Spectrometric assay of aldehydes as 6-mercapto-3-substituted-s-trizolo(4,3-b)-tetrazines

The formation of magenta and· violet colored 6-mercapto- 3-substituted-s-triazolo(4,3- b)-s-tetrazine derivatives (II) from 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (I) has been described as the basis of a sensitive and specific qualitative test for aliphatic and aromatic aldehydes (1). The intense colors which were produced in these tests by the absorption of light by the anion of the 6-mercapto-s-triazolo(4,3-b)-s-tetrazine system were recognized as being the basis of a new and useful quantitative test for aldehydes.