ABSTRACT
Urine pH measurement is part of most routine urinalyses. The pH of urine is influenced to a significant degree by the acidic or basic salts which are in the specimen. By the mechanism of excreting acid or alkaline urine, the body can eliminate relatively large quantities of either acids and/or bases and maintain a constant homeostatic state. Certain chemical constituents of urine are primarily responsible for establishing the pH of any specific urine specimen. These substances include sodium and potassium mono- and dihydrogen phosphates, sodium citrate, ammonium salts, sodium bicarbonate, and carbonic acid. In the treatment of certain diseases, it is important that the urine be kept at an acid pH. Amphetamine and pethidine are excreted in much larger quantities in acid urine, whereas porphyrins and urobilinogens seem to be excreted in larger amounts in alkaline urine.
