Carvones

Carvones Post-Lab

Discussion

Name, State, odor of oil, name of spice: Caraway spice crushed; caraway oil recovered containing (+)-carvone; oil in liquid state; sweet spicy odor with a slight peppery smell.

% recovery, sources of loss: Percent recovery calculated to be 29.44%; there was a major loss of sample during this experiment. After recovering the distillate (7 ml) and removing the Methyl Chloride layer the conical vial containing the sample was spilled. Only about 0.4ml was left in the vial. But there was enough sample left in order to perform IR spectroscopy and high performance liquid chromatography.

Difference between IR and HPLC in terms of differentiating between the two enantiomers of the oil:

How IR works? What info can be determined from IR? Infrared spectroscopy is the study of how molecules absorb infrared radiation and ultimately convert it to heat. Infrared radiation is absorbed by organic molecules and converted into energy of molecular vibration, either stretching or bending. Different types of bonds, and thus different functional groups, absorb infrared radiation of different wavelengths. So the main goal of IR spectroscopic analysis is to determine the chemical functional groups in the sample.

The infrared spectrophotometer determines the relative strengths and positions of all the absorptions in the infrared region and plots this information on a piece of paper. This plot of absorption is called the infrared spectrum. An infrared spectrum represents a fingerprint of a sample with absorption peaks which correspond to the frequencies of vibrations between the bonds of the atoms making up the material.

What were the retention times of each enantiomer analyzed with HPLC (compare the standards)? Retention time – is the time taken for a particular compound to travel through the column to the detector. This time is measured from the time at which the sample is injected to the point at which the display shows a maximum peak height for...