响应面法优化红枣中硒的提取工艺及HPLC测定

探讨研究红枣中微量硒的提取工艺。采用响应面法中的Box-Behnken试验设计原理选取试验因素与水平,对红枣中硒的提取率有影响的料液比、消化液配比和消化时间3个因素进行优化.试验结果表明:硒的最佳提取工艺参数料液比为1∶12.56(g/mL)、消化液配比为1∶3.6、消化时间为137.2min;在此条件下,红枣中硒的提取率为0.294μg/g.该研究为从食品中提取检测微量硒提供了可行的手段.具有一定的实用价值.     

超声萃取-响应面法优化淡竹叶多糖提取方法研究

利用超声辅助萃取—响应面法提取淡竹叶多糖工艺进行研究。在单因素试验基础上,采用五因素三水平响应面分析法,使用中心组合(Box-Benhnken)试验设计原理得到二次线性回归方程,以多糖产率为响应面值作响应面图,确定超声提取淡竹叶多糖最佳工艺条件为:功率200W,温度50℃,液料比35,超声时间30min,提取次数2次,多糖产率为3.42%。验证实验表明,所得模型方程能较好地预测实验结果,拟合度较好。     

响应面法优化黄连-罗汉果药对中降糖成分的超声提取工艺研究

本文优化了黄连-罗汉果药对中发挥降血糖作用的主要指标性有效成分小檗碱型生物碱、多糖和罗汉果皂苷的超声提取工艺。利用响应面法考察超声提取时间、料液比例、超声温度与超声功率对提取效果的影响。最佳提取条件为将黄连、罗汉果细粉浸泡于1∶30倍量的水中,置于75℃、400 W的恒温超声仪中提取23 min,提取3次,得到的提取液中三种指标成分质量总和最高,其中小檗碱型生物碱、多糖和罗汉果皂苷的提取率分别为22.70%、31.16%、16.55%。该提取工艺简单高效,预测性良好,有利于促进黄连、罗汉果合用发挥降血糖功效的开发利用。     

玉米粕蛋白质提取工艺的响应面法分析

探讨提取玉米粕蛋白质的最佳工艺条件。在单因素试验的基础上,选取料液比(g·mL-1)、温度、NaoH浓度为响应因子,玉米粕蛋白质的提取率为响应值,实施3因素3水平的响应面分析,建立数学模型,得出最佳工艺条件。试验结果表明,玉米粕蛋白质的最佳提取条件为:料液比1:6.89(g·mL-1)、温度44.92℃、NaoH浓度0.078mol·L-1,在此工艺条件下玉米粕蛋白质的提取率可达到40.57%。     

唐古特大黄乙醇提取物的HPLC指纹图谱研究

用高效液相色谱法建立唐古特大黄乙醇提取物的指纹图谱分析方法。采用Phenomenex Kromasil C18色谱柱(4.6 mm×250 mm,5μm);甲醇-0.1%H3PO4为流动相,梯度洗脱,检测波长为270 nm,以大黄酸为参照峰。结果共有18个共有峰。此法为有效地控制唐古特大黄乙醇提取物的质量提供了依据。     

响应面法优化黄芪多糖的提取工艺研究

为优化对黄芪多糖提取工艺.根据单因素实验结果,选取实验因素与水平,根据Box - Benhnken的试验设计原理,采用三因素三水平的响应面分析法,以获得多元二次线性回归方程,以多糖得率为响应值的响应面和等高线.结果表明,提取黄芪多糖最佳工艺条件:料水比1:13,提取温度94 ℃,提取时间64 min.在此条件下,黄芪多...     

响应面法优化蒙药瞿麦中总生物碱提取工艺研究

研究了响应面法优化蒙药瞿麦总生物碱的最佳提取工艺。采用紫外-可见分光光度法,以总生物碱含量作为评价指标,用Box-Behnken响应面设计考察各因素对其影响,对结果进行二项式拟合及响应曲面分析得到最佳提取工艺。结果表明:蒙药瞿麦中总生物碱的最佳提取工艺为超声温度53℃,料液比1∶31 g/mL,超声时间41 min,超声功率140 W。四因素影响顺序为料液比超声温度超声功率超声时间。此方法简便、快速、灵敏,结果准确可靠,优化后的提取工艺稳定可行,且具有提取率高、提取时间短等优点,对今后的科研工作有一定参考价值。     

响应面法优化石榴叶多酚闪式提取的工艺研究

为建立快捷、高效、绿色的石榴叶多酚的提取工艺,通过单因素实验确定其主要影响因素,在单因素实验的基础上利用响应面法进行分析,确定提取石榴叶多酚的最佳提取条件为:乙醇浓度58%、料液比1∶9 (g/mL),提取时间4 min,在此条件下石榴叶多酚的理论提取量为:29.37 g GAE/100 g,实际提取量为:29.12 g GAE/100 g.     

决明子药材中大黄酚量的反相HPLC法测定

以甲醇－水（体积比８０：２０）为流动相,采用反相高效液相色谱法测定了生,炔决明子中大黄酚的量,平均回收率９８．１％,ＲＳＤ为２．３％（ｎ＝５）,方法简便,灵敏,重现性好。     

响应面法优化盐肤木中漆黄素提取工艺的研究

研究盐肤木中漆黄素的最佳提取工艺。采用单因素试验基础,以湖南产盐肤木中漆黄素得率为评价指标,通过响应面分析法确定盐肤木中漆黄素最佳提取工艺和条件。盐肤木中漆黄素最佳提取工艺:水浴时间80 min、料液比1∶30、溶剂35%乙醇水溶液、pH值9.5、水浴温度87℃,盐肤木中漆黄素理论预测得率为0.18%,实际得率为0.19%。优化出的盐肤木中提取漆黄素的最佳工艺可行。     

Application of an efficient strategy based on liquid–liquid extraction,high‐speed counter‐current chromatography,and preparative HPLC for the rapid enrichment,separation, and purification of four anthraquinones from Rheum tanguticum

This study presents an efficient strategy based on liquid–liquid extraction, high‐speed counter‐current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum. A new solvent system composed of petroleum ether/ethyl acetate/water (4:2:1, v/v/v) was developed for the liquid–liquid extraction of the crude extract from R. tanguticum. As a result, emodin, aloe‐emodin, physcion, and chrysophanol were greatly enriched in the organic layer. In addition, an efficient method was successfully established to separate and purify the above anthraquinones by high‐speed counter‐current chromatography and preparative HPLC. This study supplies a new alternative method for the rapid enrichment, separation, and purification of emodin, aloe‐emodin, physcione, and chrysophanol.     

Extraction and isolation of flavonoid glycosides from Flos Sophorae Immaturus using ultrasonic‐assisted extraction followed by high‐speed countercurrent chromatography

A method of ultrasonic‐assisted extraction followed by high‐speed countercurrent chromatography was established for the extraction and isolation of three flavonoid glycosides, i.e. rutin, narcissin, and nicotiflorin from Flos Sophorae Immaturus. The effects of ultrasonic‐assisted extraction factors for the main flavonoid compound (rutin) from Flos Sophorae Immaturus were optimized using Box–Behnken design combined with response surface methodology. The optimum conditions were determined as ultrasonic power 83% (600 W), solvent‐to‐material ratio 56:1, methanol concentration 82% v/v, and extraction time 60 min. Three bioactive flavonol glucosides, rutin, narcissin, and nicotiflorin were isolated from Flos Sophorae Immaturus using high‐speed countercurrent chromatography. The separation was performed with a two‐phase solvent system containing ethyl acetate/n‐butanol/methanol/water (4:0.9:0.2:5, v/v). Amounts of 87 mg of rutin, 10.8 mg of narcissin, and 1.8 mg of nicotiflorin were isolated from 302 mg of crude extract of Flos Sophorae Immaturus in a one‐step separation within 160 min with purities of 99.3, 98.0, and 95.1%, respectively, as determined by HPLC with diode array detection. Their structures were characterized by UV, MS, and NMR spectroscopy. It was demonstrated that the established method was simple, fast, and convenient, which was feasible to extract and isolate active flavonoid glycosides from Flos Sophorae Immaturus.     

Optimization of ultrasound-assisted extraction of phenolic compounds from Sesamum indicum

Abstract

Effective extraction of phyto-biomolecules insures retaining maximum functionality along with higher recovery. In this study, ultrasound-solvent assisted extraction (USAE) was employed for optimal extraction of phyto-biomolecules from Sesamum indicum (sesame) leaves using the approach of Response Surface Methodology (RSM). The optimized condition of 200?W power, 59% methanol concentration with 1:14?g/mL solid–liquid ratio and 15?min of extraction time yielded 367.39?±?1.85?mg GAE/100?g of total phenolic content, 96.72?±?3.27% of free radical scavenging activity and 81.20?±?2.87% of iron chelating activity respectively. The extract consist of essential phytocomponents like gallic acid, chlorogenic acid, and quercetin with lipid peroxidation activities of >50% over incubation time of 48?h. Also, showed antimicrobial activity against various Gram’s negative and positive food borne pathogens. The results of this study implied the importance of USAE for effective and optimum recovery of phyto-biomolecules from Sesame leaves with retained functional properties.     

Comparison of alternative and conventional extraction techniques for the determination of zearalenone in corn

Naturally contaminated corn samples of different origin were extracted using two conventional techniques (blending and shaking) and three alternative approaches (ultrasonic extraction, accelerated solvent extraction, and microwave-assisted extraction). Use of the same extraction mixture for all trials enabled the efficiency of the various extraction techniques to be compared. Extracts were filtered and directly analyzed by LC–ESI–MS, without further clean-up. The yield from the alternative extraction techniques showed efficiency to be higher than for conventional techniques. In particular, microwave-assisted extraction was slightly superior to other techniques.     

Separation of three anthraquinone glycosides including two isomers by preparative high‐performance liquid chromatography and high‐speed countercurrent chromatography from Rheum tanguticum Maxim. ex Balf

Anthraquinone glycosides, such as chrysophanol 1‐O‐β‐d‐ glucoside, chrysophanol 8‐O‐β‐d‐ glucoside, and physion 8‐O‐β‐d‐ glucoside, are the accepted important active components of Rheum tanguticum Maxim. ex Balf. due to their pharmacological properties: antifungal, antimicrobial, cytotoxic, and antioxidant activities. However, an effective method for the separation of the above‐mentioned anthraquinone glycosides from this herb is not currently available. Especially, greater difficulty existed in the separation of the two isomers chrysophanol 1‐O‐β‐d‐ glucoside and chrysophanol 8‐O‐β‐d‐ glucoside. This study demonstrated an efficient strategy based on preparative high‐performance liquid chromatography and high‐speed countercurrent chromatography for the separation of the above‐mentioned anthraquinone glycosides from Rheum tanguticum Maxim.ex Balf.     

Ultrasound-assisted extraction, HPLC analysis, and antioxidant activity of polyphenols from unripe apple

The polyphenols were extracted from the unripe apple assisted by a highly efficient and simple method of the ultrasound. Response surface methodology was used to investigate the effects of processing parameters, including ultrasound power, extraction time, temperature, and ethanol concentration on total polyphenols yield and polyphenols composition was analyzed by HPLC. Antioxidant activity of the polyphenols was evaluated as 2, 2-diphenyl-1-picrylhydracyl scavenging activity and inhibition activity of lipid peroxidation. The results showed that 10-100 times higher total polyphenols yield was obtained from the unripe apple than those from the reported apple pomace. The optimum extraction conditions were ultrasonic power of 519.39 W, extraction time of 30 min, extraction temperature 50°C, ethanol concentration of 50% gave the total polyphenols yield of 13.26 ± 0.56 mg GAE/g. HPLC analysis indicated that (-)-epicatechin, procyanidin B2, chlorogenic acid, and procyanidin B1 were the predominant polyphenols in unripe apple, which contributed to the higher antioxidant activity to 2, 2-diphenyl-1-picrylhydracyl of unripe apple polyphenols than other apple polyphenols. The extracted polyphenols had higher ability to inhibit lipid peroxidation than butylated hydroxy toluene, which demonstrated that the unripe apple polyphenols have the potential to be used as a substitute of some synthetic antioxidants.     

Optimization and determination of polycyclic aromatic hydrocarbons in biochar‐based fertilizers

The agronomic benefit of biochar has attracted widespread attention to biochar‐based fertilizers. However, the inevitable presence of polycyclic aromatic hydrocarbons in biochar is a matter of concern because of the health and ecological risks of these compounds. The strong adsorption of polycyclic aromatic hydrocarbons to biochar complicates their analysis and extraction from biochar‐based fertilizers. In this study, we optimized and validated a method for determining the 16 priority polycyclic aromatic hydrocarbons in biochar‐based fertilizers. Results showed that accelerated solvent extraction exhibited high extraction efficiency. Based on a Box–Behnken design with a triplicate central point, accelerated solvent extraction was used under the following optimal operational conditions: extraction temperature of 78°C, extraction time of 17 min, and two static cycles. The optimized method was validated by assessing the linearity of analysis, limit of detection, limit of quantification, recovery, and application to real samples. The results showed that the 16 polycyclic aromatic hydrocarbons exhibited good linearity, with a correlation coefficient of 0.996. The limits of detection varied between 0.001 (phenanthrene) and 0.021 mg/g (benzo[ghi]perylene), and the limits of quantification varied between 0.004 (phenanthrene) and 0.069 mg/g (benzo[ghi]perylene). The relative recoveries of the 16 polycyclic aromatic hydrocarbons were 70.26–102.99%.     

超声波提取-固相萃取净化-气相色谱法分析烟草中拟除虫菊酯类农药及氟节胺残留

建立了超声波提取-固相萃取净化-气相色谱联用测定烟草中多种拟除虫菊酯类农药及氟节胺残留量的方法。与现行标准方法相比,本方法前处理简单、快速、有机溶剂消耗量少,且增加了分析目标物的数量。8种拟除虫菊酯类农药及氟节胺在0.1、0.5和1μg/g三个加标水平的回收率为86%～111%,相对标准偏差为0.2%～4.1%,满足当前烟草农药残留的检测要求。     

Comparison of microwave-assisted extraction of aloe-emodin in aloe with Soxhlet extraction and ultrasound-assisted extraction

This paper reports the extraction of aloe-emodin from aloe by microwave-assisted extraction.The effects of various factors,including the solvent,the ratio (mL/g) of the solvent to the sample,microwave irradiation time and microwave power,were discussed in the experiments.The yield of aloe-emodin was determined by HPLC.The optimized conditions for microwave-assisted extraction of aloe-emodin were concluded as follows: the solvent is 80% ethanol (V/V) solution,microwave irradiation time is 3 min and microwave...