杏仁油的物化性能及其脂肪酸组成的分析

用３种不同溶剂萃取杏仁得到杏仁油,并对其物化常数进行测定。杏仁油用饱和氢氧化钾 甲醇皂化,再用甲醇 硫酸（体积比为４∶１）甲酯化后,将乙醚萃取液作气相色谱分析。太原杏仁油中脂肪酸的主要成分为油酸（Ｃ１８∶１,质量分数约６８％）和亚油酸（Ｃ１８∶２,质量分数约２５％）,少量棕榈酸（Ｃ１６∶０）、棕榈烯酸（Ｃ１６∶１）和硬脂酸（Ｃ１８∶０）,微量花生酸（Ｃ２０∶０）。     

Separation of fatty acids or methyl esters including positional and geometric isomers by alumina argentation thin-layer chromatography

This paper describes novel and rapid thin-layer chromatography procedures for the analysis of fatty acids and methyl esters using silver-impregnated alumina sheets. These techniques are known in most laboratories, and the equipment is readily available. The fatty acid method allows a separation of petroselinic (C18:1 delta 6c), oleic (C18:1 delta 9c), elaidic (C18:1 delta 9t), erucic (C22:1 delta 13c), and brassidic acids (C22:1 delta 13t), and the methyl ester method gives an excellent resolution with respect to the number, configuration, and position of the unsaturated centers. Sufficient separation for the subsequent ozonolysis and chromatographic quantification of isomeric C18 and C22 fatty acid methyl esters is obtained with both methods.     

Assay of lipids in dog myocardium using capillary gas chromatography and derivatization with boron trifluoride and methanol

The fatty acids of three lipid classes (free fatty acids, triglycerides, and cholesteryl esters) from dog heart were analysed by gas chromatography. Samples of the left ventricle were homogenized and total lipids were extracted. After separation by thin-layer chromatography, the bands of the lipid classes studied were scraped off, transmethylated according to the boron trifluoride-methanol procedure, and the fatty acid methyl esters were extracted and analysed. The problems related to the quantitation of fatty acids were investigated, namely transmethylation procedure, thin-layer chromatography, and gas chromatographic conditions. Fatty acid methyl esters were separated on capillary columns coated in the laboratory with SP 2340 stationary phase. The high performance of the separation ensured the reliability and the precision of the analysis.     

在线热辅助甲基化-气相色谱法分析棉籽仁中的脂肪酸组成

建立了分析棉籽仁中脂肪酸组成的在线热辅助甲基化-气相色谱法。将0.3 mg棉籽仁样品与2 μ L三甲基氢氧化硫（0.2 mol/L）加入裂解器,在350℃下进行甲基化反应,通过气相色谱仪进行分离分析,共检测到8种脂肪酸甲酯成分,分别为亚油酸（C18：2）、油酸（C18：1）、棕榈酸（C16：0）、硬脂酸（C18：0）、肉豆蔻酸（C14：0）、棕榈油酸（C16：1）、花生酸（C20：0）和二十二酸（C22：0）,不饱和脂肪酸的相对含量为66.30%~72.54%,其中亚油酸的相对含量为43.20%~53.61%,相对峰面积的相对标准偏差（RSD）小于10%（n=5）。通过分析5组棉籽仁样品与3种食用油中的脂肪酸组成,结果表明不同产地的棉籽仁中的脂肪酸组成差异不明显,且棉籽仁中的脂肪酸组成与玉米油最为接近,相似度为0.960~0.992。该方法简单、快速、准确,适合分析棉籽仁中的脂肪酸组成。     

Assessment of fatty acids in cardiac tissue as 9-anthryldiazomethane esters by high-performance liquid chromatography.

A high-performance liquid chromatographic technique for the rapid assessment fatty acids in cardiac tissue is described. A level of 50.4 +/- 14.9 nmol fatty acids per g wet weight of rat myocardial tissue could be monitored. The content of the individual fatty acids C14:0, C16:0, C16:1, C18:0, C18:1, C18:2 and C20:4 amounted to 1.9, 13.5, 0.6, 14.4, 6.1, 6.5 and 7.2 nmol/g wet weight, respectively. A comparison of this method with a well established gas chromatographic technique yielded good agreement. In contrast with time-consuming gas chromatographic techniques, there is no need to isolate (unesterified) fatty acids from the other lipid classes with column chromatography or thin-layer chromatography, because the derivatizing reagent 9-anthryldiazomethane reacts highly specifically with fatty acids.     

Profiling of esterified fatty acids as biomarkers in the blood of dengue fever patients using a microliter‐scale extraction followed by gas chromatography and mass spectrometry

An improved gas chromatography with mass spectrometry procedure was developed to highlight the esterified fatty acids in 100 μL blood of dengue fever patients in the early febrile phase versus healthy volunteers. 24 adult patients and 24 healthy volunteers were included in this study. The recoveries of targeted esterified fatty acids content were in the range of 92.10–101.00% using methanol/dichloromethane (2:1, v/v) as the extraction solvent. An efficient chromatographic separation of targeted 17 esterified fatty acid methyl esters was obtained. The limits of detection and quantification were within the range of 16–131 and 53–430 ng/mL, respectively. The relative standard deviation of intraday and interday precision values ranged from 0.4 to 5.0%. The statistical data treatment showed a significant decrease of the content of four saturated fatty acids, C14:0, C15:0, C16:0, and C18:0 (P value < 0.05), and also showed a decrease of the content of eight unsaturated fatty acids, C16:1, C18:3n6, C18:2n6, C18:1n9, C20:3n3, C20:4n6, C20:2, and C22:6n3 (P value < 0.05) in dengue fever patients. Moreover, the amount of three omega‐6 fatty acids including C18:3n6, C18:2n6, and C20:4n6 was dramatically decreased in the blood of dengue fever patients to a limit of 50 ± 10%.     

碱催化法衍生化气相色谱/质谱法分析青海湖裸鲤鱼油中的脂肪酸

用碱催化法将青海湖裸鲤鱼油甲酯化,以气相色谱/质谱法分析鱼油中的脂肪酸。青海湖裸鲤可食用部分中鱼油含量为25.13%。从鱼油中共鉴定出47种脂肪酸,包括直链、单支链、多支链饱和脂肪酸,单不饱和、多不饱和脂肪酸,环丙烷基、呋喃基脂肪酸等。不饱和脂肪酸含量为73.6%,其中多不饱和脂肪酸含量为25.4%,以C18∶2(4.9%),C18∶3(3.1%),C20∶4(1.3%),C20∶5(二十碳五烯酸（EPA）, 9.4%)和C22∶6(二十二碳六烯酸（DHA）, 6.7%)为主。单不饱和脂肪酸含量为48.2%,主要由C16∶1(20.3%),C18∶1(25.9%)构成。饱和脂肪酸含量为25.7%,主要有C14∶0(3.4%),C16∶0 (19.4%)和C18∶0(1.1%)。青海湖裸鲤鱼油中还存在不常见的环丙烷基和呋喃基脂肪酸及多种奇数碳链和支链脂肪酸。因此,青海湖裸鲤是功能性脂肪酸的重要膳食来源。     

Capillary electrochromatographic enantioseparations using a packed capillary with a 3 microm OD-type chiral packing

A technique for separating methyl esters of monounsaturated fatty acids by argentation chromatography using silver nitrate-impregnated TLC plates is described. Monounsaturated fatty acid methyl esters are separated from polyunsaturated and saturated fatty acid methyl esters and the monounsaturated fatty methyl esters are resolved according to chain length. cis isomers are well resolved from the corresponding trans isomers. R(F) values for individual monounsaturated fatty acids are very reproducible. The potential of the technique in metabolic studies is demonstrated in the chain elongation of [14C]-18:1(n-9) and delta-9 desaturation of [14C]-18:0 by human skin fibroblasts. Recoveries of individual [14C]-fatty acids for scintillation counting exceed 94%.     

Separation and quantitation of plasma free fatty acids as phenacyl esters by HPLC

We have developed a rapid method for the separation of plasma free fatty acids as their phenacyl esters by high-performance liquid chromatography (HPLC) using a reversed-phase (C18) column. The derivatives of series of both saturated and unsaturated fatty acids (C12:0-C22:6) are simultaneously separated within 45 min and detected with ultraviolet at 241 nm. The limit of detection of fatty acids was approximately 0.5 nmol in 20 microL injected volume of extracts, and the coefficient of variation of the present method did not exceed 3.0%. Comparison of the results of the present HPLC method with those of gas chromatography, gave very good correlations for all fatty acids in human plasma.     

Evaluating the use of fatty acid profiles to identify Francisella tularensis

Rapid capillary gas chromatography (GC) with flame-ionization detection was used to determine the cellular fatty acid profiles of Francisella tularensis. Two subspecies of F. tularensis, the live vaccine strain (LVS) derived from holarctica and a novicida strain Utah 112 (U112), were used to compare the extracted fatty acid methyl esters (FAMEs). A data set for the 2 subspecies was prepared using fatty acid profiles of bacteria grown on 2 types of media, Mueller-Hinton and cysteine heart agar supplemented with 5% rabbit blood (CHAB), and harvested at various time intervals (Day 1 through Day 4) with replicates prepared on different days. A total of 204 samples were analyzed. The results showed that these fatty acid quantitative profiles were unique for each of the subspecies and could be used as a fingerprint for the organism. It was determined by this rapid method that approximately 88% of the fatty acids in both the LVS and U112 strains included 6 saturated fatty acids: 10:0, 12:0, 14:0, 16:0, 18:0, and 20:0; and 4 hydroxy fatty acids 10:0 2OH, 16:0 3OH, 17:0 3OH, and 18:0 3OH. Data analysis and determination of clustering were performed by principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). Both PCA and SIMCA showed clear separation of the LVS and U112 strain and would be useful for prediction of unknowns. It was determined that the incubation time can be reduced from 48 to 24 h, and results are highly predictive for the identification of F. tularensis. In summary, analysis of FAMEs from F. tularensis subspecies LVS and U112 grown on CHAB or Mueller-Hinton media, and using a rapid GC method can provide a sensitive procedure for identification of these organisms.     

High-performance liquid chromatography of cardiolipin

Resolution of freshly prepared and of commercially available (degraded) samples of cardiolipin into 15-30 components has been accomplished by reversed-phase high-performance liquid chromatography using a 3-micron particulate Microsorb C18 column irrigated with linear gradients of acetonitrile--methanol--10 mM phosphate buffer pH 7.4. Selected resolved components were crystallized and characterized by infrared absorption spectra. Saponification of other components and identification of component fatty acids by reversed-phase high-performance liquid chromatography demonstrated the presence of ten fatty acids (14:0, 14:1, 16:0, 16:1, 18:0, 18:1, 18:2, 18:3, 20:0, 20:4), with linoleic acid (18:2) identified in all resolved components. From fatty acid composition data it appears that several resolved fractions consist of single cardiolipin molecular species.     

Unambiguous detection of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana)

HPLC atmospheric pressure chemical ionization (APCI)/MS, GC MS, HPLC diode array detection (DAD), and NMR were used for the identification of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana). Matrix solid phase dispersion was applied for the extraction of the carotenoids. This gentle and expeditious extraction technique for solid and viscous samples leads to distinct higher enrichment rates than the conventional liquid-liquid extraction. The chromatographic separation was achieved employing a C30 RP column that allows the separation of shape-constrained geometrical isomers. A methanol/tert-butylmethyl ether/water gradient was applied. (all-E) Astaxanthin and the geometrical isomers were identified by HPLC APCI/MS, by coelution with isomerized authentical standard, by UV spectroscopy (DAD), and three isomers were unambiguously assigned by microcoil NMR spectroscopy. In this method, microcoils are transversally aligned to the magnetic field and have an increased sensitivity compared to the conventional double-saddle Helmholtz coils, thus enabling the measurement on small samples. The carotenol fatty acid esters were saponified enzymatically with Lipase type VII from Candida rugosa. The fatty acids were detected by GC MS after transesterification, but also without previous derivatization by HPLC APCI/MS. C14:0, C16:0, C16:1, C18:1, C20:0, C20:5, and C22:6 were found in astaxanthin monoesters and in astaxanthin diesters. (all-E) Astaxanthin was identified as the main isomer in six fatty acid ester fractions by NMR. Quantitation was carried out by the method of internal standard. (13-cis) Astaxanthin (70 microg/g), 542 microg/g (all-E) astaxanthin, 36 microg/g unidentified astaxanthin isomer, 62 microg/g (9-cis) astaxanthin, and 7842 microg/g astaxanthin fatty acid esters were found.     

A matrix-assisted laser desorption/ionization mass spectrometry approach to the lipid A from Mesorhizobium loti

The isolation, purification and analysis of the lipid A obtained from Mesorhizobium loti Ayac 1 BII strain is presented. Analysis of the carbohydrate moiety after acid hydrolysis by high-pH anion-exchange chromatography with pulse amperometric detection (HPAEC-PAD) showed the presence of glucosamine and galacturonic acid as the only sugar components. Gas chromatographic (GC) and GC/mass spectrometric (MS) analysis of the fatty acids revealed the presence of 3-OH-C12:0; 3-OH-C13:0; 3-OH-C20:0 and 27-OH-C28:0 among the major hydroxylated species. In addition, C16:0, C17:0, C18:0 and C 20:0 were shown as main saturated fatty acids. Different polyacylated species were evidenced by thin layer chromatography of lipid A, allowing the purification of two fractions. Ultraviolet matrix-assisted laser desorption/ionization time-of-flight (UV-MALDI-TOF) MS analysis with different matrices, in the positive- and negative-ion mode, was performed. The fast moving component revealed the presence of hexa-acylated species, varying in the fatty acid composition. Species containing three 3-OH fatty acids and a 27-OH-C28:0 fatty acid were observed. Individual ions within this family differ by +/-14 mass units. The slow moving component was enriched mainly in penta-acylated species. Among them, three subgroups were detected: the major one compatible with the sugar core bearing two 3-OH 20:0 fatty acids, a 3-OH 13:0 or a 3-OH 12:0 fatty acid, a 27-OH 28:0 fatty acid and one saturated fatty acid. Each signal differs in a C18:0 acyl unit from the corresponding hexa-acylated family. On the other hand, a subgroup bearing one 3-OH 20:0 fatty acid, one 27-OH 28:0 fatty acid and two non-polar fatty acids was shown. A minor subgroup compatible with structures containing two hydroxylated and three non-polar fatty acids was also detected. The results obtained showed that nor-harmane was an excellent matrix for charged lipid A structural studies in both, positive and negative ion modes.     

New N-acylamino acids and derivatives from renewable fatty acids: gelation of hydrocarbons and thermal properties

This work reports the synthesis of new fatty N-acylamino acids and N-acylamino esters from the C16:0, C18:0, C18:1, and C18:1(OH) fatty acid families and demonstrates the activity of these compounds as organogel agents. Compounds were heated and dissolved in various solvents (n-hexane, toluene, and gasoline). Only saturated C16:0 and C18:0 derived from alanine were able to form gels in toluene, and saturated C16:0 derived from phenylalanine showed gelation in n-hexane. This is the first evidence that fatty N-acylamino esters and N-acylamino acid derivatives of l-serine and fatty acids C16:0, C18:0, and C18:1 are able to form gels with hexane. This observation confirms the importance of the hydroxyl group in the segment derivative of l-serine in forming good gels.     

牙菌斑有机酸的气相色谱-质谱分析

采用ＧＣ／ＭＳ联用技术分析了正常人牙菌斑内有机酸成分。发现了１４种有机酸,其中有８种直链饱和脂肪酸、４种直链非饱和脂肪酸、２种芳香酸。含量最多的是Ｃ１６∶０,Ｃ１８∶０,Ｃ１８∶１３种脂肪酸。其中苯乙酸、苯丙酸及十五碳酸等３种成分是第１次在牙菌斑中检测出。     

Determination of cuticular and internal fatty acids of Chorthippus brunneus males and females using HPLC‐LLSD and GC–MS

Insects are of growing significance in veterinary medicine and human healthcare; therefore, an understanding of their biology is very important. The cuticular and internal fatty acid compositions of Chorthippus brunneus males and females have been studied for the first time. The lipids of males and females were separated into classes of compounds using high‐performance liquid chromatography with a laser light scattering detector. The free fatty acid (FFA) fractions obtained by HPLC were silylated and then analyzed by GC–MS. The cuticular lipids of males contained 15 saturated, four unsaturated with even‐numbered and two unsaturated with odd‐numbered carbon chains, FFAs ranging from C8 to C25. The major free fatty acids in males were C16 (20.8%), C18:2 (8.5%), C18:1 (32.9%) and C18 (24.4%). The cuticular lipids of females contained 17 saturated, four monounsaturated and two diunsaturated free fatty acids ranging from C8 to C30. The major cuticular fatty acids in females were C16 (25.1%), C18:2 (6.2%), C18:1 (23.7%) and C18:0 (33.2%). The internal FFAs of males consisted of 20 compounds ranging from C8 to C26. Four of these compounds were detected as major compounds: C16 (14.1%), C18:2 (21.6%), C18:1 (38.0%) and C18 (22.5%). Among 18 internal free fatty acids of females, C16 (22.3%), C18:2 (10.9%), C18:1 (40.2%) and C18 (20.5%) were the most abundant compounds. The following cuticular fatty acids present in the lipids of females were absent in the lipids of males: C26, C27 and C30. On the other hand, only C24 was absent from the cuticular lipids of females. Only C10 and C24 internal fatty acids present in the lipids of males were absent in the lipids of females. Copyright © 2016 John Wiley & Sons, Ltd.     

Ionic Liquid-Based Extraction of Fatty Acids from Blue-Green Algal Cells Enhanced by Direct Transesterification and Determination Using GC × GC-TOFMS

Blue-green algae commonly referred to as cyanobacteria are known to grow in freshwater bodies when they are provided with suitable growth conditions such as nutrients, temperature and light. Algae biomass is known to contain a large amount of lipids, such as saturated and unsaturated fatty acids. In this study, fatty acids from algal cells were extracted using a newly developed extraction protocol using ionic liquid enhanced by direct transesterification at an elevated temperature. The identification and quantification of fatty acids was performed using gas chromatography coupled to a time-of-flight mass spectrometer (GC × GC-TOFMS). The extracted fatty acids were dominated by those with carbon chain of C16 and C18; [i.e. 7-hexadecenoic acid (C16:1) and hexadecanoic acid (C16:0) for C16, whereas C18 includes γ-linolenic acid (γ-C18:3); linoleic acid (C18:2); linolenic acid (C18:3); 6,9,12,15-octadecatetraenoic acid (C18:4); oleic acid (C18:1) and octadecanoic acid (C18:0)]. The obtained fatty acid composition was then compared with that obtained by organic solvent extraction using a mixture of chloroform and methanol. Statistical evaluation was performed using one-way ANOVA and found that there was no statistically significant difference (P = 0.908) between the two extraction methods, a finding which indicates the usefulness of ionic liquid as a solvent to replace volatile organic solvent to minimize environmental pollution.     

High-performance liquid chromatographic determination of cholesteryl esters in the blood of obese children.

The serum of obese children and adolescents was analyzed for cholesteryl esters. The test substances were first separated from the sample matrix by solvent extraction and thin-layer chromatography and then resolved in a reversed-phase high-performance liquid chromatographic system involving a Separon SGX C18 column and a mobile phase of 2-propanol-acetonitrile (40:60, v/v), with ultraviolet detection at 206 nm. Cholesterol and 10-cholesteryl esters could be separated and determined within ca. 25 min at a flow-rate of 1 ml/min. The method was applied to a study of the effect of external conditions (physical stress, diet) on the content of cholesteryl esters in a test group of obese boys and girls aged from 13 to 16 years. The analyses have demonstrated that the above conditions do not affect the concentrations of the individual cholesteryl esters, although the total cholesterol concentration decreased significantly after spa treatment.     

超高效液相色谱法测定生物柴油中的11种脂肪酸及脂肪酸甲酯

建立了采用超高效液相色谱(UPLC)-蒸发光散射检测器(ELSD)测定生物柴油中11种常见的脂肪酸及脂肪酸甲酯含量的方法。这11种常见的脂肪酸及脂肪酸甲酯为豆蔻酸、亚油酸、棕榈酸、油酸、亚麻酸甲酯、硬脂酸、亚油酸甲酯、棕榈酸甲酯、油酸甲酯、芥酸和硬脂酸甲酯。样品经提取后用甲醇溶解,采用Acquity UPLC BEH Phenyl C18柱(100 mm×2.1 mm,1.7 μm)分离,乙腈-水（体积比为3∶1)混合液为流动相进行等度洗脱,采用的ELSD条件为增益80,漂移管温度为45 ℃,载气压力为172 kPa,雾化器为冷却模式,并用外标法进行定量分析。结果表明,在一定的质量浓度范围内,峰面积的对数和质量浓度的对数线性关系良好。与其他检测生物柴油成分的方法相比,该方法简单,分离效果好,速度快,特别是此方法可以同时实现脂肪酸及脂肪酸甲酯的分离,并进行定量分析,能有效测定反应的进行程度,从而满足生物柴油工艺研究的需要。