High temperature gas chromatography–time-of-flight-mass spectrometry (HTGC–ToF-MS) for high-boiling compounds

High temperature gas chromatography (HTGC) is a routine technique for the analysis of high boiling compounds which are eluted from the column with oven cycling up to >400 °C. In contrast, the coupling of HTGC with mass spectrometry (HTGC–MS) has received relatively little attention. This may be due to the availability of GC columns, mass spectrometers and accessories that are able to withstand constant high temperature cycling. We have assembled a HTGC–time of flight-MS (HTGC–ToF-MS) system from readily available products that is capable of rapid (<25 min) analysis of ∼C10–100 hydrocarbon boiling equivalents and full mass spectral data recording up to m/z 1850. Here we report initial results from the analysis of diverse substrates including:long-chain (>C60) n-alkanes, n-acid methyl esters up to C64, triacylglycerides (TAGs) with molecular and fragment ions in a single analysis, intact wax esters from C40–64, C80 glycerol alkyl glycerol tetraethers (GDGTs), and C33–44 metallated porphyrins. Mass spectrometry at 430 °C was achievable on a routine basis without significant thermal degradation of analytes. The method is applicable to analysis of a wide range of industrial, environmental, biological, geochemical and other samples where high molecular weight analytes are of interest.

► HTGC was coupled with a time-of-flight mass spectrometer (HTGC–ToF-MS). ► HTGC–ToF-MS is viable with oven temperatures up to 430 °C. ► Molecular and fragment ions were obtained from triglycerides in a single analysis. ► On-line mass spectra were obtained for C40+ n-acid/wax esters and C80 tetraethers. ► On-line mass spectra were obtained for metallated C33 and C44 porphyrins.