Identification and Characterization of the Isomeric Impurity of the Fungicide “Cyazofamid”

Abstract

Identification and characterization of biproducts/ impurities present in agrochemicals are critical in view of their efficacy and safety towards public health. We herein present our study on identification and characterization of an impurity, 5-chloro-2-cyano-N,N-dimethyl-4-p-tolylimidazole-1sulfonamide (2) present in the fungicide, "cyazofamid". Intermittent HPLC analysis of the reaction of substituted imidazole (1) with N,N-dimethylsulfamoyl chloride suggested that 2 is formed during the reaction. Isolation by preparative HPLC and characterization by NMR, LC/HRMS, MS/MS and single crystal XRD analysis confirmed 2 as an isomer of cyazofamid, wherein the N,N-dimethyl sulfonamide group was positioned on the other nitrogen of imidazole in close proximity to chloride group. Computational studies further supported the formation of 2 and ruled out the other possible isomeric structures.

Identification and characterization of impurities in an insecticide, commercial chlorantraniliprole using liquid chromatography–tandem mass spectrometry

“…Additionally, ungenuine/illegal agrochemicals (fake, spurious, or poor quality) and adulterated agrochemicals considerably contribute to commercial losses. [1][2][3] The main cause of the potential usage of illegal agrochemicals is the problem of distinguishing between legal and illicit agrochemicals. 4 To ensure the safety of commercial-grade agrochemicals and to distinguish them from illicit agrochemicals, it is crucial to profile agrochemicals, including characterization of the impurities greater than 0.1%.…”

“…Thus, monitoring the quality as well as the identification of impurities during the manufacture, packaging, and storage of CAP products can play a significant role in evaluating its efficacy and preventing possible environmental contaminations. The impurities present could have more harmful effects than the active component that could influence the properties of formulations or increase phytotoxicity, and the impurities could be persistent to leave undesirable residues that contaminate food and the environment 3,12 . Although some information is available in the literature on residue analysis of CAP in different foodstuffs using high‐performance liquid chromatography (HPLC) 13 and LC coupled with tandem mass spectrometry (LC–MS/MS), 14,15 detailed reports focusing on impurity profiling of CAP are limited.…”

“…Due to the potential toxicological effects of impurities on humans and the environment, the impurity profiles of agrochemicals are crucial. Additionally, ungenuine/illegal agrochemicals (fake, spurious, or poor quality) and adulterated agrochemicals considerably contribute to commercial losses 1–3 . The main cause of the potential usage of illegal agrochemicals is the problem of distinguishing between legal and illicit agrochemicals 4 .…”