Kovácsné Hadady K
Acta Pharm Hung. 1989 Sep;59(5):213-6.
Method has been developed for determination of methionine in veterinary infusions containing amino acid. Methionine was measured on the basis of color reaction with sodium pentacyano-nitrosyl-ferrate in alkaline solution. Reproducibility of the method was good (recovery: 95.9-101.9%, r.s.d. = 2.3%, p = 0.95, n = 6). Tryptophane was determined on the basis of its UV absorbency at 280 nm, methionine did not interfere on this wavelength. Reproducibility of tryptophane determination was with an order better than that of methionine determination (recovery: 97.7-98.3%, r.s.d. = 0.15%, p = 0.95, n = 9). Methionine could be regained from infusions that had been heated at 120 degrees C for sixty minutes in the same quantity as from infusions which had not been heated. On the other hand tryptophane could be regained with 10% positive error from the heated infusions. The error can mainly be attributed to absorbency increase of glucose which is present in the infusion.