Abstract: The present invention addresses to an automated gas injection system in vials with rubber septa, for simultaneous injection of gas in 24 or more positions, with injection pressure control and/or overpressure detection, applied to mass spectrometry analyses and/or gas chromatography. The present invention can be used, for example, in isotopic analyses of geological materials in equipment with carbonate extraction units, in the cleaning and decontamination of tubes to be used in isotopic or chromatographic analyses, and in the removal of contaminants from steam drag or by continuous flow, or coming from the free space of vials or tubes in the analyses of organic and inorganic materials.