Results and Discussion Rather than using organic solvent extraction, CO2 extraction was used to separate D-limonene, a component of orange oil, from orange rinds. CO2 extraction is considered a “green” experiment because it is nonflammable, relatively nontoxic, readily available, and environmentally benign. Considering that there is not a high concentration of limonene in the rinds, the experiment was successful and yielded 1.04 percent limonene relative to the mass of the rinds. The 13C NMR spectrum detects inequivalent carbons and displays them as discrete peaks. There are ten peaks on the spectrum which correspond to ten equivalent carbons. From the structural drawing of limonene, it can be determined that there are ten constitutionally
