苦瓜中提取苦瓜皂苷的工艺研究

研究了苦瓜皂苷的提取工艺,以粗苦瓜可皂苷收率为考察指标,以提取温度、提取次数、回流时间、乙醇浓度、料液比为考察因素,通过单因素实验确定了最佳提取条件:乙醇浓度80%,提取次数2次,温度60℃,回流时间1.5 h,料液比1:15。并经放大十倍的重现性试验,结果皂苷提取率3.20%。     

浸取剂-超声波协同提取苦瓜皂苷的工艺优化

以乙醇、乙酸乙酯、环己烷及其两两混合作为浸取剂,利用超声波辅助提取苦瓜皂苷,考察了不同浸提液在不同超声功率、提取温度、料液比及提取时间下对苦瓜总皂苷得率的影响。以乙醇-乙酸乙酯作浸提剂时苦瓜皂苷总得率最高。在单因素实验的基础上,利用Box-Behnken设计四因素三水平响应面试验,确定最佳提取工艺条件为:超声功率350 W、提取温度48℃、料液比1∶25、提取时间3.0 h,在此工艺条件下,总皂苷得率为3.47%。     

苦瓜中抑菌成分的提取方法研究

选择不同溶剂提取苦瓜中的抑菌物质,通过抑菌实验,找到合适的提取苦瓜中抑菌物质的方法。实验结果显示,苦瓜中抑菌物质的最佳提取工艺条件为使用85%乙醇作为提取剂,提取温度85℃,索氏提取时间6 h,料液比1∶30(V∶V),浓缩,石油醚脱色,正丁醇萃取,浓缩后以甲醇溶解。在此条件下提取的提取物具有较高的抑菌活性,抑菌效果为对金黄色葡萄球菌大于大肠杆菌;初提物经聚酰胺分离后,50%和70%的乙醇洗脱液很好的保留了抑菌活性,而10%、30%、95%的乙醇洗脱液抑菌效果不明显。定性分析表明,有效的抑菌提取物中同时含有皂苷类、黄酮类、酚类和有机酸等成分。     

响应面法优化穿山龙中薯蓣皂苷的超声提取工艺

在单因素实验的基础上,采用响应面法优化了穿山龙中薯蓣皂苷的超声提取工艺。结果表明,在超声功率为540 W、乙醇体积分数为70%、液固比为20∶1(mL∶g)、超声时间为40 min的最佳条件下,薯蓣皂苷提取率达到5.18%。     

竹节参总皂苷的纯化方法研究

比较了大孔树脂吸附与丙酮沉淀法对竹节参总皂苷的纯化效果。结果表明,大孔吸附树脂对竹节参总皂苷具有较好的纯化能力,D101大孔树脂对竹节参总皂苷的吸附能力最佳。最佳洗脱条件为:60%的乙醇洗脱,洗脱剂用量为3BV(BV为树脂体积倍数),洗脱流速为1 mL/min。该条件下竹节参总皂苷纯度可达88.12%(丙酮沉淀法64.30%)。     

固相萃取-液相色谱联用检测镍电解液中的有机磷萃取剂

建立了固相萃取(SPE)-高效液相色谱(HPLC)联用测定镍电解液中P204、P507和C272的分析方法。优化了萃取溶剂、SPE柱填料类型、SPE淋洗溶剂等前处理条件以及HPLC检测条件。采用C18填料的SPE柱进行固相萃取,检测方法的线性范围为0.1~100 mg/L;检出限为0.02 mg/L。加标样品回收率为68.6%~83.5%,RSD为5.5%~9.2%。该方法灵敏度高,重复性良好,操作简便快速,适用于镍电解液中3种有机磷萃取剂的检测。     

苦瓜中皂苷、黄酮、多糖复合提取工艺研究

本实验采用不同浓度的乙醇溶液作为提取溶剂,使用超声波辅助提取,从苦瓜中连续提取皂苷、黄酮、多糖.选择乙醇浓度、超声时间、料液比分别进行提取皂苷、黄酮、多糖的正交实验,得出提取皂苷的最优条件:95％乙醇、超声30 min、料液比1:20 g/mL;提取黄酮的最优条件:60％乙醇,超声35 min、料液比1:25 g/mL...     

微波提取苦瓜总黄酮的工艺研究

以苦瓜果实为原料,以总黄酮提取率为评价指标,通过单因素实验考察了微波功率、液固比、乙醇体积分数、苦瓜粉末粒度等对总黄酮提取率的影响;在此基础上,通过正交实验确定最佳提取工艺条件为：微波功率500 W、液固比11∶1（mL ∶ g）、乙醇体积分数60％、苦瓜粉末粒度80目,在此条件下总黄酮提取率为15.576 mg·g-1.     

微波辅助乙醇-K_2 HPO_4双水相提取黄姜总皂苷

采用微波辅助乙醇-磷酸氢二钾双水相体系从黄姜中提取总皂苷。以正交实验法研究了提取条件对总皂苷提取率的影响,确定了最佳提取条件：黄姜粉末颗粒大小为80目,微波功率为390 W,微波辐射时间为5 min。在最佳条件下,总皂苷提取率达13.32%。     

苦瓜皂甙的复合酶法提取与大孔树脂纯化工艺研究

研究了苦瓜皂甙的酶法提取和大孔树脂纯化工艺.与高温水提法相比,苦瓜皂甙的复合酶解提取具有提取速度快、条件温和的优点.利用微孔技术精制提取液,除去一些大分子化合物和多糖.微滤后的精制液上LSA-20大孔树脂柱进行纯化,乙醇洗脱,冷冻干燥洗脱液所得的产品苦瓜皂甙含量可达79%.     

Modeling the recovery patterns from solid phase extraction purification of secoisolariciresinol diglucoside,p-coumaric acid glucoside,and ferulic acid glucoside from microwave-assisted flaxseed extracts

Flaxseed extracts obtained by microwave-assisted extraction (MAE) were cleaned of leftover salts from hydrolysis by solid phase extraction (SPE). The SPE set up was affordable, non-automated and vacuum-driven. The recovery patterns of secoisolariciresinol diglucoside (SDG), p-coumaric acid glucoside (PCouAG), and ferulic acid glucoside (FerAG) were modeled in two stages using regression procedures (p < 0.05). At stage one, the recovery patterns were predicted as a function of SPE eluent concentration in ethanol (10–50%). At stage two, the accuracy of the predictions was increased by enlarging the SPE eluent regressor's range (0–100% ethanol in water) and arranging the solvent system into three practical elution groups. The groups 1, 2 and 3 reflected the major loss, the major recovery and the minor loss of SDG, respectively. Second degree polynomial regression models were fitted for accurately predicting the recoveries of compounds. Microwave-assisted extracts obtained from 0.6 and 1.5 g defatted flaxseed meal were purified; the total SDG recoveries from the SPE funnel were 97.8 and 99.8%; and the SDG amounts obtained were 8.54 and 20 mg, respectively. The HPLC analysis of eluates pooled into practical groups allows for significant reductions in HPLC analysis time and solvent consumption which could have a positive impact on future purification studies. The results of this study allow for designing simplified, efficient and economical pilot scale studies for the purification of SDG from flaxseed extracts.     

Preparative Purification of the Major Flavonoid Glabridin from Licorice Roots by Solid Phase Extraction and Preparative High Performance Liquid Chromatography

This study investigated a novel, simple, and economical method for the preparation and purification of glabridin from licorice roots. Glabridin was initially obtained from ethyl acetate extraction of licorice, followed by using solid phase extraction (SPE) and preparative high performance liquid chromatography (HPLC). The content of glabridin increased from 0.23% to 35.2% after SPE, and then a 16 mg product at a high purity of over 95% was obtained from 10 g licorice roots after purification by preparative HPLC. The purity was assessed by analytical HPLC, and the purified compound was characterized by LC-MS/MS and ¹H NMR.     

油橄榄中橄榄苦苷的提取及纯化工艺研究

采用ODS C18色谱柱,流动相为甲醇:水(0.2%醋酸)体积比45:55,检测波长为230 nm,建立油橄榄叶中橄榄苦苷的HPLC分析方法。采用单因素和正交试验筛选优化油橄榄叶橄榄苦苷浸提的最佳工艺,并进一步研究大孔树脂静态和动态吸附和解吸附性能。结果表明:1)热回流浸提的最佳工艺为乙醇体积分数80%,温度70℃,提取时间3.5 h,料液比1:15(g:mL),提取次数2次。2)通过对比不同树脂对橄榄苦苷的吸附,筛选出选择性吸附好的AB-8树脂,吸附量为每克湿树脂32.1 mg。AB-8树脂纯化的最佳条件为:上样质量浓度为2 g/L,70%乙醇-水洗脱,流速为3 mL/min,洗脱液用量为3 BV。3)橄榄苦苷的粗提物经过AB-8树脂纯化后,橄榄苦苷的纯度达到47.90%,黄酮含量为16.4%,收率为6.43%。     

Separation and purification of sulforaphane from broccoli by solid phase extraction

A simple solid-phase extraction (SPE) method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC) for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 μg/mL (r = 0.998) for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1) was 0.02 μg/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction.     

固相萃取/高效液相色谱法同时测定化妆品中13种防晒剂

利用反相高效液相色谱法建立了同时测定化妆品中13种防晒剂含量的检测方法。样品首先用5 mL二氯甲烷进行溶解,超声提取30min,经过硅胶固相萃取柱(500 mg,6 mL)净化,用5 mL正己烷-二氯甲烷(1∶1,V/V)洗脱淋洗,收集淋洗液上机。以Diamonsil C18柱(250 mm×4.6mm,5μm)为分离色谱柱,甲醇和0.5%(v/v)甲酸水溶液为流动相,梯度洗脱,以311 nm和254 nm为检测波长进行定性,外标法定量。各组分在0.5~1000 mg/L范围内成线性关系,相关系数0.99,平均回收率在84.96%~108.62%,相对标准偏差(n=6)为1.39%~7.65%。该方法样品分离效果好、成本低、回收率和重现性好,适用于化妆品中13种防晒剂的同时测定。     

Purification of Extracted Fatty Acids from the Microalgae <Emphasis Type="Italic">Spirulina</Emphasis>

The fatty acid (FA) analysis of microalgae Spirulina was studied by applying accelerated solvent extraction (ASE) and followed by purification using solid-phase extraction (SPE). The objective was to develop a sensitive and reliable purification procedure to remove pigment in lipids co-extracted from Spirulina. Four extraction solvents were used for the ASE lipids extraction. The extraction efficiency was ranked in the following order: chloroform:methanol > dichloromethane:methanol > ethanol > hexane. The major composition of fatty acids were examined. Hexane and chloroform:methanol were compared for the purification step. The amounts of sorbent (Silica gel H), sample, and the volume of eluent were optimized during SPE procedure. This purification step can successfully remove the pigments from extracted lipids. For 0.1 g algae sample, chloroform:methanol (2:1, v/v) was the optimal extraction solvent, 0.3 g silica gel was the optimal amount of sorbent, with 7 mL for the volume of eluent. For hexane as the extraction solvent, 0.5 g algae sample, 0.3 g silica gel was the optimal amount of sorbent, 5 mL was the optimal volume of eluent. The calibration curve was produced comprised from five samples that contained FAME concentrations which was ranged from 0.1 to 10 mg/L (R ² > 0.99). The recoveries of fatty acids were 67.97–134.37%, 74.20–99.13% and 98.34–115.42%, with standard deviations (SD) of three replicate detections ranged from 1.09 to 8.41%.     

Determination of aniline derivatives in water samples after preconcentration with oxidized multiwalled carbon nanotubes as solid-phase extraction disk

A sensitive and selective preconcentration method using solid-phase extraction (SPE) disk made from oxidized multiwalled carbon nanotubes (OMWCNTs), has been developed for the determination of aniline derivatives, such as 2-nitroaniline (2-NA), 4-nitroaniline (4-NA), and 2,4-dichloroaniline (2,4-DCA) in water samples. Anilines were extracted onto OMWCNT disk and then determined by high performance liquid chromatography (HPLC) with UV detector. Several parameters on the recovery of the analytes were investigated. The experimental results showed that it was possible to obtain quantitative analysis when the solution pH was 8 using 200 mL of validation solution containing 2 μg of anilines and 10 mL of acetonitrile/ethanol (8/2, v/v) as an eluent. Relative standard deviations for five determinations were 7.5% (2-NA), 6.5% (4-NA) and 3.8% (2,4-DCA) under optimum conditions. The linear range of calibration curves were 0.5 ng·mL^-1 to 15 ng·mL^-1 for each analyte with good correlation coefficients. The detection limits (3S/N) of 2-NA, 4-NA and 2,4-DCA were 30 pg·mL^-1, 31 pg·mL^-1 and 26 pg·mL^-1, respectively. Our method was successfully applied to the determination of aniline compounds in river water sample with high precision and accuracy.     

Improving Waste Cooking Oil Quality for Biodiesel Production with the Ethanolic By-product of Soybean Oil Extraction

Waste cooking oils (WCO) can be used as feedstock for biodiesel (fatty acid ethyl or methyl esters—FAEE or FAME) production. Their usual high acidity, high moisture, and low stability can impair the reaction yield and generate a low-quality biodiesel. Here, we performed liquid–liquid washings using WCO and ethanol-based solvents with the goal of generating oil-rich miscella as FAEE feedstocks with a higher quality than WCO. Three different solvents were evaluated: 99% ethanol, 95% ethanol, and the soybean oil extraction ethanolic phase (SEP), a by-product with immense unexplored antioxidant potential obtained by extracting soybean oil using ethanol. Washings were performed in a 1000 mL flat-bottom flask at 78.1 °C, using a 1:2 (w/v) oil/solvent ratio, under magnetic stirring (1200 rpm) for 10 min. Ethyl esters were prepared via homogeneous alkali transesterification using WCO and oil-rich miscella as feedstocks. Treatments reduced the acid value by 40–61% and the peroxide value by 15–50%. Improvements in feedstock quality generated 24–54% higher biodiesel yields. The oil-rich phase produced with SEP was 15% more resistant to oxidation than WCO. This was attributed to the transference of isoflavones from the SEP. However, biodiesel from treated samples presented equal or lower oxidative stability than FAEE from WCO. High-performance liquid chromatography (HPLC) analysis showed that no isoflavones remained in biodiesel after purification. Pretreatment of WCO with ethanol-based extracts such as the SEP has great potential to improve WCO quality for biodiesel production as it can be a source of plant-based antioxidants.     

中草药凉茶中苯甲酸、山梨酸、对羟基苯甲酸酯类同时测定的方法研究

目的：建立一种应用高效液相色谱法同时测定中草药凉茶中五种防腐剂含量的新监测方法。方法：样品经ODS-C18层析柱固相萃取净化、分离,20 mmoL乙酸铵与乙腈为流动相,进行梯度洗脱。结果：可将五种防腐剂完全分离,在8～200μg/mL线性范围内（r均大于0.9999）,回收率在88.9%～110.8%之间,RSD在1.18%～6.82%之间（n=6）。最低检出限分别为：2.66×10-4、3.36×10-4、7.36×10-4、3.88×10-4、3.12×10-4 mg/kg;最低定量限分别为：1.33×10-3、1.68×10-3、3.68×10-3、1.94×10-3、1.56×10-3 mg/kg。结论：通过对样品前处理条件的选择和优化,能较好地除去大部分杂质的干扰。本方法能满足中草药凉茶中苯甲酸、山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯同时测定的要求,具有较好的推广意义;亦可作为监测儿童中药合剂和凉茶饮料防腐剂含量限制的参考。     

固相萃取-高效液相色谱法测定水中氯酚类

采用固相萃取-高效色谱法测定水中酚类。通过正交试验和验证试验探讨固相萃取技术富集水中7种酚类各种因素的影响,优化固相萃取的条件。优化得到的固相萃取条件：样品的pH为2、选择Oasis HLB固相萃取色谱小柱、流速为5mL／min、洗脱溶剂为四氢呋喃、洗脱体积为2mL,分2次洗脱。使用该方法的加标回收率为94．2％～105．1％,相对标准偏差为1．2％～3．9％,检出限为0．1～0．5μg／L。固相萃取-高效液相色谱法不仅各组分的回收率和灵敏度高,而且具有操作简便、溶剂用量少的特点,符合水中酚类测定的要求。