High-Efficiency Purification of Thiodiacetic Acid and Dithiodiacetic Acid
Original Publication Date: 1985-Nov-01
Included in the Prior Art Database: 2005-Feb-19
High-performance liquid chromatography is used to separate hyperpure thiodiacetic acid and dithiodiacetic acid, respectively. During the synthesis of thiodiacetic acid, byproducts, such as dithiodiacetic acid, trithiodiacetic acid, glycolic acid thiosulfate and some unknown compounds, are formed. As dithiodiacetic acid is added as a stabilizer to thioacetic acid in the ppb range, it should not be present right from the start. The by products which are not separable by conventional purification methods are separated from thiodiacetic acid by a liquid chromatographic method. By this method, a purification of thiodiacetic acid of up to > 99.997% and of dithiodiacetic acid of up to 90% can be obtained. Operation parameters Column: Hyperchrome steel 20 mm I.D.