Method for mass spectrometry

A method for determining if an aqueous mobile phase solution is properly being delivered by a mass spectrometry liquid sample delivery device, comprising:

• Instructing, using a processor, an ion source device, before a sample is introduced into a liquid sample delivery device, to receive the aqueous mobile phase solution from the liquid sample delivery device and ionize compounds of the aqueous mobile phase solution, producing an ion beam of aqueous mobile phase solution compounds;
• instructing using the processor a tandem mass spectrometer, before the sample is introduced into a liquid sample delivery device, or after analysis of the sample but before another sample is introduced into the liquid sample delivery device, to receive the ion beam of aqueous mobile phase solution compounds from the ion source device, perform a first neutral loss scan of the ion beam with a first neutral loss value set to a molecular weight of a first known solvent, producing a first intensity, and perform a second neutral loss scan of the ion beam with a second neutral loss value set to a molecular weight of a second known solvent, producing a second intensity;
• calculating a ratio of the first intensity to the second intensity using the processor;
• and
• determining using the processor, based on the calculated ratio being constant for intensity measurements from first and second neutral loss scans, performed at different time periods using respective first and second neutral loss values, that the aqueous mobile phase solution reached steady state conditions.

A computer program product, comprising a non-transitory and tangible computer-readable storage medium whose contents include a program with instructions being executed on a processor to perform a method for determining if an aqueous mobile phase solution is properly being delivered by a mass spectrometry liquid sample delivery device, the method comprising:

• providing a system, wherein the system comprises one or more distinct software modules, and wherein the distinct software modules comprise a control module and an analysis module;
• instructing an ion source device, before a sample is introduced into a liquid sample delivery device, to receive the aqueous mobile phase solution from the liquid sample delivery device and ionize compounds of the aqueous mobile phase solution, producing an ion beam of aqueous mobile phase solution compounds, using the control module;
• instructing a tandem mass spectrometer, before the sample is introduced into a liquid sample delivery device, or after analysis of the sample but before another sample is introduced into the liquid sample delivery device, to receive the ion beam of aqueous mobile phase solution compounds from the ion source device, perform a first neutral loss scan of the ion beam with a first neutral loss value set to a molecular weight of a first known solvent, producing a first intensity, and perform a second neutral loss scan of the ion beam with a second neutral loss value set to a molecular weight of a second known solvent, producing a second intensity, using the control module;
• calculating a ratio of the first intensity to the second intensity using the analysis module;
• and
• determining using the analysis module, based on the calculated ratio being constant for intensity measurements from first and second neutral loss scans, performed at different time periods using respective first and second neutral loss values, that the aqueous mobile phase solution reached steady state conditions.