Stimultaneous quantitative analysis using dual capillary columns of different polarities

Abstract

Complex organic mixtures, such as coal liquefaction and oil shale products and by‐products, are comprised of hundreds or thousands of individual components. State‐of‐the‐art high resolution gas chromatography does not always provide sufficient resolution to allow accurate quantitation or identification of many compounds of interest. The concept of dual capillary column chromatography combines the different resolving characteristics of two capillary columns coated with different stationary phases into a single chromatographic run. In this approach, both columns are connected to the same injection port. Analysis of complex mixtures in this fashion can confirm the identification and quantitation of components on two columns of different polarity with little increased analysis time, can provide a means of obtaining quantitative data for individual components which are known to coelute on any one column, and can alert one to unknown coelution problems that would be undetected by gas chromatographic analysis on a single capillary column. Simultaneous dual column analysis was applied to three samples, the neutral polycyclic aromatic hydrocarbon (PAH) fraction of a Solvent Refined Coal‐II (SRC‐II) heavy distillate, the nitrogen‐containing polycyclic aromatic compound (N‐PAC) fraction of an SRC‐II heavy distillate, and the basic fraction from a shale oil process water. Fused silica capillary columns coated with SE‐54 and Durawax 3 were used for the analyses of the heavy distillate, while SE‐54 an Carbowax 20M capillary columns were used for the analysis of the process water.

Integrated, multiple-stage chromatographic method for the separation and identification of polycyclic aromatic hydrocarbons in complex coal liquids

“…Quantitation was based on the average response factors of standard compounds chromatographed at eight concentrations ranging over 2 orders of magnitude as previously described (34,35). All standard compounds used were either purchased from Aldrich Chemical Co. (Milwaukee, WI) or obtained from private sources.…”

Reconfigured, close-coupled reconfigured, and Wyodak coal integrated two-stage coal liquefaction process materials from the Wilsonville facility: Chemical and toxicological evaluation

“…When no quantitative values are reported, either no data was collected or none was detected above approximately 25 ppm in a particular fraction. PAH and NPAC fractions were futher monitored for the presence of nitrogen-containing components by simultaneous injection onto two 15-m x 0.25-rnm-ID fused silica columns coated with 0.25 )..lm film thickness bonded methyl (5% phenyl) silicone gum (Quadrex Corp., New Haven, Cf) according to the method of Wright (1984). One column was connected to the universal FID, while the other column was connected to the nitrogen-specific nitrogen-phosphorus detector (NPD).…”

Multidimensional High-Resolution Gas Chromatographic Investigations of Hydrocarbon Fuels and Various Turbine Engine Fuel Precursors.

“…Studies have been conducted that [22,231 employed a sequential series of columns where individual members were held at different isothermal temperatures. Also, systems have been assembled which use dissimilar stationary phase columns in parallel and in series/parallel arrangements [24,25].…”