In: Chemistry
You have been provided a mixture containing four amino acids (Glu, His, Pro and Lys) to be separated by ion-exchange chromatography using a Dowex 50 cation-exchange, prepared in a loading buffer at pH 2.0. The following solutions are made available:
The amino acid mixture in 0.04M citrate buffer at pH 2.0.
0.04M citrate buffer, pH 4.5
0.04M citrate buffer, pH 8.0
0.04M citrate buffer, pH 10.5
Is complete resolution of all amino acids achieved if the
buffers are allowed to elute through the column sequentially from
lowest to highest pH? Identify the order of elution and identify
any amino acids that may come off the column together if complete
resolution is not achieved. Support your response with an
explanation.
Assuming the amino acids in the mixture will elute from the column
ONLY at a solution pH that is above their respective pI.