Stability of emulsifiable concentrate pesticide formulations in liquid fertilizers

摘要

AbstractThe stability of some diluted emulsifiable concentrate formulations in clear liquid fertilizers, as affected by the nature and concentration of the salt solutions, was checked by a static test. The time‐induced changes in the concentration of the dispersed phase were estimated by visual observations and turbidity measurements. For each formulation a specific relationship between the electrical conductivity of all the fertilizer solutions and the emulsion stability was found. This was valid for a pH range between 4.6–6.3; in alkaline conditions the emulsion stability was relatively lower. A critical electrical conductivity range, above which irreversible destabilization occurred, was observed for each formulation: 100‐120 dS m−1for fenamiphos, 60‐70 dS m−1for metolachlor, 30‐50 dS m−1for chlorpyrifos, and about 45 dS m−1for S‐ethyl dipropylthiocarbamate (EPTC).The correlation observed between the emulsion stability and the electrical conductivity could be used in a simple and rapid qualitative test to estimate the physical compatibility between emulsifiable concentrate formulations and