Liquid Chromatographic Method for Determination of Chloridazon in Technical Concentrates and Formulated Products: Comparison with CIPAC Method

A liquid chromatographic method for determination of chloridazon in technical concentrates and formulated products has been developed and compared with the present CIPAC method. The new method uses the same procedures and reagents as does the CIPAC method, but a microbore column and a diode array detector are used instead of a normal-phase column and a single wavelength detector. A technical product, a wettable powder, and a suspension concentrate were analyzed by both methods; the results (g chloridazon/kg) were 836.7 ± 6.3 (RSDr 1.05%) and 822.1 ± 8.2 (RSDr 1.39%); 648.7 ± 7.6 (RSDr 1.64%) and 641.1 ± 6.7 (RSDr 1.45%); and 350.5 ± 5.6 (RSDr 2.24%) and 351.1 ± 4.0 (RSDr 1.57%) by the CIPAC method and the new method, respectively. Although precision, accuracy, and resolution are very similar for the 2 methods, the microbore column, diode array detector, and multichannel integrator specified in the new method give more information on the integration process and on the purity of peaks, and save on operating costs. Therefore, the authors propose that CIPAC methodology use this type of apparatus as soon as it is more generally available in laboratories. © 2020 AOAC International. All rights reserved.