Extent of Microencapsulation in Pesticide Formulations of Diazinon, Methyl Parathion, and Ethyl Parathion

Abstract A method is described that compares the amount of encapsulated pesticide and the amount of free pesticide as a percentage of the total pesticide content of a formulation. Formulations that contained pesticides encapsulated in a nylon-type polymer skin were more than 99% encapsulated. The method can be extended further to measure the amount of nonencapsulated pesticide (e.g., emulsifiable concentrates) in mixtures with encapsulated pesticides. The formulations studied were Knox-Out (encapsulated diazinon), Penncap-M (encapsulated methyl parathion), and Penncap-E (encapsulated parathion).