Functional check and variance compensation in mass spectrometry

A test method for checking the function of a mass spec-trometer (5), characterized in that it comprises the following work steps:

• (a) feeding an eluate of a chromatographic separation system (1, 2) to a mass spectrometer (5);
• (b) continuous admixing of a separate target analyte solution to the eluate of a chromatographic separation system (1, 2) fed to the mass spectrometer,
• the separate target analyte solution having a known concentration and being admixed at a constant flow rate;
• (c) injecting the mixture produced in step (b) into the mass spectrometer (5) that comprises at least one detector (5′) providing a signal and generating a detector signal for the mixture produced in step (b);
• (d) capturing a mass spectrogram based on the detector signal generated in step (c), which mass spectrogram comprises an integration line (6) and a mass-spectrographic peak (7) of the target analyte, this integration line being a lasting background signal, which is underlaid to the mass-spectrometric analysis of the eluate;
• (e) evaluating the mass spectrogram produced in step (d) by capturing an integrated mass-spectrographic peak area (A) above the integration line (6) of the target analyte and an area (B) which is found under the integrated peak area (A) of the target analyte by perpendicular drop lines from the peak integration line (6);
• (f) forming a mathematical relationship from the determined mass-spectrographic areas A and B evaluated in step (e);
• (g) determining a threshold value for the mathematical relationship formed in step (f), which threshold value designates the border of the acceptable quality of a mass-spectrometric analysis, and
• (h) accepting or rejecting the mass-spectrometric analysis of a sample on the basis of a comparison of the mathematical relationship formed in step (f) with threshold value determined in step (g).