Abstract: The purpose of this lab was to identify an unknown edible oil sample. Gas chromatographic analysis of the fatty acid methyl esters was conducted to find an unknown sample of oil. It was found that the unknown oil was olive oil. Saponification and methylation were methods that were used to prepare the sample for gas chromatography. Gas Chromatography of the olive oil showed peaks at palmitic, palmitoleic, stearic, linoleic, and alpha linolenic. The highest percentage from the chromatogram was oleic.

Introduction: Basic oils are essential for the human body. Oils are fatty acids that are utilized by the body for metabolic functioning. Fatty acids are a simple form of lipids. Lipids are chemical compounds that do not readily dissolve in water, but dissolve in organic solvents. Common lipids are Triglycerides and Phospholipids. Fatty acids consist of a carboxyl end at the alpha end and a methyl group at the omega end. Fatty acids can be either saturated or unsaturated. Saturated fatty acids have a maximum amount of hydrogen atoms. They are solid at room temperature. Common saturated fatty acids are palmitic, stearic, and lauric. Unsaturated fatty acids do not contain a high amount of hydrogen atoms, but have a double bond. These fatty acids are liquids at room temperature. Common unsaturated fatty acids are linolenic and oleic acids. An example of this is shown in olive oil. Olive oil has a high percentage of oleic acid. It reduces LDL cholesterol. The accumulation of free radicals, as a result of oxidation in the body causes serious health problems. Vitamin-E and various phenols protect the body from these radicals. The consumption of Olive oil can prevent the invasion of free radicals and reduce the aging process. The human body cannot synthesize omega-3-fatty acids and Omega 6 fatty acids. The body cannot produce these fatty acids and thus acquires them from food. Omega-3-fatty acids are a form of polyunsaturated fats. Omega-3-fatty acids include salmon, flaxseed oil, canola oil, and sardines. Omega-3-fatty acids have been found to reduce hypertension, improve heart health, and improve rheumatoid arthritis. Omega-6-fatty acids are another class of polyunsaturated fats. They have a double bond at the sixth carbon position from the methyl group (Omega-3 has the double bond at the third carbon position from the methyl group). Omega-6-fatty acids include corn, sunflower, and vegetable oils. Omega-6-fatty acids are used to treat diabetes, eczema, and anorexia nervosa.

Materials and Methods: A test tube was weighed on a test tube weighing 14.77. 2 drops of yellowish oil was put in a test tube. This test tube was measure on a balance and weighed 15.59g. 1mL of Boron Triflouride was added and nitrogen was flushed into the tube. The test tube was capped and put in a hot tray for 20 minutes. The test tube was put on ice until cool. 2.0 mL of pentane and 1.0mL of deionized water were added to the tube. Nitrogen was added again and the test tube was centrifuged at 2000rpm for 3 minutes. The new test tube was weighed on a balance at 9.79 grams. The weight of the new tube with the product was 15.74g. The top layer of the product from the centrifuged tube was put into the new tube. 2mL of dichloromethane was added to the test tube and injected with Nitrogen. When the product had dried added 2mL of dichloromethane and added to gas chromatography vial.




Results:
Fatty Acid Abbreviations Percentage
Palmitic 16:0 11%
Palmitic 16:1 .9%
Steric 18:0 2%
Oleic 18:1 75%
linoleic 18:2 9%
linolenic 18:3 .646%
It was found that the unknown oil was olive oil based on the chromatogram. See Chart
Conclusion: This experiment proved that the unknown sample was olive oil. Oleic Acid was the highest percentage. Oleic acid is a Omega-9-fatty acid, which has 18 carbons and one double bond. It is a essential fatty acid that can be synthesized in the body, because of the breakage of the double bond at the ninth carbon. Essential fatty acids help form cell membranes, strengthens the immune system, and vision.

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