Optimizing loop-type cryogenic modulation in comprehensive two-dimensional gas chromatography using time-variable combination of the dual-stage jets for analysis of crude oil.

Autor: Alexandrino GL; Institute of Chemistry, State University of Campinas, Cidade Universitária Zeferino Vaz, 13083-970 Campinas, SP, Brazil. Electronic address: guialexandrino@iqm.unicamp.br., de Sousa GR Júnior; Institute of Chemistry, State University of Campinas, Cidade Universitária Zeferino Vaz, 13083-970 Campinas, SP, Brazil., de A M Reis F; Institute of Chemistry, State University of Campinas, Cidade Universitária Zeferino Vaz, 13083-970 Campinas, SP, Brazil., Augusto F; Institute of Chemistry, State University of Campinas, Cidade Universitária Zeferino Vaz, 13083-970 Campinas, SP, Brazil.
Jazyk: angličtina
Zdroj: Journal of chromatography. A [J Chromatogr A] 2018 Feb 09; Vol. 1536, pp. 82-87. Date of Electronic Publication: 2017 Oct 25.
DOI: 10.1016/j.chroma.2017.10.054
Abstrakt: The enhanced chromatographic capability of the comprehensive two-dimensional gas chromatography (GC×GC) has already found several applications in analytical chemistry comprising complex samples. However, setting the appropriate chromatographic conditions that maximize sensitivity and separation efficiency in GC×GC may be more difficult than in conventional one-dimension gas chromatography, mainly due to the additional parameters strictly related to the modulation. Loop-type cryogenic modulators have been currently used for crude oil analysis using GC×GC, requiring sometimes a laborious try-and-error procedure to properly tune the dual-jets elapsed times on modulation. In this work, the advantages of choosing a time-variable combination of cold and hot jets pulses in a loop-type cryogenic modulator is presented when performing the fingerprinting analysis of crude oils using GC×GC-QMS, contrary to the conventional procedure based on a single combination for the dual-stage jets. A design of experiments approach is proposed to most effectively optimize the time-variable combination of the dual-jets elapsed times while modulating the wide hydrocarbons range along the GC×GC analysis. The most abundant classes of hydrocarbons contained in the maltenes fraction of a crude oil sample, such as paraffins, aromatics, steranes and hopanes were successfully resolved.
(Copyright © 2017 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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