Question: What Is the Chemical Composition of Urine?
Urine is a liquid produced by the kidneys to remove waste products from the bloodstream. Human urine is yellowish in color and variable in chemical composition, but here is a list of its primary components.
Answer: Human urine consists primarily of water, with organic solutes including urea, creatinine, uric acid, and trace amounts of enzymes, carbohydrates, hormones, fatty acids, pigments, and mucins, and inorganic ions such as sodium (Na+), potassium (K+), chloride (Cl-), magnesium (Mg2+), calcium (Ca2+), ammonium (NH4+), sulfates (SO42-), and phosphates (e.g., PO43-). A representative chemical composition would be:
urea 9.3 g/l
chloride 1.87 g/l
sodium 1.17 g/l
potassium 0.750 g/l
creatinine 0.670 g/l
with lesser amounts of other ions and compounds
Reference: NASA Contractor Report No. NASA CR-1802, D. F. Putnam, July 1971.