核桃油中主要脂肪酸的毛细管柱气相色谱分析

采用毛细管柱气相色谱程序升温的方法 ,将核桃油用正己烷稀释后直接进样 ,对 5种主要脂肪酸进行定性定量分析。 5种主要脂肪酸占出峰物质总量的 97%。     

Preparation and Characterization of Oil Rich in Odd Chain Fatty Acids from Rhodococcus opacus PD630

Odd-chain fatty acids (OCFA) are widely used in pharmaceutical and food industries, as well as the chemical industry. In this study, oil rich in OCFA was produced by Rhodococcus opacus PD630, and 1-propanol in combination with glucose was used as the carbon and energy source. Oil was extracted by the subcritical extraction system. Gas chromatography (GC), ultra-performance liquid chromatography-mass spectrometry (UPLC-MS), and differential scanning calorimetry (DSC) were used to evaluate the fatty acids composition, triacylglycerol (TAG) molecular species, and thermal properties, respectively. It was found that the content of OCFA reached 68.15%, where pentadecanoic acid (7.74%), heptadecanoic acid (18.20%), and heptadecenoic acid (42.71%) were the dominant OCFA. The most abundant TAG were HePaHa (15.82%), HePHa (11.42%), HePaHe (9.68%), HeHaHa (9.62%), HePaO (8.26%), and HePPa (8.00%). In terms of thermal profiles, recrystallization was detected in the oil rich in OCFA. Above all, these findings greatly extend the utilization of the microbial oil rich in OCFA, and they may have a significant impact on the future development of the microbial oil industry.     

气相色谱-飞行时间质谱法分析德国洋甘菊油中的挥发性成分

利用气相色谱-飞行时间质谱,对德国洋甘菊油的挥发性成分进行了分析,并用峰面积归一化法计算了各成分的相对含量。通过质谱库检索,辅助英文版精油数据库(ESO2010版)比对,分析并确定出洋甘菊油中的72个成分,占其总挥发性成分的88.35%。德国洋甘菊油的主要成分为α-红没药醇氧化物B(16.17%)、双环大根香叶烯(15.35%)、α-红没药醇氧化物A(10.11%)、蒿酮(8.23%)、大根香叶烯D(7.01%)、α-红没药酮氧化物(6.08%)、β-罗勒烯(5.39%)、(E)-β-金合欢烯(2.56%)、斯巴醇(2.48%)、母菊薁(2.46%)、香芹酮(1.49%)、薄荷醇(1.37%)等。其中萜类化合物及其衍生物共42个,占洋甘菊油总挥发性成分的79.99%。通过保留指数来鉴别同系物及同分异构体,提高了天然香原料中化合物定性的准确性。     

越南安息香种子脂肪酸的在线甲基化-GC分析研究

建立了分析越南安息香种子油、果实和果壳的脂肪酸组成的在线甲基化-气相色谱法。将微克级的安息香样品与2μL衍生化试剂三甲基氢氧化硫（0.2 mol/L）加入裂解器,在350℃下瞬间反应,由气相色谱在线检测到8种脂肪酸甲酯成分,主要有棕榈酸（ C16∶0）、硬脂酸（ C18∶0）、油酸（ C18∶1）、亚油酸（ C18∶2）和亚麻酸（ C18∶3）,不饱和脂肪酸含量在84.5%以上,其中亚油酸含量最高,达47.29%。5次平行测定的相对标准偏差（ RSD）小于3.81%。并结合相似性分析法比较了4种不同产地的安息香种仁与6种食用油的脂肪酸组成,相似性结果表明不同产地的安息香种仁的脂肪酸组成相似,其脂肪酸组成与食用植物油相近,与玉米油的组成分布最为接近,相似系数在0.987~0.990,且越南安息香种子中人体必需的多不饱和脂肪酸含量（ C18∶2和C18∶3）与大豆油和葵花籽油相近,高于一般植物油,具有较高的营养价值。结果表明该法简便、快速、准确,适合越南安息香种子油脂的测定。     

正常小鼠和肿瘤小鼠毛发中长链脂肪酸含量测定及比较

以正十七酸为内标 ,氯化氢 甲醇抽提和酯化 ,对正常、肿瘤、抗肿瘤小鼠毛发中长链脂肪酸——豆蔻酸、棕榈酸、棕榈油酸、油酸、硬脂酸和亚油酸进行毛细管柱气相色谱定量分析和比较。结果显示 :肿瘤小鼠或抗肿瘤小鼠毛发中长链脂肪酸含量明显升高 ,不饱和长链脂肪酸比例升高而饱和长链脂肪酸比例下降 ,提示毛发中不饱和长链脂肪酸尤其亚油酸与生物体内肿瘤的发生和存在有密切关系。本实验方法简单 ,所需样品量少 ,实验重现性好 ,回收率达定量分析要求。     

油脂中八种脂肪酸的分析测定

油脂经氢氧化钾-甲醇溶液甲酯化后,生成的脂肪酸甲酯用DB-WAX毛细管柱进行分离,GC-FID进行检测。该方法的回收率在91.45%~107.55%,相对标准偏差小于8%,八种脂肪酸的检出限在0.29~1.10μg/mL之间。本方法准确度高,检出限低,能满足实际检测工作的需要。     

甲醇溶剂法分离蚕蛹油多不饱和脂肪酸

采用甲醇溶剂法分离蚕蛹油多不饱和脂肪酸。通过单因素实验探讨了温度、甲醇浓度、甲醇脂肪比、时间对多不饱和脂肪酸分离效果的影响,然后通过正交实验确定了多不饱和脂肪酸分离的较佳条件。结果表明,适宜的分离条件为：温度-10℃,甲醇浓度90%（w）,甲醇脂肪比2.5,结晶时间30min,在上述条件下多不饱和脂肪酸得率为62.3%,含量由71.0%提高到95.8%。     

Simultaneous Determination of Free Fatty Acids and Esterified Fatty Acids in Rice Oil by Gas Chromatography

Free fatty acids (FFA) in crude rice oil were selectively and stoichiometrically derivatized to fatty acid N,N-dimethylamides (FADMA) by catalytic condensation at 45 °C, and then esterified fatty acids (eFA) were directly converted to fatty acid methyl esters (FAME) at 37 °C. The mixture of FADMA and FAME formed in a single test tube was injected into the capillary column of a gas chromatograph (GC). No mutual contamination occurred between FFA and eFA, and reliability of the method was confirmed by comparison between GC data obtained by this method and by a conventional isolation method. The advantages of the present method are that no FFA isolation procedures are required, the reactions proceed under mild temperature conditions, and FFA and eFA can be analyzed simultaneously by GC.     

乌桕梓油脂肪酸组成分析

乌柏是我国四大木本油料之一,种子含油量高,乌桕梓油是由种仁榨取所得的液体油脂,是轻工业、食品和国防等行业的重要油源。乌桕梓油甲酯化后,利用100 m×0.25 mm的GC毛细管柱,气相色谱法测定乌桕梓油的脂肪酸组成。测定结果表明：乌桕梓油中饱和脂肪酸占10.68%,以棕榈酸含量最高,占7.52%。不饱和脂肪酸占89.13%,单不饱和脂肪酸占18.63%,以油酸含量最高,占14.55%;多不饱和脂肪酸占70.50%;其中含量最高的为人体所必需的脂肪酸亚油酸和α-亚麻酸,分别占30.77%和39.30%。还含有相当数量天然植物中少有的奇数碳原子脂肪酸十一烷酸,占0.29%。其中月桂烯酸（占3.19%）和十一烷酸未见报道。     

怒江漆油中高级脂肪酸成分

对云南怒江漆油 (漆树籽油 )进行皂化得到了漆油的总脂肪酸 ,将总脂肪酸甲酯化得到总脂肪酸甲酯 ,用GC MS联用仪测定了所含高级脂肪酸的成分 ,结果表明云南怒江漆树油中高级脂肪酸分别为棕榈酸、油酸、硬脂酸、花生酸、二十烷二酸。其中 ,棕榈酸的质量分数高达 76.9%。     

基于气相色谱方法的植物油脂肪酸分析探究

从材料、试剂、仪器、方法等方面入手,介绍了植物油脂肪酸分析实验用到的材料与方法;其次,从定性和定量分析、色谱柱的选择、甲酯化体系的选择、反应温度影响、精密度和稳定性实验、实际样品测定及植物油脂肪酸组成特点、聚类分析七个方面入手,研究了植物油脂肪酸分析实验的结果与分析;最后,总结了植物油脂肪酸分析实验的结论。希望通过这次研究,为实验人员加深对基于气相色谱方法的植物油脂肪酸分析有更深刻的认识和了解。     

气相色谱法测定食品油脂中的十八碳反式脂肪酸

反式脂肪酸是在油脂的加氢反应或高温精炼过程中伴随产生的一类不饱和脂肪酸,过多的食用这些成分可能会对人体健康产生危害。食品油脂中以十八碳反式脂肪酸最为常见。采用气相色谱法对食品中十八碳反式脂肪酸的检测进行了实验摸索,获得了一套准确度高、精确度好的方法,可应用于日常监督检测。     

毛细管气相色谱法测定核桃油中的脂肪酸

讨论了核桃油中脂肪酸的提取方法和毛细管气相色谱法测定条件，并对5种主要脂肪酸进行定量的测定。     

Fatty and Resinic Acids Extraction from Crude Tall Oil

Abstract

The separation of fatty and resinic acidic fractions from crude tall-oil soap solutions with n-heptane by the technique of dissociation extraction is discussed. The theory of the overall process is supported by a systematic study developed to cover the high selectivity demonstrated in the differential solubility and the aptness between fatty and diterpenic acids to both liquids phases. To study the main factors affecting those liquid-liquid extraction systems and the amphiphilic behavior of such molecules involved, sodium salts aqueous solutions of crude tall oil and synthetic mixtures as molecular acidic models were used.     

顶空固相微萃取气质联用分析瘤果黑种草子挥发性成分

采用顶空固相微萃取气质联用技术分析测定了瘤果黑种草子中的挥发性成分,结果共分离得到15种成分,鉴定并确认了其中的12种成分,占成分总量的94.8%,其挥发性成分主要为百里醌(47.62%)、百里香烯(23.93%)、α-侧柏烯(11.21%)、长叶烯(2.90%)。为更深入开发利用此新疆特色资源提供了科学依据。     

Fatty acid profile and aroma compounds of lipoxygenase-modified chicken oil

Adipose fat tissue, which contributes 1.6–5.8% of total chicken carcass weight, has been underutilized by chicken processors because of its “chickenish odor.” The objective of this study was to prepare a chicken oil from which the undesirable odor notes were eliminated and in which the desirable volatile compounds were enhanced. Chicken adipose fat was dry-rendered at 140°C for 30 min and yielded 78.5% oil. Monoenoic FA constituted 55.8% of the chicken oil, and of that oleic acid constituted 92.8%. Treatment of chicken oil with an algal lipoxygenase extracted from Ulva spp. at 33°C for 30 min resulted in an increase of 0.40% in total monoenoic acids, a decrease of 33.3% in total polyenoic acids, and a decrease in total FA of 0.8%. A noticeable improvement in the odor of chicken oil after lipoxygenase treatment was observed by sensory evaluation and a GC-sniffing technique. The modified chicken oil contained more desirable volatile compounds—ethyl acetate, pentanal, 2-pentyl furan, E-2-heptenal, and nonanal—than the original chicken oil, provided fruity and tea-leaf aromas, and had reduced levels of the undesirable volatile compounds heptanal, 2,4-heptadienal, 2,4-nonadienal, and dodecanal. These modifications reduced the chickenish and oxidized odor notes.     

Structural Determination and Occurrence in Ahiflower Oil of Stearidonic Acid Trans Fatty Acids

Several marine oils and seed oils on the market contain relevant quantities of stearidonic acid (18:4n‐3, SDA). The formation of 18:4n‐3 trans fatty acids (tFA) during the refining of these oils necessitates the development of a method for their quantification. In this study, 18:4n‐3 was isolated from Ahiflower and isomerized to obtain its 16 geometric isomers. The geometric isomers of 18:4n‐3 were isolated by silver ion HPLC (Ag⁺‐HPLC) and characterized by partial reduction with hydrazine followed by gas chromatography analysis. The elution order of all 16 isomers was established using a 100 m × 0.25 mm 100% poly(biscyanopropyl siloxane) capillary column and at the elution temperature of 180 °C. The 4 mono‐trans‐18:4n‐3 isomers produced during the refining of oils rich in 18:4n‐3 were chromatographically resolved from each other, but c6,t9,c12,c15‐18:4 coeluted with the tetra‐cis isomer. These 2 fatty acids (FA) were resolved by reducing the separation temperature to 150 °C, but this change caused tetra‐cis‐18:4n‐3 to coelute with t6,c9,c12,c15–18:4. Combining the results from 2 isothermal separations (180 and 150 °C) was necessary to quantify the 4 mono‐trans 18:4n‐3 FA in Ahiflower oil.     

Up to 21 Different Sulfur-Heterocyclic Fatty Acids in Rapeseed and Mustard Oil

Three sulfur-heterocyclic fatty acids (SHFA) had been tentatively identified in rapeseed oil in the late 1980s. In this study we aimed to enrich and verify the presence of potential SHFA in one sample of native rapeseed oil, refined rapeseed oil and mustard seed oil. Fifty-gram samples of the three oils were individually saponified and converted into methyl esters. The resulting samples were hydrogenated and subjected three times to urea complexation. The resulting extracts of native rapeseed oil and mustard oil contained 21 different SHFA with 18, 20, 22 or 24 carbons. The refined rapeseed oil contained only nine C₁₈-SHFA. Structure investigation of the SHFA was performed by gas chromatography with mass spectrometry (GC/MS) using methyl esters and also 3-pyridylcarbinol esters. A direct screening of non-enriched samples by GC/MS in the selected ion monitoring mode and by GC with flame photometric detector (sulfur-selective) verified that the SHFA were native compounds of the oils and no artefacts of the sample preparation. Similar abundances of the four isomer groups of SHFA with monoenoic fatty acids of the same carbon number in these and five further rapeseed and mustard samples indicated that these could be the precursors of the SHFA.     

互叶白千层花、果与叶挥发油成分的对比分析

以水蒸气蒸馏法提取互叶白千层花、果、叶三个不同部位的挥发油,采用气相色谱法、气相色谱-质谱联用法分别鉴定了花、果和叶中挥发油的化学成分,并比较互叶白千层不同部位挥发油的主要化学成分及含量差异。分析结果可为互叶白千层花、果研究提供试验依据。     

Analysis of the volatile fraction from sunflower oil extracted under pressure

This study concerns the analysis of volatile components that may contribute to the formation of the flavor of the oil extracted from sunflower seeds. The compounds were trapped on a charcoal cartridge, then desorbed and analyzed by gas chromatography/mass spectrometry. The principal compounds were terpenes (about 225 mg/L) consisting of α-pinene (80%), limonene (5%), sabinene (3.3%), β-pinene (1.8%), 1,2,6,6-tetramethyl-1,3-cyclohexadiene (1.5%), and camphene (1.2%). There were also a small amount of hexanal (1.3%) and traces (<1%) of unidentified compounds, which probably correspond to other terpenic hydrocarbons and to terpenic alcohols and/or aldehydes.