共查询到19条相似文献,搜索用时 78 毫秒
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采用超临界CO2萃取蝼蛄总脂肪酸,对影响萃取效果的各个因素应用正交设计试验,优化了各萃取参数。各个因素的影响顺序为:压力〉温度〉时间〉流量。萃取的优化条件为压力35MPa,温度50℃,时间1h,流量45kg/h。运用该萃取条件改善了萃取物的物理性状,脂肪酸的纯度提高,总脂肪酸的含量可达83.29%;而采用常规的有机溶剂提取法,脂肪酸的纯度仅为60%左右。甲酯化采用气相色谱-质谱分析技术对其中的16个成分进行了鉴定,并测定了相对含量,其中主要有油酸甲酯(30.40%)、十六烷酸甲酯(14.19%)、9,12-十八碳二烯酸甲酯(11.99%)、油酸乙酯(11.75%)、9-十六碳烯酸甲酯(7.77%)、十六烷酸乙酯(5.97%)、9,12-十八碳二烯酸乙酯(4.53%)及9-十六碳烯酸乙酯(2.87%)等。 相似文献
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建立了母乳中反式脂肪酸(TFAs)的气相色谱-质谱(GC-MS)检测方法,并应用于母乳脂肪中TFAs的检测。母乳用氨水水解,乙醚和石油醚提取脂肪,提取的脂肪加入C21: 0内标,用三氟化硼甲醇溶液在80℃水浴中冷凝回流15 min进行甲酯化,正己烷提取,上清液用GC-MS分析,内标法定量。在低、中、高加标水平上验证方法的准确度与精密度,结果显示该方法可用于母乳中18种TFAs及其同分异构体的检测,其中12种TFAs在母乳脂肪中的方法检出限为4.0~47.1 mg/kg,回收率为80%~113%, RSD为2.9%~14.5%(n=6)。TFAs在部分母乳脂样品中检出,含量为9.54~6.9 mg/kg。该方法定性、定量准确,可有效用于母乳中TFAs的检测,但仍存在脂肪酸本底干扰等问题,可结合银离子固相萃取柱预分离技术进一步完善。 相似文献
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超临界萃取蝼蛄脂肪酸成分及其气相色谱-质谱分析 总被引:1,自引:0,他引:1
采用超临界CO2萃取蝼蛄总脂肪酸,对影响萃取效果的各个因素应用正交设计试验,优化了各萃取参数.各个因素的影响顺序为压力>温度>时间>流量.萃取的优化条件为压力35 MPa,温度50℃,时间1 h,流量45 kg/h.运用该萃取条件改善了萃取物的物理性状,脂肪酸的纯度提高,总脂肪酸的含量可达83.29%;而采用常规的有机溶剂提取法,脂肪酸的纯度仅为60%左右.甲酯化采用气相色谱-质谱分析技术对其中的16个成分进行了鉴定,并测定了相对含量,其中主要有油酸甲酯(30.40%)、十六烷酸甲酯(14.19%)、9,12-十八碳二烯酸甲酯(11.99%)、油酸乙酯(11.75%)、9-十六碳烯酸甲酯(7.77%)、十六烷酸乙酯(5.97%)、9,12-十八碳二烯酸乙酯(4.53%)及9-十六碳烯酸乙酯(2.87%)等. 相似文献
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建立了一种基于气相色谱-质谱的拟靶向代谢组学分析方法对大米中脂肪酸进行分析,共检测到16种脂肪酸,并研究了不同大米中脂肪酸的轮廓差异。以提取到饱和脂肪酸和不饱和脂肪酸的总量为评价指标,比较了6种提取方法及4种提取溶剂对脂肪酸提取效率的影响。将该方法用于5种不同大米(稻花香、吉星、金浪子、农大、状元)中脂肪酸的分析,发现稻花香大米中脂肪酸轮廓与其他4种均有较大差异;而金浪子与农大、状元间脂肪酸差异也较大,与吉星脂肪酸轮廓较为相似。该方法简单,有较好的稳定性和准确性,可为大米品质和营养价值改善研究提供基础数据。 相似文献
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肝脏是脂肪酸代谢的主要场所,研究肝脏中脂肪酸组成和含量的变化可以监测机体的健康状态。现有的检测方法存在样本消耗量大、检测出的脂肪酸种类少等缺点。通过比较不同提取方法和衍生化条件,建立了仅用1.1 mg肝脏组织即可测定39种脂肪酸含量的气相色谱-质谱方法。肝脏组织经研磨匀浆,以氯仿-甲醇(1∶2, v/v)提取总脂肪酸后,氮气吹干,加入含5%硫酸的甲醇溶液,100℃反应90 min使脂肪酸甲酯化,经SP-2560色谱柱分离后进质谱仪分析。结果表明,39种脂肪酸甲酯在各自的浓度范围内线性关系良好,相关系数(R2)大于0.994 0。将各脂肪酸甲酯的检出限(LOD)和定量限(LOQ)换算至肝脏中的含量,分别为2~272 ng/mg和7~906 ng/mg。以十三烷酸和二十三烷酸考察方法的加标回收率及精密度,在3个水平下的回收率为82.4%~101.0%,日内相对标准偏差(n=5)为3.2%~12.0%,日间相对标准偏差(n=3)为5.4%~13.4%。动物暴露于经典的持久性有机污染物全氟辛烷磺酸(PFOS)后,体内脂肪酸的代谢可能会出现异常。将该方法应用于健康和经口暴露... 相似文献
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蜡烛中香茅油成分的气相色谱-质谱分析 总被引:2,自引:0,他引:2
香茅油[1],又称香草油或雄刈萱油,为一种精油,由香茅的全草经蒸汽蒸馏而得,外观为淡黄色液体,有浓郁的山椒香气,主要成分为香茅醛、香叶醇和香茅醇。香茅油多用于提取香茅醛,供合成羟基香茅醛、香叶醇、薄荷脑,也可用作杀虫剂、驱蚊药和皂用香料。在蜡烛中加入一定量的香茅油成分,可使蜡烛在燃烧的同时具有杀虫、驱蚊的功效。关于香茅油化学成分分析的研究已有报道[2,3],但是蜡烛中香茅油成分测定却未见有报道。由于加入香茅油的蜡制品在海关进出口商品归类中属于熏蒸剂型杀虫剂,需要对其进行相应的贸易管制,所以蜡烛中香茅油成分的测定… 相似文献
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Summary In the course of our studies on the location of marine products, we have directed our attention to the saponifiable fraction of the liver oil from the deep sea shark (Centrophorus squamosus). Different analytical and preparative techniques, such as high-performance liquid chromatography (HPLC), countercurrent chromatography (CCC), and gas chromatography-mass spectrometry [GC-MS, electron impact (EI) and positive-ion chemical ionization (PCI)] were used. These methods allowed us to characterize, after various derivatizations, most of the fatty acids formed after the saponification of the oil, and to purify two of them, namely: docosahexaenoic acid (DHA or 226) and docosamonoenoic acid (DMA or 221). 相似文献
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Svein A. Mjøs 《Analytica chimica acta》2003,488(2):231-241
In hyphenated chromatography, overlapping chromatographic peaks can be resolved into pure spectra and pure chromatographic profiles by several multivariate deconvolution techniques. In general, these methods require bilinearity, which implies that the spectrum of each analyte is constant. The slow scan speeds normally used in gas chromatography-mass spectrometry (GC-MS) will destroy bilinearity and introduce systematic noise in the data because the concentration in the detector changes during the scan. This effect, described as the scan effect, may hinder successful resolution by multivariate deconvolution. In selected ion monitoring (SIM) GC-MS, the scan effect may be removed by simple transformations of the mass spectra. The effects of different transformations are demonstrated both on pure chromatographic peaks and on difficult resolution problems where there are small differences between the spectra of the analytes. 相似文献
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In this article, a laboratory-made sol-gel derived fiber with butyl methacrylate/hydroxy-terminated silicone oil (BMA/OH-TSO) coating was first used for headspace solid-phase microextraction (HS-SPME) of medium and long chain fatty acids after derivatization and applied to the analysis of fatty acids in lung tissues by coupling to gas chromatography-mass spectrometry (GC-MS). The experimental parameters for derivatization, HS-SPME and desorption were optimized. Fatty acids in cancerous lung tissues from five patients with lung cancer were determined under the optimized conditions. Normal lung tissues from the same five patients were used as controls. This fiber showed higher extraction efficiency for fatty acids after derivatization when compared with commercial polydimethylsiloxane (PDMS) and polydimethylsiloxane-divinylbenzene (PDMS/DVB) fibers due to the three-dimensional network in the coating. The method presented in this paper showed satisfactory precision, accuracy, linearity and limits of detection (LODs). The relative standard deviation values were below 13.3% (n = 5) and the recoveries obtained ranged from 76.35% to 107.0%. The results obtained using the SPME method were also compared with those got by using liquid-liquid extraction (LLE) technique. It was found that the sensitivity could be enhanced by the SPME method. The analysis of the cancerous lung tissues and normal controls from five patients with lung cancer indicated that the main components of lung tissue were palmitic acid (C16:0), stearic acid (C18:0) and lignoceric acid (C24:0). A comparison between the levels of the fatty acids in cancerous lung tissues and normal controls from the same a patient with lung cancer shows that most of the saturated fatty acids showed higher levels in cancerous lung tissues, while unsaturated fatty acids showed higher levels in normal controls on the whole. 相似文献
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采用气相色谱-质谱联用方法分析6-溴-去氢甲基睾丸素中的杂质。在30.0m×0.25mm,0.5μm的ZB-5MS毛细管柱上,柱温100℃保持3 min,后以20℃/min的速率程序升温至250℃,气化室温度270℃,载气氦气流量0.8 mL/min的条件下,6-溴-去氢甲基睾丸素及其中杂质获得很好分离。通过对各组分质谱图分析确定了6-溴-去氢甲基睾丸素中的七种杂质分别为去氢甲基睾丸素,6-烯-去氢甲基睾丸素,6-溴-17-甲基雄甾-1,4,16-三烯-3-酮的4种构象异构体以及6-溴-8-烯-去氢甲基睾丸素。 相似文献
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C. Giachetti 《Chromatographia》1998,48(5-6):443-449
Summary Low amounts of triethanolamine, collected in ORBO 53 tubes during air sampling, required the development of a very sensitive
method for determination. After desorption and silylation reaction with trimethylsilyl imidazole/trimethyl chlorosilane, the
derivative was analyzed by gas chromatography-mass spectrometry on an Ultra 2 silica capillary column in single ion monitoring
mode (retention time: about 6 min). The method has a detection limit of 1–2 pg with a desorption efficiency of about 81%.
Linearity of response was ascertained in the ranges 10–100 ng and 100–1000 ng. Short-term method validation was carried out
by intra- and inter-day assays on three amounts for each reference calibration curve. All results satisfied the pre-defined
acceptance criteria. In general, the whole procedure was easily performed and was appropriate for our needs. Breakthrough
volume was appropriate for our needs. Breakthrough volume was determined on authentic samples and was about 40–60 L, using
a flow rate of 1 L·min−1. The amounts of triethanolamine found in the samples ranged from 150 to 250 ng (about 2.5–4.2 μg·m−3). 相似文献
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Summary Binding media in samples taken from XIIth–XIIIth century polychrome sculptures in the Baptistery of Parma (Italy) were characterized by gas chromatography-mass spectrometry, after hydrolysis and derivatization procedures. The use of SE-52 capillary columns and the application of selected ion monitoring (SIM) allowed an increasing in the sensitivity and the ability to differentiate between animal glues, casein, egg and drying oils as components of the binders of paint and ground layers. Small amounts of material were enough for a satisfactory characterization. 相似文献
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