For wet acid digestion from fish meat matrix, currently I use conc. HNO3, hydrogen peroxide (1:1) (10 ml). The solution that remains after digestion should be colorless, but I always get solution with yellow color. After evaporation, the volume of the solution remains about 5 ml, but still its yellow.
According to literature, the hydrogen oxide suppresses the yellow nitrous oxides, but still I am getting it.
Can anyone suggest a solution for that.