P-32 is widely applied in biological and agricultural research. It is produced by irradiation of red phosphorus with neutrons in 31P(n,^)32P nuclear reaction. The half-life of 32P is 14.3 days, and it emits negative beta particles. By the dissolution of red phosphorus in water, phosphoric acid is formed. Therefore, the oxidation state of phosphorus is +5. When dissolving red phosphorus in hydrochloric acid, chloride and oxychloride are formed, the oxidation state of phosphorus is also 15. A 32P-labeled compound with a +3 oxidation state has not been produced yet. Carrier-free 32P can be produced from sulfur by the 32S(n, p)32P nuclear reaction. 32P can be gained as a H332PO4 solution by water vapor, and sulfur remains back as a solid. Another way to separate 32P is the dissolution of sulfur with an organic solvent (e. g., CS2), which makes the residue react with chlorine gas. The product is PCl5. For additional information, see Section 8.7.1.2.