Quantification of heterocyclic aromatic compounds (NSO-HET) in fuels by offline HPLC-GC×GC-ToFMS.

Comprehensive two-dimensional gas chromatography; Diesel and gasoline; Fuel; Nitrogen; Quantification; Sulfur and oxygen compounds; Fuel samples; High-performance liquid chromatography; matrix; Offline; Sample preparation; Sulphur and oxygen compound; Time-of flight; Analytical Chemistry; Environmental Chemistry; Biochemistry; Spectroscopy

Abstract :

[en] [en] BACKGROUND: Polycyclic aromatic heterocycles containing nitrogen, sulfur and oxygen (NSO-HET) are toxic and persistent contaminants commonly found in fuels. The simultaneous determination of NSO-HET is hindered by matrix complexity, isomer overlap, and coelution with aromatic compounds. Conventional approaches rely on laborious steps like fractionation to reduce the complexity of the matrix before chromatographic analysis. The resolution power of the comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometric (GC × GC-ToFMS) allows fewer sample preparation steps; however, quantification studies by this technique are limited. This study addressed the analytical challenge of simultaneously quantifying NSO-HET in complex fuels by GC × GC-ToFMS with minimal sample preparation. RESULTS: An offline preparative high-performance liquid chromatography (HPLC) method was applied to enrich the aromatic fraction and remove interferences, followed by GC × GC-ToFMS analysis of 55 NSO-HET across six fuel samples. Sample preparation was simplified, resulting in a reduction of solvent and sample manipulation. The method was validated and demonstrated adequate performance, with low limits of detection and quantification (0.34-70.34 ng mL-1), recoveries from 56.6 % to 103 % and RSD values below 20 %. The method was successfully applied to both unfractionated and fractionated fuels. Marine diesel and diesel S-500 showed the highest concentrations, with 2,5,7-trimethylbenzothiophene and dibenzofuran at 943 ± 85.7 ng mL-1 and 884 ± 31.7 ng mL-1, respectively. Principal component analysis revealed significant discrimination among the samples based on compound class and concentration. This is the first study on the simultaneous quantification of a wide range of NSO-HET compounds in fuels samples by GC × GC-ToFMS. SIGNIFICANCE: The offline HPLC-GC × GC-ToFMS validated method enabled the accurate and simultaneous quantification of 55 individual NSO-HETs, including benzothiophenes, dibenzothiophenes, naphthobenzothiophenes, carbazoles, indoles, and dibenzofurans, in different fuels. It provides a robust alternative to traditional approaches for both industrial and research applications.

Disciplines :

Chemistry

Author, co-author :

Bomfim Bahia, Pedro Victor ; Universidade Federal da Bahia, Instituto de Química, Programa de Pós-Graduação em Química, 40170-115, Salvador, BA, Brazil, Instituto Nacional de Ciência e Tecnologia em Energia e Ambiente - INCT E&A, Universidade Federal da Bahia, 40170-115, Salvador, BA, Brazil

Rodrigues, Anaïs ; Université de Liège - ULiège > Département de chimie (sciences) > Chimie analytique, organique et biologique

Gorska, Aleksandra ; Université de Liège - ULiège > Département GxABT > Chemistry for Sustainable Food and Environmental Systems (CSFES)

Albendea, Paula ; Université de Liège - ULiège > Département GxABT > Chemistry for Sustainable Food and Environmental Systems (CSFES)

Bensaada, Djulia ; Université de Liège - ULiège > Molecular Systems (MolSys)

Stefanuto, Pierre-Hugues ; Université de Liège - ULiège > Département de chimie (sciences)

Focant, Jean-François ; Université de Liège - ULiège > Département de chimie (sciences) > Chimie analytique, organique et biologique

Purcaro, Giorgia ; Université de Liège - ULiège > Département GxABT > Chemistry for Sustainable Food and Environmental Systems (CSFES)

Machado, Maria Elisabete ; Universidade Federal da Bahia, Instituto de Química, Programa de Pós-Graduação em Química, 40170-115, Salvador, BA, Brazil, Instituto Nacional de Ciência e Tecnologia em Energia e Ambiente - INCT E&A, Universidade Federal da Bahia, 40170-115, Salvador, BA, Brazil. Electronic address: maria.elisabete@ufba.br

Language :

English

Title :

Quantification of heterocyclic aromatic compounds (NSO-HET) in fuels by offline HPLC-GC×GC-ToFMS.

Publication date :

22 November 2025

Journal title :

Analytica Chimica Acta

ISSN :

0003-2670

eISSN :

1873-4324

Publisher :

Elsevier, Netherlands

Volume :

1376

Pages :

344621

Peer reviewed :

Peer Reviewed verified by ORBi

Additional URL :

https://api.elsevier.com/content/article/PII:S0003267025010153?httpAccept=text/xml

Funding text :

The authors acknowledge financial support from the Brazilian agencies: Conselho Nacional de Desenvolvimento Cient\u00EDfico e Tecnol\u00F3gico (CNPq, process 140518/2022\u20133) and Coordenac\u00E3o de Aperfeicoamento de Pessoal de N\u00EDvel Superior (CAPES) - Programa Institucional de Internacionaliza\u00E7\u00E3o CAPES PRINT for Ph.D. grant (process 88887.932212/2024\u201300). Author Ana\u00EFs Rodrigues was supported by the University of Li\u00E8ge under Special Funds for Research , IPD-STEMA Program . Authors Aleksandra Gorska, Paula Albandea, and Giorgia Purcaro thank LECO and Restek for their continuous support.

Available on ORBi :

since 24 November 2025

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