Experiment 8: Identification of an Adulterated Herb The purpose of this lab is to analyze the volatile oils of some herbs through TTL testing and then identify the adulterant in a sample. Unfortunately, we ran out of time to complete the lab; however, we were able to get through most of it, and were only missing the adulterant. The first step to identify our unknown samples was to create TTL plates that should results with each known compound and 95% hexane: 5% ethyl acetate, 90% hexane: 10% ethyl acetate, or 80% hexane: 20% ethyl acetate. Each student was designated one of these concentrations of solvent as well as equalization method.
After we tested and calculated the Revalues of each of the following known compounds with each concentration: anise, caraway, cinnamon, cloves, coriander, and cumin. When all the known compounds were tested only the two first compounds reacted with DUNN and that’s because alludes tend to react faster with DUNN. The next step was to identify each of our pure substances and the adulterant. My group had the unknown samples numbered 521, 522, 523, and 524. We prepared each sample with the hexane extract, so that when we spotted each ample on the TTL plate it would give us accurate results.
We then compared the RFC of these plates to previous Refs as well as the odors from the chemical to identify every compound. Since our sample 521, reacted both DUNN when tested we concluded that it would be an alluded which narrowed our choices. We then compared the RFC values of each sample and concluded that our samples with respective to their number were the following: caraway, cloves, and coriander. We noticed that both sample 521 and 524 reacted with DUNN and had similar RFC values, meaning that within sample 524, there must be some caraway.
Unfortunately, like I stated before we weren’t able to finish the lab and we never got to do plate number 5. Conclusion: I learned that although alludes and stones are very similar they have different reactivates, and at the same time it reinforced previous knowledge about reactivity. I also was able to see how some herbs relate to each other and have similar structure and odors. Questions: 1. If two students had the same Revalues and when spotted together they show 2 different results can be for a simple error of miscalculating and having different solvent fronts. No they would not spot different because Alaskan and ethers react different from one another and as well 3. 90% hexane