Simultaneous Analysis of Cyproconazole and Tebuconazole in Suspension Concentrate Formulation by Reverse-Phase High-Performance Liquid Chromatography

A novel and validated reverse-phase high-performance liquid chromatography (RP-HPLC) approach was established for the concurrent measurement of cyproconazole (CYP) isomers and tebuconazole (TBZ) in suspension concentrate (SC) agrochemical formulations. The approach employed a C18 column with a gradient elution of 0.1% formic acid in water and methanol, attaining baseline resolution of CYP isomer-1, isomer-2 and TBZ without requiring chiral columns or sample pretreatment. Linearity was confirmed within the range of 80-120% of the target concentration, with a R2 value of 0.999. Accuracy varied from 101.2% to 102.8%, with a %RSD of less than 0.8%. LC-MS analysis verified analyte identity through distinctive ion transitions (CYP: m/z 292, TBZ: m/z 308). This is the initial method for isomer-specific detection of CYP using RP-HPLC within a formulation matrix. The methodology is straightforward, resilient and appropriate for standard quality assurance and regulatory adherence in agrochemical manufacturing.