Distilled water?
L-Tryptophan has a nice steep solubility curve going from 0.23g/l at 0° to 49.9 g/l at 100°
According to the paper 'Determination and Correlation of the Solubility for Taurine in Water', which uses maddening kelvin and 10x mole fraction units
[insert rant], taurine is soluble to the extent of 1g per 18g H2O at 0°C, around 2g/18g at room temp, going up to 8g/18g at 80°C.
So, while the two compounds may have a roughly similar solubility at room temperature, taurine is much more soluble in ice cold water and two rounds
of recrystallization should remove it. |