National Standards for Grade Levels 10-14
 
Students learn the theory of chromatography; then separate two different unknown amino acid mixtures using thin layer chromatography (TLC) with amino acid standards. Ninhydrin is used as a visualizing agent; then the rate of flow (Rf) values are calculated for each spot identified on the chromatograms. Students are challenged to predict the migration of the amino acids on the TLC after looking up the structures and pKa values of the four amino acid standards. The unknown components are identified by comparing the Rf values from the unknown amino acid mixtures to Rf data obtained from the four known amino acid standards.
Allow 1 hr lab time. Designed for 24 students working in groups of four. Required, but not included: hair dryer, 600 mL beakers for chromatography chambers, clear plastic rulers, and standard laboratory supplies.