Qualitative and quantitative study of nitrogen‐containing compounds in heavy gas oil using comprehensive two‐dimensional gas chromatography with nitrogen phosphorus detection

Abstract

Qualitative and quantitative study of nitrogencontaining compounds in heavy gas oil using comprehensive two-dimensional gas chromatography with nitrogen phosphorus detectionIn this work, a GC6GC -nitrogen -phosphorus detection (NPD) methodology was developed to separate and quantitate nitrogen-containing compounds in Brazilian heavy gas oil. First, the NPD performance was improved in order to achieve best GC6GC performance. The geometry of this detector was also evaluated. The use of an extended jet improved significantly the peak shape. The GC6GC separation was studied using both first and second dimension columns with different internal diameters. The use of a thicker film in both dimensions provided better performance. LODs of 0.16 -8.49 pg of individual compounds were achieved. Two different extraction techniques of the neutral and basic nitrogen-containing compounds were also evaluated. The method using ion-exchange resins to separate neutral and basic nitrogen-containing compounds was more efficient than the method using modified silica. As an example, the amounts (lg/g) of each class reported were: indole (2.77), alkyl carbazoles ranging from C 0 to C 6+ (1.467), alkyl benzocarbazoles from C 0 to C 4+ (793), alkyl quinolines (31.2) and alkyl benzoquinolines (21.6) were quantitated.

Trace Analysis of Carbazole in Commercial Diesel by using Adsorption on Activated Biochar from Rice Husk Pyrolysis

“…To overcome the problems of having a low concentration of nitrogen compounds in diesel, it was vital perform a previous enrichment step. Several approaches have been proposed for the speciation of nitrogen in diesel, and a lot of methods for their isolation are reported in the literature [34,35,[49][50][51][52].However, these methods generally comprise a combination of several analytical steps and use different laborious techniques, such as liquid-liquid extraction [51,52], solid-phase extraction [49,50], ion-exchange chromatography [34,35], and others [53]to concentrate and isolate the nitrogen compounds in diesel. The liquid-liquid extraction methods are complex and may cause the significant loss particular types of nitrogen compounds, such as the more neutral species, due to their lower extraction selectivity.…”

“…The liquid-liquid extraction methods are complex and may cause the significant loss particular types of nitrogen compounds, such as the more neutral species, due to their lower extraction selectivity. Most of these proposed techniques involve separation by open column chromatography [34,35,49]and though useful, use large volumes of solvents and many expensive materials and demand long separation times. Furthermore, these separation processes show low selectivity for nitrogen species, poor control over sorbent activity, and incomplete separation of the specific compound classes.…”

“…Nitrogen compounds in diesel fuel have typically been studied using GC with several specific detectors, including nitrogen and phosphorus (NPD) [35], nitrogen chemiluminescence (NCD) [53] and mass spectrometer (MS) [34] detectors. However, the complexity of diesel matrices and the limited peak capacity of GC columns appear, many times, as a drawback for the identification of nitrogen compounds during analytical separation, due to co-elution with interferences [35].…”

“…Since nitrogen compounds are more difficult to be eliminated in hydroprocessing, several methods for their isolation are described in the literature [34,35]. However, many procedures use separation with open column liquid chromatography, which implies the use of large volumes of solvent, costly adsorbent materials as stationary phases, and long separation times.…”

Determination of basic azaarenes in aviation kerosene by solid‐phase extraction and HPLC‐fluorescence detection

“…The determination of azaarenes has been carried out by different chromatographic techniques, including LC with fluorescence [18,28,30] or UV photometric [27,31] detection, GC coupled with MS [6, 18 -20, 22], and 2-D GC with nitrogen -phosphorous detector used for a nitrogen-specific detection [24] and MS detection [32,33].…”