulting mass spectral information for identifying and/or quantifying the chemical content of said sample, wherein: said sample vaporization chamber is connected to said supersonic nozzle by a flow restrictor element that physically separates between the vaporization chamber and supersonic nozzle and serves to impede flow while transferring the sample vapor into the nozzle for supersonic expansion at a low pressure that eliminates formation of clusters of the sample compounds with the solvent in the supersonic expansion; and said sample vaporization is completed in said vaporization chamber prior to its entry to said flow restrictor element.