Gas Chromatography

According to AOCS lipid library (2015), the technique of gas chromatography (GC) is a form of partition chromatography in which require a mobile phase is a gas and the stationary phase is a liquid or solid packed. It is used to separate and measure of mixtures of materials that can be volatilized. In gas chromatography, specifically gas liquid chromatography which involves vaporizing a sample and injecting it onto the head of the column. The advantage of using gas chromatography is it can give very good separation. Then, the process not required the long time of analysis. Moreover, only small sample is needed to get a result and it is quantitatively analyzed. In the other hand, the disadvantage of gas chromatography is sample used

The fatty acid compositions of canola oil are made up of saturated fatty acid, monosaturated fatty acids and polysaturated fatty acids. According to Doctor Cordain who is the World’s Leading Expert on Paleolithic Diets and Founder of the Paleo Movement (2015), saturated fatty acids contain in canola oil are palmitic acid (C16:0), stearic acid (C18:0), arachidic acid (C20:0), behenic acid (C22:0) and lignoceric acid (C24:0). Monosaturated fatty acids in canola oils are palmitoleic acid (C16:1), oleic acid (C18:1), gadoleic acid (C20:1) and erucic acid (C22:1). Linoleic acid (C18:2) and alpha linolenic acid (C18:3) are the polysaturated acid found in canola oil. From the experimental result, there are some fatty acids do not in the data such as arachidic acid (C20:0), behenic acid (C22:0), lignoceric acid (C24:0), gadoleic acid (C20:1) and erucic acid (C22:1). This may due to these fatty acids are occur in too low concentration until there are hard to be detected or sample decomposed in the injector or the detector used are low sensitivity. Sample too diluted will also cause these fatty acid does not occur in our data. Injection port or column too cold will also cause the sample cannot vaporised properly. Moreover, column cannot separate components from solvent or it may also absorb or decompose canola oil sample make some fatty acids are not showed in the

There are some different between reference value and experimental value. This may due to some errors occur in the experiment. As refer back to the chromatogram of standard and chromatogram of canola oil, reason for the deviation mainly is due to the retention time for chromatogram of canola oil is shifted. Shift in retention time because change in column temperature and dimension, change in carrier gas in term of pressure and velocity and poor column connection or column not properly installed (Delloyd 2015). By comparing the reference value and experimental value, both results show that there are more monounsaturared fatty acids compare to saturated fatty acids in canola oil. The lower saturated and higher monounsaturated fatty acid contents, makes canola oil nutritionally more suitable and more prefer than other oil in making salad and cooking purpose (PRZYBYLSKI & McDONALD, 1995). It is known that consumption of unsaturated fatty acid is healthier than saturated fatty acid because consumption of saturated fatty acids in large amount will cause increase of the plasmatic cholesterol and the obesity. Unsaturated fatty acids although will not affect the HDL levels, they will reduce the LDL or bad cholesterol and triacylglicerols blood levels, thus, it may more effective to prevent heart diseases (SALES et al.,