Determination of the herbicide metribuzin and its major conversion products in soil by micellar electrokinetic chromatography

Abstract

In this paper, a multiresidue method for the analysis in soils of metribuzin (M) and its major conversion products, deaminometribuzin (DA), diketometribuzin (DK) and deaminodiketometribuzin (DADK) is developed. Considering the neutral and charged nature of the molecules, micellar electrokinetic chromatography (MEKC) is a very efficient method for the separation of these compounds, providing high efficiency and short analysis times. Different electrophoretic parameters were studied to optimize the separation, such as the buffer pH and concentration, sodium dodecyl sulphate (SDS) concentration, injection conditions and applied voltage. Excellent separation of the studied compounds was achieved within about 7 min. Soil samples were previously extracted using methanol in an ultrasonic bath and then a SPE procedure was applied to pre-concentrate the analytes by passage through a LiChrolut EN sorbent column. Detection limits at the low microgkg(-1) level were obtained. The proposed method has been satisfactorily applied in soil samples showing recoveries ranging from 86.7% to 104.2% and represents a valuable alternative to high-performance liquid chromatography (HPLC).

Recent advances in CE and CEC of pollutants

“…This method was successfully applied to the soil samples without a preliminary clean-up procedure, and the herbicides were measured without any interference from coexisting substances. Another study by Huertas-Perez et al [91] reported the use of MEKC for the analysis of metribuzin and its major conversion products in soils. Soil samples were extracted in an ultrasonic bath using methanol and an SPE procedure was then applied to cleanup and concentrate the analytes using a LiChrolut EN sorbent column.…”

“…Various approaches, including the improvement of detection system capabilities and/or preconcentration techniques, as outlined in Sections 2 and 3, have been proposed. This has resulted in the development of CE as an advantageous analytical tool that provides the separation power and detectability necessary for the analysis of trace amounts of pesticides [27,33,41] and herbicides [31,32,50,51,64,[89][90][91] in different environmental matrices.…”

Pressurised liquid extraction and capillary electrophoresis–mass spectrometry for the analysis of pesticide residues in fruits from Valencian markets, Spain

“…It is an attractive and simple analytical technique with a high efficiency, rapid separation speed of analysis, small consuming sample and low consumption of sample reagents (Hernández-Borges, Frías-García, Cifuentes, & Rodríguez-Delgado, 2004;Hernández-Borges, Rodríguez-Delgado, García-Montelogo, & Cifuentes, 2004;Hernán-dez-Borges, Rodríguez-Delgado, García-Montelogo, & Cifuentes, 2005a, 2005bHuertas-Pérez, del Olmo Iruela, García-Campaña, González-Casado, & Sánchez-Navarro, 2006;Pérez-ruíz, Martínez-Lozano, Sanz, & Bravo, 2005;Ravelo-Pérez, Hernández-Borges, & Rodríguez-Delgado, 2006;Zawiyah et al, 2007). CE has become a very useful tool for organic contaminants compounds but CE coupled to UV-detector, present a scarcely sensitive.…”

Extractive spectrophotometric method for determination of metribuzin herbicide and application of factorial design in optimization of various factors

“…Analysis of metribuzin has mainly been accomplished by different chromatographic methods such as liquid chromatography [5][6][7], micellar electrokinetic chromatography [8], solid-phase extraction and sample stacking-micellar electrokinetic capillary chromatography [9], capillary gas chromatography [10], capillary zone electrophoresis [11] and molecularly imprinted polymer [12]. All these methods are expensive, require long separation times and sometimes need the development of extremely complex gradient for the separation.…”