Gas Chromatography and Mass Spectroscopy Based Detection of Lipid Profile in Jatropha Crude Oil and its Potential as Biodiesel Feedstock

Jatropha curcas is one of the most suitable plants which seeds are non-edible in nature but rich in oil. In this research, the fatty acid composition of the extracted lipid of jatropha was studied using the gas chromatography with high resolution mass spectrometer. The major fatty acids in jatropha crude oil were the oleic (3.81%), linoleic (50%) and palmitic (35.66%) fatty acid. Some physical and chemical characteristics have been evaluated and found suitable for the application in engine. Oxidation stability oxidizability and cetane number has been calculated as 4.949, 1.076 and found 55.856. Iodine number correlates with oxidation stability, therefore iodine number is also considered as an index of oxidation stability. Standard iodine value for biodiesel was 120 for Europe’s EN 14214 specification while for Jatropha oil it was 103.62g I2/100g. This endeavor evaluates chemical and physical perspective of Jatropha crude oil and its suitability in internal combustion engine. 2 Material & Method- A gas-chromatograph with high resolution mass spectrometer was used to determine the free fatty acid composition of the Jatropha oil sample. The column length, diameter and thickness were 30m, 0.25mm and 0.25µm respectively. The conditions for analysis were set as follows; column oven temperature was programmed from 35°C-240°C (temperature at 35°C was held for 5min, raised to 210°C at 3°C/min and then finally to 240°C at 40°C/min and held for 4min); Helium gas was used as carrier gas, column flow of 1.80 mL/min for the GC. The injection volume was 2 μL with injection temperature of 250°C and a column flow of 1.80 mL/min for the GC. For the mass spectroscopy ACQ mode scanner with scan range of 30-700 amu at the speed of 1478 was used. The mass spectra were compared with the NIST05 mass spectral library ((National Institute of Standard and Technology, Gaithersburg) mass spectral library version 2). Result- Enclosed麻疯树（Jatropha curcas）是目前最具应用潜力的油料植物之一，其种子天然不可食用且油脂含量丰富。本研究采用高分辨气相色谱-质谱联用仪（gas chromatography with high resolution mass spectrometer）对麻疯树提取油脂的脂肪酸组成展开分析。结果显示，麻疯树粗油中的主要脂肪酸为油酸（3.81%）、亚油酸（50%）与棕榈酸（35.66%）。研究人员对该油脂的部分理化特性进行了评估，证实其适配内燃机应用场景。氧化稳定性与可氧化性的计算值分别为4.949、1.076，十六烷值的实测值为55.856。碘值与氧化稳定性具有相关性，因此碘值亦可作为氧化稳定性的评价指标。欧洲EN 14214生物柴油标准中规定的标准碘值为120，而麻疯树油的碘值为103.62g I₂/100g。本研究从理化层面评估了麻疯树粗油的特性，并探讨了其在内燃机中的应用适配性。 2 材料与方法：采用高分辨气相色谱-质谱联用仪对麻疯树油样品的游离脂肪酸组成进行测定。色谱柱的长度、内径与膜厚分别为30m、0.25mm与0.25μm。分析条件设置如下：柱箱升温程序为起始温度35℃并保持5min，随后以3℃/min的速率升至210℃，再以40℃/min的速率升至240℃并保持4min；以氦气作为载气，气相色谱柱流量为1.80mL/min。进样体积为2μL，进样口温度设为250℃，气相色谱柱流量为1.80mL/min。质谱检测采用ACQ模式扫描器，扫描范围为30~700amu，扫描速度为1478。将获取的质谱图与NIST05质谱库（美国国家标准与技术研究院（National Institute of Standard and Technology, Gaithersburg）版本2质谱库）进行比对。 3 结果：附后