Determination of diuron, terbuthylazine, and terbutryn in wastewater and soil by micellar liquid chromatography

Analytical capabilities of micellar liquid chromatography and application to residue and contaminant analysis: A review

Green chemistry is the use of chemistry to reduce or eliminate the use of generation of feedstocks, products, by-products, solvents, reagents, etc. that are hazardous to human health or the environment. One of the branches of green chemistry is micellar liquid chromatography. Micellar liquid chromatography is a reversed-phase liquid chromatographic mode with mobile phases containing a surfactant above its critical micellar concentration. The applications of micellar liquid chromatography for the determination of numerous compounds in pharmaceutical formulation, biological samples, food, environmental samples, and feeds have been growing rapidly. Micellar liquid chromatography technique has several advantages over other chromatographic techniques. Its main advantage is the small amount of organic modifiers used such as acetonitrile and methanol and the safety and recyclability of the mobile phase. In our work, we discuss the development of "green chemistry" and present what micellar liquid chromatography is. This article presents application methods with the use of micellar liquid chromatography for analysis on antibacterial substances, melamine, biogenic amines, plant protection products, flavonoids, as well as peptides in biological matrices such as milk, eggs, tissues, honey, and feed.

Multivariate analysis reveals significant diuron-related changes in the soil composition of different Brazilian regions

Sorption and desorption determine the amount of an herbicide in soil solution. Therefore, knowledge of the sorption and desorption coefficients in different soils is an essential factor to estimate the potential for environmental contamination by herbicides. We evaluated the feasibility of multivariate and linear discriminant analyses to predict the sorption and desorption capacity of a soil for diuron, one of the most used herbicides on sugarcane plantations. The adsorptive capacity in twenty-seven Brazilian soil samples was estimated using the sorption constant (Kfs) and desorption constant (Kfd) obtained by the Freundlich isotherms. The regression model was created from the sorbed and nonsorbed concentrations of diuron in soils. Ultra-performance liquid chromatography was applied to quantify the diuron concentrations. The multivariate analysis separated the soils into four groups considering the similarity of the following attributes: pH, organic matter, clay, and base saturation. The groups showed a similar pattern of sorption and desorption for diuron: Lom-Lclay: low sorption (5.9 ± 1.2) and high desorption (10.9 ± 0.6); Lclay: low sorption (7.5 ± 1.1) and high desorption (11.4 ± 1.3); Hom-Hclay: high sorption (11.2 ± 1.2) and low desorption (13.8 ± 1.2); HpH-Hclay: high sorption (10.1 ± 1.1) and medium desorption (11.5 ± 1.4). Linear discriminant analysis of these soil attributes was used to classify other soils described in the literature with adsorption capacity. This analysis was able to identify soils with high and low sorption using the pH, organic matter, clay, and base saturation, demonstrating the enormous potential of the technique to group soils with different contamination risks for subterranean waters. Sugarcane crops in northeastern Brazil showed a higher pollution risk through the leaching of diuron. Multivariate analysis revealed significant diuron-related changes in the soil composition of different Brazilian regions; therefore, this statistical analysis can be used to improve understanding of herbicide behavior in soils.