Mass spectrometer method and apparatus for analyzing a sample in a solution

A mass spectrometric apparatus for analyzing a sample in a liquid solution for producing mass spectral information to provide an enhanced molecular ion for improved identifying and/or quantifying the chemical content of the sample, comprising:

• means for directing a flow of a solution containing sample compounds to be analyzed towards a supersonic nozzle;
• means for thermal vaporization of said solution containing sample compounds;
• said supersonic nozzle and vacuum system enabling expansion of said vaporized sample compounds into said vacuum system, forming a supersonic molecular beam;
• electron ionization ion source means for ionizing said vaporized sample compounds;
• mass analyzer means for the mass analysis of the ions formed from said sample compounds;
• an ion detector for detecting said ions formed from said sample compounds after mass analysis;
• and
• means for data processing of the mass spectral information obtained for identifying and/or quantifying the chemical content of said sample, wherein
• said means for directing a flow of a solution includes a tubular liquid transfer line;
• said means for thermal vaporization include means for solvent spray formation prior to said sample compounds vaporization followed by its expansion from said supersonic nozzle;
• said supersonic nozzle expands said vaporized sample compounds with subsequent internal vibrational cooling;
• said supersonic molecular beam contains both vaporized solvent and vibrationally cold sample compounds;
• said electron ionization ion source means is located downstream of said supersonic nozzle and is a fly through ion source for the ionization of said sample compounds while contained in said supersonic molecular beam as vibrationally cold compounds;
• said supersonic nozzle, vacuum system and fly through ion source provide enhanced molecular ions in the mass spectra of vibrationally cold compounds;
• and
• said means for data processing of the mass spectral information obtained is adopted for improved identifying and/or quantifying the chemical content of said sample by the availability of enhanced molecular ions compared with the particle beam method.

A mass spectrometric method for analyzing a sample in a solution for identifying and/or quantifying the chemical content of a sample, comprising the steps of:

• directing a flow of a solution containing sample compounds to be analyzed towards a supersonic nozzle;
• vaporizing the solution containing the sample compounds;
• expanding the vaporized sample from said supersonic nozzle into a vacuum system, forming a supersonic molecular beam;
• ionizing with electrons the vaporized sample compounds;
• mass analyzing the ions formed from said sample compounds;
• detecting said ions formed from said sample compounds after mass analysis;
• processing the data obtained from the resulting mass spectral information, for identifying and/or quantifying the chemical content of said sample, and wherein
• the flow of said solution is a liquid flow;
• said sample compounds vaporization being aided by a prior solvent spray formation;
• said spray droplets are evaporated and the emerging sample particles are further vaporized to form vaporized sample molecules;
• the vaporization of said sprayed directed flow of a solution containing sample compounds is effected prior to its expansion from said supersonic nozzle;
• cooling said vaporized sample compounds through its expansion from said supersonic nozzle;
• forming a supersonic molecular beam of both, vibrationally cold sample compounds and solvent molecules, and
• the ionization of said vibrationally cold sample compounds while contained in said supersonic molecular beam in a fly through electron ionization ion source.

A mass spectrometer apparatus for analyzing a sample in a solution for identifying and/or quantifying the chemical content of a sample, comprising:

• means for directing a flow of a solution containing sample compounds to be analyzed towards a supersonic nozzle;
• means for vaporizing said solution containing sample compounds;
• said supersonic nozzle enabling expansion of said vaporized sample compounds into a vacuum system, forming a supersonic molecular beam;
• electron ionization ion source means for ionizing said vaporized sample compounds;
• mass analyzer means for the mass analysis of the ions formed from said sample compounds;
• an ion detector for detecting said ions formed from said sample compounds after mass analysis, and means for data processing of the mass spectral information obtained for identifying and/or quantifying the chemical content of said sample, wherein said means for directing a flow of a solution includes a tubular liquid transfer line;
• means for solvent spray formation prior to said sample compounds vaporization;
• thermal vaporization means for vaporizing said directed flow of solution and sample compounds from its spray droplets prior to its expansion from said supersonic nozzle;
• said supersonic nozzle expands said vaporized sample compounds with subsequent internal vibrational cooling;
• said supersonic nozzle and vacuum system form a supersonic molecular beam of both vaporized solvent and vibrationally cold sample compounds, and
• said electron ionization ion source means is located downstream of said supersonic nozzle and is a fly through ion source for the ionization of said sample compounds while contained in said supersonic molecular beam as vibrationally cold compounds.