Analysis of alkylbenzene samples by comprehensive capillary liquid chromatography × capillary gas chromatography

The constituents in synthetic alkylbenzene samples were analyzed by a comprehensive capillary liquid chromatography (μ-LC) × capillary gas chromatography (CGC). The μ-LC separates the mixture into aliphatic compounds, monosubstituted alkylbenzenes, multisubstituted alkylbenzenes and binuclear aromatic compounds. Each fraction from a single μ-LC injection is stored in turn in a multiloop interface, and then transferred online into CGC sequentially with large volume in-column splitless injection technique for detailed analysis. No sample discrimination was found with this coupling and injection technique. Both the μ-LC column dimension and transfer speed of fraction from interface to CGC were optimized. Quantitative results and the carbon number distribution of each chemical class are obtained by using the comprehensive μ-LC × CGC with flame ionization detection. The reproducibility of peak area is better than 2% RSD.