Wastewater monitoring by means of e-nose, VE-tongue, TD-GC-MS, and SPME-GC-MS

Mohammed Moufid; Michael Hofmann; Nezha El Bari; Carlo Tiebe; Matthias Bartholmai; Benachir Bouchikhi

doi:10.1016/j.talanta.2020.121450

Wastewater monitoring by means of e-nose, VE-tongue, TD-GC-MS, and SPME-GC-MS

Talanta. 2021 Jan 1:221:121450. doi: 10.1016/j.talanta.2020.121450. Epub 2020 Jul 31.

Authors

Mohammed Moufid¹, Michael Hofmann², Nezha El Bari³, Carlo Tiebe², Matthias Bartholmai², Benachir Bouchikhi⁴

Affiliations

¹ Sensor Electronic & Instrumentation Group, Department of Physics, Faculty of Sciences, Moulay Ismaïl University of Meknes, B.P., 11201, Zitoune, Meknes, Morocco; Biotechnology Agroalimentary and Biomedical Analysis Group, Department of Biology, Faculty of Sciences, Moulay Ismaïl University of Meknes, B.P. 11201, Zitoune, 50003 Meknes, Morocco.
² Bundesanstalt für Materialforschung und -prüfung (BAM), 8.1 Sensors, Measurement and Testing Methods, Berlin, Germany.
³ Biotechnology Agroalimentary and Biomedical Analysis Group, Department of Biology, Faculty of Sciences, Moulay Ismaïl University of Meknes, B.P. 11201, Zitoune, 50003 Meknes, Morocco.
⁴ Sensor Electronic & Instrumentation Group, Department of Physics, Faculty of Sciences, Moulay Ismaïl University of Meknes, B.P., 11201, Zitoune, Meknes, Morocco. Electronic address: benachir.bouchikhi@gmail.com.

PMID: 33076073
DOI: 10.1016/j.talanta.2020.121450

Abstract

The presence of wastewater and air pollution has become an important risk factor for citizens, not only in terms of problems related to health risks, but also because of its negative impact on the country's image. For this reason, malodorous emission monitoring and control techniques are in high demand in urban areas and industries. The aim of this work is first to build an electronic nose (e-nose) and a Voltammetric Electronic tongue (VE-tongue) in order to study their ability to discriminate between polluted and clean environmental samples. Secondly, Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS), and Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry (SPME-GC-MS) are utilized to explain this discrimination by identifying specific compounds from these samples. Indeed, the e-nose, consisted of metal oxide semiconductor gas sensors, is used for the assessment of the studied odorous air and headspace samples from water and wastewater sites. Moreover, the VE-tongue, based on metal electrodes, is utilized to determine the patterns of the sensor array responses, which serve as fingerprints profiles of the analyzed liquid samples. Chemometric tools, such as Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Support Vector Machines (SVMs) are operated for the processing of data from the e-nose and the VE-tongue. By using the both systems, the analyses of headspace and liquid samples from the seven sites allow better discrimination. To explain the cause of the obtained discrimination, TD-GC-MS and SPME-GC-MS analyses are well performed to identify compounds related sites. According to these outcomes, the proposed e-nose and VE-tongue are proved to be rapid and valuable tools for analysis of environmental polluted matrices.

Keywords: Electronic nose; Solid phase micro extraction-gas chromatography–mass spectrometry; Thermal desorption-gas chromatography-mass spectrometry; Voltammetric electronic tongue; Wastewater.