Analysis of the Volatile Organic Matter of Engine Piston Deposits by Direct Sample Introduction Thermal Desorption Gas Chromatography/Mass Spectrometry

Abstract

This article establishes an alternative method for the characterization of volatiles organic matter (VOM) contained in deposits of the piston first ring grooves of diesel engines using a ChromatoProbe direct sample introduction (DSI) device coupled to gas chromatography/mass spectrometry (GC/MS) analysis. The addition of an organic solvent during thermal desorption leads to an efficient extraction and a good chromatographic separation of extracted products. The method was optimized investigating the effects of several solvents, the volume added to the solid sample, and temperature programming of the ChromatoProbe DSI device. The best results for thermal desorption were found using toluene as an extraction solvent and heating the programmable temperature injector from room temperature to 300 degrees C with a temperature step of 105 degrees C. With the use of the optimized thermal desorption conditions, several components have been positively identified in the volatile fraction of the deposits: aromatics, antioxidants, and antioxidant degradation products. Moreover, this work highlighted the presence of diesel fuel in the VOM of the piston deposits and gave new facts on the absence of the role of diesel fuel in the deposit formation process. Most importantly, it opens the possibility of quickly performing the analysis of deposits with small amounts of samples while having a good separation of the volatiles.

Physicochemical Characterization of the Synthetic Lubricating Oils Degradation under the Effect of Vehicle Engine Operation

“…Moreover, Figure 10 shows the mass spectrum (1) of the product of one of the small bands observed, and that (2) of 4-(3,5-di-tert-butyl-4-hydroxyphenyl) butyl acrylate (C21H32O3) whose mass spectrum is available in the NIST spectrum library. The comparison of these two mass spectra reveals that the structure of the products observed in GC in the form of small bands corresponds to a phenolic type antioxidant structure [21].…”

The development of ultrasound-assisted extraction/dispersive liquid–liquid microextraction coupled with DSI-GC-IT/MS for analysis of essential oil from fresh flowers of Edgeworthia chrysantha Lindl.

“…It is based on the introduction of the sample in a disposable microvial which is then placed into a ChromatoProbe vial holder, which is directly inserted into a temperature programmable GC injector. Initially, the extraction solvent is evaporated at a temperature value corresponding to the solvent boiling point minus $5 C. 52 Then with elevation of temperature, the target analytes were thermally extracted into the early portion of the GC column, while the impurity and other nonvolatile residues remained in the vial. The technique has been reported in a wide variety of elds.…”

“…The technique has been reported in a wide variety of elds. [52][53][54] The aim of the present work was to employ UAE-DLLME coupled with DSI-GC-MS for extraction and preconcentration of essential oils of Edgeworthia chrysantha Lindl. at different owering stages.…”

Comparison of solvent extraction and thermal desorption methods for determination of volatile polyfluorinated alkyl substances in the urban atmosphere

“…The major disadvantage is the sample dilution, which could result in up to 1000-fold raise in detection limit and require large sample volumes of air. 20 Furthermore, the evaporative loss in the solvent reduction stage results in low recoveries, especially for some volatile organic compounds. 18,21 Although the loss of analytes sometimes can be corrected by the use of isotopically labeled surrogates, it might compromise the accuracy of quantitative analysis.…”