Dissipation kinetics,safety evaluation,and assessment of pre-harvest interval (PHI) and processing factor for kresoxim methyl residues in grape

A field dissipation study was conducted to evaluate the pre-harvest interval (PHI) and processing factor (PF) for kresoxim methyl (Ergon 44.3 SC) residues in grapes and during raisin making process at recommended dose (RD) and double the recommended dose (DRD). Kresoxim methyl residues dissipated following 1st-order kinetics with a half-life of 10 and 18 days at RD and DRD, respectively. The PHIs with respect to the European Union maximum residue limit (EU-MRL) of 1 mg kg^?1 for grapes were 13 and 30 days at RD and DRD, respectively. The degradation data during grape to raisin making process were best fitted to nonlinear 1st?+?1st-order kinetics with a half-life ranging between 4 and 8 days for both shade drying and with raisin dryer at different doses. The PFs were 1.19 and 1.24 with shade drying and 1.09 and 1.10 with raisin dryer, respectively, which indicates concentration of the residues during raisin making process. The dietary exposure of kresoxim methyl on each sampling day was less than the respective maximum permissible intake both at RD and DRD. The residues of kresoxim methyl in market samples of grapes and raisins were well below the EU-MRL and were also devoid of any risk of acute toxicity related to dietary exposure.     

Kresoxim methyl dissipation kinetics and its residue effect on soil extra-cellular and intra-cellular enzymatic activity in four different soils of India

The rate of degradation of kresoxim methyl and its effect on soil extra-cellular (acid phosphatase, alkaline phosphatase and β-glucosidase) and intra-cellular (dehydrogenase) enzymes were explored in four different soils of India. In all the tested soils, the degradation rate was faster at the beginning, which slowed down with time indicating a non-linear pattern of degradation. Rate of degradation in black soil was fastest followed by saline, brown and red soils, respectively and followed 1st or 1st + 1st order kinetics with half-life ranging between 1–6 days for natural soil and 1–19 days for sterile soils. The rate of degradation in natural against sterilized soils suggests that microbial degradation might be the major pathway of residue dissipation. Although small changes in enzyme activities were observed, kresoxim methyl did not have any significant deleterious effect on the enzymatic activity of the various test soils in long run. Simple correlation studies between degradation percentage and individual enzyme activities did not establish any significant relationships. The pattern and change of enzyme activity was primarily due to the effect of the incubation period rather than the effect of kresoxim methyl itself.     

Eco-friendly dyeing of cotton with brown natural dye extracted from Ficus amplissima Smith leaves

Environmental Chemistry Letters - We have extracted a new brown-coloured natural dye from the leaves of Ficus amplissima Smith using Soxhlet extraction. The dye was assessed for...