Development of a Derivatization-free GC-FID Method for Evaluation of Free Fatty Acid Levels in Plasma of Diabetic Nephropathy Patients

Metabolism of free fatty acids（FFAs） is related to several important physiological events and therefore their quantitaion in biological samples arouses extensive interest and efforts.Existing gas chromatography with flame ionization detector（GC-FID） methods for the analysis of FFAs normally require derivatization of them in order to lower boiling points.But this extra procedure tends to induce additional error and it is laborious and time-consuming.A derivatization-free method was therefore established in the present investigation to determine FFAs in human plasma by capillary（GC-FID）.After extraction of FFAs from plasma,a highly polar FFAP（free fatty acid in plasma） column was employed to directly quantitate FFAs concentration,free from derivatization reaction.All sample pretreatments were carried out at room temperature,improving recovery of short-chain FFAs.Heptadecanoic acid（C17：0） was employed as internal standard,and the proposed method was validated for recovery,precision,sensitivity,stabi-lity,and linearity.Validation data show that it is suitable for clinical study that has been applied to the evaluation of FFAs levels in plasma of diabetic nephropathy（DN） patients during the course of treatment.Forty-seven patients diagnosed with DN were admitted to the double-blind experiment.Control group（n=17） underwent solely basic treatment and the patients did not show significant change in FFAs concentration during six months of treatment.Experiment group（n=30） was supplied with traditional Chinese medicine besides basic treatment.After six months of medication,their plasma concentration of palmitic acid（C16：0）,stearic acid（C18：0） and oleic acid（C18：1n-9） decreased while linolenic acid（C18：3n-3） increased significantly（P〈0.05）.These four compounds could be served as biomar-kers in the evaluation of drug efficacy,and their quantitation in plasma may provide additional information for disease progression in DN patients.

Analytical Method Assessment for the Determination of DHA and Fatty Acids Present in Unextracted <i>Aurantiochytrium limacinum</i>Biomass

Research into long-chain polyunsaturated fatty acids (LC-PUFA), such as docosahexaenoic acid (DHA C22:6 n-3), has shown that their inclusion in the human diet is linked with many health benefits. This has led to an increased interest in the enrichment of certain foodstuffs with DHA by supplementing animal fed with DHA-rich ingredients which can lead to an increased uptake in the meat, milk and eggs animal by-products. The microalgae Aurantiochytrium limacinum has been found to be especially useful in this pursuit. It is subsequently desirable to availably have a simple and robust method for the routine analysis of DHA and other fatty acids in the algal biomass. The AOAC method 996.06 is often followed for the analysis of fatty acids in foods and demonstrating that its fitness for purpose in the analysis of DHA and additional fatty acids in Aurantiochytrium limacinum is therefore the objective of this paper. A validation of the method for the determination of DHA and three other fatty acids in Aurantiochytrium limacinum is presented. The method was found to be linear over the following ranges for each fatty acid methyl ester (FAME) analyte;50 to 15,000 μg/ml (C14:0), 300 to 95,000 (C16:0), 25 to 15,000 (C18:0) and 300 to 59,375 (C22:6). The accuracy, precision and LOD and LOQ of the method were confirmed and its robustness tested. The application of the method to assess the stability of Aurantiochytrium limacinum containing two alternative antioxidants was further examined. The investigation showed that DHA was stable over six months with the inclusion of either Duralox? or ethoxyquin as an antioxidant and ethoxyquin could additionally stabilize DHA in Aurantiochytrium limacinum up to 24 months.

Matrix Extension with Fitness for Purpose and Stability Assessment of DHA and Additional Fatty Acids in Individual Whole Chicken Eggs

The consumption of long chain polyunsaturated fatty acids (LC-PUFA) is associated with several human health benefits. Most notable of these LC-PUFA is docosahexaenoic acid (DHA C22:6) whose inclusion is considered essential for optimum human health. Biofortification of common foods such as eggs with DHA has emerged as a specific approach to increase the intake of DHA in human populations. This can be achieved by supplementing poultry rations with feeds like microalgae or fish oil that are rich in DHA, which results in an increased uptake in the egg. Gas chromatography with flame ionization detection (GC-FID) is the method of choice when analyzing food such as eggs for DHA and other fatty acids. For regulatory studies it is desirable to demonstrate that the method is specifically suitable for the analysis of DHA and fatty acids in eggs. The purpose of this paper is to further extend the scope of the AOAC 996.06 methodology examined in the paper by Dillon et al., and to demonstrate the fitness for purpose of the method by examining specific validation parameters. It is a further objective to investigate the stability of DHA and other fatty acids of short and long timepoints. A validation of the method for the determination of DHA and three other fatty acids in eggs is thus presented.

Smashing Tissue Extraction and GC Analysis of Active Fatty Acids from Oil Cake of Perilla Seeds

Objective To optimize the extraction technology of perilla seeds oil from the oil cake of perilla seeds(OCPS)by using the contents of active fatty acids as evaluation standard.Methods The fatty acids were extracted from OCPS,the residue of perilla seeds after cold-press,by smashing tissue extraction(STE),the new technology selected through comparing with classical leaching extraction(LE),Soxhlet extraction(SE),ultrasonic extraction(UE),and supercritical-CO2 fluid extraction(SFE).For optimized condition of STE,orthogonal test was designed and completed.The contents of five fatty acids in extracted oil and OCPS were determined by GC.Results The optimized extraction parameters were smashing for 1.5 min under extraction power of 150 W and 1:6 of the material/solvent ratio.The contents of five fatty acids in the oils extracted by five techniques from OCPS and determined by GC were as follows:α-linolenic acid(41.12%-51.81%),linoleic acid(15.38%-16.43%),oleic acid (18.93%-27.28%),stearic acid(2.56%-4.01%),and palmitic acid(7.38%-10.77%).Conclusion The results show that STE is the most efficient technology with the highest yield(LE:0.57%;SE:1.03%;UE:0.61%;SFE:0.80%;STE: 1.17%)and shortest time(LE:720 min;SE:360 min;UE:30 min;SFE:120 min;STE:1.5 min)among five tested extraction technologies.It is first reported using STE to extract herbal oil enriched with active fatty acids.

A new metabonomics method for simultaneous determination of EFAs and NEFAs in plasma using GC-MS and its application

A new metabonomics method was developed for simultaneous qualitative and quantitative analysis on esterified and nonesterified fatty acids （EFAs and NEFAs） in plasma. Merely 10 μL of plasma was required. The pretreatment of the sample was simple without disposing the protein. After simple extraction and derivation, 15 FAs in plasma were precisely quantified. Gas chromatography tandem mass spectrometry （GC-MS） was used in the study and the quantities of the analytes, which varied in abundance over three orders of magnitude. The established method showed good accuracy. The curve correlation coefficients were all above 0.997. The RSDs of precision for all compounds were below 15% and recoveries were all between 80 and 110%. PLS-DA modal was used in the data management. 2009 Guo An Luo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

富DHA鸡蛋蛋黄中多不饱和脂肪酸的GC-MS分析

建立了富DHA鸡蛋蛋黄中脂肪油提取及其脂肪酸种类和相对百分含量的气相色谱-质谱(GC-MS)联用检测方法.分别采用索氏提取法和Bligh-Dyer提取法对富DHA鸡蛋蛋黄中的脂肪油进行提取,利用KOH-CH3OH溶液将其甲酯化,并用GC-MS对其进行分析测定.结果表明,不同提取方法提取鸡蛋蛋黄中脂肪酸的种类和相对百分含量均不相同,索氏提取法检出多不饱和脂肪酸5种,相对百分含量为8.94%;Bligh-Dyer提取法检出多不饱和脂肪酸6种,相对百分含量为14.28%.

GC-FID快速测定人粪便中7种短链脂肪酸含量的方法研究

短链脂肪酸是结肠粘膜的重要能量来源,具有协调肠道菌群稳态、调节免疫及抗炎等功能。为准确、快速表征机体健康状况及体内肠道菌群丰度,该文建立了一种成本低、灵敏度高、检测速度快的人粪便中短链脂肪酸气相色谱检测方法。结果表明,取10 mg 4℃保存的新鲜样本,先用50%(w/w)的浓硫酸酸解,再用乙醚提取2次,乙酸、丙酸、丁酸、异丁酸、戊酸、异戊酸、己酸的提取率均超过97%;GC-FID法检测短链脂肪酸的最低检测限为0.01~0.02 mM,最低定量限为0.02~0.08 mM,加标回收率为83.32%~111.89%,日内精密度为0.91%~1.79%,日间精密度为1.21%~2.29%。健康人群及功能性消化不良患者粪便样本实验结果表明,该方法准确度优、操作简单、成本低,能够为大样本量人群实验提供指导。

GC-MS法测定不同地区生鲜牛乳中的脂肪酸组成及含量

[目的]比较分析不同地区生鲜牛乳中的脂肪酸种类和含量。[方法]于2019年5月—2020年3月,从河南省、河北省、山西省各选取1个规模化奶牛养殖场,按照四个季节分别采集健康奶牛生鲜乳样,每个地区采集12份,3个地区共36份。使用GC-MS法进行脂肪酸的提取和甲酯化,利用CP-WAX 52 CB毛细管色谱柱和质谱联用分析仪进行脂肪酸种类和含量分析。通过与37种脂肪酸甲酯混合标准品的保留时间比对和NIST05谱库检索对脂肪酸进行定性分析,脂肪酸含量通过面积归一化法进行计算。[结果]从河南省采集的生鲜牛乳中共检出28种脂肪酸,其中,饱和脂肪酸15种,癸酸甲酯、月桂酸甲酯、肉豆蔻酸甲酯、硬脂酸甲酯、棕榈酸甲酯5种饱和脂肪酸的含量较高,占检出脂肪酸总含量的57.03%;检测到不饱和脂肪酸13种,多数含量较低,只有油酸/反油酸甲酯含量较高,占检出脂肪酸总含量的32.26%。从河北省以及山西省采集的生鲜牛乳中均检出30种脂肪酸,但其组成略有不同;2个省份生鲜牛乳的脂肪酸含量检测结果与河南省生鲜牛乳的检测结果相似,饱和脂肪酸含量占检出脂肪酸总含量的比例均在60%左右。河北省生鲜牛乳中的油酸/反油酸含量为39.80%,在3个地区中最高。3个地区的生鲜牛乳中均未检测到反亚油酸甲酯、γ-亚麻酸甲酯、顺-15-碳烯酸甲酯、芥酸甲酯、顺-4,7,10,13,16,19-二十二碳六烯酸甲酯。[结论]3个地区生鲜牛乳中的脂肪酸含量都比较丰富,以饱和脂肪酸为主,所有脂肪酸中以油酸/反油酸含量最高,但脂肪酸组成及含量也存在一定的地区差异。

常见动植物油脂及人体脂肪的GC-MS法分析

利用GC-MS法对生活中常见的18种植物油、8种动物油及公安实践中收集的5个人体脂肪样品进行检测,提取其特征组分及含量进行比较,发现动物油中均检出有C14:0和C16:1,可据此将动植物油有效区分,同时根据检出的脂肪酸成分及其含量,可实现植物油、动物油及人体脂肪种属内的进一步鉴别.

Fatty Acids Profile, Atherogenic (IA) and Thrombogenic (IT) Health Lipid Indices, of Raw Roe of Blue Fin Tuna (<i>Thunnus</i><i>thynnus</i>L.) and Their Salted Product “Bottarga”

The fatty acids composition and the related health lipid indices (IA, atherogenic and IT thrombogenic) of Blue Fin Tuna’s (Thunnus thynnus L.) raw roe and their cured product bottarga, both considered a delicacy, were studied. The fatty acid (FA) composition of tuna’s roe and bottarga showed a relevant proportion (40.87% and 36.62% respectively) of poly-unsaturated fatty acids (PUFAs) with a prevalence of the n – 3 series, that showed values almost ten folds higher than those of n – 6 fatty acids, in both classes of analyzed samples. The IA and IT indices resulted comparable in tuna’s roe and in the bottarga samples respectively. To the best of our knowledge, this is the first detailed report on the fatty acids composition and the related lipid health indices in tuna’s raw roe and in their cured product “bottarga”.

GC-MS在实验教学中的应用

为培养化学类专业本科生的现代重要仪器使用和数据分析能力,将气相色谱-质谱联用仪(GC-MS)结合全扫描(Scan)/选择离子监测(SIM)模式分析应用于本科优班的实验教学。通过提出问题进行思考式预习,有针对性地引导学生提前进行文献检索和基本原理学习。设计了针对挥发性脂肪酸(VFA)定性/定量分析的实验,对VFA(C 1~C 4)丁酯化产物进行Scan模式定性分析、SIM模式绘制标准曲线以定量分析,最终测定实际样品中VFA的含量。使学生充分了解了仪器分析的常规思路和方法,加深了对仪器构造、原理的理解,掌握了仪器操作、样品前处理等实验技能,并培养了科学思维和创新探索能力。

The synthesis of astaxanthin esters,independent of the formation of cysts,highly correlates with the synthesis of fatty acids in Haematococcus pluvialis

The compositions and contents of astaxanthin esters and fatty acids in four types of Haematococcus pluvialis cells were studied by HPLC and GC-MS. Results showed that the synthesis and accumulation of astaxanthin was independent of the formation of cysts, but was highly correlated with the synthesis and accumulation of fatty acids, though it is an well known phenomenon that the accumulation of astaxanthin is usually accompanied by the formation of cyst. The red cysts contain more than 30% of fatty acids, with 81% of the unsaturated fatty acids. Taken together, besides a resource of astaxanthin, H. pluvialis would be a good resource of valuable fatty acids.

Supplemental Feeding of Laying Hens with Wood Vinegar to Decrease the Ratio of n-6 to n-3 Fatty Acids in Eggs

A balanced ratio of fatty acids n-6 to n-3 in chicken eggs is important for health and to help prevent and manage obesity and other diseases.Traditionally,fish oil or flax seed has been utilized as feed additives to decrease the ratio of n-6 to n-3(n-6:n-3)fatty acids in eggs.The hull of spina date seed(HSDS)is a common agricultural waste product in China,from which wood vinegar(HSDSWV)may be derived.This study evaluated HSDSWV as a sup-plement in hen feeds to improve the quality of eggs and decrease the ratio of fatty acids n-6:n-3.HSDSWV was obtained via carbonization,and refined.Six concentrations(nil to 0.5%)of HSDSWV were prepared and fed to 6 hen groups,respectively,for 50 d.The fatty acids of the hen’s egg yolks were analyzed by gas chromatography/electron ionization-mass spectrometry(GC/EI-MS)in the selected ion monitoring(SIM)mode.The 0.2%HSDSWV resulted in the best egg yolk quality,with a lower percentage of linoleic acid(C18:2n6)and higher percentages of cis-5,8,11,14,17-eicosapentaenoic acid(C20:5n3)and cis-4,7,10,13,16,19-docosahexaenoic acid(C22:6n3),and thus a lower n-6:n-3 ratio compared with the other HSDSWV concentrations.In addition,the eggs contained higher levels of yolk fat and egg yolk than the controls did.In conclusion,to modify the fatty acid composition of hens’eggs and obtain a balanced ratio of n-6:n-3,0.2%HSDSWV may be considered suitable as a dietary supplement in hens’feed.

基于肠道菌群-短链脂肪酸途径的人参改善运动性疲劳作用机制探索

目的:探索人参提取物通过调节肠道菌群发挥抗疲劳作用的机制。方法:制备大鼠负重游泳运动性疲劳模型,连续灌胃给予人参提取物21 d。采用负重游泳实验评价人参提取物抗疲劳作用;收集大鼠血清、肠道内容物及各组织,采用紫外-可见分光光度法测定人参提取物中总皂苷和总多糖含量;采用比色法检测尿素氮、乳酸和肝/肌糖原水平;采用酶联免疫吸附法检测白细胞介素-6 (IL-6)、IL-1β和C反应蛋白(CRP)水平;采用16S rRNA结合多元统计分析探索肠道菌群变化;采用液相色谱-质谱法(LC-MS/MS)测定血清短链脂肪酸变化。结果:人参提取物中总皂苷和总多糖质量分数分别为205.6、321.8 mg·g~(–1)。与模型组比较,人参提取物给药后能够显著延长大鼠负重游泳时间,同时上调肝脏和骨骼肌组织中糖原水平,下调血清中尿素氮和乳酸水平。与模型组比较,人参提取物可促进生成短链脂肪酸的肠道菌群表达,并提高血清中短链脂肪酸水平,同时下调炎症因子水平。结论:人参提取物具有明显的抗疲劳作用,其机制可能与调控肠道菌群促进短链脂肪酸生成,进而促进糖原生成,同时抑制炎症因子表达有关。

五个小麦品种麸皮脂质成分分析

小麦麸皮中有一定量对人体健康有益的脂质成分,这些脂质可以作为优质植物原材料应用于食品或工业生产。为了解不同小麦品种麸皮的脂质组成,用乙酸乙酯萃取法提取脂质,并进行硅烷化衍生处理,建立气相色谱-质谱(GC-MS)联用法测定了5个小麦品种的麸皮脂质成分及含量。结果表明,从麸皮脂质中共鉴定出20种化合物,可归纳为游离脂肪酸、烷基间苯二酚(ARs)、甾醇(β-谷甾醇、菜油甾醇、豆甾烷醇)、单酰基甘油酯、甲基烷基间苯二酚和烷烃等六大类。ARs(相对含量31.8%~41.7%)和游离脂肪酸(相对含量24.0%~31.3%)在总脂质中占比较高,甾醇含量次之,其他化合物含量较少。ARs由侧链长度为17~25奇数链烷烃组成,二十一烷基间苯二酚含量(732.7~1158.4μg·g^(-1))显著高于ARs其他同系物(P<0.05)。不同小麦品种麸皮的脂质各组分含量不同,且品种之间存在显著差异,西农979和淮麦21中的ARs含量最高。

南瓜籽油脂肪酸的GC-MS分析

用正已烷抽提南瓜籽,然后将样品进行皂化、甲酯化,以毛细管色谱-质谱联用法(GC-MS)测定了南瓜籽油的组成,共鉴定出12种成分,其中主要成分为亚油酸和油酸,其相对含量分别为38.60%和28.63%。

GC-MS分析蚕蛹油中脂肪酸的成分

目的：化学法提取的蚕蛹油经甲酯化后，分析其脂肪酸的成分。方法：用气相色谱质谱（ＧＣＭＳ）技术及图谱检索，对蚕蛹油中脂肪酸的成分进行鉴定和分析。结果：蚕蛹油中含９种脂肪酸，其中不饱和脂肪酸占７９．８８％，α亚麻酸的相对含量高达７１．４５％。结论：α亚麻酸具有降血脂、降血压和抗癌等生物功能，本研究为α亚麻酸的应用提供了重要的依据。

白果中脂肪酸的GC-MS分析

将萃取所得白果油进行皂化、甲酯化后 ,进行GC-MS定性及相对含量分析 ,取得了满意的结果。实验检出30种脂肪酸 ,其中亚油酸和油酸占71.8%,不饱和脂肪酸占87.86%。

香椿子油成分的GC-MS分析

用正己烷抽提香椿子,然后将样品进行皂化、甲酯化 ,以毛细管色谱 -质谱联用法 (GC -MS)测定了香椿子油的组成 ,共鉴定出39种成分 ,其中亚油酸相对含量为83.4 %

人参脂肪酸和挥发油成分的GC-MS分析

利用索氏提取法和水蒸气蒸馏法提取人参根中的脂肪酸和挥发油成分,采用气相色谱-质谱(GC-MS)联用技术,分别鉴定了脂肪酸中的19个化合物和挥发油中的46个化合物,运用气相色谱峰面积归一化法确定了它们的相对百分含量,脂肪酸中主要是亚油酸和油酸等不饱和脂肪酸,挥发油中含量较高的是2,2’-亚甲基双[6-(1,1-二甲基乙基)-4-甲基苯酚](10.56%)、1,2-苯二羧酸二异辛酯(6.52%)、7,11-二甲基-3-亚甲基-1,6,10-十二碳三烯(5.45%)和乙酸-13-十四碳烯-1-酯(4.14%).