Back-flushing and heart cut capillary gas chromatography using planar microfluidic Deans’ switching for the separation of benzeneand alkylbenzenes in industrial samples

Planar microfluidic devices coupled with modern electronic pressure control have allowed gas chromatography (GC) practitioners to easily manipulate chromatographic systems to achieve heart cut and back-flushing configurations. These planar microfluidic devices have enhanced the connectivity between different components of GC instrumentation and have improved the inertness and minimised system dead volumes compared to classical chromatographic unions and valves. In the present contribution the setup and configuration of two multidimensional GC (MDGC) platforms is described for achieving the separation and quantification of trace level target C₆–C₈ alkylbenzenes in styrene monomer and Isoparaffin™ solvents, using flame ionisation detection (FID). The performance of these MDGC platforms indicated excellent retention time (0.2% relative standard deviation, RSD) and peak area repeatability (1% RSD) for all analytes of interest. The limit of detection (LOD) was 0.8 mg kg⁻¹ for benzene in styrene monomer, and 2.4–2.8 mg kg⁻¹ for C₆–C₈ alkylbenzenes such as benzene, toluene, ethylbenzene and xylene in Isoparaffin™ solvent.