Abstract: The method includes extraction of gases contained in a mud, in order to obtain a gas stream of extracted gases containing hydrocarbons to be analyzed and at least one parasitic compound. The method includes transporting the gas stream through a transport line (54) and passing it through a separation column (121) in order to separate the hydrocarbons to be analyzed according to their elution times in the separation column (121). The parasitic compound is likely to have an elution time in the separation column (121) between the elution time for the first hydrocarbon to be analyzed and the elution time of the final hydrocarbon to be analyzed. The method includes passing the gas stream over a surface (141) for chemical and/or physical interaction with the parasitic compound in order to selectively retain the or each parasitic compound without retaining the hydrocarbons to be analyzed.

Abstract: This device comprises a means (111) for forming a gaseous flow from the sample, and a means (121) for separation by means of selective retention each gaseous constituent. It comprises a means (113) for combustion of the gaseous flow in order to form a gaseous residue from each constituent, and a means (115) for quantifying the content of each constituent to be analysed in the gaseous flow. The quantification means (115) comprise an optical measurement cell (127) which is connected to the combustion means (113), and a means (161) for introducing a laser incident optical signal into the cell (127). The quantification means (115) also comprise means (133) for measuring a transmitted optical signal resulting from an interaction between the optical signal and each gaseous residue in the cell (127), and means (125) for calculating said content on the basis of the transmitted optical signal.

Abstract: This device includes a stage for forming a gaseous flow from the sample, and a column for separation by selective retention of each gaseous constituent. It includes an oven for combustion of the gaseous flow in order to form a gaseous residue from each constituent, and a quantification unit for quantifying the content of each constituent to be analyzed in the gaseous flow. The quantification unit includes an optical measurement cell connected to an oven, and a mirror for introducing a laser incident optical signal into the cell. The quantification unit also measures a transmitted optical signal resulting from an interaction between the optical signal and each gaseous residue in the cell, and calculates the content on the basis of the transmitted optical signal.