Impact of Formulation Type on Stability of Metribuzin Herbicide Under Certain Environmental Conditions

Document Type : Original Article

Authors

1 Pesticides Residues&Environmental pollution Dept, Central Agricultural Pesticides Laboratory, Agricultural Research Center (ARC), Dokki, Giza, Egypt

2 Pesticides Analysis Researches Dept, Central Agricultural Pesticides Laboratory, Agricultural Research Center (ARC), Dokki, Giza, Egypt.

Abstract

This study examined the stability of active ingredient (a.i) and three different commercial formulations of metribuzin herbicide (suspension concentrate (SC), water dispersible granules (WG) and wettable powder (WP)) after exposure to UV-rays, direct sunlight, different temperature degrees, and different pH values at different intervals. In addition, the effect of accelerated storage at 54 2 oC for 14 days under laboratory conditions and the degradation rate of metribuzin for test samples were evaluated. The metribuzin content and degradation products were determined using GC–FID and GC–MS. Results indicated that direct sunlight and high temperatures were more effective than ultraviolet rays in accelerating the rate of metribuzin degradation. In contrast, the degradation rate of metribuzin was faster in acidic and alkaline pH than in neutral medium. The formulations of metribuzin are stable after accelerated storage at 54 2 oC. There were no discernible differences in metribuzin content before and after 14 days of storage. Metribuzin formulation in SC was more stable than metribuzin in formulation WG and WP, but overall, formulation type had a limited effect on the metribuzin degradation rate. Analysis of metribuzin a.i after exposure to direct sunlight using GC-MS identified four photodegradation products: deamino metribuzin (DA), diketo metribuzin (DK), 6-(tert butyl) -1,2,4-triazin-5(4H)-one and 4-amino-6-(tert butyl)-3- (methylsulfonyl)-1,2,4-triazin-5(4H)-one.

Keywords

Main Subjects

Egyptian Journal of Chemistry
Volume 66, Issue 13 - Serial Number 13
Special Issue: Applied Chemistry for Greener Life and Sustainability
December 2023
Pages 2045-2057

Files

History

  • Receive Date: 13 July 2023
  • Revise Date: 29 August 2023
  • Accept Date: 05 September 2023

Share

How to cite

Statistics