The invention discloses a method for detecting racemic ketoisoleucine
calcium impurities in a compound alpha-
keto acid tablet, which comprises the following steps: dissolving a racemic ketoisoleucine
calcium reference substance in a
solvent to obtain a reference substance solution, taking the
solvent as a blank solution, injecting the blank solution into a liquid chromatograph until a
base line is stable, and measuring the content of the racemic ketoisoleucine
calcium impurities in the compound alpha-
keto acid tablet. Injecting the reference substance working solution into a liquid chromatograph for detection; the method comprises the following steps: dissolving a sample in a
solvent to obtain a
test solution, injecting the
test solution into a liquid chromatograph, recording a chromatogram, calculating the single
impurity of the racemic ketoisoleucine calcium by an external standard method, and calculating the total amount of the impurities. The invention belongs to the technical field of racemic ketoisoleucine calcium
impurity determination, and particularly relates to a method which can accurately detect some specific racemic ketoisoleucine calcium degradation impurities, is not interfered by other components in compound
amino acid, meets the requirement that the degree of separation among the impurities meets the applicability of a chromatographic
system, and is high in detection accuracy. The sample treatment is simple and convenient, the sample detection result is accurate and reliable, and the sensitivity is high.