Resolution and binding site determination of d,l-thyronine by high-performance liquid chromatography using immobilized albumin as chiral stationary phase. Determination of the optical purity of thyroxine in tablets

✍ Scribed by L. Dalgaard; J.J. Hansen; J.Lang Pedersen

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 557 KB
• Volume: 7
• Category: Article
• ISSN: 0731-7085
• DOI: 10.1016/0731-7085(89)80103-7

✦ Synopsis

Human and bovine serum albumin bound to silica or aminopropyl silica were used as chiral stationary phases (CSPs). D,L-Thyronine, D,L-tryptophan, N-benzoyl-D,L-phenylalanine, D,L-warfarin and D,L-benzoin could be resolved on these CSPs using a mobile phase of 0.05 M phosphate buffer, pH 7.0. The capacity factor of D-thyronine was higher than that of L-thyronine. The resolution of D,L-thyronine was completely lost by the presence of bilirubin in the mobile phase, but only little affected by caprylate. By contrast, the resolution of D,L-tryptophan was not affected by bilirubin, but lost by the presence of caprylate. These results are consistent with binding of D-thyronine to the bilirubin binding site and L-tryptophan to the caprylate binding site in albumin, respectively, and suggests that such "displacement chromatography" can be used for the determination of binding sites. The optical purity of D-thyroxine in tablets was determined indirectly after de-iodination by catalytic hydrogenation.