The document discusses the principles and applications of diazotization titration. Diazotization involves the reaction of an aromatic primary amine with sodium nitrite in acidic medium to form a diazonium salt. The titration endpoint is determined using an indicator reaction that detects excess nitrous acid. Common applications described include assays of benzocaine, dapsone, and isocarboxazid which involve diazotization and detection of the endpoint with starch-iodide paper. Diazotization titration can be used to analyze many sulfa drugs and other pharmaceuticals containing aromatic amine groups.