In this project, chromatography, an analytical technique used for the separation of components from a mixture was performed to remove the impurities from the crude LUV dye. The mixture is dissolved in a solvent as the mobile phase which is carried through a system containing adsorbent material called the stationary phase. Components have differing affinities to the stationary phase, ie. the components in the mixture travel through the stationary phase at different rates, separating during the process. There are many forms of chromatography, this project focused primarily on thin layer chromatography (TLC) and column chromatography for the separation of quat-propylamine and dihexylamine when purifying LUV dye.
Over the course of the semester, chromatography prototypes were created and evaluated in terms of the separation of the impurities from the crude LUV dye. As shown in Figure 2, the prototypes evolved in a sequential manner with the findings of the previous prototypes being used to make judgments regarding subsequent prototypes.
The purpose of each prototype is outlined as follows:
- TLC – determine appropriate solvent in the mobile phase and adsorbent in the stationary phase for the separation of impurities from the crude LUV dye
- Pipette Column – visually inspect the presence of impurities and confirm appropriate solvents + adsorbent material to be put into the column
- Burette column – increasing scale from pipette column, evaluate crude dye loading conditions (continuous vs batch), and examine yield of purified LUV dye
- Larger diameter column – examine yield of purified LUV dye and assess scalability from conditions determined from burette prototypes
Analytical tests were also performed to assess the relative presence of the impurities in the purified samples. At Kodak, UV-Vis spectroscopy and Gas Chromatography with Flame Ionization Detection (GC-FID) were performed on the collected samples from the prototype columns to evaluate the relative presence of dihexylamine and quat-propylamine.