Abstract: A method for determining a composition of a gas sample comprising the following steps: running the sample through a processing chain comprising a gas chromatography column and a gas detector arranged at the outlet of the gas chromatography column; obtaining, at the output of the detector, a representative electrical signal of the composition; determining the gas composition by processing this electrical signal. The determination of the composition of the sample is performed on the basis of a combination of a direct probabilistic model of the chromatography column, this model comprising at least one law of probability defining, for at least one gas species liable to be found in the sample, a probability at each moment that a molecule of this gas species is discharged from the chromatography column, and an impulse response model of the detector. It is performed by inverting this combination of models using the electrical signal.

Abstract: A model of evolution of a signal of a chromatographic column is formed, then inversed as a function of the measured signals, to calculate solute concentrations by using the entire signal. The model is based on equations that govern the transport of solutes in the column as a function of various physical parameters, which can be re-evaluated. The method can be used for searching and measuring rare components, such as proteins, in liquid biological samples.