DECOMPOSITION OF 2 METHYLBENZOTHIOPHENE SULFOXIDES IN A COMMERCIAL GAS-CHROMATOGRAPHY INJECTION PORT LINER

2-Methylbenzothiophene sulphoxide and 3-methylbenzothiophene sulphoxide were produced as metabolites by an aromatic hydro-carbon-degrading bacterial culture. Because dibenzothiophene sulphoxide is know to decompose in gas chromatography injectors, the two bacterial products were tested for their stability in a gas chromatography injection port containing a standard Jennings/cup mixing chamber. The two methylbenzothiophene sulphoxides were purified by silica gel chromatography and reversed-phase high-performance liquid chromatography. These sulphoxides decomposed in the injection port giving the corresponding methylbenzothiophene as the major product and the corresponding sulphone as a minor product. The proportions of decomposition products were quite variable and the amount of decomposition was greatest in an injection port liner that had been soiled by the routine analyses of dozens of petroleum samples.