Abstract
Potassium 1, 2-naphthoquinone-4-sulfonate gives a coloration of the absorption maximum at 490mμ with sulpyrine and the chromogen produced can be extracted with chloroform, which shows an absorption maximum at 474mμ. Interferences caused by coexisting substances were investigated and the presence of reducing substances like ascorbic acid was found to exert no influence by using 0.5% potassium 1, 2-naphthoquinone-4-sulfonate solution under adequate conditions. The interferences by the presence of aliphatic primary amines like amino acid may be eliminated by chloroform extraction. Based on these facts, method of determination of sulpyrine with a high selectivity has been established.
