Evaluation of a novel controlled-atmosphere flexible microtube plasma soft ionization source for the determination of BTEX in olive oil by headspace-gas chromatography/mass spectrometry

• Published in: Analytica chimica acta 2021-09, Vol.1179, p.338835-338835, Article 338835
• Main Authors: Moreno-González, David, Castilla-Fernández, Delia, Vogel, Pascal, Niu, Guanghui, Brandt, Sebastian, Drees, Carolin, García-Reyes, Juan F., Molina-Díaz, Antonio, Franzke, Joachim
• Format: Article
• Language: English
• Subjects: Ambient ionization source; BTEX; Gas chromatography; Mass spectrometry; Olive oil; Plasma
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2021.338835

Although electron impact ionization (EI) remains the standard ionization source for GC-MS, it presents extensive fragmentation as its main limitation. The potential of a novel plasma-based soft ionization source named controlled-atmosphere flexible microtube plasma (CA-FμTP) has been evaluated in this work for the determination of monoaromatic volatile BTEX group (namely benzene, toluene, ethylbenzene, and o-, m- and p-xylenes) in olive oil, based on headspace technique. The obtained results show an attractive advantage over EI due to no fragmentation was observed. A nitrosated ion [M + NO]+ is obtained as the most abundant species. Thus, the BTEX mass spectrum identification can be carried out without major effort. In general, the sensitivity for CA-FμTP was comparable to those obtained by EI, achieving LODs ranged from 0.6 to 1.0 μg kg−1. The potential usefulness of GC-CA-FμTP-MS for the detection of BTEX was demonstrated by analyzing olive oil samples and identifying traces of these compounds in one sample. Therefore, the proposed plasma-based soft ionization is suitable for BTEX analysis in fatty complex matrixes as olive oil. [Display omitted] •Evaluation of the analytical performance of CA-FμTP source for GC-MS.•The proposed interface provided a no fragmented spectrum.•Sensitivity matching commercial electronic impact ionization.•The proposed GC-CA-FμTP-MS method was applied for the analysis of BTEX in olive oil samples.