Development Of A Fatty Acid Reference Material In Soya Oil Used For Discrimination Waste Cooking Oil And A Fatty Acid Reference Material In Olive Oil

Vegetable oil is essential in daily life. Fatty acid is one of the essential nutrients for human, which is the main component in vegetable oil. Along with the people’s requirement for healthy eating higher and higher, supervision and management of vegetable oil is particularly important. The reference material of fatty acid in vegetable oil can effectively detect different kinds of fatty acids in vegetable oil. In this dissertation, two reference material of fatty acid in vegetable oil were developmented. One used soya oil for matrix, which can discriminate the waste cooking oil. The other one used olive oil for matrix.In this research first optimize the conditions for preparation of fatty acid methyl esters. The final procedure was as follow:8 mg of sample oil was saponificated in 2 mL of NaOH-CH3OH (2%) for 15 min, then methyl esterificated by 10 mL of H2SO4-CH3OH (2%) for 10 min.Secondly, the CRM(3274-1) from NIST was used for method validation in this research. The result of method validation showed the isotopic dilution mass spectrometry (IDMS), which used for development reference material in this paper was accurate and reliable.For development matrix reference material, two kinds of fatty acid purity reference material were development. There are octylic acid reference material and decanoic acid reference material. Both of them are the necessity for development of fatty acid reference material in soya oil, which can discrimination waste cooking oil. Homogeneity and stability studies were based on GC-FID.Certified values were based on potentiometric titration. The values certified of two purity reference material are the following:octylicacid (99.70±0.19)%; decanoic acid (99.72±0.28)%The method of homogeneity, stability studies and certified values for two fatty acid reference material in vegetable oil were used IDMS which same as in method validation. The values certified of soya oil reference material are the following (unitg/100g):octylicacid (0.73±0.04); decanoic acid (1.02±0.06);hendecanoic acid (0.78±0.04); lauricacid (1.04±0.05);myristicacid (0.99±0.05); palmitic acid (10.00±0.30);stearicacid (4.05±0.12); oleic acid (21.73±0.64);linoleicacid (48.92±1.50); a-linolenicacid (4.64±0.22);eicosanoic acid (0.39±0.03); eiconsenoic Acid (0.21±0.02);behenic acid (0.49±0.03)。The values certified of olive oil reference material are the following (unit g/100g):palmitic acid (11.03±0.75); palmitoleic acid (0.77±0.04);stearicacid (3.19±0.28); oleic acid (73.95±2.96);linoleicacid (6.24±0.34); a-linolenicacid (0.62±0.04);eicosanoic acid (90.38±0.03); behenic acid (0.15±0.02)。...