We use ion exchange chromatography for sample separation. Levels of invididual amino acids are measured by using ninhydrin detection. This is the gold standard method for quantitative analysis of amino acid and protein levels in samples, and is suitable for analysis of all types of sample.
Prior to separation, proteins are hydrolised by boiling in hydrochloric acid under vacuum for 24 hours at 110 degrees.Different buffers are used to resolve amino acids in different types of sample. For example, to separate hydrolised protein samples, sodium citrate buffers are used. Whereas, lithium citrate buffers are used with physiological samples.