Quantitative carbon detector for enhanced detection of molecules in foods, pharmaceuticals, cosmetics, flavors, and fuels

Abstract

Analysis of trace compounds, such as pesticides and other contaminants, within consumer products, fuels, and the environment requires quantification of increasingly complex mixtures of difficult-to-quantify compounds. Many compounds of interest are non-volatile and exhibit poor response in current gas chromatography and flame ionization systems. Here we show the reaction of trimethylsilylated chemical analytes to methane using a quantitative carbon detector (QCD; the Polyarc™ reactor) within a gas chromatograph (GC), thereby enabling enhanced detection (up to 10×) of highly functionalized compounds including carbohydrates, acids, drugs, flavorants, and pesticides. Analysis of a complex mixture of compounds shows that the GC-QCD method exhibits faster and more accurate analysis of complex mixtures commonly encountered in everyday products and the environment.

Application and Validation of a Determination Method Using Post-column Reaction Gas Chromatography of Nitrogen-containing Organic Compounds

“…[11][12][13][14] Applications of postcolumn reaction GC-FID systems have also been reported by other research groups. [15][16][17][18][19] In this system, target components separated by column are completely converted to carbon dioxide at the oxidizing part and then completely reduced to methane, followed by detection using the FID. Therefore, the sensitivity is proportional to the number of carbon atoms of a target component, irrespective of the compound, and it is not necessary to prepare all the standard materials related to the target components to calibrate the system.…”

“…13,14 Applications for measuring NOCs have been reported before. [17][18][19] However, performances of the determined values were not sufficient in accuracy and precision. The reported result had a too large error (over 8% relative) 17 compared with the hydrocarbons measurement results (relative standard uncertainties of measured values: 0.15 -2.10%), 15 and the obtained value was not proportional to the number of carbon atoms in the target component (the effective carbon number was 0.96 ± 0.01, not 1.00), 18 therefore it is presumed that there was some bias or fault in the results.…”

“…[17][18][19] However, performances of the determined values were not sufficient in accuracy and precision. The reported result had a too large error (over 8% relative) 17 compared with the hydrocarbons measurement results (relative standard uncertainties of measured values: 0.15 -2.10%), 15 and the obtained value was not proportional to the number of carbon atoms in the target component (the effective carbon number was 0.96 ± 0.01, not 1.00), 18 therefore it is presumed that there was some bias or fault in the results. Only the average measurement error (2.6%) and the estimated standard deviation of measurement error (0.91%) were shown, and concrete measurement errors of each target species were not indicated.…”

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

“…When QCD is used, organic compounds eluting a column are first fully oxidized with air to carbon dioxide with heteroatoms forming their respective oxidized forms (e.g., nitrogen forms NO x ), as depicted in Figure A. In a subsequent reaction, fully oxidized products such as CO 2 undergo complete reduction on a catalyst surface in the presence of hydrogen gas to form methane . Consecutive catalytic reactions (oxidation and hydrogenation) occur in separate chambers of a microreactor filled with fixed beds of heterogeneous supported metal catalysts.…”

“…A broad range of chemicals has been evaluated by this method, including organic acids, furanics, paraffins, olefins, and aromatics, such as benzene/toluene/xylene . Additionally, the method was recently evaluated for the quantification by gas chromatography of low‐volatility compounds such as glucose, acetaminophen, vanillin, and furandicarboxylic acid (FDCA) via trimethylsilylation sample preparation . The compact, integrated design of the microreactor reduces the complexity of the setup and eliminates the need for additional valves, which increase the risk for leaks and chemical exposure.…”