Comprehensive two-dimensional gas chromatography for the analysis of nitrogen-containing compounds in fossil fuels: A review

The present review reports, for the first time, various comprehensive two-dimensional gas chromatography (GC x GC) applications for different fossil fuel matrices (crude oil, heavy gas oil (HGO), light and middle distillates, coal and shale oil) for the determination of nitrogen-containing compounds. The focus is on the various types of detectors (universal and specific), and their applicability for the separation and speciation of nitrogen compounds (N-compounds) was evaluated. The capability of GC x GC to provide additional chemically specific information using different detector types, including a flame ionization detector (FID), a nitrogen chemiluminescence detector (NCD), a nitrogen-phosphorus (NPD) detector and detectors in combination with mass spectrometry (MS), is described. The coelutions (detection by MS) for various N-compounds, analytes and components of other classes, such as those that are oxygenates and hydrocarbons, are discussed.