Chlorination of benzothiazoles and benzotriazoles and transformation products identification by LC-HR-MS/MS

Maria-Christina Nika; Anna A Bletsou; Elena Koumaki; Constantinos Noutsopoulos; Daniel Mamais; Athanasios S Stasinakis; Nikolaos S Thomaidis

doi:10.1016/j.jhazmat.2016.03.035

Chlorination of benzothiazoles and benzotriazoles and transformation products identification by LC-HR-MS/MS

J Hazard Mater. 2017 Feb 5;323(Pt A):400-413. doi: 10.1016/j.jhazmat.2016.03.035. Epub 2016 Mar 17.

Authors

Maria-Christina Nika¹, Anna A Bletsou¹, Elena Koumaki², Constantinos Noutsopoulos², Daniel Mamais², Athanasios S Stasinakis³, Nikolaos S Thomaidis⁴

Affiliations

¹ Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Panepistimioupolis Zografou, 15771, Athens, Greece.
² Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou, Zografou 15780, Athens, Greece.
³ Water and Air Quality Laboratory, Department of Environment, University of the Aegean, 81100, Mytilene, Greece.
⁴ Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Panepistimioupolis Zografou, 15771, Athens, Greece. Electronic address: ntho@chem.uoa.gr.

PMID: 27036095
DOI: 10.1016/j.jhazmat.2016.03.035

Abstract

The fate of four benzotriazoles [1-H-benzotriazole (1-H-BTRi), tolyltriazole (TTRi), xylyltriazole (XTRi) and 1-hydroxy-benzotriazole (1-OH-BTRi)] and three benzothiazoles [benzothiazole (BTH), 2-hydroxy-benzothiazole (2-OH-BTH) and 2-amino-benzothiazole (2-amino-BTH)], during chlorination batch experiments was investigated. In the first step, their degradation under different experimental conditions (applied molar ratio of NaOCl and the target contaminant (m.r.), reaction's contact time, pH value of the reaction's solution and the influence of total suspended solids (TSS) presence) was investigated and their removal kinetics parameters (k_obs and t_1/2) were determined. In the second step, LC-QTOFMS/MS was used for the detection and identification of transformation products (TPs) formed during chlorination, through the application of suspect and non-target screening approaches. Four and five TPs of XTRi and 2-amino-BTH, respectively, were detected and tentatively identified, while 1-H-BTRi was proven to be formed by the chlorination of 1-OH-BTRi. Moreover, since the identified TPs were also detected in spiked wastewater samples, after lab-scale chlorination experiments, toxicity assessment was carried out by ECOSAR calculations for the environmental relevance of their occurrence. The proposed chlorinated TPs were proven to be more toxic than their parent compounds.

Keywords: Chlorination; High resolution mass spectrometry (HRMS); Kinetics; Micropollutants; Transformation products.