Aronia Melanocarpa: Identification and Exploitation of Its Phenolic Components

The phenolic components of Aronia melanocarpa were quantitatively recovered by three successive extractions with methanol. They comprise anthocyanins (mainly cyanidin glycosides) phenolic acids (chlorogenic and neochlorogenic acids) and flavonols (quercetin glycosides). Approximately 30% of the total phenolic compounds are located in the peel and the rest in the flesh and seeds. Peels contain the major part of anthocyanins (73%), while the flesh contains the major part of phenolic acids (78%). Aronia juice, rich in polyphenols, was obtained by mashing and centrifugation, while the pomace residue was dried and subjected to acidified water extraction in a fixed bed column for the recovery of residual phenolics. A yield of 22.5 mg gallic acid equivalents/g dry pomace was obtained; however, drying caused anthocyanins losses. Thus, their recovery could be increased by applying extraction on the wet pomace. The extract was encapsulated in maltodextrin and gum arabic by spray drying, with a high (>88%) encapsulation yield and efficiency for both total phenols and anthocyanins. Overall, fresh aronia fruits are a good source for the production of polyphenol-rich juice, while the residual pomace can be exploited, through water extraction and spray drying encapsulation for the production of a powder containing anthocyanins that can be used as a food or cosmetics additive.     

An electrokinetic bioreactor: using direct electric current for enhanced lactic acid fermentation and product recovery

The microbiological production of organic acids by fermentation processes is growing in commercial importance. However, the removal of product and pH control are two main issues that limit the technical and commercial viability of such processes. A laboratory scale bioreactor combining conventional electrodialysis and bipolar membrane electrodialysis has been developed for in situ product removal and pH control in lactic acid fermentation. The electrokinetic process enabled removal of the biocatalytic product (lactic acid) directly from the bioreactor system, in a concentrated form, as well as enabling good pH control without generation of troublesome salts. Moreover, end-product inhibition of glucose catabolism was reduced, resulting in a greater generation of the end-product lactic acid. An automatic pH sensor and current application system was developed and successfully implemented for lactic acid fermentation in the electrokinetic bioreactor.     

Rapid Protein Hydrolysis by Microwave Irradiation Using Heat-Resistant Teflon-Pyrex Tubes

A rapid peptide-bond hydrolysis by means of microwave irradiation is introduced for the facile preparation of protein hydrolysates used for amino acid analysis. The optimal hydrolysis condition has been determined using several enzymes with known amino acid compositions. The effects of hydrolysis time on the recovery of various labile and hydrophobic amino acids are also exemplified in the microwave heating of standard amino acids. The method has been applied to the complete amino acid analysis with a single nonvolatile solvent of methanesulfonic acid with good recovery of tryptophan and half-cystine. It provides a radical expedition of protein and peptide hydrolysis via commercial microwave ovens and specially-designed Teflon-Pyrex tubes, circumventing the tedious procedures using vacuum-sealed pyrex lubes heating at 110°C for more than 24 h. This novel type of microwave chemistry associated with rapid peptide-bond cleavage is of great potential in the automation of the complete process of amino acid analysis starting from the preparation of protein hydrolysates.     

Recovery Techniques Enabling Circular Chemistry from Wastewater

In an era where it becomes less and less accepted to just send waste to landfills and release wastewater into the environment without treatment, numerous initiatives are pursued to facilitate chemical production from waste. This includes microbial conversions of waste in digesters, and with this type of approach, a variety of chemicals can be produced. Typical for digestion systems is that the products are present only in (very) dilute amounts. For such productions to be technically and economically interesting to pursue, it is of key importance that effective product recovery strategies are being developed. In this review, we focus on the recovery of biologically produced carboxylic acids, including volatile fatty acids (VFAs), medium-chain carboxylic acids (MCCAs), long-chain dicarboxylic acids (LCDAs) being directly produced by microorganisms, and indirectly produced unsaturated short-chain acids (USCA), as well as polymers. Key recovery techniques for carboxylic acids in solution include liquid-liquid extraction, adsorption, and membrane separations. The route toward USCA is discussed, including their production by thermal treatment of intracellular polyhydroxyalkanoates (PHA) polymers and the downstream separations. Polymers included in this review are extracellular polymeric substances (EPS). Strategies for fractionation of the different fractions of EPS are discussed, aiming at the valorization of both polysaccharides and proteins. It is concluded that several separation strategies have the potential to further develop the wastewater valorization chains.     

利用根霉菌发酵生产富马酸*

富马酸是一种重要的平台化合物和精细化学品,广泛应用于材料、医药、食品及饲料添加剂等领域,市场潜力巨大。利用可再生生物质为原料发酵生产富马酸符合当前社会对绿色环保、健康安全及可持续发展的总体需求。本文对发酵生产富马酸的常见根霉菌及其代谢机理进行了评述,并详细讨论了营养成分、菌体形态、pH控制及产物分离回收技术等对富马酸生产强度和生产成本的影响。随着科技的不断发展,应用各种新兴手段不断改良现有菌种及工艺,必将实现发酵法生产富马酸的大规模工业化。     

一种基于电洗脱的核酸纯化回收芯片的设计及优化

提出了一种基于电洗脱原理的核酸纯化回收芯片, 通过对芯片上电极进行适当的切换操作, 可一次完成核酸样品分离和纯化回收. 同时采用数值模拟的方法对纯化回收芯片管道的几何形状及电场分布进行了优化设计, 并进行了实验验证. 实验结果与模拟分析非常吻合, 证明优化设计达到了预期的效果.     

离子色谱法测定水中4种有机酸

建立了水样中甲酸、乙酸、丙烯酸和甲基丙烯酸的离子色谱测定方法,采用IonPac AS11-HC阴离子分离柱,以KOH为淋洗液,采用浓度梯度洗脱,可同时测定上述4种有机酸。方法对实际水样中甲酸、乙酸、丙烯酸和甲基丙烯酸的平均加标回收率在80.2%~103.3%,相对标准偏差在5.8%之内,检出限分别为:0.005,0.003,0.005和0.004mg/L;定量下限分别为:0.020,0.012,0.020和0.016mg/L。方法准确、简便、环保,能够满足实际水样的测定需要,且水样中常见的阴离子不会对目标污染物的测定产生影响。     

Simultaneous Determination of Mefenamic and Flufenamic Acids in Real Samples by Terbium-Sensitized Luminescence

A simple luminescent methodology for the simultaneous determination of mefenamic and flufenamic acids is proposed. The method takes advantage of the lanthanide-sensitized luminescence, which provides increased sensitivity. Due to the strong overlapping between the luminescence spectra, the use of decay curves to resolve mixtures of the analytes is proposed, particularly as these curves are more selective.

A factorial design with three levels per factor coupled to a central composite design was selected to obtain a calibration matrix of thirteen standards plus three blank samples which was processed using a partial least-squares (PLS) analysis. In order to assess the effectiveness of the proposed method, a prediction set of synthetic samples was analyzed, and recovery percentages between 96 and 106% were obtained. Limits of detection, calculated by means of a new criterion, were 3.73 µg L^?1 and 14.61 µg L^?1 for flufenamic and mefenamic acids, respectively. The method was tested in two different pharmaceutical preparations containing the analytes, obtaining recovery percentages close to 100%. Finally, the simultaneous determination of both fenamates in human urine samples was successfully carried out by means of a correction of the aforementioned model. No extraction method or prior separation of the analytes were needed.     

Growth Performance,Biochemical Composition and Nutrient Recovery Ability of Twelve Microalgae Consortia Isolated from Various Local Organic Wastes Grown on Nano-Filtered Pig Slurry

This paper demonstrated the growth ability of twelve algae-microbial consortia (AC) isolated from organic wastes when a pig slurry-derived wastewater (NFP) was used as growth substrate in autotrophic cultivation. Nutrient recovery, biochemical composition, fatty acid and amino acid profiles of algae consortia were evaluated and compared. Three algae-microbial consortia, i.e., a Chlorella-dominated consortium (AC_1), a Tetradesmus and Synechocystis co-dominated consortium (AC_10), and a Chlorella and Tetradesmus co-dominated consortium (AC_12) were found to have the best growth rates (µ of 0.55 ± 0.04, 0.52 ± 0.06, and 0.58 ± 0.03 d⁻¹, respectively), which made them good candidates for further applications. The ACs showed high carbohydrates and lipid contents but low contents of both proteins and essential amino acids, probably because of the low N concentration of NFP. AC_1 and AC_12 showed optimal ω6:ω3 ratios of 3.1 and 3.6, which make them interesting from a nutritional point of view.     

Ultrasound-assisted extraction and determination of tartaric and malic acids from grapes and winemaking by-products

The optimization of an ultrasound-assisted extraction (UAE) method for tartaric and malic acids from grape derived samples is shown. A fractional factorial experimental design allowed for the determination of the effects of seven extraction variables. Relationships between all the variables were examined. By applying graphical analysis, the best extractions conditions were obtained. The most important variables were the extracting liquid and the extraction temperature. Later, a central composite design was applied for optimizing the temperature and the composition of the extracting liquid. The optimized method was applied to grapes and to winemaking by-products. The repeatability of the method was studied and the recovery of tartaric and malic acids was established. Organic acids quantification was done by liquid chromatography (LC) using a post-column buffer and a conductivity detector.     

Electrodialysis with Bipolar Membranes: Principles,Optimization, and Applications

This paper is an overview of the bipolar membrane technology. The process of electrodialysis with bipolar membrane (EDBM) along with the different EDBM process configurations are presented. Some ways of optimization of both the bipolar membranes and the EDBM technology are envisaged. Most of the applications relate to the production or recovery of organic acids while the first plant has been commissioned by 1986 at Washington Steel (USA) for the recovery of HF/HNO₃ from waste pickling liquors. In the last few years, there has been increasing interest in using bipolar electrodialysis stacks in chemical and agro industrial processes to directly acidify or basify process streams without the addition of chemicals. This attractive feature of this technology has contributed to the implementation of several plants in fermentation process for the production of organic and amino acids.     

Electrochemical biosensors for monitoring malolactic fermentation in red wine using two strains of Oenococcus oeni

Amperometric biosensors for the determination of l-malic and l-lactic acids were optimised and used to monitor micro-malolactic fermentations (micro-MLFs) in red wine. Platinum-based probes, coupled with appropriate enzymes, were assembled in electrochemical flow-injection analysis systems. A classical lactate oxidase based sensor was used for l-lactic acid, while l-malic acid was detected via a new biosensor based on the malic enzyme immobilised in a reactor using phenazine methosulphate as mediator. After a preliminary optimisation phase, a recovery study to evaluate the effect of the matrix (red wine) on biosensor performance was carried out by the addition of different standard solutions of the two analytes to the samples. Recoveries from 93 to 100% and from 94 to 102% were observed for l-malic acid and l-lactic acid, respectively. These optimised biosensors were finally employed to monitor micro-MLFs induced by inoculation of two different strains of Oenococcus oeni into red wine. During the micro-MLFs, samples of wine were collected and assayed for l-malic, l-lactic, and citric acids by use of both biosensors and spectrophotometric techniques. In parallel the viable bacterial cell count was also evaluated. The kinetics of bacterial growth, degradation of l-malic and citric acids, and production of l-lactic acid was found to be a function of the strains inoculated.     

Novel Determination of Organic Acids in Diesel and Motor Oil by Ion Chromatography

A robust analytical method is required for the determination of low-molecular weight organic acids, which are potential causes of refinery and internal combustion engine corrosion. The ion chromatographic method developed in this study allows the determination of acetic acid and formic acid in diesel oil mixtures with a motor oil volume fraction of up to 10%. The hydrophobic matrix is automatically removed in-line through a matrix elution step with organic solvent and nonaqueous anion-exchange analyte extraction. Acetic acid and formic acid, as the smallest and most acidic aliphatic naphthenic acids, were determined. Gradient anion-exchange chromatography on high-capacity columns in combination with suppressed conductivity detection allowed their selective and sensitive determination. Typical recovery values were from 82 to 107% for each acid in the matrices evaluated with reproducibility less than 5% for acid fortified samples.     

Benign Recycling of Spent Batteries towards All-Solid-State Lithium Batteries

Lithium-ion batteries (LIBs) are one of the most significant energy storage devices applied in power supply facilities. However, a huge number of spent LIBs would bring harmful resource waste and environmental hazards. In this study, a benign hydrometallurgical method using phytic acid as precipitant is proposed to recover useful metallic Mn ions from spent LiMn₂O₄ batteries. Besides Mn-based cathodes, this recovery process is also applicable for other commercial batteries. More importantly, for the first time, the as-obtained manganous complex is employed as a nanofiller in a polyethylene oxide matrix to largely improve Li⁺ conductivity and transference number. As a result, when applied in all-solid-state lithium batteries, high capacity and outstanding cyclic stability are achieved with capacity retention of 86.4 % after 60 cycles at 0.1 C. The recovery of spent lithium batteries not only has benefits for the environment and resources, but also shows great potential application in all-solid-state lithium batteries, which opens up a costless and efficient circulation pathway for clean and reliable energy storage systems.     

Enhancing the microdialysis recovery for sampling of Cu and Ni by incorporating humic acid in the perfusion liquid

A strategy to enhance the microdialysis relative recovery for sampling of Cu and Ni ions is presented. Enhanced recovery was achieved by incorporating humic acid, a binding agent, in the microdialysis perfusion liquid during sampling from a Cu and Ni standard solution mixture. All microdialysis sampling experiments were carried out at room temperature under quiescent conditions using a concentric type of microdialysis probe with an adjustable effective dialysis length. For all metal determinations electrothermal atomic absorption spectrometry was employed. Metal recoveries were shown to be dependent on the membrane molecular weight cut-off, perfusion rate, sample solution pH, perfusion liquid composition as well as perfusion liquid pH. Complete recoveries (100%) of Cu and Ni were obtained by microdialysis sampling using a 10 kDa molecular weight cut-off polysulfone membrane at a flow-rate of 2 μl/min employing a 0.05% (w/v) optimal composition of humic acid incorporated in the perfusion liquid. The optimal sampling pH of humic acid was determined to be 6 where most oxygen containing functional groups are dissociated and available for metal binding. These data have important ramifications for sampling and determination of metal ions in small sample solutions (∼10 ml) at very low concentrations in the ppb range.     

红橘油中脂肪酸组成的 GC-MS分析

用正己烷溶解达川和万县产的两种红橘油,将样品皂化和甲酯化后,以毛细管柱DB－WAX作为分离柱,用气相色谱－质谱法测定其中的脂肪酸组成,两种红橘油的主要脂肪酸成分有明显的差别,两者的不饱和脂肪酸相对含量分别为92．1％及76．7％。     

Aqueous two‐phase systems based on deep eutectic solvents and their application in green separation processes

As a new environmentally friendly separation technology, deep eutectic solvent based aqueous two‐phase systems are extensively applied in various fields. Herein, we review recent advances in this field and highlight the possible directions of future developments. This article focuses on the effects of deep eutectic solvent and inorganic salts on the phase equilibrium, the microstructure of deep eutectic solvent based aqueous two‐phase systems, the applications of deep eutectic solvent based aqueous two‐phase systems in separation (proteins, biopolymers, saponins, and organic acids), and removal and recovery technologies for deep eutectic solvent from aqueous two‐phase systems.     

废水中铜银的分离和银的回收研究

废水中铜银的分离和银的回收研究黄秀山（四川三峡学院化学系万县６３４０００）关键词分解电压，还原电势，回收一、引言本实验采用电解还原的方法回收贵金属银。目前此法主要用于回收废水中的铬、汞等，对银的研究很少。曾有人进行过自然渗析还原法回收银的研究。用自然...     

模拟移动床色谱分离二十碳五烯酸乙酯和二十二碳六烯酸乙酯

二十碳五烯酸和二十二碳六烯酸是两种非常重要的ω-3多不饱和脂肪酸,广泛用于膳食补充剂和药品,同时它们的生理作用并不完全相同,因此分离制备它们的高纯度单体十分必要。首先以聚苯乙烯/二乙烯基苯（PS/DVB）聚合物为固定相,在液相色谱上分离二十碳五烯酸乙酯（EPA-EE）和二十二碳六烯酸乙酯（DHA-EE）,考察了流动相、填料粒径、温度对分离的影响。然后采用粒径20 μ m、孔径10 nm的PS/DVB填料装填了8根150 mm×10 mm的半制备色谱柱,测定了半制备柱装填的均一性。最后尝试在模拟移动床（SMB）色谱上分离EPA-EE和DHA-EE的混合物,探究了Ⅱ区和Ⅲ区的流量、进料流量、进料浓度对分离的影响,结果表明SMB制备的EPA-EE和DHA-EE的相对纯度分别为91.6%和93.6%,回收率分别为97.0%和91.6%,固定相生产率为5.97 g/（L\5h）,溶剂消耗为1.52 L/g。SMB制备EPA-EE和DHA-EE具有较大的应用潜力。     

Effect of amphoteric surfactant on phase behavior of hydrocarbon-electrolyte-water system-an application in enhanced oil recovery

The different techniques such as enhanced oil recovery (EOR) and improved oil recovery (IOR) have been used to enhance oil production. The surfactant flooding is a tertiary oil recovery technique that has been widely used in oil field industry. A variety of surfactant chemicals have been used in which among them the amphoteric type, which has two groups of opposite charges, needs more investigation. In this work, we use cocamidopropyl betaine as an amphoteric surfactant that is used to investigate its influence on the aquifer?+?hydrocarbon system. The effects of surfactant concentration, salinity, and hydrocarbon type on the phase behavior of the various saline aqueous-hydrocarbon mixtures are investigated. Moreover, the surfactant flooding is carried out using a glass micromodel. Thus, to investigate the wettability, the contact angle is also measured for the present system that it is an influential factor in oil recovery. First, by increasing salinity from 0?wt% to 20?wt% in n-hexadecane, the phase change take placed so that a Winsor formation from type I to III and then to type II occurs. However, for n-heptane upon enhancing salinity, Winsor type III is transformed to type II so that hydrocarbon (oil) recovery increases and break through occurs with a delay. By increasing salinity, water solubilization parameter decreases for both hydrocarbon and by enhancing both surfactant concentration and salinity leads to reduce the contact angle. Thus, cocamidopropyl betaine works better for the longer hydrocarbon chain.

In the micromodel flooding test upon formation of Winsor II, the recovery is higher and the break through takes place with a delay. However, for the case of Winsor I, the recovery is lower and the break through occurs earlier. Finally, one can conclude that the low concentration of amphoteric surfactants needs to use that plays an important role in chemical EOR and results a higher recovery in high salinity.