Each sample was exposed to three different types of treatment1 because certain compound spots are only revealed under the right treatment. I2 vapors show both unsaturated and aromatic compounds due to its high affinity to those compounds. Under UV light, compounds that are UV-active are revealed. p-Anisaldehyde dip followed by heating generally reveal compounds with functional groups that are nucleophilic. None of the compounds were visible to the naked eye because none of the compounds were originally colored. The maximum number of spots for (1R, 2S, 5R)-(-)-Menthol and (R)-Carvone was one, meaning that both were pure compounds. The peppermint and spearmint oil consisted of several compounds as shown by the number of spots. Based on the data from Table 1 and observations, one component of spearmint oil was carvone. The spot?s Rf value was 0.43 which matched the Rf value of the standard (R)-Carvone. Both spots also turned yellow after the p-anisaldehyde dip. A second component of spearmint oil is menthol, which was also shown under the p-anisaldehyde dip. The spot had an Rf value of 0.31 which matched the standard?s Rf value. Both spots were blue but the standard (1R, 2S, 5R)-(-)-Menthol spot was much bigger because there was very little menthol in spearmint oil. One of the spots for peppermint oil also matched the Rf value for (1R, 2S, 5R)-(-)-Menthol. Both spots were blue but the standard (1R, 2S, 5R)-(-)-Menthol spot was only slightly bigger, indicating that there was a significant amount of menthol in peppermint oil. The speed that compounds travel up the plate is directly related by their polarity. The less polar the compound is the closer it is to the solvent front. This is because the silica gel on the TLC plate is adsorptive of polar molecules so the more polar a compound is, the more it attaches to the silica gel and the slower it moves. Out of a total of 5 spots seen for spearmint oil under the different treatments, menthol was second from the bottom and carvone was third. This means that menthol is more polar than carvone. There is one unknown compound shown that is more
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