Dispersive multi-walled carbon nanotubes extraction of benzenesulfonamides, benzotriazoles, and benzothiazoles from environmental waters followed by microwave desorption and HPLC-HESI-MS/MS

Abstract

This work shows a novel analytical method for the simultaneous extraction of environmental emerging contaminants as benzenesulfonamides (BSAs), benzotriazoles (BTRs), and benzothiazoles (BTs) from water samples. Pristine multi-walled carbon nanotubes (MWCNTs), not yet tested for such analytes, are here employed as the sorbent phase for dispersive solid-phase extraction (d-SPE) followed by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-HESI-MS/MS). Quantitative sorption is gained by treating 50 mL sample with 100 mg MWCNTs (2 g L) in 10 min contact, both in tap and raw river water. After sorption, the analytes are quantitatively desorbed by microwaves (20 min, 160 °C, 250 W) by using 5 mL methanol-ethylacetate-acetic acid (10:70:20, v/v), according to the indications obtained by a chemometric study. The extract is reduced to small volume before analysis, thus reaching overall enrichment factors up to 400. Recovery of the entire procedure, evaluated on tap and surface water samples spiked with 0.1/0.5-50 μg L of each analyte, was in the range 70-116%, with excellent inter-day precision (RSD < 7%). Selectivity and firm analyte identification were assured by MRM detection, and suitable sensitivity was obtained for determination of these pollutants in actual matrices (experimental MDLs 30-170 ng L). The proposed analytical method was applied to the analysis of surface water samples, containing concentrations of these contaminants ranging from 100 ng L to 2 μg L. Pristine MWCNTs proved to be a valid alternative to other commercial sorbents, both in terms of cost and sorption capacity. Graphical abstract Determination of benzenesulfonamides, benzotriazoles, and benzothiazoles in environmental waters by dispersive multi-walled carbon nanotube extraction prior HPLC-MS.

Presence of benzotriazoles, benzothiazoles and benzenesulfonamides in surface water samples by liquid chromatography coupled to high‐resolution mass spectrometry

“…Typically, BTRs, BTs and BSAs in water samples are determined by liquid chromatography mainly coupled to tandem mass spectrometry [11][12][13][14][15][16][17][18]24] even though highresolution mass spectrometry (HRMS) is also used in some studies [19,23]. In the past few years, the use of HRMS based on time-of flight or Orbitrap analysers for trace analysis has become more widely accepted and affordable.…”

“…However, results have also been satisfactory when mixed‐mode anion and cation exchange sorbents have been used to extract BTRs, BTs and BSAs from river, influent and effluent wastewaters. Dispersive liquid‐liquid microextraction , solid‐phase microextraction , stir bar sorptive extraction and dispersive solid‐phase extraction have also been used to extract these compounds from aqueous matrices such as tap water, river water, treated wastewater and raw wastewater.…”

Humic Acids Pyrolyzed onto Silica Microparticles for Solid-Phase Extraction of Benzotriazoles and Benzothiazoles from Environmental Waters

“…In this work, HA-C@silica has been investigated for pre-concentration from environmental waters of benzothiazoles (BTs) and benzotriazoles (BTRs), heterocyclic compounds made of two fused aromatic rings, classified as high-volume production chemicals and contaminants of environmental concern [9,10]. BTs are extensively used as vulcanisation accelerators in the manufacture of rubber, biocides in paper and leather manufactures, corrosion inhibitors in antifreeze formulations and photosensitizers in photography [11][12][13][14]. BTRs are widely used as complexing agents, reactants in chemical syntheses for pharmaceuticals, dyes and fungicides, ultraviolet stabilisers and corrosion inhibitors in some fluids (e.g.…”

“…BTRs are widely used as complexing agents, reactants in chemical syntheses for pharmaceuticals, dyes and fungicides, ultraviolet stabilisers and corrosion inhibitors in some fluids (e.g. antifreeze formulations, cooling systems, hydraulic fluids or dishwasher detergents) [12][13][14][15][16][17]. Their extensive usage-just in the United States the annual usage of BTRs has been estimated to be about 9000 t/year [18,19]-and their chemical properties, such as polarity and high solubility in aqueous phases [13], make BTs and BTRs ubiquitous contaminants so much to be considered as the footprint of daily use products [16].…”

“…Their extensive usage-just in the United States the annual usage of BTRs has been estimated to be about 9000 t/year [18,19]-and their chemical properties, such as polarity and high solubility in aqueous phases [13], make BTs and BTRs ubiquitous contaminants so much to be considered as the footprint of daily use products [16]. Previous studies have reported their occurrence at concentrations from few to some thousands of micrograms per litre also in treated wastewater due to the poorly abatement by conventional wastewater treatment plants (WWTP) [13,14,16,17,19]. Presently, trigger limits (≤ 20 µg L −1 ) have been fixed in surface water only for 1-H-benzotriazole (BTH) and 5-methyl-1-H-benzotriazole (5-TTR) [9,17,20], but their widespread in the environment is reason of concern due to their adverse effects on aquatic organisms, microbial communities and mammals, even at low concentrations.…”