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银环蛇蛇蜕的化学成分研究Ⅱ . 脂肪酸和氨基酸组分 总被引:1,自引:0,他引:1
用色谱-质谱(GC-MS)联用技术分析了银环蛇蛇蜕的脂肪酸成分,鉴定出36种脂肪酸(饱和酸28种不饱和酸8种),在蛇蜕中发现16种饱和二元酸,并发现了自然界中少见的奇数碳脂肪酸14种及支链酸2种,用氨基酸自动分析仪测定了蛇蜕水提取液中的13种游离氨基酸,酸性水解液中17种氨基酸,在蛇蜕中发现存在牛 磺酸。 相似文献
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对印度楝树油中高级脂肪酸成分进行分析,经甲酯化后用气相色谱-质谱联用仪鉴定了 其中所含高级脂肪酸的成分,用气相色谱法-火焰离子化检测器对其成分进行定量分析.溶剂浸泡萃取和二氧化碳超临界萃取两种不同方法得到的脂肪酸成分基本相同,其中油酸相对含量为51.15%,硬脂酸相对含量为19.13%,棕榈酸相对含量为16.78%,亚油酸相对含量为9.86%,花生酸相对含量为1.24%,其他含量低于1%的高级脂肪酸还有顺-3-辛基-环氧乙烷-辛酸,山萮酸,9-十八(碳)烯酸,11-二十碳二烯酸,9-十六碳烯酸,十七(烷)酸等. 相似文献
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气相色谱-质谱测定红树植物桐花树叶中的挥发油和脂肪酸的组成 总被引:2,自引:0,他引:2
采用气相色谱-质谱联用分析法,分析测定了红树植物桐花树AegicerasCorniculatum叶子中挥发油和脂肪酸的成分.结果表明:挥发油中分离出24个峰,鉴定出8种化合物,2,6-二叔丁基-4-甲基苯酚含量丰富,占挥发油总量的20.60%;脂肪酸中分离出16个峰,鉴定出10种脂肪酸,其中主要成分有十六酸(棕榈酸,16.17%)、9,12-十八碳二烯酸(亚油酸,25.73%)、9-十八碳烯酸(油酸,41.52%)等. 相似文献
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本文研究维药柽柳实中脂肪酸的化学成分。采用石油醚和乙醚两种溶剂提取柽柳实中的脂肪酸,经甲酯化后,使用气质联用技术对脂肪酸的组成及含量进行检测。结果表明,两种方法分别鉴定出18种和17种脂肪酸成分,占提取成分总峰面积的99.33%和89.65%,两者所包含的成分基本一致,但含量有一定的差异。石油醚和乙醚提取物中分别鉴定出棕榈酸(35.61%和32.77%),亚油酸(27.26%和18.76%)和油酸(11.33%和9.15%)等脂肪酸,其中不饱和脂肪酸含量分别占总脂肪酸含量的38.59%和27.91%。维药柽柳实中富含不饱和脂肪酸,具有很好的开发利用价值。 相似文献
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用双 (2 乙基己基 )酚酞酸酯 (DEHP)诱导大鼠肝过氧化物酶体增殖 ,再用蔗糖密度梯度离心法分离大鼠肝细胞过氧化物酶体 ,并用十七烷酸作内标 ,以毛细管气相色谱法在非极性SPB 1石英毛细管柱上对其中的 11种脂肪酸进行分离测定。正常组和诱导组的大鼠肝过氧化物酶体中的不饱和脂肪酸和长链脂肪酸所占总脂肪酸的比例及总脂肪酸的统计结果是 :诱导组的不饱和脂肪酸的含量高于正常组的 (P <0 0 5 ) ,而两个组的脂肪酸总量及长链脂肪酸的含量无明显差别。结果提示 :诱导组的大鼠肝过氧化物酶体的脂肪酸成分发生了变化 ,其膜结构与正常组的不相同。 相似文献
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淋洗液自动发生-离子色谱法同时测定食品中的21种有机酸 总被引:5,自引:0,他引:5
建立了一种利用离子色谱法同时测定样品中奎尼酸、乙酸、丙酮酸、草酰乙酸、甘露酸、乳酸、琥珀酸、苹果酸、酒石酸、草酸、富马酸、抗坏血酸、α-酮戊二酸、肉桂酸、水杨酸、柠檬酸、异柠檬酸、阿魏酸、顺乌头酸、反乌头酸、β-香豆酸等21种有机酸的方法。样品经提取、脱色、过滤后用IonPac AS11分离柱分离,以EG40自动淋洗液发生器生成的5~34 mmol/L KOH为淋洗液洗脱,抑制电导检测器检测。21种有机酸的浓度与其峰面积在一定的范围内呈良好的线性关系,检出限均低于0.188 mg/L,加标回收率为91.5%~101.8%。该法用于多种食物样品中有机酸的测定,结果令人满意。 相似文献
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Hydroxycarboxylic and oxocarboxylic acids in urine: products from branched-chain amino acid degradation and from ketogenesis 总被引:2,自引:0,他引:2
Hydroxy- and oxomonocarboxylic acids in urine of healthy individuals and of patients with diabetic ketoacidosis are analysed as methyl esters and methyl esters/O-methyloximes, respectively, by gas chromatography and gas chromatography-mass spectrometry. The derivatives are pre-fractionated by thin-layer chromatography. The acids originate mainly from ketogenesis and from the metabolism of valine, leucine and isoleucine. The amino acid metabolites fall into three groups: the 2-oxocarboxylic acids (2-oxoisovaleric acid, 2-oxoisocaproic acid and 2-oxo-3-methylvaleric acid); the 2-hydroxycarboxylic acids (2-hydroxyisovaleric acid, 2-hydroxyisocaproic acid and 2-hydroxy-3-methylvaleric acid); and the 3-hydroxycarboxylic acids (3-hydroxyisobutyric acid, 3-hydroxyisovaleric acid, 3-hydroxy-2-ethylpropionic acid, threo-3-hydroxy-2-methylbutyric acid and erythro-3-hydroxy-2-methylbutyric acid). The threo form of 3-hydroxy-2-methylbutyric acid is the major constituent within the diastereomeric pair. Of the three groups of amino acid metabolites, the 3-hydroxycarboxylic acids in particular are elevated during ketoacidosis. The characteristic general features of the mass spectrometric fragmentation of the derivatives of the identified components are systematically described. The discussion of the fragmentation includes constituents of low concentrations, such as 3-oxocaproic acid, 4-oxobutyric acid and 5-oxocaproic acid, which can be detected only when the pre-fractionation technique is applied. 相似文献
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Use of complexing ligands in the determination of antimony and tin by atomic-absorption spectrometry
The atomic-absorption spectrophotometric determination of antimony is best achieved in the presence of either an ammonium fluoride, hydrochloric acid, nitric acid mixture, or one of the following complexing agents: tartaric acid, citric acid, oxalic acid, 2-mercaptopropanoic acid. The interference of the 29 metals tested is least in the ammonium fluoride-hydrochloric acid-nitric acid mixture and is similar in tartaric acid, citric acid and 2-mercaptopropanoic acid media. However, the interference is pronounced in oxalic acid. Tin can be determined if any of the complexing agents or 6M hydrochloric acid is present. 相似文献
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本文研究了甲酸、乙酸、丙酸和戊酸在三乙醇胺交联聚硅氧烷树脂上的吸附行为。通过其吸附速度、吸附等温线的研究,得出甲酸和乙酸在该树脂上以单分子吸附为主,丙酸和戊酸以多分子吸附为主,而且吸附的强弱与羧酸的解离有关,解离越强吸附越弱,反之,吸附越强。 相似文献
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非抑制型电导检测离子排斥色谱法分析有机酸 总被引:1,自引:0,他引:1
本文以对甲苯磺,酸加硼酸作为淋洗液,采用非抑制型电导检测,研究了离子排斥色谱法分离和检测苹果酸,抗坏血酸,乳酸,琥珀酸,甲酸,乙酸,丙酸等有机酸的色谱条件,并进行了实际样品的分析。 相似文献
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该文对单咖啡酰奎宁酸和二咖啡酰奎宁酸的位置异构体分别进行液相色谱分析和不同碰撞能下的二级质谱分析,并对其质谱裂解规律进行了研究。结果发现,单咖啡酰奎宁酸的母离子377和子离子163在不同碰撞能下其强度发生显著变化,通过377/163的强度比值可区分其位置异构体。377/163比值大小依次为3-O-咖啡酰奎宁酸、4-O-咖啡酰奎宁酸、5-O-咖啡酰奎宁酸。二咖啡酰奎宁酸的母离子539和子离子377、163在不同碰撞能下其强度发生显著变化,通过539/377、377/163的强度比值可区分其位置异构体。539/377比值大小依次为4,5-O-二咖啡酰奎宁酸、3,4-O-二咖啡酰奎宁酸、3,5-O-二咖啡酰奎宁酸。377/163比值大小依次为3,5-O-二咖啡酰奎宁酸、4,5-O-二咖啡酰奎宁酸、3,4-O-二咖啡酰奎宁酸。基于Agilent Poroshell 120 SB-Aq C_(18)色谱柱,不同梯度下咖啡酰奎宁酸位置异构体的洗脱顺序均为5-O-咖啡酰奎宁酸、4-O-咖啡酰奎宁酸、3-O-咖啡酰奎宁酸、3,4-O-二咖啡酰奎宁酸、3,5-O-二咖啡酰奎宁酸和4,5-O-二咖啡酰奎宁酸。通过色谱保留特征和质谱裂解规律对金银花中咖啡酰奎宁酸的位置异构体实现了准确鉴别。 相似文献
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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2μL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。 相似文献
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建立了一种新的检测蚀刻槽废氢氟酸中六氟硅酸的离子色谱方法。色谱柱为Metrosep A Supp 7阴离子交换柱,流动相为3.2 mmol/L碳酸钠-1.0 mmol/L碳酸氢钠,流速为0.7 m L/min。六氟硅酸经过抑制型电导检测器后进行衍生化反应,在360 nm波长下用紫外检测器检测。六氟硅酸的线性范围为2.4~120 mg/L,相关系数r2大于0.999,定量限为0.24 mg/L,平均加标回收率为97.2%。本方法还可以同时利用电导检测器检测废氢氟酸中的氢氟酸、醋酸、盐酸、硝酸、磷酸和硫酸的含量。该方法快速、准确,适用于蚀刻槽液中六氟硅酸的检测。 相似文献
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The product pattern found for the dimethyldioxirane-mediated oxidation of phenylethyne strongly depends on the reaction conditions. Dimethyldioxirane generated in situ from caroate (HSO(5)(-)) and acetone in acetonitrile-water furnishes phenylacetic acid as the main product. With solutions of dimethyldioxirane in acetone, mandelic acid and phenylacetic acid are mainly formed. The relative abundances of the two acids depend on the residual water present in the dimethyldioxirane-acetone solution. Application of thoroughly dried solutions of the reagent effects increased formation of mandelic acid. When phenylethyne is oxidized by dimethyldioxirane transferred into tetrachloromethane, to minimize traces of water even further, oligomeric mandelic acid is obtained. The results are rationalized by the initial formation of phenyloxirene, which is known to equilibrate with phenylformylcarbene and benzoylcarbene. Subsequent Wolff rearrangement produces intermediate phenylketene, which can be trapped by water as phenylacetic acid or suffer from further oxidation to the alpha-lactone of mandelic acid. The alpha-lactone can either react with water to yield mandelic acid or, under anhydrous conditions, to yield oligomeric mandelic acid. In addition to mandelic acid and phenylacetic acid phenylglyoxylic acid, benzoic acid and benzaldehyde are observed as reaction products. The formation of phenylglyoxylic acid by transfer of two oxygen atoms to the unrearranged carbon skeleton of phenylethyne followed by oxygen insertion into the aldehydic C-H bond of the intermediately formed phenylglyoxal is discussed. In a second pathway this acid is formed by partial oxidation of mandelic acid. Benzaldehyde and benzoic acid are explained as products of the oxidative degradation of the alpha-lactone by dimethyldioxirane. Under in situ conditions benzoic acid is also formed by caroate initiated oxidative decarboxylation of phenylglyoxylic acid and/or intermediate phenylglyoxal. 相似文献