Amino acid analysis is a technique based on ion exchange liquid chromatography, used in a wide range of application areas to provide qualitative and quantitative compositional analysis. It is a key part of the ICH Q6B guidelines for characterization of biopharmaceuticals. The Biochrom 31+ offers full automation for the fast and reliable quality/authenticity analysis of generic drugs and infusion fluids to a high standard that satisfies legislation. Long-life columns can tolerate various matrices and a high-salt content in the analysis of infusion liquids and recombinant or synthetic peptides. The ability of Biochrom 31+ to rapidly deal with complex samples, requiring virtually no sample preparation makes it a powerful quality-control technique for the analysis of soft drinks and beverages. Protein hydrolysates are analysed using a sodium citrate-based buffer system. Protein hydrolysates are referred to as samples containing most or all of the 20 amino acids normally found in proteins. A buffer system using 3 or 4 sodium citrate buffers is sufficient for these samples. The protein hydrolysate system cannot achieve the following separations eg the two amides asparagines (Asn) and glutamine (Gln) will not be resolved from the amino acids threonine (Thr) and serine (Ser). The separation of the methylated histidines is also very difficult, as is the separation of beta-alanine and beta-aminoiosbutyric acid. If these separations are required, then lithium citrate based buffers are recommended.