Abstract: A method for extracting and separating a rare-earth element by extracting and separating the rare-earth element from an aqueous solution of rare-earth nitrate into n-heptane, with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester trialkyl methyl ammonium or di-2-ethylhexyl phosphoric acid trialkyl methyl ammonium as an extractant, and n-heptane as a diluent by contacting the aqueous solution of rare-earth nitrate with the extractant and the diluent to extract and separate the rare earth element into n-heptane from the aqueous solution of rare earth nitrate.

Abstract: A method for extracting and separating a rare-earth element. Cations and anions in a quaternary ammonium ionic liquid extractant, that is, 2-ethylhexyl phosphate mono-2-ethylhexyl acrylate trialkyl methyl ammonium and phosphate di(2-ethylhexyl) phthalate trialkyl methyl ammonium, react with rare-earth ions to form neutral complex molecules, also, a collaborative effect and a competitive effect are present between the cations and the anions in the quaternary ammonium ionic liquid extractant in a rare-earth element extraction process, the separation factor for the rare-earth element is thus increased. The method for extracting and separating the rare-earth element provides good interfacial phenomena in the extraction process, does not generate emulsification, obviates the need for extractant saponification, and provides increased separation factor for rare-earth elements, and particularly increased separation factor for heavy rare-earth elements.

Abstract: A preparation process of (6R)-tetrahydrobiopterin hydrochloride is provided, which comprises hydrogenating L-biopterin in the presence of a catalyst of Pt group metal in the basic substrate containing solvent, potassium hydroxide and potassium dihydrogen phosphate to obtain (6R)-tetrahydrobiopterin hydrochloride, wherein the pH value of the basic substrate is controlled by potassium hydroxide and potassium dihydrogen phosphate in the range of about 10 to about 13.

Abstract: A preparation process of (6R)-tetrahydrobiopterin hydrochloride is provided, which comprises hydrogenating L-biopterin in the presence of a catalyst of Pt group metal in the basic substrate containing solvent, potassium hydroxide and potassium dihydrogen phosphate to obtain (6R)-tetrahydrobiopterin hydrochloride, wherein the pH value of the basic substrate is controlled by potassium hydroxide and potassium dihydrogen phosphate in the range of about 10 to about 13.