Tashiro's indicator is a pH indicator (pH value: 4.4–6.2), mixed indicator composed of a solution of methylene blue (0.1%) and methyl red (0.03%) in ethanol or in methanol.
It can be used for the titration of ammonia in Kjeldahl analysis.
Colours In acids: violet At equivalence point (pH 5.2): grey In bases: green Methylene blue functions to change the red-yellow shift of methyl red to a more distinct violet-green shift.
See also Litmus pH Indicator
References