Accuracy profile validation of a new analytical method for butane measurement using headspace-gas chromatography–mass spectrometry

The aim of our study was to provide an innovative HS-GC/MS method applicable to the routine determination of butane concentration in forensic toxicology laboratories. The main drawback of the GC/MS methods discussed in literature concerning butane measurement was the absence of a specific butane internal standard necessary to perform quantification. Because no stable isotope of butane is commercially available, it is essential to develop a new approach by an in situ generation of standards. To avoid the manipulation of a stable isotope-labelled gas, we have chosen to generate in situ an internal labelled standard gas (C4H9D) following the basis of the stoichiometric formation of butane by the reaction of deuterated water (D2O) with Grignard reagent butylmagnesium chloride (C4H9MgCl). This method allows a precise measurement of butane concentration and therefore, a full validation by accuracy profile was presented.

► We develop a method for gaseous alkanes generation analysis.
► This generation is based on the reaction of water and Alkyl-Grignard reagents.
► We apply this method to perform butane precise quantification.
► All gaseous alkanes can be investigated following this method.
► The method is especially designed for forensic applications.