青稞中β-葡聚糖的水法提取及性质分析

以水法分离纯化藏青稞 β 葡聚糖 ,探索了一种高效简便的 β 葡聚糖提取方法以适应生产的需要 .对所获多糖进行了相关的性质分析 ,纸层析、紫外吸收光谱分析的和红外光谱结果表明 ,该多糖为单一多糖 。

黔银杏叶总黄酮水法提取最优方案的筛选

对黔产银杏叶中总黄酮水法提取的影响因素和最佳提取条件进行了筛选,当提取温度为100℃,加水量(固液比)10倍,提取2次,每次1小时,此条件为黔银杏叶总黄酮水法提取的最优方案。实验结果对实际生产具有一定的指导意义。

水法提取鱼油生产工艺研究

近年来,鱼油因富含DHA(二十二碳六烯酸)和EPA(二十碳五烯酸)而受到世人关注,被广泛用作保健药品和保健食品原料。然而目前我国市场的DHA、EPA保健产品原料都取自鱼粉厂的副产品(即粗鱼油),虽然价格便宜,但由于鱼油铁杂质多,在空气中暴露时间长,受到日晒等因素影响,其中的不饱和脂肪酸。

超临界CO_2法与酸水法提取苦豆子的比较研究

目的:优选苦豆子中总生物碱的提取方法。方法:正交法设计超临界CO2法提取工艺,与传统的酸水法相比较。结果:最佳工艺为A2B2C3;提取温度40℃;提取时间3h;提取压力35MPa;超临界CO2法和酸水法提取的苦豆子提取物中均含有苦参碱、槐定碱等。GC-MS对超临界CO2法提取的苦豆子提取物进行测定分析,检出36个成分,占提取物总量的78.5%。结论:超临界CO2法提取总生物碱收率较传统的酸水法提取收率低,但其有效成分含量高。

水提法提取百合多糖优选工艺的研究

[目的]优选水提法提取百合多糖的工艺条件。[方法]以新鲜兰州百合为原料,采用水提法提取百合多糖,以浸提时间、固液比、温度以及浸提次数作为因素进行单因素试验,在单因素试验的基础上,采用L9(34)正交试验设计优化百合水溶性多糖的提取工艺条件。[结果]试验表明,百合水溶性多糖的最优提取工艺条件为:固液比1∶20 g/ml,温度80℃,浸提时间1 h,浸提2次,此条件下百合粗多糖提取率为0.92%。[结论]研究可为兰州百合的研究与利用提供一定的理论依据。

岩白菜素的提取新工艺

用饱和石灰水提取岩白菜素,控制 pH,其收率可高于3%。

Comparison of Two Methods for Measuring Flavonoid Content of Fagopyrum megaspartanium Leaves

[Objective] The aim was to study the flavonoid content of Fagopyrum megaspartanium leaves by water bath and ultrasonic extractions.[Method] By using water bath extraction and ultrasonic extraction,the total flavonoid content in buckwheat leaves was measured with UV spectrophotometer.[Result] The optimum wavelength for determination of the content of flavonoid extracted from buckwheat leaves was 420 nm;the content of total flavonoid extracted by ultrasonic extraction and water bath extraction from buckwheat were 5.26% and 5.40% respectively;and the average total flavonoid content by water bath extraction was significantly higher than that by ultrasonic extraction.[Conclusion] The result is significant for the improvement of flavonoid content measurement of buckwheat.

Enzymatic Aqueous Extraction of Soybean Oil

The procedure of enzymatic aqueous extraction of soybean oil was assessed when two-step controlled enzymatic hydrolysis was applied. With aqueous extraction of soybean oil-containing protein, the highest yield of oil was 96.1% at the optimized conditions studied. Soybean oil-containing protein was hydrolyzed and resulted in releasing part of oil. The separated protein that contained 40% oil was enriched due to its adsorption capacity of released oil, the average oil extraction yeild reached 93.5%. Then the high oil content protein was hydrolyzed again to release oil by enzyme, the oil extraction yeild was 80.4%. As a result, high quality of soybean oil was obtained and the content of total oil yield was 74.4%.

Kinetics of Forward Extraction of Boric Acid from Salt Lake Brine by2-Ethyl-1,3-hexanediol in Toluene Using Single Drop Technique

The kinetics of forward extraction of boric acid from salt lake brine by 2-ethyl-1,3-hexanediol in toluene was investigated using the single drop technique. The factors affecting the extraction rate include interfacial area between aqueous phase and organic phase, initial concentration of boric acid in aqueous phase, initial concentration of 2-ethyl-1,3-hexanediol in organic phase, and extraction temperature. The experimental results show that the extraction rate increases with the increase of the initial concentration of boric acid and2-ethyl-1,3-hexanediol, interfacial area of two phases, and temperature. With the temperature-dependence study, it is showed that the extraction is a diffusion-controlled process. The kinetic equation is presented for pH 1.0 in the aqueous phase and temperature of 318 K.

Behavior of different phosphorus species in suspended particulate matter in the Changjiang estuary

Suspended particulate matter （SPM） collected in the Changjiang （Yangtze River） estuary in June 2006 was separated into five fractions via water elutriation： clay-very fme silt （〈8 μm）, fine silt （8-16 μm）, medium silt （16--32 μm）, coarse silt （32~53 μm） and sand （〉63 μm）. The SPM and fractionated particles were sequentially analyzed by a modified SEDEX sequential extraction method to obtain six species of phosphorus： exchangeable or loosely-sorbed P, organic P, Fe-bound P, authigenic P, detrital P and refractory P. The results indicated that all particulate phosphorus species except for detrital P were negatively correlated to particle size; a high detrital P content was found in coarse silt and very coarse silt. From the inside of the river mouth to the gate of the fiver mouth, organic P, Fe-bound P and refractory P in the suspended particles decreased and a higher amount of exchangeable P appeared around the gate of the fiver mouth. From the gate of the river mouth to the sea, exchangeable P and organic P in suspended panicles increased distinctly. The total particulate P flux into the estuary from the Changjiang River was about 45.45×10^8μmol/s during sampling. Of this, about 8.27×10^8μmol/s was associated with the ＂truly suspended＂ fraction. The bio-available particulate P flux was about 13.58×10^8μmol/s. Of this, about 4.24 ×10^8μmol/s w as transported by ＂truly suspended＂ particles.

Comparative Study on the Different Extraction Processes of Dietary Fiber from Sweet Potato

[Objective] To compare the extraction results of several different methods. [Method] The dietary fiber was extracted from sweet potato respectively by the sieve method, the enzymatic process and enzyme-alkali method. The extraction results of the three methods were optimized and compared. [Result] The extraction rate of dietary fiber by enzymatic method was the highest, which could reach 38% of total potato residue. The properties of dietary fiber extracted by the three methods were compared, the results indicated that the dietary fiber extracted by enzymatic method had good water-holding capacity, soil absorption and expansion. [Conclusion] The enzymatic method is the best for extracting dietary fiber from sweet potato.

Flow-Based Iodometric Extraction Method by the Hollow Fiber Membrane for the Determination of Selenium Sulfide Levels in Cosmeceutical Products

A flow-based iodometric extraction method for the determination of selenium sulfide was developed and applied to cosmeceutical products. Iodine which was generated from the reduction of selenium（IV） ions by iodide ion was on-line extracted using a polypropylene HFM （hollow fiber membrane） liquid extraction technique. The HFM extraction unit was constructed and used to support an organic solvent （hexane） and separate between the organic phase and aqueous phase. The resulting purple extract was carried to a fiber optic spectrophotometric detector for the measurement at 521 nm. Parameters which affected the extraction efficiency, sensitivity and sample throughput such as iodide （selenium molar ratio, extraction time and washing time between the cycles） were investigated and optimized. A linear dynamic range of 80-373 mg.Lt selenium solution was obtained with an extraction time of 60 sec. The total analysis time including washing was about 180 sec which provided a sample throughput of approximately 20 samples＇hr1 and excluded the sample pre-treatment. The recoveries for the determination of selenium in the forms of selenium dioxide and selenium sulfide were in the range of 103%-104% with 1%-3% RSD （relative standard deviation）. The relative errors of this method which was applied for determination of selenium sulfide levels in an anti-dandruff shampoo and a cosmeceutical bead sample were both less than 2.5%.

Different Carbon Fractions in Soils and Their Relationship with Trace Elements Content

Luvisols, Stagnogleys and Cambisols, although less fertile, are used intensively for mixed farming, grazing and as forestland. Therefore we aimed our study at determination of total organic carbon （TOC） content, humic substances （HS） content, humic acids （HA） content, fulvic acids （FA）, hot water extractable carbon （Chw） content and content total and labile trace elements content. Humic substances quality was assessed by HA/FA ratio and by coloured indexes measured in ultraviolet and visible UV-VIS spectral range. The total and labile contents of Zn, Cd, Cu, Co, Pb, Mo and Se were determined by flame or electro-thermal atomic absorption spectrometry after extraction of the soil samples in the aqua regia （total content） and in the solution of 0.01 M CaCI2. Total and labile trace elements content was correlated with determined carbon fractions and soil reaction. Results showed that studied soils content low amount of TOC and had low quality of humic substances. HA/FA ratio was less than 1 and colour indexes were higher than 4. All determined carbon fractions correlated with labile form of Zn and Cd. Correlation between soil reaction and total zinc content was found. Significant effect of humic substances content on to water-soluble forms of heavy metals was detected.

红景天苷提取工艺的研究

对红景天苷的提取工艺进行了比较研究。红景天苷的提取采用水法和醇法分别提取。研究结果表明:水法提取红景天苷的工艺条件为:料液比为1 g:20 mL,浸泡24 h,40%微波功率处理20 s(微波炉最大功率700 w),80℃提取1.5 h,提取率为0.733%。醇法提取红景天苷的工艺条件为:80%乙醇做溶剂,料液比为1 g:20 mL,70℃提取2 h,提取率为0.623%。水法提取红景天苷的提取率优于醇法提取,但是醇法提取的红景天苷提取液澄清度、颜色优于水法提取。

盘龙七的提取工艺

将盘龙七粉碎除去泥沙,以饱和的石灰水为溶剂,加热回流提取3次,每次4h、合并提取液,常压浓缩至溶液密度为1.15—1.20g/cm3。冷至室温调pH为2—3,70℃保温结晶得岩白菜素粗品。后用95%乙醇加活性炭煮沸脱色,趁热过滤,得精品。

Water bodies extraction from TM images

Aiming at the problems of high time-consuming, low accuracy and weak versatility of the existing methods of wa- ter extraction based on TM image, this paper combines principal component analysis （PCA） with the modified normalized difference water index （MNDWI） which was improved by XU Han-qiu to construct a false color composite image that could separate water from others easily. This method can realize the water extraction based on TM image by analyzing the spectral characteristics of water in this false color image and establishing a water extraction model. This paper also compares the effi- ciency of this method with MNDWI, （TM2 ＋ TM3） - （TM4 ＋ TM5） and new water index （NWI）, which were applied in the city and mountain of Taiyuan, respectively. The results show that the proposed method can extract water body from TM im- age more rapidly and efficiently and its accuracy is up to 94.03 %. In addition, this method does not require a manual selec- tion threshold, which meets the research reuuirement of high automaticm.

A Rapid Extraction Procedure for the Determination of Strontium-90 in Water Samples

A beta spectrometric method for the rapid determination of strontium-90 （90Sr） in water samples was developed and tested. 90Sr is extracted directly from the water samples by means of a scintillator cocktail, containing the crown ether dicyclohexano-18-crown-6 as an extracting agent （STRONEX）. Minimal clean-up is necessary when other beta nuclides are present, such as barium-140. These nuclides are eliminated by a barium chromate scavenge, prior to the extraction step. The method presented here allows for the investigation of at least 12 water samples a day and is therefore a suitable tool for emergency analysis.

Gasification of Bio-waste and Biomass Products through Exposure to HD and LD Supercritical Water

Biomass as a sustainable and renewable energy source is starting to gain momentum, especially as more economical energy extraction methods prevail. SCWBG （supercritical water biomass gasification） is one of the more promising methods to extract energy from biomass in a gaseous form due to its lower temperature and simpler setup. In this work, two biomass and two bio-waste samples are gasified in SCW （supercritical water） under two temperatures （hence water densities）. As temperature increases and water density decreases, combustible gas yields tend to increase due to changes in reaction pathways and reaction rates. An analytical comparison is also made between the four different types of biomass in terms of the combustible gases produced and hence the energy value. As a result of this analysis beet skin produces the most methane and corn silage yields the most hydrogen. The two bio-waste samples （straw and beet skin） are found to have the highest HHV （higher heating values）.

Mesoporous Silica Nanoparticles for the Analytical Extraction of Triphenyltin from Water

A rapid, precise, sensitive and simple method has been developed for the extraction and determination of TPT （triphenyltin）, DPT （diphenyltin） and MPT （monophenyltin） in seawater samples. The procedure is based on the use of the dual functionalization of mesoporous silica with diol and Cl6 alkane groups for the collection of TPT and its derivatives, DPT and MPT, from seawater samples, followed by ethylation of the target matrices using sodium tetraethylborate （NaBEt4） and quantification by gas chromatography with pulsed flame photometric detection. The modified extraction method replaces conventional solid- and liquid-phase extraction with solid dispersion of silica nanoparticles. The partitioning of the analyte between a carefully size-selected silica nanoparticles （solid phase） and a liquid phase occurs as the solid moves through the sample as a colloidal sol. By tailoring the size of the particles to approximately 250 nm in diameter, they can be easily dispersed in aqueous solution, without the need for any mechanical or hand shaking and the solid can then be readily recovered, together with the analytes, by simple filtration or centrifugation. Recoveries of TPT, DPT and MPT chloride spiked matrices rang from 87.3±1.1 to 98.1±1.3 in seawater samples （n = I 1 samples）. The limit of detection obtained was typically in the range of 0.1-3 ng Sn/L. The proposed method shows excellent linearity in the range of 0.5-2 ng Sn/L and good repeatability （RSD 〈 5% at 0.02 ng TPT （as Sn）/L）. The method performance is demonstrated with real seawater samples.

Bench-top aqueous two-phase extraction of isolated individual single-walled carbon nanotubes

Isolation and purification of single-walled carbon nanotubes （SWCNTs） are prerequisites for their implementation in various applications. In this work, we present a fast （-5 min）, low-cost, and easily scalable bench-top approach to the extraction of high-quality isolated SWCNTs from bundles and impurities in an aqueous dispersion. The extraction procedure, based on aqueous two-phase （ATP） separation, is widely applicable to any SWCNT source （tested on samples up to 1.7 nm in diameter） and independent of defect density, purity, diameter, and length. The extracted dispersions demonstrate that the removal of large aggregates, small bundles, and impurities is comparable to that by density gradient ultracentrifugation, but without the need for high-end instrumentation. Raman and fluorescence-excitation spectroscopy, single-nanotube fluorescence imaging, atomic force and transmission electron microscopy, and thermogravimetric analysis all confirm the high purity of the isolated SWCNTs. By predispersing the SWCNTs without sonication （only gentle stirring）, full-length, pristine SWCNTs can be isolated （tested up to 20 μm）. Hence, this simple ATP method will find immediate application in the generation of SWCNT materials for all levels of nanotube research and applications, from fundamental studies to high-performance devices.