Method for mass spectrometry

A method for predicting during a batch sample analysis when a measurement of a known compound of interest will be affected by mass spectrometer orifice contamination, comprising:

• instructing an ion source device, before each sample of a series of batch samples is introduced into a liquid sample delivery device, to receive aqueous mobile phase solution from the liquid sample delivery device and to ionize compounds of the aqueous mobile phase solution using a processor, producing an ion beam of aqueous mobile phase solution compounds;
• instructing a tandem mass spectrometer, before each sample of the series of batch samples is introduced into the liquid sample delivery device, to receive the ion beam of aqueous mobile phase solution compounds from the ion source device, to perform a neutral loss or precursor ion scan to measure intensities of two or more precursor ions with different mass-to-charge ratio (m/z) values corresponding to a known aqueous mobile phase solution compound of the ion beam, producing an intensity measurement for each of the two or more different precursor ions and to store the measured intensity and time for each of the two or more different precursor ions in a memory device;
• comparing the measured intensity of each of the two or more different precursor ions with a previously measured intensity stored in the memory device until a threshold time is found for each of the two or more different precursor ions where a measured intensity of each of the two or more different precursor ions is reduced below a threshold intensity due to contamination of an orifice of the tandem mass spectrometer;
• and
• predicting a time when an intensity of a known compound of interest of the batch samples is reduced due to contamination of the orifice based on an m/z value of the known compound of interest and an m/z value and the threshold time of each of the two or more different precursor ions using the processor.

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 predicting during a batch sample analysis when a measurement of a known compound of interest will be affected by mass spectrometer orifice contamination, 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 each sample of a series of batch samples is introduced into a liquid sample delivery device, to receive aqueous mobile phase solution from the liquid sample delivery device and to ionize compounds of the aqueous mobile phase solution using the control module, producing an ion beam of aqueous mobile phase solution compounds;
• instructing a tandem mass spectrometer, before each sample of the series of batch samples is introduced into the liquid sample delivery device, to receive the ion beam of aqueous mobile phase solution compounds from the ion source device, to perform a neutral loss or precursor ion scan to measure intensities of two or more precursor ions with different mass-to-charge ratio (m/z) values corresponding to a known aqueous mobile phase solution compound of the ion beam, producing an intensity measurement for each of the two or more different precursor ions, and to store the measured intensity and time for each of the two or more different precursor ions in a memory device using the control module;
• comparing the measured intensity of each of the two or more different precursor ions with a previously measured intensity stored in the memory device until a threshold time is found for each of the two or more different precursor ions where a measured intensity of each of the two or more different precursor ions is reduced below a threshold intensity due to contamination of an orifice of the tandem mass spectrometer using the analysis module;
• and
• predicting a time when an intensity of a known compound of interest of the batch samples is reduced due to contamination of the orifice based on an m/z value of the known compound of interest and an m/z value and the threshold time of each of the two or more different precursor ions using the analysis module.