Accurate Analysis and Evaluation of Acidic Plant Growth Regulators in Transgenic and Nontransgenic Edible Oils with Facile Microwave-Assisted Extraction-Derivatization

Effects of soil bulk density and corresponding soil infiltration rate on the migration and transformation of gibberellic acid

High intensity agricultural activities can lead to a decrease in soil fertility and an increase in soil bulk density, which may significantly impact the migration and transformation of pesticides in soil. As a new widely-used micro-toxic pesticide, gibberellic acid (GA3) is more soluble and hydrophilic than most pesticides, which could readily migrate throughout the soil during water infiltration and impact groundwater quality. In this study, the leaching of GA3 in saturated soils with different bulk densities (1.15-1.75 g/cm3) and infiltration rates (0.2215-0.0017 mm/s) were analyzed using column experiments. The migration and distribution of GA3 in the soil with a depth of 50 cm were also investigated. The results indicated that GA3 could completely penetrate the soil with bulk densities less than 1.45 g/cm3, and GA3 mass variation in the effluent was normally distributed. The maximum mass of GA3 in the effluent was calculated using the equation Moutlet(max) = 79.01 t-0.97 (R2 = 0.9811), and 83.69-93.16 % mass of the added GA3 migrated downward in the soil. The analysis of the distribution of GA3 in the soil showed that GA3 accumulated in the upper soil layers with depths of 0-25 cm (the total depth of soil was 50 cm). In addition, the residual and hydrolyzed GA3 amounts in the soil were 75.07-96.47 % and 5-30 % of the added GA3, respectively. Overall, the soil bulk density and irrigation volume determine what type of impact that GA3 may potentially have on the environment.

Novel ferrofluid based on water-based deep eutectic solvents: application in dispersive liquid-liquid microextraction of naphthalene-derived plant growth regulators in edible oil

A new ferrofluid extractant (Fe3O4 @SiO2-WDES) was ingeniously prepared by coating magnetic Fe3O4 @SiO2 microspheres with water-based deep eutectic solvent (WDES) and used for dispersive liquid-liquid microextraction (DLLME) and HPLC determination of naphthalene-derived plant growth regulators (PGRs, i.e., 1-naphthylacetic acid, 2-naphthylacetic acid, 1-naphthoxy acetic acid, 2-naphthyloxyacetic acid and 1-naphthylacetamide) in edible oil. Herein, mass transfer of the analytes in DLLME was significantly enhanced via increasing the contact surface by employing the microspheres as the supporter and dispersant of WDES, and phase separation can be efficiently achieved using an external magnet rather than centrifugation in traditional DLLME. Response surface methodology (RSM) based on Box-Behnken design (BBD) was employed for the optimization of core experimental conditions, and Analytical Eco-Scale and Analytical GREEnness Metric Approaches were adopted to evaluate the degree of greenness of the procedure. Under the optimal conditions, satisfactory performances of linearity ranged from 5 to 100 μg/L (R2 ≥ 0.9982), limit of detection (0.58-0.91 μg/L), limit of quantitation (1.9-3.0 μg/L), precision (RSDs ≤ 5.5%), recovery (81.3%-108.1%) and negligible matrix effect were achieved, which introduced a promising alternative route for the determination of naphthalene-derived plant growth regulators in edible oil.