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衍生化毛细管气相色谱法分析血清中的游离脂肪酸 总被引:11,自引:0,他引:11
用H2SO4/甲醇对血清中游离脂肪酸进行甲酯化反应,考察了不同温度和时间以及不同的衍生条件对甲酯化完全程度的影响,确定了对血清中游离脂肪酸衍生化完全的条件为:在62℃下用10%H2SO4/甲醇溶液衍生化2h。大部分脂肪酸的衍生反应和色谱分析的相对标准偏差都在3.00%以内。用各脂肪酸和内标色谱峰面积的比值对脂肪酸浓度作标准曲线,线性回归系数在0.999-1之间,定量测定了5个不同地区的250个血清样品中12种游离脂肪酸的含量。 相似文献
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高效液相色谱荧光测定及质谱鉴定土壤和苔藓中的脂肪酸 总被引:1,自引:0,他引:1
以吖啶酮-9-乙基对甲苯磺酸酯(AETS)作荧光衍生化试剂,建立了灵敏、简单的游离脂肪酸反相高效液相色谱测定方法。在Ec lipse XDB-C8色谱柱上,实现了19种游离脂肪酸(FFA)衍生物的完全基线分离。选取AETS摩尔数为脂肪酸的6倍,以DMF作溶剂,在85℃条件下以K2CO3作催化剂可获得稳定的荧光产物,条件温和、衍生产率高。利用柱后在线串联质谱以APC I大气压化学电离源正离子模式实现了各组分的质谱定性。对土壤和3种苔藓植物中(树藓、狭叶绢藓、曲尾藓)FFA组分定量结果表明,苔藓植物从土壤中富集了大量的游离脂肪酸。荧光检测的激发和发射波长分别为404 nm和440 nm。绝大多数脂肪酸的线性相关系数大于0.9996,检出限为12.3~43.7 fmol。本方法具有良好的重现性,用于实际样品测定,结果满意。 相似文献
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气相色谱法测定血清中游离脂肪酸及其在临床中的应用 总被引:4,自引:0,他引:4
测定体内游离脂肪酸(FFA)的含量,对了解机体脂肪代谢情况、诊断因某种必需脂肪酸含量异常引起的疾病等方面具有重要意义。我们以Silar 10C固定相作填充柱,采用正廿烷作内标,BF_3-甲醇甲酯化,对血清中九种游离脂肪酸进行 相似文献
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健康人血清中游离脂肪酸含量的测定 总被引:5,自引:0,他引:5
应用气相色谱法对60例健康人血清样品中6种重要脂肪酸定量测定,测定方法简便,获得6个年龄组血清样品游离脂肪酸含量的正常值范围,为临床科学研究及疾病的诊断提供参考依据 相似文献
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建立了金银花中游离脂肪酸的微波快速萃取方法,采用柱前荧光衍生化法,测定了金银花中16种长链饱和与不饱和游离脂肪酸的含量。微波萃取功率800 W,溶剂V(氯仿):V(甲醇)=1:1,70℃萃取8 min,萃取率>98.8%。采用酸性乙腈/水流动相在反向C8色谱柱上进行梯度洗脱,HPLC荧光检测波长为505 nm,在线联用质谱辅助鉴定(APCI-MS),提高了检测的准确度。方法检出限在0.366~2.58μg/L之间,回收率88.3%~107.6%。 相似文献
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Yinghao Wang Xianxie Zhang Wenya Hu Chenglong Dong Dali Fu Sara Girmay Habtegabir Yehua Han 《Journal of separation science》2022,45(10):1818-1826
Free fatty acids are involved in many metabolic regulations in the human body. In this work, an ultra-fast screening method was developed for the analysis of free fatty acids using trapped ion mobility spectrometry coupled with mass spectrometry. Thirty-three free fatty acids possessing different unsaturation degrees and different carbon chain lengths were baseline separated and characterized within milliseconds. Saturated, monounsaturated, and polyunsaturated free fatty acids showed different linearities between collision cross-section values and m/z. The establishment of correlations between structures and collision cross-section values provided additional qualitative information and made it possible to determine free fatty acids which were out of the standards pool but possessed the confirmed linearity. The gas-phase separation made the quantitative analysis reliable and repeatable at a much lower time cost than chromatographic methods. The sensitivity was comparable to and even better than the reported results. The method was validated and applied to profiling free fatty acids in human plasma. Saturated free fatty acids abundance in the fasting state was found to be lower than that in the postprandial state, while unsaturated species abundance was found higher. The method was fast and robust with minimum sample pretreatment, so it was promising in the high-throughput screening of free fatty acids. 相似文献
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Quantitative determination of the fatty acid composition of human serum lipids by high-performance liquid chromatography 总被引:2,自引:0,他引:2
A high-performance liquid chromatographic method for the analysis of the fatty acid composition of human serum lipids with fluorescence detection was examined. Both free and total fatty acids extracted from serum were derivatized with 9-anthryldiazomethane and were analysed using methanol-water (94.7:5.3) as mobile phase. Twelve kinds of fatty acid were detected, both in the free and total fatty acids, and were well separated. Concentrations of individual fatty acids of serum lipids were estimated from an internal standard, heptadecanoic acid. The results correlated well with those from two other quantitative analyses. These results indicate that the high-performance liquid chromatographic analysis of fatty acids is a reliable method for determining individual fatty acids of human serum lipids. The compositions of free fatty acids and total fatty acids of serum lipids were analysed and compared in 27 normal subjects, 27 diabetics, and 20 angina pectoris patients by this method. 相似文献
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Summary A gas chromatographic method with a capillary column and a programmed temperature vaporizer injector has been used to analyze the individual free fatty acids in cheese. The lipids were extracted from an acidified cheese slurry with diethyl ether and treated with tetramethylamonium hydroxide (TMAH) to convert the free fatty acids to tetramethylammonium soaps (TMA-soaps), which were subsequently pyrolyzed to methyl esters in the injector. Carrying out injection at the initial column temperature resulted in lower dispersion of the results, but the solvent front prevented quantitative determination of butyric and caproic acids, and an injector temperature of 300°C was therefore employed. Under the conditions tested, trimethylamine (tma) flash-off did not affect the determinations. The accuracy of the method improved at higher free fatty acid contents (coefficient of variation of 0.53% for a total free fatty acid content of 9000 mg/kg as opposed to 7.0% for a total free fatty acid content of 1400 mg/kg). The recovery rate for individual free fatty acids ranged between 91 and 103%. 相似文献
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A modification of a procedure by Hage [1] is proposed for the gas chromatographic evaluation of the content of free medium-chain fatty acids and related ethyl esters in beer. The method involves extraction of free fatty acids and ethyl esters by SPE using C18 bonded phase columns, derivatization of free fatty acids and related ethyl esters with diazomethane, and GC analysis using an SP-2340 capillary column. The results obtained have shown the method to be rapid and highly reproducible. The technique has been compared with other methods used for determination of free fatty acids. 相似文献
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A high-performance liquid chromatographic (HPLC) method was developed for microanalysis of thirteen free fatty acids using 200 microliter of plasma. Fatty acids were derivatized with 9-anthryldiazomethane for HPLC analysis. Use of an ODS minicolumn for pretreatment of plasma gave a more accurate determination of free fatty acids in plasma than by chloroform extraction. Using this method, thirteen free fatty acids in the plasma of normal human, dog, rabbit, guinea pig and rat were determined. 相似文献
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Alister D. Muir Martin J. Reaney Andrew J. Aubin 《Journal of chromatography. A》1998,810(1-2):241-244
A rapid sensitive method has been developed for the detection and quantitation of poly(ethylene glycol) 300 (PEG 300) in long-chain free fatty acid mixtures that requires minimal sample preparation. The PEG 300 was separated from the free fatty acids by RP-HPLC using a water–tetrahydrofuran gradient. PEG and the free fatty acids were detected using evaporative light scattering detection. The minimum detectable level of PEG in a free fatty acid mixture was 0.0125%. 相似文献
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Mass spectrometric analysis of free fatty acids in infant milk powders by frozen pretreatment coupled with isotope‐labeling derivatization 下载免费PDF全文
Tianxiao Zhou Jiapeng Leng Yaoshan Peng Lei Zhang Yinlong Guo 《Journal of separation science》2016,39(5):873-879
In combination with frozen pretreatment and carboxyl group derivatization, a novel workflow was developed for the determination of free fatty acids in milk powder. The workflow showed a significantly enhanced performance for comprehensive free fatty acid analysis owing to a highly efficient frozen extraction method. In addition, the advantages of the workflow also involved high sensitivity and great tolerance to a complex matrix. Characteristic fragment ions of derivatization reagents also provide clear evidence for the qualitative analysis of free fatty acids. Fourteen types of free fatty acids in a number of domestic and overseas infant milk powders have been successfully detected. The content of free fatty acids in the different samples was different, which probably indicates the diverse quality of infant milk powder. The workflow is expected to be a pragmatic tool for the analysis of free fatty acids in intricate matrices. 相似文献
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M R Prasad R M Jones H S Young L B Kaplinsky D K Das 《Journal of chromatography. A》1988,428(2):221-228
Gas chromatographic analysis revealed that polyunsaturated fatty acids such as arachidonic acid and total tissue free fatty acids isolated from an aminopropyl bonded-phase column yield a two- to three-fold higher recovery of arachidonic acid as compared to those isolated from thin-layer chromatographic plates. This method was further improved by packing the aminopropyl bonded phase in glass columns, since the glass column significantly eliminated the other contaminants (from polypropylene columns) coeluting with fatty acids in both a neutral lipid thin-layer chromatographic system and on a 5% DEGS-PS column of gas chromatographic analysis. In aminopropyl bonded-phase columns, the standard triglycerides and phospholipids were completely separated from free fatty acids as judged by gas chromatographic analysis. These results warrant the use of an aminopropyl bonded-phase column for the isolation of free fatty acids to obtain better recovery of polyunsaturated fatty acids. 相似文献
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K G Allen J MacGee M E Fellows P A Tornheim K R Wagner 《Journal of chromatography. A》1984,309(1):33-42
Fatty acids were analyzed by a new method which involved their isolation from hexane extracts of serum or brain tissue in aqueous potassium hydroxide (10 microliter) and methylation directly in this solution with methyl iodide. The resulting fatty acid methyl esters were partitioned into ethylene chloride (25 microliter) and were quantitated by gas-liquid chromatography. The procedure was documented by comparison with conventional methylation reactions on serum fatty acids. This method, which avoids thin-layer chromatography and which measures individual free fatty acid concentrations in 20-mg brain tissue samples, should be of particular value for examining regional free fatty acids in brain following ischemia and trauma. 相似文献
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Summary This report describes a modified method for the separation and analysis of polyunsaturated fatty acids such as 20:4, 20:5,
and 22:6, using HPLC. The results show that these fatty acids are well separated from the saturated acids. Since the unsaturated
fatty acids elute earlier than saturated acids, and this method does not require the fractionation of free fatty acids using
thin layer chromatography, a necessary step for the gas chromatographic analysis, the recoveries of polyunsaturated fatty
acids were significantly higher as compared to those from gas chromatography. Furthermore, HPLC and gas chromatographic methods
gave identical results for the acyl chain composition of phosphatidylserine. The advantages of using HPLC over gas chromatography
in determining the acyl chain composition of free fatty acids and phospholipids are also discussed. 相似文献