Validation of Two Variations of the QuEChERS Method for the Determination of Multiclass Pesticide Residues in Cereal-Based Infant Foods by LC–MS/MS

Review of sample preparation methods for chromatographic analysis of neonicotinoids in agricultural and environmental matrices: From classical to state-of-the-art methods

This review specifically examines the development of sample preparation methods for residue analyses of neonicotinoid insecticides in agricultural and environmental matrices. Pesticide residue analysis is fundamentally important to ensure the safety of foods and processed foods of plant and animal origin, and to preserve the environment, particularly soil and water. For the development of pesticide residue analysis, the sample preparation process is an important key to maximizing the analytical performance of highly sensitive and accurate chromatographic instruments and to acquiring reliable analytical results. This review outlines sample preparation methods that have been proposed to date for extraction of neonicotinoids that might remain in a complicated sample matrix in quantitatively trace amounts, and for cleaning up, to the greatest extent possible, the interfering components that coexist in the sample extract.

Assessment of methyl 2-({[(4,6-dimethoxypyrimidin-2-yl)carbamoyl] sulfamoyl}methyl)benzoate through biotic and abiotic degradation modes

Detoxification and management of environmental contaminants is an exigent issue of current times. Sulfonylurea herbicide, Bensulfuron-methyl was investigated for its degradation demeanour in soils, through biotic and abiotic modes (biodegradation and hydrolysis). Solid-liquid extraction of the herbicide was followed by GC-MS and UV-visible spectrophotometry analysis. The main metabolites observed were pyrimidinamine [149 m/z] and benzylsulfonamide [182 m/z]. The rate of biodegradation achieved by Aspergillus niger and Penicillium chrysogenum was 95% and 71%, respectively. The maximal decline in Bensulfuron-methyl concentration through hydrolysis was 48%. Furthermore, hydrolytic elimination was also evaluated based on time and pH. Both these parameters had a strong influence on the rate of transformation. Soils with lower pH exhibited an increased rate of degradation while a temperature of 27±2°C gave ideal conditions for herbicide decomposition. Percentage degradation and rate constant (k) followed first order reaction kinetics. Non-inoculated soils displayed less amounts of degradation. Furthermore, relative standard deviations were calculated for the residuals extracted in all soils. Analysis of variance (ANOVA) provided a p value < 0.05 for both strains with R2 closer to 1 signifying the significance of the results. Both fungal strains proved their potential for Bensulfuron-methyl remediation in soils.

Dissipation and residues of flutriafol in wheat and soil under field conditions

The dissipation and residues of flutriafol in wheat and soil under field conditions in Beijing, Anhui and Shandong in China were determined based on high performance liquid chromatography. Flutriafol were extracted with acetonitrile and cleaned up by solid-phase extraction with florisil cartridges before UV detection. The limits of detection and quantification of flutriafol were 0.04 ng and 0.01 mg/kg for both wheat and soil samples, respectively. The mean recoveries ranged from 93.4% to 96.4%, with relative standard deviation between 3.8% and 6.8% at three spiked levels (0.01, 0.1, 1.0 mg/kg). Half-lives were 13.3, 9.9 and 13.6 days in soil, while 15.2, 10.8 and 9.2 days in wheat plant in Beijing, Anhui and Shandong, respectively. The terminal residues of flutriafol were below the maximum residue limit 0.02 mg/kg set by Japan in wheat when pre-harvest interval were 35 days.