Q = Should the Phenolphthalein solution be used neat, straight from the bottle? When using it neat it caused the solutions being tested to go a cloudy white colour. This does not happen when we make a Phenolphthalein solution ourselves.
A = The Phenolphthalein solution we sell is a 1% solution, but when you make it up I think it is normally a 0.1% solution (1g solid Phenolphthalein dissolved in 600 – 700ml meths (IDA) and made up to one litre with water).
It might be worth diluting the stock solution down to 0.1% and seeing if this gives good results?