The use of a “microbead” resin with a uniform diameter of about 10 µm or less improved buffer composition, and high pressure chromatographic techniques have decreased the analysis time from 24 hr to approximately 1 hr, while microbore columns and improved spectrophotometer design have increased sensitivity about 100-fold. After Reversed-phase ion-pair chromatography of the amino acids the eluate passes to a heated reaction coil where color development occurs. The sources of fluorescence contamination have been attributed to impurities in the water, buffer solutions, and HC1. Impurities in amino acid analyzer buffers derive from contaminated reagents used in buffer production. A major source of contamination in amino acid determination is commercially available HC1, which contains amino acids and ammonia in sufficient amounts to interfere with cleanliness requirements during buffer preparation and peptide hydrolysis.