N263萃取铌的研究

本文研究了Ｎ２６３萃取铌的实验条件,在０．１～０．３ｍｏｌ．Ｌ＾－１Ｈ２Ｃ２Ｏ介质中,用０．５ｍｏｌ．Ｌ＾－１Ｎ２６３萃取铌,其分配比大于１００。     

Extraction and Destruction of Organics in Wastewater Using Ozone-Loaded Solvent

Originally developed as a heat exchange fluid, Volasil 245 (decamethylcyclopentasiloxane) has been found to dissolve 10 times more ozone than water does. This article proposes and investigates the extraction of wastewater contaminants to ozone-loaded Volasil 245 as a means of providing rapid treatment. In a series of bench-scale tests, the effectiveness of ozone-loaded Volasil 245 contact was compared with that of conventional gas contact. Tests were conducted with respect to a range of organic compounds: namely, phenol, 2-chlorophenol, 2,3-dichlorophenol, 1,3-dichlorobenzene, o-nitrotoluene, and nitrobenzene. Contact with the ozone-loaded solvent was suggested to be the more rapid technique, reducing aqueous concentrations by at least 85% within 30 s. In the case of 2-chlorophenol, Volasil 245 contact was shown to require just ~0.5 min to achieve a residual aqueous fraction of 5%, as opposed to ~4.5 min of gas contact. However, water/solvent interfacial mass transfer resistance was suggested to limit the degree of aqueous decontamination ultimately achieved.     

顺酐溶剂吸收装置的关键控制工艺分析

吐哈石化厂通过引进意大利CONSER公司的溶剂吸收工艺,对原有水吸收工艺进行改造。通过对CONSER溶剂吸收工艺的研究,分别对溶剂吸收装置中的溶剂吸收系统、溶剂解析系统和溶剂洗涤系统操作过程中的关键控制工艺进行分析,提出了可行的生产控制指导建议。     

溶剂萃取在有机化合物提取和分离方面的应用（上）

回顾了溶剂萃取技术发展的历史。对于该技术在有机化合物提取和分离方面的研究和应用现状进行了综述。展望了未来的发展趋势。     

萃取溶剂中水分的测定与控制

以苯中饱和水值为基准，采用气相色谱外标法检测了萃取溶剂中的含水量，回收率102．05％，相对标准偏差1．222，该方法灵敏度高，简便，准确。     

Comparative Assessment of Phenolic Content and in Vitro Antioxidant Capacity in the Pulp and Peel of Mango Cultivars

Mango (Mangifera indica L.), also called “the king of fruits”, is one of the most popular fruits in tropical regions. Pulp and peel samples of mango cultivars were analyzed to estimate total phenolic, total flavonoid and total anthocyanin contents. Phenolic acids, hydrophilic peroxyl radical scavenging capacity (hydro-PSC) and oxygen radical scavenging capacity (ORAC) in vitro were also determined. Total phenolics and flavonoid contents were found maximum in the peel of Xiao Tainang and Da Tainang cultivars, respectively, whereas Xiao Tainang also exhibited significant antioxidant capacity. Noteworthy, concentrations of gallic acid, protocatechuic acid, ferulic acid, chlorogenic acid and caffeic acids at 79.15, 64.33, 33.75, 27.19 and 13.62 mg/100 g fresh weight (FW) were quantified for Da Tainang, Xiao Tainang and of Jidan cultivars, respectively. Comparatively, a higher level of phenolics and significant antioxidant capacity in mango peel indicated that it might be useful as a functional food and value-added ingredient to promote human health.     

Irradiation Effects on Phenolic Content,Lipid and Protein Oxidation and Scavenger Ability of Soybean Seeds

The effect of medium doses of γ-irradiation (1–10 kGy) on total phenolic and tannin contents, lipid peroxidation, protein oxidation intensity and soluble protein content of soybean seeds, (genotype Ana), was investigated. Screening for antioxidant ability was performed using FRAP and DPPH methods. Total phenolic and tannin contents and DPPH scavenger activity were increased, while protein oxidation intensity was decreased by applied doses of γ-irradiation. Gamma irradiation provoked insignificant changes in lipid peroxidation and soluble protein content, while protein oxidation intensity was significantly decreased when dose of 10 kGy was applied. Presented results implicated that increased antioxidant capacity and protein stability of soybean seeds were increased after application of γ-irradiation.     

Effect of Emulsification Conditions on the Properties of Microspheres Prepared by a Solvent Extraction Process

Microspheres can be prepared using a hydrocarbon‐perfluorocarbon‐based solvent extraction process. The effect of changing the surfactant amount, emulsification temperature, and stirring speed on the size of microspheres was investigated. The surfactant concentration was found to greatly affect the microsphere size and size distribution. The Sauter mean diameter of the microspheres decreased exponentially as a function of surfactant concentration. The microsphere size distribution became narrower with increasing surfactant concentration. A clear correlation between the Sauter mean diameter of the microspheres and the Weber number was found. A surfactant concentration was identified at which the size of microspheres remained constant although the Weber number was changed. Finally, a lower emulsification temperature decreased the coalescence of the droplets and microspheres with smaller Sauter mean diameter were produced when using a low surfactant concentration.     

快速溶剂萃取-高效液相法测定茶叶中多菌灵残留量

文章建立了一种新型快速测定茶叶中多菌灵残留量的方法,利用快速溶剂萃取仪萃取多菌灵,利用高效液相法进行测定。本方法操作过程简单、快速,重复性好,能满足茶叶中多菌灵残留量的检测要求。     

Effect of Extraction Method on the Phenolic and Cyanogenic Glucoside Profile of Flaxseed Extracts and their Antioxidant Capacity

The application of flaxseed extracts as food ingredients is a subject of interest to food technologists and nutritionists. Therefore, the influence of the extraction method on the content and composition of beneficial compounds as well as anti‐nutrients is important. In the study, the effects of two solvent extraction methods, aqueous and 60 % ethanolic, on phenolic and cyanogenic glucoside profiles of flaxseed extract were determined and compared. The impact of extracted phenolic compounds on the antioxidant capacity of the extracts was also investigated. Defatted meals from brown and golden flax varieties were used as extraction material. The ethanolic extraction was more selective for phenolics (100.8–131.7 mg g^?1) than the aqueous one (11.5–15.7 mg g^?1). However, the contribution of particular phenolic compounds to total phenolics was much more dependent on flax variety than extraction method. A strong relationship was observed between both radical scavenging and ferric reducing activity and the content of phenolics (particularly secoisolariciresinol diglucoside). The correlation between extract chelating ability and phenolics was moderate suggesting that other flaxseed compounds are involved in this activity. The extraction method strongly affected cyanogenic glucoside content of flaxseed extracts; the aqueous extraction caused 96 % reduction in cyanogenic glucoside content (0.56–0.62 mmol g^?1) when compared to the content in defatted meal (9.1–11.6 mmol g^?1). On the contrary, ethanolic extraction resulted in the high cyanogenic glucoside content in the extracts (71–89 mmol g^?1). The results reveals that ethanolic extraction gives extracts rich in antioxidant lignans; aqueous extracts have lower antioxidant activity than ethanolic but cyanogenic glucosides are significantly reduced.     

Canola Oil with High Antioxidant Content Obtained by Combining Emerging Technologies: Microwave,Ultrasound, and a Green Solvent

In this work, the ultrasound‐assisted extraction (UAE) of canola oil from canola seeds pretreated with microwaves using ethanol 99% as solvent is studied. Different process parameters are evaluated, such as extraction time, temperature, solid:solvent ratio, and ultrasound amplitude, optimizing the process using response surface methodology. Under optimum conditions, the extraction time is decreased by up to 75% with respect to conventional extractions, obtaining an oil with a higher content of total tocopherols and canolol, and with oxidation indexes within the established standard limits. The addition of a microwave pretreatment to the UAE with ethanol 99% shows a synergic effect between both processes, improving the oil yield. The results obtained in this study show the potential of the use of UAE for the extraction of canola oil using a green solvent, reducing processing times, environmental pollution, and achieving an oil of high quality and antioxidant concentration. Practical Application: The industrial use of petroleum‐derived solvents such as hexane has problems concerning sustainability, environment, and safety. In recent years, the use of “green” solvents for the extraction of vegetable oils began to be studied; however, it is necessary to develop stages that allow improving the extraction process by increasing the yield, reducing the processing times, and optimizing the oil quality. In this sense, ultrasound allows to shorten the extraction times while microwave pretreatments applied to canola seeds generate an increase in the concentration of antioxidants in the oil, facilitating the implementation of a “green” process in the industrial production.     

Evaluation of the Phenolic Content and Antioxidant Activity of Different Seed and Nut Cakes from the Edible Oil Industry

The objective of this work was to extract water‐soluble compounds from different seed and nut cakes under the same conditions and compare the phenolic content and antioxidant activity of the cake extracts. Seed cakes of sunflower, pumpkin, flaxseed and defatted sesame, and nut cakes of almond, pecan, macadamia and hazelnut were used in the experiments. Extracts were obtained by solid–liquid extraction with a water/ethanol solution (20:80, v/v). Total phenolic content, flavonoids, flavan‐3‐ols and condensed tannins in the extracts were determined using spectrophotometric analysis. Antioxidant properties of the extracts were determined by the DPPH and ABTS radical scavenging methods, and by determination of the reducing power and chelating activity. The extract from pecan nut cake presented the highest amounts of all compounds analyzed, followed by sunflower seed and hazelnut cake extracts. These samples also had the highest effects on the ABTS and DPPH radicals, as well as the uppermost reducing powers. The extracts from pecan nut and sunflower and sesame seeds were analyzed using HPLC and individual phenolics were further characterized.     

Effect of Solvent,Preheating Temperature,and Time on the Ultrasonic Extraction of Phenolic Compounds from Cold‐Pressed Hempseed Cake

The effect of different solvents (aqueous methanol [70%, v/v], aqueous acetone [80%, v/v], and a solvent mixture [MA] of aqueous methanol [70%, v/v] and aqueous acetone [70%, v/v] in a ratio of 1:1 [v/v]), preheating temperatures (140, 160, and 180°C), and times of exposure (5, 15, and 30 min) on the ultrasonic extraction of the main phenolic compounds from hempseed cake (Cannabis sativa) was investigated. A simplified new high‐performance liquid chromatography (HPLC) method was developed to identify and quantify the main phenolics (namely, N‐trans‐caffeoyltyramine and cannabisin B) in the extracts. Two other main compounds, numbered 3 and 4 , were also detected. The results showed that the nature of the extracting solvent had a significant (P < 0.05) impact on the ultrasonic extraction of phenolic compounds. The acetone extracts exhibited the highest total phenolic content (TPC), followed by MA and methanol. The preheating temperature and time of exposure enhanced the TPC for all solvents examined. The main phenolics, N‐trans‐caffeoyltyramine, cannabisin B, and compound 3 , were positively affected by the temperature and time of exposure, irrespective of the solvents used. In sharp contrast, compound 4 appeared to be thermally sensitive: increasing preheating time and temperature decreased the yields of this compound. This study demonstrated that acetone was the most effective extracting solvent and that preheating enhanced the yield of the main phenolics.     

海南蒲桃叶黄酮的提取及抗氧化性研究

采用正交试验法研究了海南蒲桃叶黄酮提取条件对黄酮得率的影响,确定了最佳提取条件为:乙醇体积分数70%,料液比1:20(g:mL),提取温度80℃提取3 h,此条件下黄酮得率为6.06%。利用体外试验检测不同浓度海南蒲桃叶黄酮对二苯基苦基苯肼DPPH·的清除作用。结果表明海南蒲桃叶黄酮是一种有效的自由基清除剂,对DPPH·有显著的清除作用。黄酮溶液质量浓度在31.25～250m g/L范围内,清除率随质量浓度增大而增大,最高可达93.04%。     

Separation of Cadmium,Cobalt, and Nickel by Solvent Extraction using the Nickel Salts of the Extractants

A new solvent‐extraction process for the separation of cadmium, cobalt, and nickel in sulphate solutions coming from the hydrometallurgical processing of spent Ni‐Cd batteries is proposed. The main innovation is to use nickel salts of the extractants, thus avoiding external pH control in the extraction operation. The extractants are first loaded with nickel in conditioning steps, using a neutralizer for pH control, and afterwards contacted with the aqueous processing solutions for extraction of interested metals with no further need of neutralization. This process is an alternative to the usual approach, which uses the sodium or ammonium salts of the extractants, avoiding introducing these cations in the process stream. Using this approach, the extraction of cadmium with nickel salt of 1 M DEHPA was performed at resulting pH values of 3.8–4.3 producing an organic phase loaded with 35 g/L Cd. Cobalt extraction with the nickel salt of Cyanex 272 was further achieved at resulting pH of 5.1–5.7 obtaining a organic loaded with 6.5 g/L Co.     

气相色谱法测定吗啉、N-甲酰吗啉及其杂质含量

提出了用HP-5毛细管色谱柱测定在萃取液中吗啉、N-甲酰吗啉及其杂质含量的分析方法，研究了其测定条件，并对分离后的组分用质谱方法进行了定性，按照确定的分析条件，对甲乙酮原料萃取剂中各组分都得到较好的分离，精密度好，分析结果准确可靠。     

Effect of Solvent Content on the Separation and the Energy Consumption of Extractive Distillation Columns

This article sets out to evaluate the effect of solvent content in the extractive section on the separation efficiency and energy consumption of extractive distillation columns. Contrary to the classical approach, the proposed approach enables a simultaneous evaluation of the effect of the major decision variables (reflux ratio, solvent flow rate, and the number of stages of the extractive section [NSE]). The procedure allows calculating the minimum solvent flow rate for the separation and the minimum specific energy consumption. The results show that the minimum specific energy consumption is obtained for the minimum reflux ratio and not for the minimum solvent flow rate. Moreover, the results show that it is not always the case that a larger NSE results in lower energy consumption. Due to its industrial importance, the dehydration of aqueous mixtures of ethanol using ethylene glycol as solvent has been chosen as a case study.     

Comparison of the Phenolic Content and Antioxidant Activities of Apocynum venetum L. (Luo-Bu-Ma) and Two of Its Alternative Species

The leaves of Apocynum venetum L. (AV), a native Chinese plant, have been used as folk medicine in China and Japan. This study evaluated the content of the active antioxidant component and antioxidant activities of AV, and its two alternative species, Poacynum pictum (Schrenk) Baill. (PP) and Poacynum hendersonii (Hook.f.) Woodson (PH). The total phenolic and total flavonoid contents were determined. In addition, the quantitative analysis of two major flavonoid compounds (hyperoside and isoquercitrin) was carried out by HPLC. The antioxidant activities were investigated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity method, the reducing power test and the chelating ability of ferrous ions. The highest total phenolic and flavonoid contents were observed in the AV methanolic extract, followed by the PP and PH methanolic extracts. HPLC analysis indicated that isoquercitrin was one of the major components in all three species, however, hyperoside was only detected in AV at high levels. All the antioxidant assays we performed demonstrated that the AV extract was markedly superior to those of the other two species.     

Analysis of Phenolic Compounds and Antioxidant Abilities of Extracts from Germinating Vitis californica Seeds Submitted to Cold Stress Conditions and Recovery after the Stress

The material for this study consisted of stratified seeds of Vitis californica submitted to germination under optimum conditions (+25 °C) or under chill stress (+10 °C), also followed by recovery. It has been determined that the germinating seeds contain considerable amounts of tannins, catechins as well as phenolic acids such as gallic, p-coumaric, caffeic and ferulic acids. Gallic acid appeared in the highest amount in the germinating seeds (from 42.40–204.00 µg/g of fresh weight (FW)), followed by caffeic acid (from 6.62–20.13 µg/g FW), p-coumaric acid (from 2.59–5.41 µg/g FW), and ferulic acid (from 0.56–0.92 µg/g FW). The phenolic acids occurred mostly in the ester form. Under chill stress, the germinating seeds were determined to contain an elevated total amount of phenolics, as well as raised levels of condensed tannins, catechins, gallic acid, and gafeic acid. The levels of p-coumoric and ferulic acids were found to have decreased. In extracts isolated from a sample exposed to low temperature, increased antioxidant activity and reduction potential were also demonstrated. Tissue of the germinating seeds which underwent post-stress recovery was found to have less total phenolics.