Development of heart-cutting multidimensional gas chromatography coupled to time of flight mass spectrometry for silicon speciation at trace levels in gasoline samples

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• 作者：Fabien Chainet ; Charles-Philippe Lienemann ; J¨¦r¨¦mie Ponthus ; Marion Courtiade ; Olivier Fran?ois Xavier Donard
• 关键词：Gas chromatography ; Heart cutting ; Deans switch ; Silicon ; Trace level ; Characterization ; Gasoline
• 刊名：Journal of Chromatography A
• 出版年：2012
• 出版时间：16 November, 2012
• 年：2012
• 卷：1264
• 期：Complete
• 页码：80-86
• 全文大小：818 K

文摘

To improve the understanding of hydrotreatment (HDT) catalyst poisoning by silicon species, these molecules must be characterized in petroleum products using powerful analytical systems. Heart-cutting gas chromatography coupled to time of flight mass spectrometry (GC-GC/TOFMS) method equipped with a Deans switch (DS) system was developed for the direct characterization of target silicon compounds at trace level (¦Ìg kg^?1) in gasoline samples. This method was performed to identify silicon compounds never characterized before. After the selection of the second dimension column using GC-GC-FID, GC-GC/TOFMS was performed. The calibration curves obtained by the GC-GC/TOFMS method were linear up to 1000 ¦Ìg kg^?1. Limits of detection (LOD) were ranging from 5 to 33 ¦Ìg kg^?1 in spiked gasoline. The method provided sufficient selectivity and sensitivity to characterize known silicon compounds thanks to their specific ions and their retention times. The analysis of a naphtha sample by GC-GC/TOFMS has shown the presence of cyclic siloxanes (D_n) as major compounds of PDMS thermal degradation with the occurrence of linear siloxanes, especially hexamethyldisiloxane (L₂), which was never characterized in petroleum products but already known as severe poison for catalyst.