Method of improving a mass spectrometer, module for improving a mass spectrometer and an improved mass spectrometer

A method of determining the accuracy of an initial chemical identification obtained from mass spectral matching software:

• a) determine a retention time for each of 10 or more known chemicals, or determine a retention time for each of 68 or more known chemicals, each known chemical having an individual Chemical Abstracts Service (CAS) number (No.) and boiling point, using a mass spectrometer comprising mass spectral matching software, wherein the mass spectrometer and/or the mass spectral matching software sends an electronic signal indicating the determined retention time, the individual CAS No., and the boiling point for each of the known chemicals to an input/output controller, wherein the input output controller is configured to receive electronic signals from the mass spectrometer and/or the spectral matching software, to transmit electronic signals to one or more processing units, and to retrieve electronic signals from said one or more processing units;
• b) determine an actual retention time, a library match probability and a fragment pattern for each of one or more unidentified chemicals using the mass spectrometer used to determine the retention times of said one or more of known chemicals and determine one or more initial identifications for each of said one or more unidentified chemicals from said fragment patterns using said mass spectral matching software, wherein the mass spectrometer and/or the mass spectral matching software sends an electronic signal indicating the one or more identifications for each of the unidentified chemicals to the input/output controller;
• c) assign each of said one or more unidentified chemicals an individual CAS No. and boiling point based on each of said one or more unidentified chemicals initial identifications, wherein said one or more processing units is configured receive electronic signals indicating the initial identifications from input/output controller and assign the individual CAS No. and the boiling point to each of said one or more unidentified chemicals based on the initial identifications;
• d) using a cubic linear regression model, derive, using the one or more processing units, the line of best fit from the boiling point and retention time pairs of said known chemicals wherein each x value of a pair is the boiling point and each y value is the retention time and then generate, using the one or more processing units, a cubic linear regression curve for said known chemicals, wherein said one or more processing units is configured to derive said line of best fit and to generate said cubic linear regression curve;
• e) generate, using said one or more processing units, an equation corresponding to said cubic linear regression curve, wherein said one or more processing units is configured to generate an equation corresponding to said cubic linear regression curve;
• f) determine, using said one or more processing units, an extrapolated retention time for each unknown chemical by inserting, using said one or more processing units, each unknown chemical's boiling point into said equation, wherein said one or more processing units is configured to determine the extrapolated retention time for each unknown chemical by inserting each unknown chemical's boiling point into said equation;
• g) generate, using said one or more processing units, a boiling point score by:
• (i) comparing the extrapolated retention time for each unknown chemical with the actual retention time obtained for each unknown chemical, said comparison comprising calculating, using said one or more processing units, an adjusted z-test statistic for each unknown chemical;
• (ii) calculating, using said one or more processing units, a p-value for each unknown chemical using a two-tailed z test statistic on a normal curve;
• and
• (iii) then multiplying, using said one or more processing units, each said p-value by 100 to generate said boiling point score for each unknown chemical on a 0-100 scale;
• h) generating, using said one or more processing units, a final library matching score for each unknown chemical by multiplying, using said one or more processing units, each library match probability by 0.5;
• i) generating, using said one or more processing units, a Total Score for each unknown chemical by adding together, using said one or more processing units, said unknown chemical's Boiling Point Score and Final Library Matching Score;
• and
• j) optionally, rejecting, using said one or more processing units, the initial chemical identification of each unknown chemical having a Total Score of less than 75 and/or accepting, using said one or more processing units, the initial chemical identification of each unknown chemical having a Total Score of 75 or greater.