罗布麻叶黄酮类化合物的酸化提取及PC12细胞保护作用评价

目的研究不同浓度的"盐酸-乙醇"溶液对罗布麻叶化学成分的影响并进行抗抑郁活性评价。方法用不同浓度"盐酸-乙醇"溶液对罗布麻叶中黄酮类化合物进行提取,应用液质联用技术对化合物进行结构鉴定。结果随着盐酸浓度的增加,金丝桃苷和异槲皮素的含量明显降低,而白麻苷的含量升高。结论罗布麻叶经酸化的提取物对皮质酮损伤的PC12细胞有明显的保护作用。

土霉素酸化提取工艺的研究

本文在不同pH值和不同的黄血盐钠用量条件下进行了影响酸化液中土霉素效价因素的正交实验分析;测定酸化液中土霉素效价。通过实验得到以下结论:1pH值是酸化工段中影响土霉素质量的主要因素,黄血盐钠的用量次之;2本实验中最佳酸化条件为:pH值控制在1.43左右,黄血盐钠的用量控制在发酵液体积的0.35%时得到土霉素效价最高,为5102u/g;3经过酸化处理后,酸化液中土霉素的效价比发酵液中土霉素的效价最大提高了47.1%。

PID调节在酸化过程中pH值控制的应用

青霉素生产中酸化提取采用离心机连续萃取工艺,废酸水的pH值为关键工艺控制参数,其控制结果直接影响产品质量及收率。传统手动调节存在人员操作经验依赖性强、工作效率低、系统稳定性差等缺点,很难满足实时控制的要求。为了提高酸化提取过程废酸水pH值的可控性及稳定性,提出了采用PID自控技术取代人工调节的方案。结合青霉素的生产设备、工艺流程、参数要求等,设计出了一套PID控制废酸水pH值的系统,通过PID参数调试,实现了酸化提取过程废酸水pH值的可控及稳定。在保证产品质量的前提下,提高了产品收率,降低了运行人员的劳动强度。

Extraction of alumina from fly ash by ammonium hydrogen sulfate roasting technology

NH4HSO4 roasting technology was used for preparing Al2O3 from fly ash. First, Al and Fe were extracted from fly ash by NH4HSO4 roasting and deionized water leaching. Then, the Al and Fe in the leached liquid were precipitated by adding NH4HCO3 solution. After the mixed precipitations of Al（OH）3 and Fe（OH）3 were leached by NaOH solution, the NaAl（OH）4 solution was decomposed by carbonation. Finally, the pure Al（OH）3 was calcined to α-Al2O3. The optimal conditions of the whole technology were determined by experiments. The quality ofa-Al2O3 product is up to the technical indicator of YS/T 274-1998 standard.

Optimization of acidic extraction of astaxanthin from Phaffia rhodozyma

Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated, regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition： concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 ℃, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 μg/g and 1516.0 μg/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice.

Extraction and Characterization of Biological Humic Acids from Fermented Furfural Residue

Objective] This study aimed to eliminate the negative effects brought about by continuous, long-term accumulation of sodium ions in soil on soil environ-ment. [Method] Biological humic acids （BHAs） were extracted from fermented furfural residue via alkali-dissolution and acidification. The effects of solid-liquid ratio （mass ratio of fermented furfural residue to water）, alkali concentration, extraction tempera-ture and extraction time on the content of BHA were investigated. Also its structure was characterized by FTIR. [Result] The optimal extraction conditions were as fol-lows： solid-liquid ratio of 1：7, KOH concentration of 6%, extraction temperature of 70℃ and extraction time of 1 h. Under the optimal conditions, the content of BHAs extracted was up to 8.5%. The infrared spectrum analysis indicated that BHA had more types of functional groups and lower molecular weight than commercial humic acid although they had similar structures. [Conclusion] The technique has the ad-vantages of simple operation and good stability, and is suitable for extracting BHAs. BHAs have a good prospect in developing new types of humic acid fertilizers.

Extraction of cobalt from laterite ores by citric acid in presence of ammonium bifluoride

Citric acid was used to selectively extract cobalt from limonite-type laterite ores in the presence of ammonium bifluoride.The results show that ammonium bifluoride enhances the leaching of cobalt by citric acid,and 84.5% cobalt is extracted from a laterite ore containing 0.13% Co when leached at ambient temperature for 2 h with 30 g/L citric acid and 10 g/L ammonium bifluoride.Pyrolusite is reduced by citric acid during leaching,cobalt intergrown with which is liberated and subsequently chelated by the citric acid.The extraction of cobalt is enhanced in the presence of ammonium bifluoride because the matrix of silicate minerals is destroyed by ammonium bifluoride and the adsorbed cobalt is subsequently liberated.

Kinetics of nickel leaching from roasting-dissolving residue of spent catalyst with sulfuric acid

Sulfuric acid leaching process was applied to extract nickel from roasting-dissolving residue of a spent catalyst, the effect of different parameters on nickel extraction was investigated by leaching experiments, and the leaching kinetics of nickel was analyzed. The experimental results indicate that the effects of particle size and sulfuric acid concentration on the nickel extraction are remarkable; the effect of reaction temperature is mild; while the effect of stirring speed in the range of 400-1 200 r/min is negligible. Decreasing particle size or increasing sulfuric acid concentration and reaction temperature, the nickel extraction efficiency is improved. 93.5% of nickel in residue is extracted under suitable leaching conditions, including particle size （0.074-0.100） mm, sulfuric acid concentration 30% （mass fraction）, temperature 80 ~C, reaction time 180 min, mass ratio of liquid to solid 10 and stirring speed 800 r/min. The leaching kinetics analyses shows that the reaction rate of leaching process is controlled by diffusion through the product layer, and the calculated activation energy of 15.8 kJ/mol is characteristic for a diffusion controlled process.

Dynamics of Humic Substance-Complexed Copper and Copper Leaching During Composting of Chicken Manure

Chicken manure was composted for 110 d to evaluate changes in organic carbon (C) and humic substance-complexed copper (HS-Cu) extracted with water,sodium hydroxide (NaOH),and sodium pyrophosphate and sodium hydroxide mixture (Na 4 P 2 O 7-NaOH).The average HS-Cu content from the Na 4 P 2 O 7-NaOH extraction accounted for 46.8% of the total Cu in the compost,followed by those from the NaOH and water extractions,which accounted for 34.5% and 6% of the total Cu in the compost,respectively.NaOH-Na 4 P 2 O 7-extractable HS-Cu increased throughout the composting process.NaOH-extractable HS-Cu increased during the first 50 d of composting and then leveled off.Water-extractable HS-Cu enhanced during the first 21 d and then decreased.Water-extractable HS-Cu was not correlated to NaOH-or NaOH-Na 4 P 2 O 7-extractable organic C.The average amount of Cu leached from the compost was about 20% of the total Cu in the chicken manure and Cu leaching increased during the first 35 d of composting and then decreased.Leaching of Cu was significantly correlated to the concentrations of HS-Cu extracted with NaOH and water,but was not correlated to the concentration of HS-Cu extracted with NaOH-Na 4 P 2 O 7.Thus,NaOH-and water-extractable HS-Cu were relatively labile and NaOH-Na 4 P 2 O 7-extractable HS-Cu was relatively immobile.Composting process after rapid decomposition could result in low potential of Cu leaching because of formation of more NaOH-Na 4 P 2 O 7-extractable HS-Cu.

Kinetic study on selective extraction of HCl and H_3PO_4 in a microfluidic device

In the extraction method for preparing KH2PO4, one of the key processes is the selective extraction of HCI over H3PO4. In our work, extraction kinetic studies have been carried out in a microfluidic device with a coaxial microchannel, using the extractant of 33.3% （by volume） trioctylamine （TOA） dissolved in n-octanol, with differ- ent aqueous phases： the HCI solution, the H3P04 solution, and H3PO4 and KCI solutions of different concentra- tions. The changes of the extraction efficiency of HC1 and H3P04 and the selectivity for HC1 along with the residence time were investigated. We found that fast extraction kinetics could be realized in microfluidic devices, and that HC1 could be extracted faster than H3P04 due to smaller mass transfer resistance and much stronger re- action between HCI and TOA. For the extraction of H3PO4 and KC1 solutions, the selectivity for HC1 first increased and then decreased when TOA was in excess of H3PO4 in the initial feeds, and in contrast, always increased when H3PO4 was in excess of TOA in the initial feeds. The diverse changes of selectivity for HCI along with the residence time indicate that a dynamic control of selectivity in microfluidic devices may be important and accessible for im- proving the KH2P04 conversion efficiency in extraction method.

Antioxidant Activity of Isothiocyanate Extracts from Broccoli

Isothiocyanates(ITCs) extracts were prepared from fresh broccoli.Their antioxidant properties were evaluated by using the in vitro bioassays,including superoxide anion radical( 2 O·-) ,hydroxyl radical(HO·-) and 2,2-diphenyl-1-picrylhydracyl(DPPH·) radical-scavenging methods,lipid peroxidation assay,and reducing power assay.The ITCs extracts exhibited significant dose-dependent antioxidant activities(P<0.01) .Its antioxidant-stability was affected by temperature and storage condition,although it was more stable than vitamin C(Vc) .GC-MS iden-tified sulforaphane in the ITCs extracts.The antioxidant activity of sulforaphane was approximately one tenth to one fifth of that of Vc.Sulforaphane was experimented to be one of dominating contributors to antioxidant capacity of ITCs extracts.However,there was no direct antioxidant activity found for benzyl isothiocyanate(BITC) in vitro. Therefore,it could be concluded that the general group(-N=C=S) was not the essential part for the antioxidant activity of sulforaphane.It is suggested that the ITCs extracts from broccoli can be developed into a promising food additive for healthy food.

Equilibrium of Extraction of p-Aminobenzenesulfonic Acid by Aliquat 336

p-Aminobenzenesulfonic acid was selected as a typical solute withamphoteric functional groups to be separated from dilute solution. Aquaternary ammonium chloride, Aliquat 336, was used as theextractant. The effects of pH, extractant concentration and diluenttypes on distribution coefficient, D, were investigated. Meanwhile,the ion exchange reaction for Aliquat 336 with p-aminobenzenesulfonicacid in the extraction process Was discussed. The description of Dwas proposed according to the mass action law.

Studies on Oxidation States of Cobalt Extracted from Soils with EDTA·HO Ac·NH_4OAc

A method determining di-and tri-valeht cobalt extracted from soils with EDTA·2HOAc·NH4OAc solution (pH 4.65) was developed based on the difference of the stability constants of Co(II)EDTA and Co(III)EDTA. Analytical results indicated that soil cobalt existed in both two oxidation states, i. e. , di-and tri-valent cobalt. Extractable di-valent cobalt in 60 soil samples collected from various soils in China ranged from 0.02 ppm to 3.54 ppm, with the mean of 0.62 ppm, and extractable tri-valent cobalt from 0.04 ppm to 27.65 ppm, with the mean of 2.93 ppm.

Removal of tin and extraction of indium from acid-dissolved solution of waste indium-tin targets

The recovery of indium from waste indium tin oxide （ITO） target has great significance for the economy and environment.Based on our previous study on the optimization of acid leaching technique,the present study focuses on tin removal via zinc substitution and indium recovery from a tin-free leach solution.The results show that when the amount of added zinc powder and reaction time increase,the tin removal effect can be improved.The optimal conditions obtained are as follows：additional content of zinc powder from 20 g/L to 25 g/L,reaction temperature of 60 ℃,and reaction time from 3 h to 4 h.Under this condition,the tin removal rate exceeds 98%,and the tin content in the tin removal solution is lower than 0.05 g/L.After tin removal,the substitution time could be reduced from 3-5 d to 1-2 d by neutralizing the residual acid by using alkaline residue and maintaining the pH value less than 2.The indium recovery rate is also improved when this condition is used.The indium content in the tin residue is reduced to lower than 0.1% and the acid-insoluble β-SnO2 could be obtained via the strong nitric acid leaching of the indium-containing tin residue.Indium could be recovered from ITO with a high purity of 99.995% via electrorefining.

Improvement of saponification extraction method for fatty acids separation from geological samples

The conventional saponification method could result in lower recoveries and artificial changes of longchain fatty acids. The main reason is the error judgment of the intermediate layer suspended between the aqueous and organic layer during the liquid–liquid extraction process.This study shows that the intermediate layer consists of lots of medium- to long-chain carboxylic salts for their special physical and chemical properties. An improved saponification extraction method is also developed and the results show that the carboxylic salts distributed in the intermediate layer could be obtained completely, which greatly enhances the authenticity and accuracy of fatty acid analysis. Additionally, the possible reasons of formation of the intermediate layer are also discussed.

Screening and isolation of the algicidal compounds from marine green alga Ulva intestinalis

Twenty species of seaweed were collected from the coast of Zhejiang, China, extracted with ethanol, and screened for algicidal activity against red tide microalgae H eterosigma akashiwo and Prorocentrum micans. Inhibitory eff ects of fresh and dried tissues of green alga U lva intestinalis were assessed and the main algicidal compounds were isolated, purifi ed, and identifi ed. Five seaweed species, U. intestinalis, U. fasciata, Grateloupia romosissima, Chondria crassicaulis, and Gracilariopsis lemaneiformis, were investigated for their algicidal activities. Fresh tissues of 8.0 and 16.0 mg/m L of U. intestinalis dissolved in media signifi cantly inhibited growth of H. akashiwo and P. micans, respectively. Dried tissue and ethyl acetate(Et OAc) extracts of U. intestinalis at greater than 1.2 and 0.04 mg/m L, respectively, were fatal to H. akashiwo, while its water and Et OAc extracts in excess of 0.96 and 0.32 mg/m L, respectively, were lethal to P. micans. Three algicidal compounds in the Et OAc extracts were identifi ed as 15-ethoxy-(6z,9z,12z)-hexadecatrienoic acid(I),(6E,9E,12E)-(2-acetoxy- β- D-glucose)-octadecatrienoic acid ester(II) and hexadecanoic acid(III). Of these, compound II displayed the most potent algicidal activity with IC_(50) values of 4.9 and 14.1 μg/m L for H. akashiwo and P. micans, respectively. Compound I showed moderate algicidal activity with IC_(50) values of 13.4 and 24.7 μg/m L for H. akashiwo and P. micans, respectively. These fi ndings suggested that certain macroalgae or products therefrom could be used as ef fective biological control agents against red tide algae.

Phytochemicals Analysis, Antioxidant Capacities and Antimicrobial Properties of Ethyl Acetate Extract of Stem Bark of the Garlic Tree Scorodocarpus borneensis Becc.

The objective of this study was to examine the phytochemical components, antioxidant activity and antibacterial property of ethyl acetate extract of the stem bark of garlic tree （Scorodocarpus borneensis）. The dried stem bark of S. borneensis were collected and homogenized after drying at room temperature （32℃） for 30 d. The stem barks were extracted by macerated method using 95% ethanol and then fractionated with ethyl acetate. The dried ethyl acetate extract was subjected to phytoehemical screening to determine the presence of bioactive components using gas chromatography-mass spectrometry （GC-MS）. Antioxidant activity of the extract in vitro was examined by 2,2-diphenyl-l-picryl-hydrazyl （DPPH） radical scavenging assay. The antibacterial activity against gram-positive bacteria Staphylococcus aureus and gram-negative bacteria Escherichia coli was performed by disc diffusion assay. GCMS results revealed the presence of 14 different phytocompounds, viz, tetratriacontyl trifluoroacetate （41.61%）, 2-pentanone （13.65%）, oxacyclotetradecane-2,11-done （7.87%）, cinnamic acid （7.53%）, 10-octadecanoic acid （6.50%）, 1,2-benzeno dicarboxylix acid （4.99%）, octadecanoic acid （4.51%）, hexadecanoic acid （4.16%）, beta tumerone （3.01%）, 9-octadecenoic acid （1.70%）, tricosanol （1.38%）, hexadecano-phenone （1.36%）, 1-nonadecanol （0.93%） and n-nonadecanol （0.82%）. In vitro antioxidant activity （IC50） was found at 55.524 ppm as high powerful. The results of agar diffusion method showed that the ethyl acetate extracts had an antibacterial activity of 6.687 ± 0.800 mm againts S. aureus at 10% （w/v） and 7.500 ± 0.735 mm against E. coli at 10% （w/v） as moderate category. These findings suggest that S. borneensis stem bark is a valuable sources of bioactive compounds with promising as antioxidant and antibacterial sources.

Acid volatile sulfide and simultaneously extracted metals in superficial sediments from Baihua Lake, China

The bioavailability of five divalent cationic heavy metals （Pb, Cd, Cu, Zn and Ni） in 10 superficial sediment samples from Baihua Lake was assessed based on the molar ratio of simultaneously extracted metals （SEMs） to acid volatile sulfide （AVS）. Atomic absorption spectrometry （AAS） and X-ray powder diffraction （XRD） were used to determine the heavy metal concentrations and examine the mineralogy of the crystalline phases, respectively. The AVS loadings in sediments from Baihua Lake ranged from 64.30 to 350.08 ~rnol/g （dry weight）. The corresponding SEM levels for the sampling sites varied from 1.770 to 14.660 vrnol/g. The molar ratio of SEMs to AVS ranged from 0.014 to 0.084 with a mean value of 0.034. The XRD analysis also confirmed the presence of some metal sulfides in sediments from Baihua Lake. The SEMs/AVS ratios for all sampling sites were significantly lower than 1.0, indicating that AVS in the sediments was sufficient to bind the five heavy metals; thus, these heavy metals are currently not significantly bioavailable to benthic organisms. Comparing the SEMs results to published guideline values for metal toxicity to benthic organisms in sediments, however, suggests that Zn and Ni pose a risk at some sampling locations in Baihua Lake.

Purification and Antioxidant Activities of Phycocyanin from Spirulina Platensis

This study aimed to purify and determine antioxidant activities of different fractions obtained during the purification process of phycocyanin from Spirulina platensis. The dried powder of Spirulina platensis, after ground with sands, was extracted with 50 mM sodium phosphate buffer at pH 6.8 before centrifuged to precipitate unwanted proteins. Then the supernatant was separated by celit column to obtain semi-pure phycocyanin and further purified by treated with ammonium sulfate. The purity of phycocyanin was monitored by measuring the absorbance spectrum from 200 to 700 nm. Its purity ratio A620A280 was determined. The antioxidant activities of the obtained phycocyanin were determined by 2,2＇-azino-bis（3-ethylbenzthiazoline-6-sulphonic acid） （ABTS） assay and lipid peroxidation （linoleie acid） assay. The purity ratio of phycocyanin in the Spirulina crude extract was 0.36 and increased to 2.68 after purification. The fraction with the highest purity ratio of phycocyanin demonstrated the hightest antioxidant activities. For ABTS assay, it presented the Vitamin C Equivalent Antioxidant Capacity （VCEAC） value of 0.0405 ±0.0002 mg of ascorbic acid/mg of sample and the Trolox Equivalent Antioxidant Capacity （TEAC） value of 0.0485 ±0.0002 mg oftrolox/mg of sample respectively. The result from lipid peroxidation assay exhibited IC50 value of 5.9336 ±0.2565 mg/mL. The purification of Spirulinaplatensis crude extract obtained from this study increased the purity ratio of phycocyanin and its antioxidant activities. This will be further investigated for the development into anti-aging cosmetic products.