Selective separation and enrichment of proteins in aqueous two-phase extraction system

A simple aqueous two-phase extraction system （ATPS） of PEG/phosphate was proposed for selective separation and enrichment of proteins. The combination of ATPE with HPLC was applied to identify the partition of proteins in two phases. Five proteins （bovine serum albumin, Cytochrome C, lysozyme, myoglobin, and trypsin） were used as model proteins to study the effect of phosphate concentration and pH on proteins partition. The PEG/phosphate system was firstly applied to real human saliva and plasma samples, some proteins showed obviously different partition in two phases. The primary results manifest the selective separation and enrichment of proteins in ATPS provided the potential for high abundance proteins depletion in proteomics. ~ 2009 Feng Qu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Catalytic spectrophotometric determination of trace selenium in microemulsion after separation and enrichment by SDG

A new catalytic spectrophotometric method was developed for the determination of trace amount of Se（Ⅳ） in microemulsion medium. The method is based on the catalytic effect of traces of Se（Ⅳ） on the oxidation of 2＇,4＇-dichlorophenylfluomne （p-CPF） by potassium bromate with HNO3 as an activator in the presence of nonionic microemulsion medium. Under optimum conditions, the calibration graph is linear in the range of 0.4-15 μg·L^-1 of Se（Ⅳ） at 480 nm. The detection limit achieved is 9.86 × 10^-10μg·L^-1. Samples were dissolved and the obtained trace Se（Ⅳ） was separated and enriched by sulphydryl dextrane gel （SDG）. The method has been applied for determination of trace selenium with satisfactory results.

Fluorescence determination of platinum with dibromohydroxyphenyl-fluorone in microemulsion after separation and enrichment by sulfhydryl dextrose gel

A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion medium.This method is based on the fact that platinum can form a stable chelate with dibromohydroxyphenyl-fluorine（DBHPF） when they are in the molar ratio of 1：2 in the nonionic microemulsion medium.Under optimum conditions,the system,having the maximum excitation and emission wavelengths at 468 nm and 532 nm,respectively,shows constant fluorescence intensity in the pH range of 3.5-4.0 and high selectivity and sensitivity as well as low interference from foreign ions.Furthermore,this fluorescence intensity is a linear function of Pt（IV） concentration in the range of 0.002-1.00 μg·mL^-1 and the limit of detection is 2.90 ng·mL^-1.

Separation and Enrichment of Rare Earth Elements in Phosphorite in Xinhua,Zhijin,Guizhou

The phosphorite ores-deposits rich in rare earth elements(REE) in Zhijin, Xinhua, Guizhuo occurs in the early Cambrian Meishucun and at the bottom part of Qiongzhusi stage (the upper layer of phosphorites), belonging to Yangzi stratum section. The living creature scraps was proved existent in dolomitic-phosphorites by experiments, The REE could be extracted to provide the worthy data for the further using. Adopting the HNO3 to extract REE, through the ion exchange method, the REE recovery rate could be reached 85.44% , having certain reference value.

Recent advances of rhenium separation and enrichment in China： Industrial processes and laboratory trials

China is a major producer of rhenium, which is widely used in aerospace technologies （as superalloy） and petrochemical industries （as catalyst）. There is a gap between the demand and fact for the enrichment of rhenium, due to its rather small content （10-9） in the earth＇s crust. Also, there is no available single occurrence of mineral rhenium. Instead, the rhenium is associated with either molybdenum or copper （of up to 0.2% in content） as a by-product in metallurgical industry. This makes the separation of rhenium from the major mineral metals a challenge. The recent progresses in the separation and enrichment of rhenium were reviewed in this paper, especially, the advances in China. The details of varied separation methods used either in laboratories or factories, such as ion-exchange, solvent extraction, separation utilizing extractive resins, liquid membrane, or novel materials, etc., were elaborated. Comparison of the different methods was disclosed and an outlook on the rhenium chemistry and industry in the future was brought forward.

Opportunities and challenges of high-pressure ion exchange chromatography for nuclide separation and enrichment

With the rapid development of the nuclear industry,more-stringent requirements are proposed for highlevel radioactive waste liquid treatment and the enrichment of isotope products.High-pressure ion exchange chromatography has been widely accepted for the fine separation of elements and nuclides due to its advantages,such as high efficiency,environmental friendliness,ease of operation,and feasibility for large-scale industrial applications.Here,we summarized the evolution of high-pressure ion exchange chromatography and the relevant research progress in ion exchange equilibrium and related separation technology.The prospects for application of high-pressure ion exchange chromatography to rare earth elements,actinide elements and isotope separation were discussed.High-pressure ion exchange chromatography represents a promising strategy for the extraction of rare earth elements and actinide elements from high-level radioactive waste liquid,as well as being an effective method for the automated production of high purity isotope products with great environmental benefits.

Application of magnetic solid phase extraction in separation and enrichment of glycoproteins and glycopeptides

The analysis of endogenous glycoproteins and glycopeptides in human body fluids is of great importance for screening and discovering disease biomarkers with clinical significance.However,the presence of interfering substances makes the direct quantitative detection of low-abundance glycoproteins and glycopeptides in human body fluids one of the great challenges in analytical chemistry.Magnetic solid phase extraction(MSPE)has the advantages of easy preparation,low cost and good magnetic responsiveness.Magnetic adsorbents are the core of MSPE technology,and magnetic adsorbents based on different functional materials are widely used in the quantitative analysis of glycoproteins and glycopeptides in human body fluids,making it possible to analyze glycoproteins and glycopeptides with low abundance as well as multiple types,which provides a technical platform for screening and evaluating glycoproteins and glycopeptides in body fluids as disease biomarkers.In this paper,we focus on the recent advances in the application of MSPE technology and magnetic adsorbents for the separation and enrichment of glycoproteins and glycopeptides in human body fluids,and the future trends and application prospects in this field are also presented.

Study of spectrophotometric method for determination of trace copper after the separation and enrichment with solid phase extractant-microcrystalline phenolphthalein

A new method of using phenolphthalein loaded with 1-(2-pyridylazo)-2-naphthol (PAN) as solid phase extractant to separate and enrich trace copper in diverse water samples has been developed. The ef- fects of different parameters, such as the amounts of PAN and phenolphthalein, stirring time, various salts and metal ions on the enrichment yield of Cu(II) have been investigated to select the experimental conditions. Under the optimum conditions, Cu(II) can be totally adsorbed on the surface of microcrys- talline phenolphthalein. By controlling appropriate acidity (pH=1.0), Cu(II) is completely separated from Cd(II), Pb(II), Mn(II), Co(II), Fe(III), Ni(II), Al(III), Zn(II) and Hg(II) in the solution. The possible reaction mechanism of the enrichment of copper is discussed in detail in this paper. The detection limit of this proposed method is found to be 0.03 μg·L-1 with the enrichment factor of 200. The recovery is in a range of 96.8%―105%. The standard deviation is less than 2.5%. The proposed method has been successfully applied to the determination of trace copper in different water samples with satisfactory results.

Preparation of Chelating Cellulose Filters and Their Application to the Separation and Enrichment of Trace Elements

hreekinds of chelating cellulose filters were prepared and ten trace elements were preconcentrated simultaneously on the microcolumn that was filled with the chelating cellulose filters. Alkali and alkaline earth metal ions were quantitatively separated as matrix elements at the selected pH values. The microcolumn has high enrichment factors and recoveries.

STUDY ON ENRICHMENT AND SEPARATION OF TRACE ELEMENTS WITH SILICA GELS MODIFIED BY HETEROCYCLIC AZO DYES

Two types of modified silica gels were prepared by adsorption method and bonding method respectively. Enrichment and separation of trace metal ions have been done by using the column packed with modified silica gels.

Tailoring morphology symmetry of bismuth vanadate photocatalysts for efficient charge separation

Although spatial charge separation between different facets of semiconductor crystals has been recognized as a general strategy in photocatalysis, the vital role of crystal morphology symmetry in charge separation properties still remains elusive. Herein,taking monoclinic bismuth vanadate(BiVO_(4)) as a platform, we found distinct charge separation difference via rationally tailoring the morphology symmetry from octahedral to truncated octahedral crystals. For octahedral BiVO_(4), photogenerated electrons and holes can be separated between edges and quasi-equivalent facets. However, as for truncated octahedral crystals,photogenerated electrons tend to transfer to {010} facets while photogenerated holes prefer to accumulate on {120} facets, thus realizing the spatial separation of photogenerated charge between different facets. Morphology tailoring of BiVO_(4) crystals leads to a significantly improved photogenerated charge separation efficiency and photocatalytic water oxidation activity. The built-in electric field for driving the separation of photogenerated electrons and holes is considered to be modulated by tuning the morphology symmetry of BiVO_(4) crystals. This work discloses the significant roles of morphology symmetry in photogenerated charge separation and facilitates the rational design of artificial photocatalysts.

Separation and Concentration of Indium from Leaching Solution Containing Indium, Antimony and Iron Ions

Processing conditions of effectively separating indium from the leaching solution of a smelting antimony slag were studied. For the leaching solution containing indium and antimony and iron ions, indium was separated by extracting with HDEHP kerosine solution, washing antimony and iron ions with oxalic acid solution and stripping indium with a dilute solution of hydrochloric acid. InCl 3 solution with purity above 90% is obtained. Indium can be enriched through a circulation of stripping with a dilute HCl solution. The concentration of InCl 3 solution is about 25～30 g/L.

Efficient and selective extraction of uranium from seawater based on a novel pulsed liquid chromatography radionuclide separation method

The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation method was proposed,and a pulsed nuclide automated separation device was developed,alongside a new chromatographic column.The length of this chromatographic column was 10 m,with an internal warp of 3 mm and a packing size of 1 mm,while the total separation units of the column reached 12,250.The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2,sample injection flow rate=5.698 mL/min,chromatographic column heating temperature=60℃.Separation experiments were also carried out for uranium,europium,and sodium ions in mixed solutions;uranium and sodium ions in water samples from the Ganjiang River;and uranium,sodium,and magnesium ions from seawater samples.The separation factors between the different nuclei were then calculated based on the experimental data,and a formula for the separation level was derived.The experimental results showed that the separation factor in the mixed solution of uranium and europium(1:1)was 1.088,while achieving the initial separation of uranium and europium theoretically required a 47-stage separation.Considering the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River,achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation.Furthermore,for the seawater sample separation experiments,the separation factor of uranium and sodium ions was 1.2885;therefore,more than 28 stages of sample separation would be required to achieve uranium extraction from seawater.The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment,while expanding the possibilities of extracting uranium from seawater through chromatography.

Preconcentration/separation and determination of mercury using microcrystalline phenolphthalein modified by ethyl violet

A novel method was developed for enrichment and separation of trace mercury using phenolphthalein modified by ethyl violet （EV）. The effects of different parameters, such as stirring time, various metal ions and salts, and the amounts of phenolphthalein, NH4SCN, and EV on the extraction rate of mercury were studied, to select the experimental conditions. Under optimum conditions, mercury can be adsorbed on the surface of microcrystalline phenolphthalein by the intermolecular acdon strength. The possible reaction mechanism for the enrichment of mercury was discussed in detail. Hg（Ⅱ） could be completely separated from Fe（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Mn（Ⅱ）, Cd（Ⅱ）, Cr（Ⅲ）, and Al（Ⅲ） in the solution. The proposed method has been successfully applied to the determination of trace mercury in industrial wastewater with the recoveries above 99%. The relative standard deviation for five replicate determinations of 0.04 μg·mL^-1 of Hg（Ⅱ） was found to be 1.4%, 1.1%, and 1.2%, respectively. The analytical results were very satisfactory.

Effects of Pressure on Bubble Size and Separation of BSA by a Semi-batch Foaming Process

Experiments were conducted to obtain the values of the Sauter bubble size, enrichment and recovery of bovine serum albumin （BSA） in a semi-batch col- umn fitted with a stainless steel sparger at elevated pressure. The effects of Sur- face tension, surfactant concentration, foam/solution height ratio and air flow rate on the separation performance were investigated, and the results showed that good en- richments and recoveries can be achieved for bovine serum albumin operated at el- evated pressures. Especially the size of bubbles generated by the stainless steel sparger was smaller at higher pressures which is favorable to the foam separation process. Furthermore, the separation mechanism of bovine serum albumin operated at elevated pressure was also discussed.

Enrichment of Trace Cerium by Liquid Membrane and Its Determination by Spectrophotometry

Introduction Since it was discovered in 1968,liquid membrane separation technique has been widely studied,particularly in separating or recovering some metal ions.It is a novel study that trace substances in analytical chemistry are enriched by liquid membrane.There have been few reports on enriching cerium by emulsion liquid membrane (ELM) now.Therefore,authors studied the liquid membrane methed for enriching trace cerium.The sensibility measuring cerium by spectrophotometry was increased greatly.

Research on Experimental and Application for the High Efficient Enrichment of the Low-grade Precious Metal Materials

On the basis of reviewing the progress in the high efficient enrichment from secondary resources of low grade precious metals at home and abroad, a process route of the high efficient enrichment precious metals from secondary resources of low-grade metals by adding iron oxide as the trapping agent, reducing agent, additive, mixing uniformly and grinding, pelletizing, reduction, grinding and separation, and selectively acid leaching iron has been put forward in this paper. The experiments of reduction, grinding and separation, and selectively acid leaching iron were carried out mainly. Under the decided experiment parameters and conditions, iron generated during the reduction can trap precious metals during reduction, high active alloy powders were obtained from the reduced products by grinding and separation, the concentration of precious metals was obtained by acid leaching high active alloy powders. The better enrichment effect was obtained by adopting the technical route of processing. Other low grade noble metal materials and enrichment ratio of precious metals from the materials to acid products was high through acid leaching. This process has the advantages of simple process, environmental-friendly, strong adaptability of raw materials, high concentration ratio, which was regarded as a kind of the general efficient enrichment technology of low grade precious metal materials.

Rich oxygen vacancies mediated bismuth oxysulfide crystals towards photocatalytic CO-to-CH conversion

Oxygen vacancy-rich bismuth oxysulfide(Bi_(2)O_(2)S)with layered structure was prepared for efficient photocatalytic CO_(2) reduction under visible light irradiation.The existence of rich oxygen vacancies in Bi_(2)O_(2)S,which was proven by sufficient characterization,can provide abundant active sites,improve CO_(2) adsorption and activation abilities and boost the separation efficiency of photogenerated carriers,as determined by theoretical and experimental analyses.As a result,Bi_(2)O_(2)S with rich oxygen vacancies achieves excellent CO_(2) conversion with a CH4 production of 65.8μmol g^(-1) under 90 min of visible light irradiation,which was 27-fold higher than the pristine Bi_(2)O_(2)S.The mechanism of photocatalytic conversion of CO_(2) to CH4 was also determined by in situ FT-IR analyses.This study provides an in-depth understanding of the development of Bi-O-S system photocatalysts through defect engineering for photocatalytic CO_(2) reduction.

Cell biomechanics and its applications in human disease diagnosis

Certain diseases are known to cause changes in the physical and biomechanical properties of cells.These include cancer,malaria,and sickle cell anemia among others.Typically,such physical property changes can result in several fold increases or decreases in cell stiffness,which are significant and can result in severe pathology and eventual catastrophic breakdown of the bodily functions.While there are developed biochemical and biological assays to detect the onset or presence of diseases,there is always a need to develop more rapid,precise,and sensitive methods to detect and diagnose diseases.Biomechanical property changes can play a significant role in this regard.As such,research into disease biomechanics can not only give us an in-depth knowledge of the mechanisms underlying disease progression,but can also serve as a powerful tool for detection and diagnosis.This article provides some insights into opportunities for how significant changes in cellular mechanical properties during onset or progression of a disease can be utilized as useful means for detection and diagnosis.We will also showcase several technologies that have already been developed to perform such detection and diagnosis.

Development of a Kind of Immunomagnetic Bead Kit to Separate and Enrich Salbutamol

An immunomagnetic bead kit to separate and enrich salbutamol was prepared through the reaction between salbutamol and 4-aminobenzoic acid.The kit had a catch of 20 ng/ml to salbutamol in samples,and showed no cross reaction with competitive drugs with structure and function similar to salbutamol: clenbuterol,ractopamine,phenylethanolamine A, bromchlorbuterol, brombuterol, terbutaline, hydroxymethyl salbutamol,cimaterol,tulobuterol,mapenterol,cimbuterol,clenpenterol,zilpaterol,penbutolol,clenproperol,mabuterol and clorprenaline.