An improved method of plasma deproteination with sulphosalicylic acid for determining amino acids and related compounds

✍ Scribed by Angelo Mondino; Gianni Bongiovanni; Silvano Fumero; Lucia Rossi

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 899 KB
• Volume: 74
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(01)86154-9

✦ Synopsis

After critically evaluating some plasma deproteination procedures involving the use of sulphosalicylic acid reported in the literature, a new method is proposed in which this protein precipitating agent is used that is particularly suitable when lithium buffers are used as resin elutrisnts. By buffering the deproteinating medium at pH 1.8, the final pH of the test solution becomes very close (without any additional adjustment) to that of the calibrating solution. In this way, the resolution in the earlier regions of chromatograms is not impaired when lithium systems are used for determining neutral and acidic amino acids. The amino acid recovery has been experimentally tested and found to be excellent for all the amino acids and related compounds except tryptophan, for which it was less than 94%. A scintillation technique with tritium-labelled lysine has also been used in order to check the validity of the proposed method.