Complete carbon analysis of sulfur‐containing mixtures using postcolumn reaction and flame ionization detection

Abstract

Quantitative analysis of complex mixtures containing hundreds-to-thousands of organic compounds rich in heteroatoms, including oxygen, sulfur, and nitrogen, is a major challenge in the fuel, food, and chemical industries. In this work, a two-stage (oxidation and methanation) catalytic process in a 3-D-printed metal microreactor was evaluated for its capability to convert sulfur-containing organic compounds to methane. The microreactor was inserted into a gas chromatograph between the capillary column and flame ionization detector. Catalytic conversion of all sulfur-containing analytes to methane enabled carbon quantification without calibration, by the method identified as "quantitative carbon detection" or QCD. Quantification of tetrahydrothiophene, dimethyl sulfoxide, diethyl sulfide, and thiophene indicated complete conversion to methane at 4508C. Long-term performance of a commercial microreactor was evaluated for 2000 consecutive injections of sulfur-containing organic analytes. The sulfur processing capacity of the microreactor was identified experimentally, after which reduced conversion to methane was observed.

Low Temperature Catalytic Combustion Reactors for High Precision Carbon Isotope Measurements in Gas Chromatography Combustion Isotope Ratio Mass Spectrometry

“…PolyARC reactors were designed as methanizers, where the components in the effluent from the GC are combusted to CO 2 and then reduced to CH 4 using combustion and reduction chambers with transition metal catalysts. − This provides enhanced and consistent signal detection based on absolute carbon number of each molecule using flame ionization detectors (FID) at relatively low temperature (450–500 °C), and facilitates straightforward quantitative calibration of detector response. Here, the reactor was redesigned to contain only a catalytic combustion microchamber operating at a lower temperature (620 °C) than conventional IRMS combustion reactors.…”

“…Figure A and B show images of the two versions of the reactors “ARC1” and “ARC2” respectively. Figure C depicts a schematic of the device and its catalytic chemistry. − Input and output tubing to the ARC are on the bottom consisting of deactivated metal input/output capillaries in the flow path between the GC and IRMS and use robust leak-free metal ferrule unions. On the top is the input for the oxidation gas, such as Zero Air or He/1%O 2 blend, that mixes with the GC effluent to maintain oxidative capacity for the catalyst.…”

“…In this work, we customized, developed, and characterized low temperature catalytic reactors for GCC-IRMS based on the original PolyARC or “ARC” reactor (Activated Research Company, Eden Prairie, MN). − Performance of the reactors was evaluated with steroids that are normally analyzed by GCC-IRMS in doping control for detection of synthetic steroid use in sport. The reactor capabilities were determined using well- characterized pure steroid isotopic standards that were previously developed in our laboratory. , In addition to natural gas to explore combustion efficiency and sample linearity, here by directly injecting various amounts of CH 4 , we analyzed an isotopically standardized n -alkane mixture to demonstrate the method’s usefulness in both oil and gas exploration applications (e.g., tracing geological history of hydrocarbons). , …”

Quantification of 23 Volatile Organic Compounds with a Single Reference Material Using Post-column Reaction Gas Chromatography Combined with a Stainless-steel Heating Furnace

“…Thus, this technique is emerging as a reliable and convenient strategy for quantifying various types of organic compounds containing not only carbon, hydrogen, and oxygen, but also nitrogen and sulfur. 7,8 In contrast, although application notes have been provided by a manufacture, 9 there are no studies sufficiently on the application of this technique to organohalogen compounds, such as organochlorine and -bromine compounds; this should be partly attributed to their relatively poor oxidation characteristics, suspected from the polychlorinated biphenyls and brominated flame retardants.…”

Complex mixture quantification without calibration using gas chromatography and a comprehensive carbon reactor in conjunction with flame ionization detection

“…The use of a GC‐Polyarc/FID instrument has been demonstrated previously to determine highly functionalized molecules, including carbon monoxide, carbon dioxide, formic acid, formaldehyde, and formamide with higher detection response compare to a standard FID detector . It also was able to quantify sulfur‐containing hydrocarbon mixtures in a very simple fashion and no calibration method was involved . Furthermore, it was shown for use to accurately quantify (TMS‐derivatized‐) pharmaceutical, cosmetic, flavor, and fuel compounds, in mixtures without calibration, using a single IS .…”