Abstract
A simple and sensitive method for the determination of pyraclostrobin, a widely used fungicide, is described here which is based on diazotization and coupling with 4- aminosulphonic acid in alkaline medium. The reaction mechanism is based on the pre-equilibrium formation of amine and diazonium salt followed by a rate-limiting attack of the diazonium ion at an N-atom (N-coupling) to appear the corresponding red colored azo complex. The λmax, molar absorptivity and Sandell’s sensitivity related to the UV-Visible absorption spectrometry were found λmax = 600 nm, 2.7 × 104 L mol−1 cm−1 and 1.01 × 10−5 μg cm−2, respectively. Some of the important parameters like linearity range, limit of detection (LOD), limit of quantification (LOQ), correlation coefficient (R2) and recovery% were calculated 3 to 12 μgmL−1, 1.01 μgmL−1, 3.08 μgmL−1, 0.984 and 93.5–99.3%, respectively for the determination of organochlorine like pyraclostrobin using coupling reagent. The advantages of the present method are its simplicity, high selectivity and cost effective. In this article, the method has been validated by applying it to samples from different environmental conditions.