Multiple approaches to the separation of amino acids and biologically-relevant compounds

by 1979- Riddle, Lance Andrew

The branch of analytical chemistry known as separations has continued to grow and expand ever since its beginnings a century ago. With all the technological advances occurring to make separations a more powerful technique, the main goal continues to be the desired separation of the compounds of interest in a mixture. Although a desired separation may be achieved, there can always be room for improvement with regards to the time necessary for the separation as well as better resolution of closely-related species as well as enantiomers of the same analyte. In this work, a variety of separation methods and variations are used to achieve separations of biologically-related compounds. The technique of high performance liquid chromatography was used for the separation of the peptides from a protein digest as well as sterols from synthetic mixtures as well as from naturally occurring fruit juices. Monolithic column technology was used for the separation of the protein digest, but the use of different mobile phases as well as mobile phase gradients afforded different separation orders of the peptides. High temperatures were incorporated for the separation of the sterols, so this separation included the study of how different stationary phases that could withstand the high temperatures affected the resolution of the sterols investigated. Amino acids labeled with a fluorescent tag were also separated in this work. The investigation of a polyamide column for the separation of amino acids was performed, and capillary electrophoresis incorporating the use of cyclodextrins as well as mixed micelles for the separation of amino acids is presented here. v