Development of Ecologically Acceptable Chlorpyrifos Formulation for Effective and Safe Application

Yasser El-Nahhal,Bayan Wheidi,Said El-Kurdi

doi:10.4236/jeas.2016.63008

Abstract

Application of the commercial formulation of chlorpyrifos has resulted in considerable environmental contamination. This study was designed to develop environmentally acceptable chlorpyrifos formulation for safe and effective application. This involved the modification of clay surfaces from hydrophilic to hydrophobic via ion-exchange reaction with organic cations. The resulting organo-clay complexes were tested for adsorption and release of chlorpyrifos. HPLC and FTIR measurements showed considerable adsorption and strong interaction between chlorpyrifos molecules and the organo-clay complexes. Basal spacing results emphasized the formation of suitable micro-pores for chlorpyrifos molecules. HPLC and bioassay techniques confirmed the slow release of chlorpyrifos. Leaching potential showed retention of chlorpyrifos in the top soil. Therefore application of organoclay formulation of chlorpyrifos may reduce their potential environmental contamination and produce safe applications.

Highlights

Chlorpyrifos is an organophosphate insecticide widely used in agricultural and public health sectors [1]
Pre-adsorption of the clay mineral with a smaller organic cation (e.g phenyltrimethyl ammonium (PTMA)), at 0.5 mmol/g clay increasing the basal spacing to 14.09 A, whereas using a larger organic cation benzyltributyl ammonium (BTBA), the basal spacing increased up to 15.9 A. These results agree with El-Nahhal [31] who found similar basal spacing for organic cation adsorbed on Montmorillonite. These results suggest that the basal spacing is increased as the size of the aliphatic part of the organic cation increased (Figure 1)
This study presents an attempt to develop a controlled release formulation of chlorpyrifos to reduce leaching of the compound into soil and water

Summary

Introduction

Chlorpyrifos is an organophosphate insecticide widely used in agricultural and public health sectors [1]. The application of the commercial formulations of chlorpyrifos created many environmental problems. Y. El-Nahhal et al 92 environmental health problems [13]-[15], ecological disturbance [16] and toxic effects to aquatic life [17]-[21]. Recent published work revealed human toxicity due to long term exposure to chlorpyrifos formulations [22]. Chlorpyrifos has been shown to: induce neurite retraction in differentiating neuronal cells, [23], cause cytotoxicity [24] and reduce growth, enzyme activity and chlorophyll A synthesis of fresh water microalgae [25]. The annual report revealed the application of large quantities of chlorpyrifos that reached to 18,125 Liter [26]

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Conclusion