Human urine consists primarily of water (91% to 96%), 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:
water (H2O): 95%
urea (H2NCONH2): 9.3 g/l to 23.3 g/l
chloride (Cl-): 1.87 g/l to 8.4 g/l
sodium (Na+): 1.17 g/l to 4.39 g/l
potassium (K+): 0.750 g/l to 2.61 g/l
creatinine (C4H7N3O): 0.670 g/l to 2.15 g/l
inorganic sulfur (S): 0.163 to 1.80 g/l
Lesser amounts of other ions and compounds are present, including hippuric acid, phosphorus, citric acid, glucuronic acid, ammonia, uric acid, and many others