Analysis of mixed plastic pyrolysis oil by comprehensive two-dimensional gas chromatography coupled with low- and high-resolution time-of-flight mass spectrometry with the support of soft ionization

• Published in: Talanta (Oxford) Vol. 252; p. 123799
• Main Authors: Beccaria, Marco, Piparo, Marco, Zou, Yun, Stefanuto, Pierre-Hugues, Purcaro, Giorgia, Mendes Siqueira, Anna Luiza, Maniquet, Adrien, Giusti, Pierre, Focant, Jean-François
• Format: Journal Article Web Resource
• Language: English
• Published: Elsevier B.V 15.01.2023
• Subjects: Analytical Chemistry; Bio-Oil; Central composite design; Central composite design (CCD); Central composite designs; Chemistry; Chimie; Comprehensive 2D-GC (GC×GC)-TOFMS; Gas Chromatography-Mass Spectrometry; Gas Chromatography-Mass Spectrometry/methods; GC soft Ionization HRMS; GC×GC-TOFMS; Mass Spectrometry; Mass Spectrometry/methods; Optimisations; Organic Chemicals; Photoionization interface; Photoionization interface (PI); Physical, chemical, mathematical & earth Sciences; Physique, chimie, mathématiques & sciences de la terre; Plant Oils; Plant Oils/chemistry; Plastic pyrolyse oil; Plastic pyrolysis; Plastic pyrolysis oil; Plastics; PTV optimization; Pyrolysis; Pyrolysis oil; Soft ionization; Plastic pyrolysis oil; Comprehensive 2D-GC (GC×GC)-TOFMS; GC soft Ionization HRMS; PTV optimization; Central composite design (CCD); Photoionization interface (PI)
• ISSN: 0039-9140; 1873-3573; 1873-3573
• DOI: 10.1016/j.talanta.2022.123799

According to the annual production of plastics worldwide, in 2020 about 370 million tons of plastic were produced in the world. Chemical recycling, particularly pyrolysis of plastic wastes, could be a valuable solution to resolve these problems and provide an alternative pathway to produce “recycled” chemical products for the petrochemical industry. Nevertheless, the pyrolysis oils need a detailed characterization before the upgrading test to re-use them to generate new recycled products. Multidimensional gas chromatography coupled with both low- and high-resolution time-of-flight mass spectrometers was employed for a detailed investigation among and within different chemical classes present in bio-plastic oil. The presence of several isomeric species as well as homologs series did not allow a reliable molecular identification, except for a few compounds that showed both MS similarity >800/1000 and retention index within ±20. Indeed, the identification of several isomeric species was assessed by high-resolution mass spectrometry equipped with photoionization interface. This soft ionization mode was an additional filter in the identification step allowing unambiguous identification of analytes not identified by the standard electron ionization mode at 70 eV. The injection method was also optimized using a central composite design to successfully introduce a wide range of carbon number compounds without discrimination of low/high boiling points. [Display omitted] •GC × GC-LR and HRTOFMS was employed for a deeper bio-plastic oil investigation .•Use of soft ionization MS interface in GC × GC (PI-HRTOFMS) to characterize isobaric molecules not identified using EI at 70 eV.•Optimization of PTV injection using CCD to limit discrimination among low/high boiling points.