Dispersive micro solid-phase extraction of triazines from waters using oxidized single-walled carbon nanohorns as sorbent

Abstract

This article evaluates the usefulness of dispersed single-walled carbon nanohorns as sorbent for the isolation and preconcentration of triazines from waters. For this purpose, the carbon nanoparticles were oxidized to increase their solubility in aqueous media in order to obtain a stable dispersion that can be used as extractant of the selected pollutants. Then, 1 mL of the dispersion containing the oxidized single-walled carbon nanohorns at a concentration of 0.2 g/L was added to 10 mL of sample and stirred for 2 min using a vortex. Then, the whole volume was passed through a disposable 0.45 μm Nylon filter which retained the nanoparticles enriched with the triazines. Further elution with methanol permitted the gas chromatographic analysis of the analytes and subsequent identification and quantification by mass spectrometry working under the selected ion monitoring mode (SIM). The limits of detection (LODs) were in low nanogram per liter level, which allowed the detection of the selected triazines at the concentration stated by legislation. The precision of the method, calculated as relative standard deviation, was acceptable in all instances. Finally, the recovery study carried out in different water samples provided average values between 87% and 94%. The results obtained revealed the applicability of oxidized single-walled carbon nanohorns for the proposed analytical problem.