[fugate]

Hello Chemical Forums...
I have a cleaning product with an unidentified acid in it that I want to identify. I did some research and got mixed results, some sources say the product contains sulfamic acid, and others say phosphoric. One page even said it was hydrochloric.
Does anyone have any good and safe methods of distinguishing between the two (or three)?
Thanks in advance!

[Babcock_Hall]

There are many colorimetric methods for the determination of phosphoric acid based on complexation with ammonium molybdate.  Some reduce this complex with ascorbic acid, and some make a charge-transfer complex with malachite green.  In my experience they are quite specific.  HCl at 1 M gives no reaction.  I can't be certain that sulfamic acid does not, but it could be tested.  I am not sure that this is what you are looking for, however.