Degradation of imazapyr and imazapic in aqueous solutions and soil under direct sunlight; [Degradasi imazapyr dan imazapic dalam larutan akueus dan tanah di bawah cahaya matahari]

• Published in: Malaysian Journal of Analytical Sciences
• Main Author: Shaifuddin S.N.M.; Hussain H.; Hassan H.F.; Dom N.C.; Rashid R.I.M.
• Format: Article
• Language: English
• Published: Malaysian Society of Analytical Sciences 2017
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032033307&doi=10.17576%2fmjas-2017-2105-09&partnerID=40&md5=4c7d749ca7fdeef40df4c132abbf9445

Photolytic degradation of imazapyr and imazapic in aqueous solutions (pH 3, 7 and 9) and soil under direct sunlight were studied. A total of 0.1 mL of aqueous solutions containing herbicides were collected at 0, 1, 2 and 3 days and were directly analyzed using high performance liquid chromatography equipped with ultraviolet detector (HPLC-UV) without further clean-up process. Soils that were treated with herbicides were sampled at seven different days (0, 1, 5, 10, 16, 23 and 30). The photolytic results showed that imazapyr and imazapic degraded faster in solutions compared to soils (> 90%). Photolysis of imidazolinone herbicides became more effective as the pH value increased. The half-lives for imazapyr and imazapic degradation on soil surface under sunlight were calculated at 126 days and 85.56 days, respectively. Low degradation of imazapyr and imazapic in soil becomes a concern since it may contribute to the persistency of imidazolinone herbicides in this media. The use of these herbicides should be planned well to reduce the risk of herbicides leaching into groundwater and posing risk to non-target crops and organism. © 2017, Malaysian Society of Analytical Sciences. All rights reserved.