L-(+)-Lactic Acid-13C3 Sodium Salt is the isotope labelled analog of L-(+)-Lactic Acid Sodium Salt. Sodium Salt of Lactic Acid (L113500). L-Lactic Acid occurs in small quantities in the blood and muscle fluid of man and animals. The lactic acid concentration increases in muscle and blood after vigorous activity. L-(+)-Lactic acid is also present in liver, kidney, thymus gland, human amniotic fluid, and other organs and body fluids. Molecular Formula: 13C3H5NaO3 Solubility: Aqueous Base (Slightly), Methanol (Slightly), Water (Slightly) Molecular Weight: 115.04