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Home , Caprylic acid, Fatty acid methyl ester

EXPERIMENTAL NOTES Clarus™600 C GC-MS

GC-PETRO-002 Author Dileep Kumar Mamidala Application Specialist – Chromatography Centre of Excellence for Analytical Sciences PerkinElmer (India) Pvt. Ltd. Hyderabad – 500 081 India. Email: application.india @perkinelmer.com

Analysis and Identifi cation of Fatt y Acid Methyl Composition in Diff erent () Source Using Gas Chromatography – Mass Spectrometry

Abstract Vegetable oils have been attracted attention has a potential renewable source for the production of an alternative for-petroleum based . Various products obtained from vegetable oils have been proposed as an alternative fuel for diesel engines, including neat vegetable oil, mixtures of vegetable oil with petroleum diesel fuel and alcohol of vegetable oils. Out of which Alcohol esters of vegetable oils appear to be the most promising alternative. Vegetable oils are (glycerin esters) of fatty acids and alcohol esters of fatty acids have been prepared by the of the , wherein linear, monohydroxy alcohols reacts with the vegetable oils in the presence of catalyst to produce alcohol esters of vegetable oil. The alcohol esters of vegetable oil when used as an alternative diesel fuel have been identified as a biodiesel. This experimental note demonstrates the analytical capability of PerkinElmer Clarus™ 600C GC-MS for the analysis and identification of methyl ester composition (Biodiesel) in various vegetable oils.

Preparation of biodiesel Transesterification: Weighed about 250 g of Kusum oil, Palash oil, Mehwa oil and Thumba oil and transferred in to individual 100 mL conical flasks. Weigh about 2.5 g of Potassium Hydroxide (1% by weight of the oil) and dissolve it in 72 g anhydrous methanol. Completely dissolve the KOH in methanol, apply heat if required. transfer the resulting solution slowly to the sample in a conical flask with Analytical results & discussion stirring. After complete transfer of KOH solution in methanol Biodiesel samples were analyzed using PerkinElmer Clarus™ 600 continue the stirring for 120 minutes to complete the reaction. C GC-MS in total scan mode to identify the fatty acid methyl ester After completion of the reaction time pipette out and transfer composition in different vegetable oil sources with the help of approximately 8-10 mL of reaction mixture to 15mL test tube NIST library. The samples were analyzed and the composition of and keep it for phase separation. fatty acid methyl esters was identified were as follows. Phase separation and washing: After 120 minutes of reaction time, the reaction was stopped and reaction mixture was allowed to stand overnight while the phase separations occurred in different reaction mixtures in individual flasks. The ester phase was decanted from the mixture and transferred to glass column for further washing to remove the any traces of methanolic KOH solution. Fig 1. Total ion chromatogram of Palash Fig 2. Total ion chromatogram of Excess alcohol and residual catalyst were washed from the ester biodiesel. 1. Caprylic acid methyl Mehwa biodiesel. 1. Caprylic acid ester, 2. , methyl ester, methyl ester, 2. Myristic acid, methyl with water. The ester phase was placed in a glass column 1.26 cm 3. , methyl ester, 4. ester, 3. , methyl ester, 4. in diameter and 100 cm in length. Water was sprayed into the top Palmitic acid, methyl ester, 5. Margaric , methyl ester, 5. , methyl ester, 6. Linoleic acid, acid, methyl ester, 6. , methyl of the column at a low velocity. The excess alcohol and catalyst methyl ester, 7. Oleic acid, methyl ester, 7. , methyl ester, 8. were removed by the water as it percolated through the column. ester, 8. Stearic acid, methyl ester, 11-Eicosenoic acid, methyl ester, 9. During the washing, some of the ester formed an emulsion with 9. 11-Eicosenoic acid, methyl ester, , methyl ester, 10. Behenic 10. Arachidic acid, methyl ester, 11. acid, methyl ester, 11. Lignoseric acid, the water; a time of 24-48 hours was required for the water Heneicosanoic acid, methyl ester, 12. methyl ester, 12. Pentacosanoic acid, phase containing alcohol, catalyst, and emulsified ester to settle 13-Docosenoic acid, methyl ester, methyl ester, 13. , methyl 13. , methyl ester, 14. ester. and the ester phase to become clear. Tricosanoic acid, methyl ester, 15. Lignoseric acid, methyl ester, 16. Sample preparation and analysis: Pentacosanoic acid, methyl ester, 17. Cerotic acid, methyl ester. Weigh 25 mg of the ester phases of different oils and dissolve it in 0.5 mL of n-heptane. The resulting sample solution is filled in GC auto sampler vial and injected in GC/MS to analyze and identify the fatty acid methyl ester composition in different types of vegetable oils.

Instrumental Conditions:

Clarus™ 680 GC Optimized Experimental Conditions Fig 3. Total ion chromatogram of Kusum Fig 4. Total ion chromatogram of Column Elite-5MS, 30m x 0.25mm x 0.25um biodiesel. 1. Palmitoleic acid, methyl Th umba biodiesel. 1. Caprylic acid ester, 2. Palmitic acid, methyl ester, 3. methyl ester, 2.Azelaaldehydic acid, Injector temperature 220 °C Linoleic acid, methyl ester, 4. Oleic acid, methyl ester, 3. Myristic acid, methyl Carrier gas Helium methyl ester, 5. Stearic acid, methyl ester, 4. Pentadecanoic acid, methyl ester, 6. 11-Eicosenoic acid, methyl ester, 5. Palmitoleic acid, methyl ester, 6. Carrier gas fl ow 0.2 mL/min ester, 7. Cis-11-Eicosenoic acid, methyl Palmitic acid, methyl ester, 7. Margaric Split ratio 50:1 ester, 8. Arachidic acid, methyl ester, 9. acid, methyl ester, 8. Linoleic acid, Heneicosanoic acid, methyl ester, 10. methyl ester, 9. Oleic acid, methyl Oven Programme 35 °C hold for 10 min 13-Docosenoic acid, methyl ester, 11. ester, 10. Stearic acid, methyl ester, 10 °C/min 200 °C hold for 10 min Methyl 11-docosenate, 12. Behenic acid, 11. 13-Docosenoic acid, methyl ester, Total run time 36.5 min methyl ester, 13. Lignoseric acid, methyl 12. Behenic acid, methyl ester, 13. ester. Lignoseric acid, methyl ester. Diluent n-Heptane Injection volume 0.1 ul Conclusions Clarus™ 600 C MS Parameters This experimental result confirms the effectiveness of the Ionization source EI analysis procedure and also demonstrated the capability of Electron energy 70 eV PerkinElmer Clarus™ 600 C GC-MS to identify the fatty acid Source temperature 200 °C methyl ester composition (biodiesel) in different types of Transfer line temp 200 °C vegetable oil sources. Multiplier (V) 366 V Ion energy 1.5 V Scan range 10-600 m/z