Column Chromatography Lab
A polarimetry tube was filled to the filler neck with the carvone/hexane mixture and was mixed thoroughly. The tube was rocked back and forth to remove any bubbles present. The tube was placed in the polarimetry machine and the observed rotation, wave length, and temperature were recorded. The path length was 1 dm and the concentration was 0.94 g/ml. The solution that was inside the polarimetry tube was moved back to its original vial for future …show more content…
The only compounds that were used for this plate were the spearmint oil, standard for carvone, and the carvone product. The solvent was hexane:ethyl acetate (90:10). This, along with the spotted TLC plate, were added to a 150 ml beaker and covered with a watch glass. The solvent was allowed to move up the plate. The TLC was removed and examined with an iodine jar and a UV light. Each spot had its Rf value recorded. A 10 ml graduated cylinder was filled with hexane. Then, two microliters of the carvone-hexane solution were added to the hexane using a micro pipette. This solution was moved into the crystal container for UV spectroscopy. The UV spectra was taken from 200 to 400 nm and the concentration of the sample was 2.0E-4. The absorbance was recorded at 232 nm and 273 nm.
The carvone product was weighed to be 1.88 g and appeared to be a mostly clear liquid. The starting mass of spearmint oil was 2.81 g and the percent recovery for the carvone product was 66.9%. For the first TLC plate the mobile phase was hexane:ethyl acetate (90:10). The analysis was conducted by using an iodine chamber to stain and a UV light to reveal hidden spots. The solvent front moved 4.1 cm. Some spots such as the spearmint oil showed signs of streaking before a full spot