超临界CO2流体萃取与乙酸乙酯提取蛇床子化学成分的对比

用超临界CO2流体萃取(SFE-CO2)和乙酸乙酯提取(SE)蛇床子中的有效成分,采用气相色谱-质谱法(GC-MS)对SFE-CO2和SE提取物进行了化学成分的对比研究。鉴定出SE提取物的43个成分,SFE-CO2提取物的39个成分,占各提取物质量的80%~90%;SE提取蛇床子有效成分的能力较弱,而采用SFE-CO2萃取釜压力40 MPa,温度40℃,解析釜Ⅰ、Ⅱ压力5 MPa,解析釜Ⅰ温度45℃,解析釜Ⅱ温度46℃的工艺条件萃取出的蛇床子提取物,较SE选择性强,有利于萃取总香豆素以及萜烯类化合物;萃取总香豆素的质量分数(35.32%)比SE(17.39%)提高了18%,尤其萃取蛇床子素(23.83%),约为SE(6.32%)的4倍;萜烯类化合物(5.35%)也比SE(2.09%)提高了3%。     

超高效液相色谱法同时测定烟用香精中的蛇床子素和二氢欧山芹醇当归酸酯

建立了同时测定烟用香精中蛇床子素和二氢欧山芹醇当归酸酯的超高效液相色谱方法。以体积比为1∶1的乙腈-水溶液为萃取剂,采用ACQUITY UPLCBEH C18(2.1 mm i.d.×50 mm,1.7μm)色谱柱,柱温30℃,乙腈水为流动相进行梯度洗脱;流速为0.3 mL/min,检测波长324 nm,对20种烟用香精样品进行测定。结果表明:蛇床子素和二氢欧山芹醇当归酸酯标准品的色谱峰峰型尖锐且对称,两种物质的分离度大于1.5,在0.20～10.00mg/L范围内呈良好线性关系(r=0.9999);20种烟用香精中均未检测出蛇床子素和二氢欧山芹醇当归酸酯;空白样品中添加高、中、低三个浓度水平的两种物质,检测所得蛇床子素的平均回收率在98.00%～100.44%之间,三日内相对标准偏差在0.74%～2.54%之间;二氢欧山芹醇当归酸酯的平均回收率在99.41%～101.02%之间,三日内相对标准偏差在0.92%～2.27%之间。     

RP-HPLC法测定不同产地延胡索中延胡索乙素含量

用RP-HPLC法测定了对不同产地延胡索中延胡索乙素的含量。测定使用Kromasil C18色谱柱(200 mm×4.6 mm,5μm),以甲醇-0.1%磷酸溶液(用三乙胺调至pH 6.09)(V∶V,55∶45)为流动相,流速为1.0 mL/min,检测波长为280 nm。该方法的线性范围是22.0~352.0μg/mL,平均回收率98.6%,RSD=0.4%(n=9)。该法可用于质量控制。     

HPLC波长切换法测定不同产地紫菀中芹菜素、槲皮素和紫菀酮的含量

建立HPLC波长切换法同时测定紫菀中芹菜素、槲皮素和紫菀酮的含量。色谱柱为Agilent ZORBAX SB-C18(4.6×250mm,5μm)柱;流动相：乙腈-0.1%磷酸溶液,梯度洗脱;柱温40 ℃;流速1.0mL/min;检测波长：0～30min设为360nm(测定槲皮素和芹菜素),30～55min设为200nm(测定紫菀酮)。结果表明,芹菜素、槲皮素和紫菀酮分别在8.23～131.71μg/mL(r=0.9999)、11.08～177.29μg/mL(r=0.9998)、12.58～201.29μg/mL(r=1.000)范围内线性关系良好,平均回收率分别为99.53%(RSD=1.51%)、99.38%(RSD=1.68%)、99.75%(RSD=1.74%)。     

金龟子绿僵菌中苦马豆素的提取

称取金龟子绿僵菌干燥菌丝体200 g,甲醇浸泡24 h,减压浓缩至浸膏,c(HCl)=1 mol/L盐酸溶解后依次用环己烷、氯仿和正丁醇分段萃取,酸水液上732型强酸性阳离子交换树脂柱,c(NH3.H2O)=1 mol/L氨水洗脱并挥干,得到总生物碱。总生物碱用无水乙醇索氏提取24 h,挥干后干燥物上硅胶柱,V(氯仿)∶V(甲醇)∶V(氨水)∶V(水)=70∶26∶2∶2混合溶剂洗脱,薄层色谱检测发现101～142份洗脱液含有苦马豆素,合并101～142份洗脱液并挥干,氨性氯仿反复溶解,冷冻干燥后在110℃、-0.094 Pa真空条件下升华,得到白色针状结晶3.6mg。经薄层色谱检测、熔点测定及气相色谱检测,可确定该白色针状结晶为苦马豆素,苦马豆素的提取率为18μg/g。气相色谱法测定金龟子绿僵菌干燥菌丝体中苦马豆素的质量分数为0.212%。     

HPLC法测定盐酸托莫西汀口服溶液中对映异构体含量

建立高效液相色谱法(HPLC)测定盐酸托莫西汀口服溶液中对映异构体含量的方法.色谱柱为大赛璐DAICEL CHIRALPAK IB N-3 (4.6×250 mm,3μm),流动相为0.1％正丙胺溶液(用磷酸调节pH为8.5)-乙腈(V∶V=50∶50),流速0.5 mL/min,柱温30℃,进样量10 μL,检测波长273 nm.对映异构体在0.6450～12.90μg/mL范围内与峰面积线性关系良好(R2=0.9997).方法 专属性、重复性、灵敏度满足盐酸托莫西汀口服溶液中对映异构体含量测定要求.     

高效液相色谱测定水中微囊藻毒素

应用高效液相色谱法测定水中微囊藻毒素的含量.水样经C18柱固相萃取后进行HPLC分析.通过优化固相萃取方法,采用Symmentry C18色谱柱,以甲醇：水（含0.05%三氟乙酸）=60：40（V/V）溶液为流动相,紫外238nm检测.对两种常见微囊藻毒素MC-RR、MC-LR的检测限为0.02～0.05μg/L.实验表明该法可有效检测水样中的痕量微囊藻毒素.     

LC/MS/MS测定动物源食品中利巴韦林药物残留

建立了用LC/MS/MS测定动物源食品中利巴韦林药物残留方法。样品中加入内标,用1%三氯乙酸-乙腈(1∶1,V/V)溶液提取,用氨水调至碱性,经Agilent PBA固相萃取小柱净化,净化后溶液经色谱柱IntertsilHPLC HILIC column(3.0 mm×150 mm,5μm)进行分离,用乙腈和水作为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式进行检测。实验结果,利巴韦林在2.0~50.0 ng/m L范围内有很好的线性关系(r2≥0.995);方法的定量限为2.0μg/kg;在2.0、10.0、50.0μg/kg添加浓度水平回收率为87.5%~97.07%,相对标准偏差(n=6)在2.76%~3.43%之间。此方法灵敏、准确、方便,适合于动物源食品中利巴韦林残留通量分析。     

HPLC法同时测定风湿马钱片中士的宁和马钱子碱的含量

建立了HPLC同时测定风湿马钱片士的宁和中马钱子碱含量的方法。采用反相高效液相色谱法,色谱柱为Wondasil-C18柱(250mm×4.6mm,5μm),流动相为乙腈-0.2%庚烷磺酸钠与0.27%磷酸二氢钾等量混合溶液(用磷酸调节pH值2.8)(12∶88,V/V),流速为1.0mL·min-1,检测波长为260nm,柱温为25℃。士的宁和马钱子碱分别在2.006~40.12μg·mL-1(r=0.9998)及2.002~40.04μg·mL-1(r=0.9997)范围具有良好的线性关系,平均回收率分别为为99.8%和99.7%。本方法可用于风湿马钱片中士的宁和马钱子碱的同时测定。     

黄瓜中农药残留甲氧虫酰肼的反相高效液相色谱法测定

建立了一种反相高效液相色谱法–紫外检测法(HPLC–UV)测定黄瓜中残留甲氧虫酰肼的方法。采用酸化的甲醇高速匀浆提取,正己烷除脂类杂质,二氯甲烷萃取–反萃取去除亲水性杂质,经氟罗里硅土柱层析净化。在Symmetry C18色谱柱上分离,以V(甲醇)∶V(乙腈)∶V(水)=50∶15∶35(pH=7)为流动相,在波长230nm处进行测定。结果表明,甲氧虫酰肼的峰面积与其质量浓度有良好线性关系。其最小检出量为0.01mg/kg(S/N=3),回收率为84.06%～97.93%,标准偏差小于5.92。该法简便快速、灵敏准确。     

Mechanical extraction

The mechanical screw press was the principal means of extracting vegetable oilseeds in the United States from the 1930s through the 1940s and 1950s. Then the utilization of solvent extraction cut drastically into their use for full extraction, but created a great demand for screw presses for prepressing of high oil content seeds for solvent extraction. However, use of the screw press for full extraction has been increasing over the years in the less developed countries, and is the main modern machine utilized for some products such as palm fruit. Today ever larger and more efficient machines are being developed for full extraction and pre-pressing of vegetable oilseeds and fruits.     

加压溶剂法提取雷公藤甲素及其条件优化

以雷公藤为原料,采用加压溶剂法提取雷公藤甲素,以1,2-二氯乙烷为溶剂,考察了提取时间、料液比和提取温度等因素对提取工艺的影响,并在单因素试验基础上,根据中心组合试验设计原理采用三因素三水平的响应面分析法进行工艺优化,得到提取过程优化的工艺条件为:料液比1:9.7,提取温度115℃,提取时间80min,雷公藤甲素的实际得率可达0.173‰,纯度为1.21%,与常规回流提取法相比优势明显。     

蛇床子中蛇床子素的提取工艺研究

采用乙醇加热回流法提取蛇床子中的蛇床子素,对提取工艺进行优化。结果表明,最佳工艺条件为:提取液为75%乙醇溶液,用量为药材的8倍,提取时间为1.5 h和提取温度为80℃。     

Using membrane-supported liquid-liquid extraction for the measurement of extraction kinetics

Membrane-supported liquid-liquid extraction uses artificial membranes for the generation of a phase interface between the two liquid phases involved in extraction. Additional equipment for the generation of droplets as well as phase separation afterwards is no longer necessary. Since the membranes used for this special type of extraction are quite well described concerning thickness, porosity, tortuosity and material it is possible to generate information about the diffusion coefficient of the component to be extracted within the preferred solvent from extraction trails easily. This article describes an experimental set-up for both the proof of principle of membrane-supported liquid-liquid extraction and, using a dedicated computer-aided data treatment, how to calculate the overall mass transfer coefficient as well as the diffusion coefficient for a given system within moderate testing duration.     

Mechanical oil extraction

Competitive pieces of equipment for full-pressing and prepressing oilseeds are described. “Enhanser” machines to treat seeds before solvent extraction considerably increase the capacity of the solvent extraction system.     

Comparison of membrane extraction with traditional extraction methods for biodiesel production

Three traditional methods for the refining step in biodiesel production were compared: (i) washing with distilled water; (ii) washing with acid (HCl); and (3) dissolving and extracting in a solvent (hexane or petroleum ether) and then washing with distilled water. Biodiesel with a high purity (97.5%) could be obtained by all three methods, but serious emulsification occurred during the refining processes, which led to high refining losses. A novel refining method was developed by using hollow fiber membrane extraction, and polysulfone was selected as the most suitable membrane. This process effectively avoided emulsification during refining and decreased the refining loss. The purity of the biodiesel obtained was about 99%; and other properties, such as density, kinematic viscosity, water content, and acid value, conformed to the standards.     

往复振动筛板萃取塔萃取机理研究进展

介绍了往复振动筛板萃取塔（RPEC）流体力学性能和传质性能研究现状。