Comparison of extraction procedures for the determination of mesosulfuron methyl and iodosulfuron methyl sodium from soil and wheat using response surface modelling

Abstract

Screening of herbicides is important due to their widespread use, phytotoxicity to succeeding crop and residues in soil and crop produce. For this development of simple, sensitive and cost effective analytical method for tracer level quantification of herbicides in different matrices is a challenging task. In present study, different extraction techniques viz. ultrasonic assisted extraction (UAE), matrix solid phase dispersion (MSPD), microwave assisted extraction (MAE) and liquid solid extraction (LSE) were compared for recovery and quantification of mesosulfuron methyl and iodosulfuron methyl sodium from soil and wheat samples by high performance liquid chromatography. Different factors affecting the extraction efficiency of the herbicides using these extraction methods were optimised. Response surface methodology (RSM) based on three factor and three level box behnken designs (BBD) were also employed to obtain a mathematical model representing the relationship between the response (percent recovery) and variables. The mean percent recoveries of herbicides varied from 89.80 to 101.20%, 89.20 to 99.75%, 81.10 to 90.75% and 83.40 to 94.75% using UAE, MSPD, MAE and LSE, respectively with RSD% <14% for all the four methods. The developed methods are reliable and can be useful for routine monitoring in soil and crop produce. The experimental results were extended to the analysis of real sample and residues in these were below the maximum residue limits (<0.01 mg kg−1) imposed by the principal regulatory agencies.