Titration of Indigo and Sodium Hydrosulfite in Indigo Vat 40

Analysis outlining the method for the determination of indigo via simultaneous titration using potassium ferricyanide as a titrant. The analysis is performed using the TitroLine 7000 Advanced Titrator. Indigo is a so-called vat dye that it needs to be reduced to its water soluble leuco-form before dying. The reduced form is absorbed into the fibers and when oxidized back to its blue form it stays within the fiber. Note: The solution must be yellow. If the solution is brown or even blue, then the purging with nitrogen was not enough.

Titration of Indigo and Sodium Hydrosulfite in Indigo Vat 40

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