Q = What is the solubility of these?
A = Dye name / Sol. in water g/l @ 25°C
E102 Tartrazine / 150 g/l
E110 Sunset Yellow / 80 g/l
E122 Azorubine (Carmoisine) / 100 g/l
E127 Erythrosine / 100 g/l
E131 Patent Blue V / 50 g/l
E133 Brilliant Blue FCF / 200 g/l
E142 Green S / 60 g/l
Q = How do you make up into solution?
A = To make a solution:
• Weigh out the required quantity of dye
• Make a paste using cold water
• Add hot water to this paste whilst stirring
• Continue to stir until the dye is dissolved
• Allow to cool or add cold water
The dye is now ready to use.
Regarding the amount of each dye to use, it depends partly on the solubility and on how strong you want it to be – so you would not add more than the maximum solubility of each dye (see above).
The stability of solutions are good provided they are kept in a cool place and not exposed to direct sunlight.
Some of the dyes have varying solubility i.e. they can be very soluble at high temperatures but on cooling they can come out of solution.
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