The HI83730-20 reagents are high-quality, pre-measured solutions designed for quick and precise colorimetric analysis. Based on an adaptation of the EC 2568/91 method, these reagents react with peroxides in the sample, producing a yellow color proportional to the peroxide concentration. When the HI83730A-0 and HI83730B-0 reagents are added, the resulting color change can be measured by the HI83730 photometer to determine the peroxide value, displayed in milliequivalents of oxygen per kilogram (meq O₂/kg). These reagents are suitable for samples with peroxide values ranging from 0.0 to 25.0 meq O₂/kg.