Diphenylcarbazone bromophenol blue mixed indicator is specifically used in the mercuric nitrate titration method for the accurate determination of chloride content. In this procedure, the indicator detects the endpoint by forming a distinct violet-colored complex with excess mercury(II) ions in an acidic medium, providing sharp and reliable color change for precise titration. The addition of bromophenol blue enhances the visibility of the endpoint. It is widely applied in water quality analysis, environmental testing, food and beverage industries, and pharmaceutical quality control to measure chloride levels effectively.