Analysis of pesticides residues in environmental water samples using multiwalled carbon nanotubes dispersive solid-phase extraction

• Published in: Journal of separation science 2013-02, Vol.36 (3), p.556-563
• Main Authors: González-Curbelo, Miguel Ángel, Herrera-Herrera, Antonio V., Hernández-Borges, Javier, Rodríguez-Delgado, Miguel Ángel
• Format: Article
• Language: English
• Subjects: Adsorption; Analysis methods; Analytical chemistry; Applied sciences; Biological and medical sciences; Chemistry; Chlorpyrifos; Chromatographic methods and physical methods associated with chromatography; Chromatography; Chromatography, Gas; Dispersive solid-phase extraction; Drinking water and swimming-pool water. Desalination; Environmental waters; Exact sciences and technology; Extraction processes; Food industries; Fundamental and applied biological sciences. Psychology; Gas chromatographic methods; Gas chromatography; Multiwalled carbon nanotubes; Nanotubes; Nanotubes, Carbon - chemistry; Natural water pollution; Non alcoholic beverage industries and mineral waters; Pesticide Residues - analysis; Pesticide Residues - isolation & purification; Pesticides; Pollution; Solid Phase Extraction - instrumentation; Solid Phase Extraction - methods; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - isolation & purification; Water treatment and pollution
• ISSN: 1615-9306; 1615-9314
• DOI: 10.1002/jssc.201200782

In this manuscript, a dispersive SPE method based on the use of multiwalled carbon nanotubes has been developed for the determination of 15 organophosphorus pesticides residues including some of their metabolites (disulfoton sulfoxide, ethoprophos, cadusafos, dimethoate, terbufos, disulfoton, chlorpyrifos‐methyl, malaoxon, fenitrothion, pirimiphos‐methyl, malathion, chlorpyrifos, terbufos sulfone, disulfoton sulfone, and fensulfothion) from real environmental waters (run‐off, mineral and tap water) by GC with nitrogen phosphorus detection. Factors that affect the enrichment efficiency such as sample volume, multiwalled carbon nanotubes amount, and volume of eluent were studied. The optimized method was validated in terms of matrix‐matched calibration, recovery, precision, and accuracy for the three analyzed samples. In this last case, the developed Student´s t test demonstrated that there were no significant differences between real and spiked concentrations. Optimum dispersive SPE conditions (extraction of 200 mL of water, pH 6.0, with 130 mg of multiwalled carbon nanotubes, elution with 25 mL of dichloromethane for run‐off and tap water and 30 mL for mineral water) allowed the quantitative extraction of analytes at levels lower than the maximum residues limits legislated by the European Union, with LODs between 1.16 and 93.6 ng/L. Absolute recovery values achieved were in the range of 67–107% (RSD values