Volatilization of alachlor from polymeric formulations

Area of Science:

• Environmental Chemistry
• Agricultural Science
• Polymer Science

Background:

• Pesticide dispersal occurs via groundwater, surface water, and atmospheric transport.
• Previous research focused on microencapsulation to prevent groundwater contamination.
• Polymeric herbicide formulations were previously assessed for greenhouse efficacy.

Purpose of the Study:

• Evaluate laboratory volatility of three polymeric alachlor formulations.
• Compare microencapsulated alachlor volatility against pure alachlor and a commercial formulation (Lasso 4EC).
• Assess the impact of soil incorporation versus surface application on alachlor volatilization.

Main Methods:

• Laboratory volatility studies conducted in a contained system with controlled humidity (53%) and airflow.
• Alachlor formulations (technical, Lasso 4EC, two polymeric) applied to soil.
• Volatilized alachlor collected in ethylene glycol, extracted using C18 solid-phase extraction, and analyzed via HPLC-densitometry.
• Study duration ranged from 32 to 39 days.

Main Results:

• Uniformly incorporated polymeric alachlor formulations consistently showed lower total volatilization than alachlor and Lasso 4EC.
• Surface-applied cellulose acetate butyrate microcapsules exhibited the least amount of volatilized alachlor.
• Polymeric encapsulation effectively reduced alachlor release into the atmosphere.

Conclusions:

• Polymeric microencapsulation is an effective strategy for reducing pesticide volatilization.
• Cellulose acetate butyrate microcapsules offer superior control over alachlor release, particularly when surface-applied.
• This technology has potential for mitigating atmospheric pesticide transport and deposition.