The HI38023-100 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate total chlorine measurements with the chemical test kit. These reagents follow an iodometric titration method to determine total chlorine concentration.

For determination of total chlorine, a slow reaction with iodide in acidic solution occurs with the chlorine present in the sample. The amount of iodine generated is equivalent to the chlorine in the sample. The liberated iodine is then titrated with standard sodium thiosulfate solution that reduces the iodine back to iodide ions. The number of drops of titrant used to reach the visual endpoint will determine the total chlorine concentration in mg/L. These reagents are designed to be used with samples that have an expected total chlorine range of 10 to 200 mg/L Cl₂.