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）是最为适宜的油料植物之一，其种子天然不可食用但油脂含量丰富。本研究采用高分辨气相色谱-质谱联用仪（gas chromatography with high resolution mass spectrometer）对麻疯树提取脂质的脂肪酸组成展开分析。麻疯树原油中的主要脂肪酸为油酸（3.81%）、亚油酸（50%）与棕榈酸（35.66%）。研究团队对其部分理化特性进行了评估，结果表明该原油适用于内燃机应用。氧化稳定性、氧化可氧化性与十六烷值的计算值分别为4.949、1.076，实测十六烷值为55.856。碘值与氧化稳定性存在显著相关性，因此碘值亦可作为氧化稳定性的评价指标。欧盟EN 14214标准中，生物柴油的标准碘值为120，而麻疯树油的碘值为103.62g I2/100g。本研究从理化视角评估了麻疯树原油的特性及其在内燃机中的应用潜力。

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。色谱柱的柱长、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35℃起始，35℃下保持5min，以3℃/min升至210℃，随后以40℃/min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，进样口温度为250℃，气相色谱柱流量为1.80mL/min。质谱检测采用ACQ模式扫描，扫描范围为30~700amu，扫描速率为1478。将所得质谱图与NIST05质谱库（美国国家标准与技术研究院，盖瑟斯堡，版本2）进行比对。

结果：见附件