Determination of cyromazine in commercial insecticides using HPLC-DAD

Each commercial cyromazine insecticide has different HPLC conditions. The aim of this study was to establish a standardized chromatographic method for the determination of cyromazine in commercial insecticides. The separation was achieved on two C18 columns - Waters Ⓡ Bondapak C (4×300 nm i.d., 10 μm) and X bridge (4.6×250 nm i.d., 5 μm) using a mobile phase composed of water/methanol/ ethanolamine (76:24:0.1, v/v), with UV detection at wavelengths 230 nm and 254 nm. A total of six commercial cyromazine insecticides were analyzed. In this study, the optimal high-performance liquid chromatography conditions for the analysis of cyromazine were as follows: a mobile phase of water/ methanol/ethanolamine (76:24:0.1, v/v) at a flow rate of 1.0 mL/min and a detection wavelength of 230 nm using a X bridge C18 column (4.6×250 nm i.d., 5 μm) at a column temperature of 25°C. The calibration curve was linear in the concentration range of 5∼50 μg/mL, with a correlation coefficient of 0.99995. The cyromazine detection limit was 0.2 μg/mL, and the limit of quantification was 0.59 μg/mL. The percentage recovery ranged from 99.8% to 101.0% for cyromazine, and the relative standard deviation was not over 2.0%. The cyromazine concentration ranged from 92.7% to 109.4% and was within the acceptable range (90∼120%) for the percent of the labeled amount. This method was found to be suitable for determining cyromazine in commercial insecticides.