Determination of the Content of Cystine in Compound Amino Acids Injection (18AA) with Performic Acid Oxidation by Amino Acid Analyzer

OBJECTIVE E To establish a method to determine the content of cystine in Compound Amino Acids injection (18AA). METHODS The pre-column derivation and amino acid analyzer were adopted. RESULTS This method showed that the concentration-response relationship was linear over the range of 20.46-184.10 μg·mL^-1(r=0.999 8). The average recovery was 100.8% (RSD=0.91%, n=9). CONCLUSION The method is specific, accurate, rapid, sensitive and suitable for the determination of content of cystine in Compound Amino Acids injection (18AA).