Evaluation of comprehensive two-dimensional gas chromatography with flame photometric detection: Potential application for sulfur speciation in shale oil

作者：Mitrevski Blagoj; Amer Mohammad W; Chaffee Alan L; Marriott Philip J^*

来源：Analytica Chimica Acta, 2013, 803: 174-180.

DOI：10.1016/j.aca.2013.07.021

• Gas chromatography flame photometric
• detection
• Flame ionisation detection
• Shale oil
• Sulfur speciation
• Thiophenes
• Benzothiophenes

Flame photometric detection in the sulfur channel has been evaluated for sulfur speciation and quantification in comprehensive two-dimensional gas chromatography [GC x GC-FPD(S)] for S-compound speciation in shale extracts. Signal non-linearity and potential quenching effects were reportedly major limitations of this detector for analysis of sulfur in complex matrices. However, reliable linear relationships with correlation coefficient %26gt;0.99 can be obtained if the sum of the square root of each modulation slice in GC x GC is plotted vs. sulfur concentration. Furthermore, the quenching effects are reduced due to essentially complete separation of S-containing components from the hydrocarbon matrix. An increase of SIN of up to 150 times has been recorded for benzothiophene and dibenzothiophene in GC x GC-FPD when compared to GC-FPD due to the modulation process. As a consequence, 10 times lower detection limits were observed in the former mode. The applicability of the method was demonstrated using shale oil sample extracts. Three sulfur classes were completely separated and the target class (thiophenes) was successfully quantified after the rest of the sample was diverted to the second detector by using a heart-cut strategy. Based on the proposed method, 70% of the sulfur in the shale oil was assigned to the thiophenes, 24% to benzothiophenes, and 5% to dibenzothiophene compounds.

• 出版日期2013-11-25