Anion-exchange separation of gallium from indium,thallium, aluminium and other elements in malonic acid

Summary Systematic studies of gallium on Dowex-21K in malonate media are reported. On the basis of the value of the elution constant (E) it was separated from large number of metal ions. By selective sorption it was separated from the alkalis, alkaline earths, bismuth, thallium (I), mercury (II), iron (II) and germanium (IV). With water as eluant it was separated from cobalt, nickel, zinc, manganese and palladium, with ammonium chloride it was possible to separate it from copper, iron and vanadium, and with a specific eluant it was separated from lead and zirconium. Finally the sequential separation of gallium from thallium, aluminium and indium was accomplished.     

Extraction of gold, palladium and platinum from chloride, bromide and iodide solution with di-n-octyl sulphide (DOS) in cyclohexane

The extraction of gold, palladium and platinum from hydrochloric acid, hydrobromic acid and iodide media by solutions of di-n-octyl sulphide in cyclohexane was examined. From distribution data it was concluded that the monosolvates AuX(3).DOS and disolvates PdX(2).2DOS are extracted. Extraction of platinum was efficient only from iodide solutions; a disolvate PtI(4).2DOS was formed. The possibility of separation of gold and palladium from platinum by extraction from bromide or chloride solutions and simultaneous extraction of palladium and platinum from an iodide medium was demonstrated.     

In vitro pH-dependent drug release from N4-(4-carboxybutyryl)-1-beta-D-arabinofuranosylcytosine and its conjugate with poly-L-lysine or decylenediamine-dextran T70

N4-(4-Carboxybutyryl)-1-beta-D-arabinofuranosylcytosine (glu-ara-C), the conjugate of glu-ara-C and poly-L-lysine (PLL), (PLL-glu-ara-C), and the conjugate of glu-ara-C and decylenediamine-dextran T70 (T70-C10), (T70-C10-glu-ara-C), were prepared. Drug regeneration from glu-ara-C and the conjugates was investigated in buffered solutions of pH 4,5,7,7.4 and 8. The character of the drug release from the conjugates was different from that from glu-ara-C. Namely, the release of 1-beta-D-arabinofuranosylcytosine (ara-C) from glu-ara-C was accelerated under both weakly acidic and weakly basic conditions, while it was accelerated only under weakly basic conditions from the conjugates. Overall, the drug release profiles from the conjugates showed similar patterns. However, under neutral and weakly basic conditions, ara-C was regenerated more rapidly from PLL-glu-ara-C than from T70-C10-glu-ara-C. During the incubation of glu-ara-C and the conjugates under weakly acidic conditions, 1-beta-D-arabinofuranosyluracil (ara-U) was detected and its amount increased with time to similar extents.     

Separation of thorium as ascorbato complex by extraction with Aliquat 336S

Thorium was quantitatively extracted with 0.1M Aliquat 336S at pH 4.5 from 0.01M ascorbic acid. It was then stripped with 2M hydrochloric acid. Thorium arsenazo III complex was determined spectrophotometrically at 655 nm. It was separated from binary and tertiary mixtures by exploiting the difference in distribution ratios of various elements from ascorbic acid media. Some separations were accomplished by selective stripping of thorium from nitric and hydrochloric acid. The method was extended for the analysis of thorium in monazite and gas mantles.     

甲基纤维素/二氯乙酸液晶溶液的相转变

本文研究了甲基纤维素/二氯乙酸液晶溶液液晶相与各向同性相之间相互转变的过程。在连续升温过程中,由于液晶相内部有序度的非均一性,升温速率对液晶相织构随温度的变化有较大的影响。在等温相转变过程中,无论是从各向同性态转变为液晶态,还是其逆过程,从液晶态转变为各向同性态,相转变曲线均具有指数方程特征。利用与 Avrami 方程相似的指数方程进行处理,在从各向同性态转变为液晶态时,指数 n 大部分约为1。但液晶相向各向同性相在低于 Tc 时的相转变中,n 均小于1。相转变速率受溶液浓度和温度的影响。在质量分数为0.259的浓度时,液晶相向各向同性相的转变在低于 Tc 时39.5℃进行得最快。     

黄体酮的合成工艺改进

以植物甾醇为原料,分离得豆甾醇(1); 1经沃氏氧化和臭氧化制得中间体孕甾-4-烯-3-酮-22-醛(3); 3经加成缩合并在CuCl催化下经空气氧化合成了黄体酮,总产率69.1%,其结构经¹H NMR和ESI-MS确证。     

Low-molecular-weight poly(alpha-methyl beta,L-malate) of microbial origin: synthesis and crystallization

Low-molecular-weight poly(alpha-methyl beta,L-malate) made of approximately 25-30 units was prepared from microbial poly(beta,L-malic acid) by treatment with diazomethane. The thermal characterization of the polymalate methyl ester was carried out and its crystalline structure was preliminary examined. Its ability to crystallize both from solution and from the melt was comparatively evaluated.     

Industrial-scale preparation of akebia saponin D by a two-step macroporous resin column separation

A simple and efficient procedure for the industrial preparation of akebia saponin D, one of the bioactive compounds commonly found in the well-known Chinese Medicinal herb Dipsaci Radix, was developed. First, HPD-722 was selected from among 10 kinds of macroporous absorption resins. Following this step, the purity of akebia saponin D was increased about 10 times from 6.27% to 59.41%. In order to achieve a higher purity, ADS-7 was chosen from among five kinds of macroporous absorption resins, and the purity of akebia saponin D was increased from 59.41% to 95.05%. The result indicated HPD-722 and ADS-7 were the most suitable resins to purify akebia saponin D from Dipsaci Radix. Under these conditions, large-scale preparation of akebia saponin D was carried out successfully. The preparation method is simple, efficient, and has been demonstrated to be effective for large scale preparations of akebia saponin D from Dipsaci Radix.     

Preconcentration and separation of iron, zinc, cadmium and mercury, from waste water using Nile blue a grafted polyurethane foam

The present work describes a novel method for the incorporation of Nile blue A into polyurethane foam matrix. This foam material was found to be very suitable for the extraction of metal ions from aqueous solutions. The characterization of Nile blue A grafted foam and the effect of halide concentration, pH, shaking time, extraction isotherm and capacity have been investigated. This foam material was found to be suitable for the separation and preconcentration of iron (III), zinc (II), cadmium (II) and mercury (II) from waste water. The extraction was accomplished in (15-20) minutes. Iron was separated from acid medium (2-4 M HCl), zinc from (3-5 M HCl), cadmium from (4-6 M HCl) as thiocyanate complexes and mercury was separated from (1-2 M HCl) as chloride.     

Deposition characteristics of γ-ureidopropyltrimethoxysilane onto E-glass fibres using toluene and carbon tetrachloride as carrier solvents

Industrial grade γ-ureidopropyltrimethoxysilane was adsorbed onto industrial grade E-glass fibres from toluene and carbon tetrachloride at 23 °C. The treated surfaces were characterised using thermogravimetry, diffuse reflectance Fourier transform IR spectroscopy, electron spectroscopy for chemical analysis, scanning electron microscopy and the zeta potential. When ureidosilane was deposited from toluene and CCl₄, both of which have very low hydrogen-bonding ability, a ureido surface was obtained. The ureidosilane deposited from CCl₄ hydrolysed at the surface and condensed to form a solvent-swollen Si–O–Si network. The ureidosilane deposited from toluene also hydrolysed at the E-glass surface. Condensation of the silane deposited from toluene was not apparent. Aluminium dissolved from the E-glass surface was condensed into the network of the silane deposited from CCl₄. Aluminium was not detected at the surface of the samples with ureidosilane deposited from toluene. Received: 10 November 2000 Accepted: 23 March 2001     

Remediation of soil/concrete contaminated with uranium and radium by biological method

Biological method was studied for remediation of soil/concrete contaminated with uranium and radium. Optimum experiment conditions for mixing ratios of penatron and soil, and the pH of soil was obtained through several bioremediations with soil contaminated with uranium and radium. It was found that an optimum mixing ratio of penatron for bioremediation of uranium soil was 1 %. Also, the optimum pH condition for bioremediation of soil contaminated with uranium and radium was 7.5. The removal efficiencies of uranium and radium from higher concentration of soil were rather reduced in comparison with those from lower concentration of soil. Meanwhile, the removal of uranium and radium in concrete by bioremediation is possible but the removal rate from concrete was slower than that from soil. The removal efficiencies of uranium and radium from soil under injection of 1 % penatron at pH 7.5 for 120 days were 81.2 and 81.6 %, respectively, and the removal efficiencies of uranium and radium from concrete under the same condition were 63.0 and 45.2 %, respectively. Beyond 30 days, removal rates of uranium and radium from soil and concrete by bioremediation was very slow.     

Separation of selenium(IV) and tellurium(IV) from mixtures by extraction chromatography with trioctylphosphine oxide

The reversed-phase extraction chromatographic separation of selenium(IV) and tellurium(IV) from several elements with trioctylphosphine oxide as extractant is reported. Selenium was extracted from 6M hydrochloric acid containing 7M lithium chloride was stripped with 4M hydrochloric acid, and tellurium was extracted from either the same medium as selenium or from 4M hydrochloric acid, and stripped with 1-2M hydrochloric acid. Selenium and tellurium can be separated from multicomponent mixtures.     

Liquid Chromatographic Assay for Amodiaquine in Tablets and Biological Fluids

Abstract

A high performance liquid chromatographic assay for quantitating amodiaquine (A) in tablets, urine, plasma, bile and saliva is described. The method involved acid extraction of the drug from tablets and chloroform extraction of its base from the biological fluids after alkalinization with ammonia. Quinidine was used as the internal standard. A μ-Bondapak phenyl column was used for separation together with a mobile phase made of methanol, water and glacial acetic acid (pH 2.3). Good chromatograms with efficient separation of drug and internal standard peaks were observed. Retention times of 5.2 and 7.1 min. were obtained for the drug and the internal standard respectively. Correlation between areas under the curve and drug concentration was high. The mean percentage recovery of A from tablets was 102.03%, while from the biological fluids, it ranged from 85.2 to 104.61%. Urine and saliva obtained from volunteers and bile obtained from animals administering amodiaquine showed chromatograms similar to those obtained for blank samples spiked with A. Interference from table't excipients of biological fluids was undetectable or negligible. The method was found to be precise and simple.     

Hydrogen Evolution from Glucose with the Combination of Glucose Dehydrogenase, Ferredoxin NADP Reductase and Hydrogenase from A. Eutrophus H16

Hydrogen evolution system from glucose consisting of glucose dehydrogenase from Bacillus sp., ferredoxin NADP reductase from spinach leaves and hydrogenase from Alcaligenes eutrophus H16 was established. When the solution containing glucose, glucose dehydrogenase, NAD, ferredoxin NADP reductase, methyl viologen and hydrogenase was incubated at 30°C, hydrogen evolution was observed.     

High-performance liquid chromatographic determination of cyanide in human red blood cells by pre-column fluorescence derivatization.

A method for the determination of cyanide in human red cells has been developed. Cyanide was extracted from red cells by adding water and methanol, and then derivatized with 2,3-naphthalene-dialdehyde and taurine to give a fluorescent product, which was determined by reversed-phase high-performance liquid chromatography with fluorescence detection. The recovery of cyanide from red cells was ca. 83%, and the limit of detection was 100 pmol/ml. The mean concentrations of red cell cyanide from ten smokers and from ten non-smokers were 705 and 466 pmol/ml, respectively. The method was also applicable to whole blood.     

Competitive adsorption of the herbicide fluroxypyr and tannic acid from distilled and tap water on activated carbons and their thermal desorption

A study was conducted on batch and column competitive adsorption of fluroxypyr (FLX) and tannic acid (TA) from distilled (DW) and tap water (TW) on activated carbon cloth (ACC) and granular activated carbon (GAC). Thermal desorption of the adsorbates from the spent ACC was also studied. FLX adsorption was higher from TW than from DW at low FLX equilibrium concentrations, and the inverse was observed at high FLX concentrations. The presence of TA diminished the amount of FLX adsorbed from both solvents due to partial blocking of the microporosity, but the same trends as before were observed at low and high FLX concentrations. Carbon consumption, obtained from the breakthrough curves, was lower as a function of superficial contact time with ACC than with GAC. The presence of TA increased carbon consumption, which was related to the microporosity of the adsorbents. Thermal desorption profiles of the spent ACC showed two peaks and one peak after adsorption from DW and TW, respectively. Desorption peaks shifted to higher temperatures with an increase in the heating rate, allowing the apparent activation energies and pre-exponential factors of the desorption processes to be determined.     

无机膜反应器在丙烷选择氧化反应中的应用

将无机膜反应器用于丙烷部分氧化制丙烯醛的反应中,考察了不同膜操作方式和反应条件的影响。实验结果表明,采用ＰＰＯＲ膜操作方式,即丙烷从渗透侧通入,氧气从反应侧通入,丙烷可获得较大的自由活化空间,避免与气相氧反应,因此提高了部分氧化反应的选择性。采用分别进样的膜反应,丙烯醛产率可比混合进样的固定床反应高出达３倍。     

Remediation of textile effluent using agricultural residues

The sorption of artificial dye effluent made from two different dyes, Solar orange 7 GLL and Solar Jade Green FFB from Clariant, onto three different agricultural residues—barley husk, sugarcane bagasse, and wheat straw—was studied. Twenty percent of 600-μm particle size of these agricultural residues was used as substrates and studied individually. The percentage of dye removal was observed in concentrations of dye varying from 50 to 200 mg/L. The effect of temperature ranging from 25 to 50°C and pH from 6.0 to 12.0 on the dye removal by the substrates was also studied. The effective adsorption of the substrates was calculated.     

Effect of Aging on the Synthesis of Kaolin-Based Zeolite Y from Ahoko Nigeria Using a Novel Metakaolinization Technique

Zeolite Y was systematically synthesized from Ahoko Nigerian kaolin in a conventional hydrothermal system using novel metakaolinization technique. The effect of aging on the formation of zeolite phase was investigated during the course of the synthesis. A rapidly processed metakaolin at a temperature of 600°C and exposure time of 50 minutes, which is capable of reducing the energy and cost of producing it was used to study the synthesis of zeolite Y. It was found that aging conditions play a prominent role in the preparation of zeolite Y from Ahoko metakaolin. Aging played a significant role by increasing the crystallinity of the final product even though zeolite Y was obtain without aging. The outcome of zeolite Y synthesized from Ahoko kaolin in 9 hours at 100°C was different from most reports on the synthesis of zeolite Y from kaolin where longing time (72 hours) of crystallization are reported.     

Separation of molybdenum(VI) from other elements by solvent extraction with dibenzo-18-crown-6 from hydrochloric acid medium

DB-18-C6 was used for the extractive separation analysis of molybdenum(VI) from a range of other elements. Molybdenum(VI) was quantitatively extracted from 8M hydrochloric acid with 0.01M DB-18-C6 in nitrobenzene. It was stripped from the organic phase with 2M nitric acid and determined spectrophotometrically with Tiron at 390 nm. Molybdenum was separated from a large number of elements in binary mixtures, the tolerance limit for most elements being very high. Selective extraction of molybdenum permits its separation from barium, thorium, cesium, rubidium, strontium, lanthanum, chromium(III) and cerium(III). The method was extended for the analysis of molybdenum in a soil sample.