In that post she demonstrates that the pH of diluted samples does not start to drift towards the pH of the diluent (distilled water) until the dilution dips below 10%.
That diluting a formulation by 90% wouldn’t meaningfully alter the pH rather defies logic, so I did a similar experiment. I created 10%, 20%, 30%, 40%, and 50% dilution testing solutions of a formulation. I also tested the formulation at 100% concentration as it was thin enough to do so.
I took multiple readings for each solution, averaged them, and plotted them on a graph.
The difference between the 10% dilution and the pure product was less than 0.1 pH point. Creating a 10% dilution of your formulation does not meaningfully alter the pH reading you’ll get. You could test any level of dilution above 10% if you were so inclined and get nearly identical results; 10% simply wastes the least amount of product.
Still skeptical? Try it yourself!
Posted in: Measurements