Persistence of Quizalofop Ethyl in Soil and Safety to Ground Nut by Ultrasonic Bath Extraction and HPLC-DAD Detection

Abstract

Quizalofop ethyl applied regularly in broad leaved field crops as post emergence to control annual and perennial grass weeds. The experiment was carried out to determine the harvest time residues of quizalofop ethyl in soil and ground nut plant using ultra sonic bath extraction and HPLC-DADin Randomized block design. The quizalofop ethyl (5% EC) was applied at four rates along with control treatment. Standardized methodology supported by recovery studies was adopted to estimate quizalofop ethyl residues on groundnut and soil. The recoveries at different spiking level ranged from 74.0 to 99.3 % with the quantification limit of 0.01 μg g-1. The quizalofop ethyl residue in soil was ranged from 0.012 to 0.038 mg/kg at harvest. The residues were below the quantification limit (0.01 mg/kg) and maximum residue limit (MRL) in groundnut haulm and kernels. The study established that quizalofop ethyl at 50 g/ha can be used safely to control grass weeds with the pre harvest interval of 110 days.