超声条件下蔗糖-6-月桂酸单酯及蔗糖-6'-月桂酸单酯的合成、纯化与结构鉴定

采用薄层层析(TLC)和硅胶柱层析分离纯化了超声处理条件下合成的蔗糖月桂酸单酯,并对纯化后的组分采用高效液相色谱(HPLC)、红外光谱(IR)、质谱(MS)、核磁共振(1H-NMR、13C-NMR)进行了结构鉴定和表征TLC分离蔗糖月桂酸酯的理想条件:点样量4μL,以氯仿/甲醇/冰乙酸/水(V/V/V/V,75∶15∶7∶3)展开25min,然后用10％磷钼酸乙醇溶液喷雾,105℃显色10min 硅胶柱层析分离蔗糖月桂酸酯的较佳条件为:3g样品溶于10mL洗脱剂上,35mm×700mm硅胶(200～300目)层析柱,流动相为TLC展开剂配比,流速为40～50mL/h,每30min收集一份洗脱液 两种单酯组分分别为蔗糖-6-月桂酸酯和蔗糖-6’-月桂酸酯.     

硝酸银-硅胶柱层析法分离纯化华山松籽油亚油酸

采用KOH-乙醇皂化再通过盐酸酸化的方法制备华山松籽油混合脂肪酸,利用硝酸银-硅胶柱色谱分离纯化华山松籽油中亚油酸,对纯化过程中硝酸银-硅胶对多不饱和脂肪酸(亚油酸)的动态吸附特性进行初步研究。在12.0 g活化的银化硅胶色谱柱中,加入与吸附剂比例1︰15脂肪酸,洗脱剂流速0.8 m L/min,以丙酮-正己烷为洗脱剂,可使华山松籽油中亚油酸由原来的57.7%柱层析分离后提高到98.12%。结果表明,以硝酸银-硅胶为吸附剂,采用柱层析法是一种高效分离亚油酸的方法。     

硅胶柱层析精制中长链结构甘油三酯

为探究硅胶柱层析在中长链结构甘油三酯（MLCT）精制方面的应用,以亚麻籽油和中链脂肪酸甘油三酯为原料合成MLCT粗产品,采用硅胶柱层析进行精制,优化精制工艺条件并对硅胶柱层析精制前后MLCT的质量指标进行了测定。通过硅胶薄层层析确定硅胶柱层析的洗脱剂,通过洗脱曲线确定洗脱液收集体积,以甘二酯脱除率和产品回收率为评价指标,确定洗脱流速和上样量。结果表明：以正己烷-无水乙醚（体积比5∶ 1）为洗脱剂,等梯度洗脱,洗脱流速2.0 mL/min,上样量4 g,硅胶40 g,收集洗脱液500 mL条件下对MLCT粗产品进行精制,所得产品甘二酯脱除率达到99.40%,MLCT回收率为95.07%。精制后产品酸值（KOH）和过氧化值显著降低,分别为0.04 mg/g和0.00 g/100 g,色泽变浅,色值为R0.0,Y0.1。硅胶柱层析具有同时脱除副产物,降低酸值、过氧化值、脱色等综合效果,在MLCT精制方面有良好的应用前景。     

乌桕梓油甲酯中2,4-癸二烯酸甲酯的分离

乌桕梓油中含有一种特殊结构的四酯成分,四酯分子水解得到结构特殊的中长链脂肪酸2,4-癸二烯酸,这种烯酸含有多种官能团,性能活泼,具有潜在的应用价值和研究意义。通过酯交换,将梓油中的三酰甘油和四酰甘油转化为脂肪酸甲酯。经过气相色谱-质谱联用仪(GC-MS)分析,得出乌桕梓油的脂肪酸甲酯主要为亚油酸甲酯和亚麻酸甲酯,它们各占梓油脂肪酸甲酯总量的30.1%和41.3%,2,4-癸二烯酸甲酯大约占梓油脂肪酸甲酯的4.2%。采用减压间歇精馏的方法,在精馏压力低于500 Pa、回流比为1的工艺条件下,收集塔顶温度在93~93℃的塔顶馏分,得到纯度为96.0%的2,4-癸二烯酸甲酯产品,2,4-癸二烯酸甲酯的收率为76.5%。     

大孔树脂-硅胶柱层析法纯化花生根中白藜芦醇

研究了大孔树脂-硅胶柱层析法分离纯化花生根中白藜芦醇的工艺。通过动静态解吸附试验确立大孔树脂最佳分离工艺为:大孔树脂为聚酰胺,上样质量浓度26.58μg/mL,解吸剂为80%乙醇,洗脱流速2 BV/h。通过薄层色谱与硅胶柱层析试验,确定最佳纯化条件为:洗脱剂V(氯仿)∶V(甲醇)=40∶1、流速30 mL/min、m(硅胶)∶m(样品)=1∶1。产物经V(甲醇)∶V(氯仿)=3∶1重结晶后,采用高效液相色谱测定其纯度为97.01%。     

分离纯化番茄油树脂中的番茄红素的研究

采用柱层析法和高效液相色谱法研究了番茄油树脂中番茄红素的分离纯化条件。结果表明最佳条件为:柱层析的吸附剂为:100-200 目层析硅胶;常温下吸附,洗脱;加样浓度:番茄红素油树脂与丙酮的比例为 1:10;洗脱剂为丙酮;洗脱流速为 3.5ml/min;高效液相色谱(HPLC)的色谱条件为:色谱柱:C-18;流动相:甲醇:乙腈:二氯甲烷=45:10:45;载液流速:0.6ml/min;紫外检测器;波长为:472nm。     

大豆胚芽甾醇酯的分离纯化

以大豆胚芽为原料,筛选出合适的溶剂浸提大豆胚芽粗提物,并采用柱层析从大豆胚芽粗提物中分离纯化大豆胚芽甾醇酯。通过单因素及正交试验优化出柱层析技术分离纯化大豆胚芽甾醇酯的最佳工艺条件,并采用高效液相色谱、红外光谱及气质联用色谱等对纯化产物进行表征。结果表明：大豆胚芽甾醇酯的最佳分离纯化条件为吸附剂200 目～300 目硅胶粉、上样量 2.0 g、层析柱高度与直径比（H/D）12∶1、洗脱剂（正己烷∶乙醚∶乙酸）体积比 90∶10∶1,在最佳分离纯化条件下大豆胚芽甾醇酯纯度为（96.11±0.41）%,得率为（94.99±0.19）%（以大豆胚芽粗提物计）。通过液相色谱、红外光谱、气质联用色谱分析出大豆胚芽甾醇酯上甾醇组成主要为β-谷甾醇、豆甾醇、菜油甾醇、羊毛甾醇;气相色谱分析可知甾醇酯的脂肪酸组成主要为亚油酸、棕榈酸、亚麻酸。     

乌桕梓油理化特性及其酶法制备生物柴油的研究

测定了乌桕梓油常规理化特性.采用柱层析、薄层层析和气相色谱法,研究了乌桕梓油中甘油酯种类及其脂肪酸组成.采用高温气相色谱/EI质谱联用仪直接分析了乌桕梓油中甘油酯结构.结果表明,乌桕梓油中性脂占98.79%,磷脂占0.22%,糖脂占0.99%.乌桕梓油中性脂的脂肪酸组成主要有C12:0、C14:0、C16:0、C17:0、C18:0、C18:1、C18:2和C18:3,磷脂中没有检出C12:0和C17:0,糖脂中则没有检出C17:0.乌桕梓油中甘油酯组成主要有月桂酸棕榈酸亚油酸甘油三酯、硬脂酸亚油酸亚麻甘油三酯、双棕榈酸亚油酸甘油三酯、棕榈酸亚油酸亚麻酸甘油三酯和双亚油酸亚麻酸甘油三酯等5种.最后,比较了无溶剂体系和叔丁醇体系中,以杂醇油为酰基受体,初步研究了脂肪酶法制备乌桕梓油生物柴油效果.结果表明,对于无溶剂体系和叔丁醇体系而言,当Novozym435与Lipozyme TLIM脂肪酶复合比例为2:4时,生物柴油转化率达到最高,分别为98.28%和76.33%.     

硬脂酸三乙醇胺酯的分析

以V(氯仿)∶V(甲醇)=25∶1的混合溶剂作为柱层析的洗脱剂,硬脂酸三乙醇胺酯经硅胶柱层析分离得到了3个馏分.利用高效液相色谱(HPLC)、红外光谱(IR)及质谱(MS)对其进行了定性分析,结果表明,3个馏分分别是硬脂酸三乙醇胺三酯、硬脂酸三乙醇胺双酯和硬脂酸三乙醇胺单酯.利用3个高纯组分作出了对应的标准曲线,结合HPLC和柱色谱分离的结果表明:采用HPLC对硬脂酸三乙醇胺酯进行定量分析是一种方便、快捷和准确的方法.     

砂仁粉调味料的有效成分研究

采用水蒸气蒸馏法提取砂仁粉的挥发性成分,以硅胶柱层析分离所得的精油组分,利用气相色谱/质谱(GC/MS)联用技术进行分析鉴定;鉴定了31个化合物,其中相对质量分数1.0%以上有:醋酸龙脑酯、龙脑、柠檬烯、樟脑、樟烯、α-松油醇、莰烯、α-蒎烯、3-蒈烯和β-月桂烯。     

Improved sample extraction and clean-up for the GC-MS determination of BADGE and BFDGE in vegetable oil.

A straightforward method was established for the determination of migration contaminants in olive oil with a special focus on the two can-coating migration compounds bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE). The preferred sample preparation was a single liquid-liquid extraction of compounds from the oil into 20% (v/v) methanol in acetonitrile, followed by clean-up with solid-phase extraction on aminopropyl bonded to silica. This purification procedure selectively removed all free fatty acids from the extracts without removing phenolic compounds of interest. The solid-phase extraction columns were used many times by implementing a procedure of washing out the strongly retained fatty acids with 2% acetic acid in methanol. Gas chromatography coupled with full scan (m/z 33-700) electron ionization mass spectrometry was used for the determination of several model compounds in olive oil samples. BADGE and BFDGE could be determined in the 0.05-2 mg kg(-1) range in oil samples with a relative SD of <6% (six replicates). The method was used in an enforcement campaign for the Norwegian Food Control Authority to analyse vegetable oil samples from canned fish-in-oil.     

关于地沟油极性组分指标的研究

目的 研究地沟油极性组分的共同特性, 为有效检测地沟油提供参考。方法 用石油醚: 乙醚分离地沟油与杂质, 挥干有机溶剂后用柱层分析法进行极性组分指标测定。 结果 所检测到的地沟油的极性组分含量值为23.37 % ±3.33 %(在15.71 % ~32.50 %之间), 而未经烹饪过的正常食用油的极性组分含量值明显较低, 为4.55 % ±1.41 %(在3.05%~6.76%之间)。地沟油和未经烹饪油的层析柱洗脱物的比较也有较明显的差异。 结论 可以用柱层分析法检测区分正常食用油与地沟油。     

Sensitive determination of volatile aliphatic aldehydes in autoxidized fats and oils by gas chromatographic/electron-capture detection of their O-pentafluorobenzyloxime derivatives

 This paper describes a novel method for the sensitive determination of the volatile aliphatic aldehydes formed by autoxidation in fats and oils. In a solution of fats, the aldehydes are derivatized to the O-pentafluorobenzyloximes (PFBOs) without any isolation procedure. From the mixture, the lipids are removed by silica gel column chromatography using pentane/dichloromethane (4+1) as the eluant. The eluate is evaporated to dryness and the PFBOs are extracted from the residue with a small volume of acetonitrile. They are separated by capillary column gas chromatography and are determined with high selectivity and sensitivity by using an electron-capture detector. The determination limit was as low as 0.01 mg/kg for hexanal. Analysis of a series of corn oil samples yielded high recoveries for 14 aldehydes added at the 1 mg/kg level, with low relative standard deviations of between 3 and 17%. Received: 9 May 1997     

Sensitive determination of volatile aliphatic aldehydes in autoxidized fats and oils by gas chromatographic/electron-capture detection of their O-pentafluorobenzyloxime derivatives

 This paper describes a novel method for the sensitive determination of the volatile aliphatic aldehydes formed by autoxidation in fats and oils. In a solution of fats, the aldehydes are derivatized to the O-pentafluorobenzyloximes (PFBOs) without any isolation procedure. From the mixture, the lipids are removed by silica gel column chromatography using pentane/dichloromethane (4+1) as the eluant. The eluate is evaporated to dryness and the PFBOs are extracted from the residue with a small volume of acetonitrile. They are separated by capillary column gas chromatography and are determined with high selectivity and sensitivity by using an electron-capture detector. The determination limit was as low as 0.01 mg/kg for hexanal. Analysis of a series of corn oil samples yielded high recoveries for 14 aldehydes added at the 1 mg/kg level, with low relative standard deviations of between 3 and 17%. Received: 9 May 1997     

A simple quantitative HPLC method for determination of aflatoxins in cereals and animal feedstuffs using gel permeation chromatography clean-up

A simple and sensitive procedure is described for the analysis of aflatoxins B1, B2, G1 and G2 in cereal and animal feedstuff samples. Aflatoxins are extracted with dichloromethane:water (10:1). Gel permeation chromatography (GPC) using a column packed with Bio-beads S-X3 and dichloromethane:hexane (3:1) as the eluent is used for clean-up of extracts prior to separation and quantification of aflatoxins by HPLC. The eluent fraction containing the aflatoxins is concentrated by evaporation under reduced pressure and the aflatoxins separated by reverse phase HPLC on an ODS column. Quantitative results have been obtained at levels down to 1 microgram/kg, and average recoveries from samples of wheat, maize and compound feed spiked at levels of 10 and 40 micrograms/kg were greater than 80%, 70% and 65% respectively.     

DIRECT DETERMINATION OF TRANS-OCTADECENOIC ACID IN DIET COMPOSITES USING A COMBINATION OF SILVER ION-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY AND CAPILLARY GAS CHROMATOGRAPHY

Silver ion-high performance liquid chromatography (Ag-HPLC) and capillary gas chromatography (GC) were combined to quantify total trans -octadecenoic acid (18:1t) in diet composites and oils. The 18:1 cis and trans fatty acid methyl esters (FAME) of saponified and methylated (BF₃/methanol) oils and food composite total lipid extracts were separated by Ag-HPLC (ChromSpher5 Lipids column); total 18:1t in the trans fraction was quantified by GC (105m × 0.25mm SP-2560 capillary column). Positional isomers 18:1c and 18:1t which coeluted in direct GC were clearly separated by preparatory Ag-HPLC. Quantitative recovery of 18:1t from a standard mixture of FAME, an oil, and a diet composite was obtained for additions of 4–57 mg. The analytical range for total 18:1t was 1.6–260 mg/mL per aliquot of total lipid extract or oil. Relative standard deviations were < 6% for food composites and < 3% for oils and pure standards.     

气相色谱技术与白酒分析

气相色谱技术以分离效率高、分析速度快、灵敏度高、样品用量少而广泛用于酿酒行业的理化指标分析。白酒行业常用的色谱柱有DNP填充柱、大口径毛细柱和细口径毛细管柱。利用气相色谱可对白酒卫生指标甲醇和杂醇油进行控制；对白酒中的主体香含量、四大酯含量、微量香味成分含量进行测定；开展对白酒芳香成分的剖析和风味关系的研究；以及对白酒中酒用香精含量的测定。     

响应面试验优化红花籽油水酶法提取工艺

通过二水平因子分析设计和响应面试验,优化水酶法提取红花籽油工艺。以红花籽油提取率为指标,对酶的种类及添加比例、料液比、总加酶量、酶解时间、酶解温度、酶解p H值进行研究。结果表明:在木聚糖酶UTC-X50、果胶酶NCB3/ZG-040和碱性蛋白酶NCB3/ZG-002比例1∶2∶3(酶活比),总加酶量197.36 U/g,料液比1∶4(g/mL)条件下,先用细胞壁多糖酶(木聚糖酶、果胶酶)在p H 4.2、50℃酶解131 min,再用碱性蛋白酶在p H 9.8、40℃酶解60 min,此工艺条件下红花籽油提取率最高,为84.68%;采用气相色谱法分析脂肪酸组分,发现红花籽油中不饱和脂肪酸相对含量高达91.18%,其中亚油酸相对含量为78.27%,油酸相对含量为12.61%,亚麻酸相对含量为0.10%。