Abstract
For the rapid and accurate determination of anionics, a new volumetric method, “4-Amino-4'-Chlorobiphenyl Hydrochloride Diazotitration Method” has been developed.
The active component of anionics is precipitated in dilute acidic aqueous solution with 4-amino-4'-chlorobiphenyl hydrochloride (ACBH), and the excess of ACBH in the filtrate is titrated back with sodium nitrite standard solution by diazotitration, using potassium-iodide-starch paper until it turns blue.
The experimental results with various anionics showed that the new method was quite satisfactory. Higher mole-ratio of ACBH to anionics than 6 resulted too high analytical values. Potassium-iodide-starch paper showed clearer end point of diazotitration than p-dimethyl-aminobenzaldehyde test paper in this new method.
