Agrochemical Mobility Studies
Modern agriculture has used a large number of agro-pesticides to control insect pests, pathogens and unwanted weeds. Many of these agrochemicals persist in the soil and plant systems, and pose a risk of migration into the drinking water sources and the food chain. In recent years, these pesticides have been found to cause adverse effects on the environment, mainly in terms of contamination of water bodies and soil. Therefore, it has become essential to study and understand the environmental behavior of pesticides. Due to the simultaneous and/or subsequent seasonal applications, these agrochemicals are often present in the soil as a mixture of multiple compounds. The mobility, fate and transformation of these agrochemicals depend mainly on the soil type, especially on the type and content of soil clay, organic matter content, pH and microbial activity. The sorption-desorption behavior of agrochemicals on soil clay, the most active particulate component of the soil, may be significantly altered when these compounds occur as mixtures. Mobility studies assess a test substance's potential for adsorption and desorptionof to soil, sediment and sludge. At BOC Sciences, we carry out agrochemical mobility studies to estimate the movement of a test substance in the natural environment, and these data are used to determine the environmental compartment to which the agrochemical will migrate and the potential for it to contaminate groundwater.
Figure 1. Residual cyhalofop concentration as a function of the number of iterations, using polymerin, ferrihydrite, and ferrihydrite-polymerin as adsorbents, at s/l = 1/2000 and at the pH of maximum adsorption. (Marocco, A.; et al. 2020)
BOC Sciences Agrochemical Mobility Research
We have studied the sorption and desorption of insecticides on different types of soils including clay, sandy clay, sandy clay and sandy clay. Our expert teams can study various soil properties that control the sorption-desorption of agrochemical contaminants in soils under different soil-plant systems.
Our Workflow
- Collection of soils
- The physicochemical properties of the selected soil samples are analyzed according to the standard test method (STM) and then their sorption studies are studied by a batch equilibrium method involving UV-Vis spectrophotometer and HPLC techniques.
- Data analysis
Figure 2. Freundlich Desorption isotherms of chlorfluazuron by selected soils. (Shaheen, I, F.; et al. 2017)
Agrochemical Biodegradation Testing
Soil Adsorption Testing
- BOC Sciences offers adsorption/desorption testing in soils, sediments and activated sludge. We source soils from multiple regions and endpoints include %sorption, Kd, Kdes, and Koc. Moreover, endpoints such as Kom and Freudlich isotherm constants, KF can be determined based on specific customer designs.
(Aging) Soil Column Leaching Studies
The aging column leaching test is designed to obtain the leaching potential of the test substance and its metabolites by pre-incubating the treated soil in the soil for up to 30 days prior to application to the soil column. We perform standard testings in accordance with OECD and EPA testing guidelines. Our teams calculate and report the relative mobility factor based on reference substances with known migration potential and sorption coefficients.
Figure 3. Determination of total values of the physicochemical parameter of the soil samples. (Shaheen, I, F.; et al. 2017)
BOC Sciences Advantages
- Highly specialized technical and analytical services for the worldwide registration and regulatory compliance of agrochemicals
- Robust analytical testing programs that span from research and product development through the production process to final product
- Relies on broad industrial experience, ensuring that all of our work meets the high standards expected by our clients
- Our regulatory experts, toxicology consultants, scientists and inspectors will ensure that you receive maximum levels of guidance, testing and inspection you need.
References
- Marocco, A.; et al. Removal of Agrochemicals from Waters by Adsorption: A Critical Comparison among Humic-Like Substances, Zeolites, Porous Oxides, and Magnetic Nanocomposites. Processes. 2020, 8(2): 141.
- Shaheen, I.; et al. Evaluating the fate of agrochemical through adsorption and desorption studies of chlorfluazuron in selected agricultural soils. Journal of King Saud University-Science. 2017: S1018364717311230.