A rapid and sensitive method for the determination of inorganic chloride in oil samples

Abstract

A novel isotope dilution method for the analysis of inorganic chloride in fuel oil matrix is presented. The samples were diluted by isopropyl alcohol:toluene, mixed with 37Cl 12 internal standard and reacted with triethyloxonium tetrafluoroborate at room temperature. This reagent promoted conversion of Cl 12 into stable ethyl chloride (EtCl) which was selectively detected by headspace GC\u2013MS/MS with no matrix effects. A limit of detection of 0.2\u202fmg\u202fkg 121 Cl 12 was obtained in fuel oil. The method was tested on the NIST SRM 1634c (trace elements in residual fuel oil) and validated through a series of robustness tests. Over 18 days, the variation in the signal response was less than 10% and the RSD for quantitative isotope dilution results was below 3%. Overall, the method is fast, simple and allows robust quantitation of inorganic chloride directly in the non-aqueous media.Peer reviewed: YesNRC publication: Ye