A SIMPLE METHOD FOR DETERMINATION AND CHARACTERIZATION OF IMIDAZOLINONE HERBICIDE (IMAZAPYR/IMAZAPIC) RESIDUES IN CLEARFIELD® RICE SOIL

A study was conducted to evaluate residues of imidazolinone (IMI) in soil. Samples were taken from three Clearfield® rice fields as IMI which have been used for six years. IMI herbicides (imazapic/imazapyr) were widely used in Clearfield® rice soils. To date, few studies are available on the residues of these herbicides, especially in the context of Malaysian soil. Therefore, for this purpose, high performance liquid chromatography (HPLC) with UV detection was performed using a Zorbax stable bond C18 (4.6× 250 mm, 5 µm) column, with two mobile phases. The average percentage recovery for imazapyr and imazapic varied from 76%-107% and 71-77%, with 0.1-5 µg/ml fortification level, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.05 and 4.09 for imazapic and 0.171 and 0.511 µg/ml for imazapyr respectively, in the top 15 cm. In the extracted soil sample, it was 0.19 µg/ml for imazapic and 0.04 µg/ml for imazapyr, respectively. Based on this study, a pre-harvest period of 40-60 day is suggested for rice crops after IMI application

Inhibition Effect of 6-bromo-3-nitro-2-phenylimidazol[1,2-α] pyridine on the Corrosion of C38 Steel in H2SO4 Solution

The inhibition effect of 6-bromo-3-nitro-2-phenylimidazol[1,2-α] pyridine (BNPP) on the corrosion of C38 steel in 0.5 M H2SO4 was studied by weight loss , electrochemical methods. The results showed that BNPP was a good inhibitor in 0.5 M H2SO4 and this adsorption obeyed the Langmuir adsorption isotherm. The results obtained from the different corrosion evaluation techniques are in good agreement. Polarization curves showed that BNPP acted as a mixed-type inhibitor in sulfuric acid. The effect of the temperature on the corrosion behavior with addition of 10-3M of the inhibitor was studied in the temperature range 298-328 K, and the thermodynamic parameters were determined and discussed. Quantum chemical approach, using the density functional theory (DFT), was applied in order to get better understanding about the relationship between the inhibition efficiency and molecular structure of BNPP. The theoretical results were found to be consistent with the experimental data

Disappearance of Azoxystrobin and difenoconazole in green beans cultivated in Souss Massa valley (Morocco)

A study was undertaken to evaluate the degradation behavior and residue levels of azoxystrobin and difenoconazole in Belma green beans variety grown in an experimental plastic greenhouse. The measurements were made over a 3 week period in which up to two successive treatments with azoxystrobin and a 5 week period in which up to two successive treatments with difenoconazole were carried out. Residue levels of dicofol and difenoconazole were determined by Gas chromatography with electron capture detection (GC-ECD), liquid-liquid extraction (LLE), solid phase extraction (SPE) and high-performance liquid chromatography (HPLC). During the study, residue levels in the plantation ranged between 0.35 and 0.01 mg/kg for azoxystrobin and between 0.25 and 0.01 mg/kg for difenoconazole. The residual concentrations after the preharvest intervals (PHI) were below the legal limits