Quantitation - MateuszFido/LCMSpector GitHub Wiki

Accurate concentration determination often lies at heart of chromatographic and/or mass spectrometric analysis.

LC-Inspector features a simple calibration curve calculation based on external standards or benchmarking samples, allowing the user to select whichever files they want to use for quantitation and calculating concentrations in all the other samples using linear regression.

The linear model follows the standard Y = a + bX equation where Y is the detector's response (e.g., counts per second) and X is the concentration.

Concentrations can be defined by the user or inferred from the sample name by LC-Inspector. By default, if the regular expression detects a molar concentration, it's going to interpret it using the following conversion factors:

conversion_factors = {'m': 1e3, 'mm': 1, 'um': 1e-3, 'nm': 1e-6, 'pm': 1e-9}

with milimolar concentration being the default unit.

These inferences are only a suggestion and serve to speed up the analysis process -- the user can simply delete the inferred entries with one click and input their own concentration values as they see fit.

[!IMPORTANT] The concentration estimation is calculated by summing all the ion intensities for a given compound entry, that is adding the intensities of XICs of every m/z value entered for that compound on the Upload tab.

Example: I want to calculate the concentration of Caffeine in my samples. I have defined two ions to trace for Caffeine: [M+H]+ and [M-CH3OH+H]+. The concentration will be calculated by summing the integrated intensities for both ions and estimating from the calibration curve.