The QuEChERS analytical method combined with low density solvent based dispersive liquid–liquid microextraction for quantitative extraction of multiclass pesticide residues in cereals

Abstract

ABSTRACT. In this study, a combination QuEChERS and low density solvent based DLLME was developed for extraction and preconcentration of five multiclass pesticide residues including atrazine, ametryn, terbutryn, carbaryl and chlorothalonil, from selected cereals: Teff, barley and maize samples. Liquid chromatography with variable wavelength detector (VWD) was used for quantitative determination of the pesticides. Various experimental parameters affecting the extraction and the preconcentration efficiencies were optimized. Calibration curves constructed using Teff samples were linear over wide ranges, 7.1-200 μg kg -1 with R 2 ≥ 0.990. LODs of the method were ≤ 8.9 μg kg -1 , below the MRLs of EU for maize and barley. The RSDs were in the range of 2.3-9.5%. The method has also been applied to different cereal samples and satisfactory average recoveries ranging 69.0-117% were obtained for the spiked cereal samples at two concentration levels. Therefore, the developed method can be successfully utilized as a simple alternative for the analysis of multiclass pesticide residues in cereals and other related samples.

Removal of imidacloprid using activated carbon produced from ricinodendron heudelotii shells

“…Quantitative determination of functional groups of carbonized akpi shells was done using Boehm titration method. 50 mL of the solutions of NaOH, Na 2 CO 3 , NaHCO 3 and HCl with the same concentration of 0.05 M were placed into 100 mL flasks, and 1 g of akpi activated carbon was added. The flasks were closed and stirred up to 48h at room temperature (27 o C).…”

“…are substances used in a wide range of applications especially in agriculture and households to eradicate pests including insects, wild grasses and vector-borne diseases. Although their use has revolutionized worldwide agricultural practices and forced back some diseases [1][2][3], pesticides can easily spread to all parts of environment thus, causing enormous ecosystem problems. In addition, they can bring resistance in some target species which can contribute to deteriorate the environment and to threaten human well-being [4].…”

Simultaneous Determination of Multiple Contaminants in Chicken Liver Using Dispersive Liquid-Liquid Microextraction (DLLME) Detected by LC-HRMS/MS

“…The quinolone class of antibiotics is also amphoteric, with pKa values ranging from 5.63–6.73 and 5.69–6.68). In addition, multiple forms (cationic, anionic, zwitterionic, and neutral) could be expected in basic donor solutions [ 40 , 41 ]. The target pesticides are also ionisable.…”

Metal Organic Framework-Based Dispersive Solid-Phase Microextraction of Carbaryl from Food and Water Prior to Detection by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

“…Many instruments were applied for the determination of carbaryl, including high-performance liquid chromatography (HPLC) and gas chromatography (GC); however, these techniques still suffer from many limitations, such as relatively high detection limits as well as matrix interference [29,30]. The application of sample purification and extraction can solve these limitations [31,32]. Common analyte extraction procedures include solid-phase extraction, dispersive liquid-liquid microextraction, supramolecular microextraction and solid-phase microextraction [17,19,[33][34][35][36][37][38][39][40].…”