Flow injection gas chromatography with sulfur chemiluminescence detection for the analysis of total sulfur in complex hydrocarbon matrixes

Abstract

A fast and reliable analytical technique for the determination of total sulfur levels in complex hydrocarbon matrices is introduced. The method employed flow injection technique using a gas chromatograph as a sample introduction device and a gas phase dual-plasma sulfur chemiluminescence detector for sulfur quantification. Using the technique described, total sulfur measurement in challenging hydrocarbon matrices can be achieved in less than 10 s with sample-to-sample time <2 min. The high degree of selectivity and sensitivity toward sulfur compounds of the detector offers the ability to measure low sulfur levels with a detection limit in the range of 20 ppb w/w S. The equimolar response characteristic of the detector allows the quantitation of unknown sulfur compounds and simplifies the calibration process. Response is linear over a concentration range of five orders of magnitude, with a high degree of repeatability. The detector's lack of response to hydrocarbons enables direct analysis without the need for time-consuming sample preparation and chromatographic separation processes. This flow injection-based sulfur chemiluminescence detection technique is ideal for fast analysis or trace sulfur analysis.

GC–MS with photoionization of cold molecules in supersonic molecular beams—Approaching the softest ionization method

“…This name was adopted from LC-MS systems in which a syringe pump is used to inject samples in liquids directly into the ion source and mass spectrometer without any column in order to save time while giving up separation. Flow injection was used and is described by Hua et al with GC-Sulfur Chemiluminescence detection in complex hydrocarbon mixtures 24 but to the best of our knowledge not in GC-MS. We used the GC-MS with Cold PI setup as is but maintained the column at high temperature such as 300 C to F I G U R E 1 A schematic diagram of GC-MS with photoionization of cold molecules in supersonic molecular beams (GC-MS with Cold PI). The various numbered components are described in the text eliminate (or minimize) the lengthy separation and thus sample injection is as usual from the GC injector yet it provides fast, several seconds analysis of unseparated sample compounds.…”