Selective extraction/isolation of hemoglobin with ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate (BtmsimPF6)

Ionic liquid was for the first time employed for selective isolation of heme-protein species. Direct extraction of hemoglobin into ionic liquid without using any concomitant reagent or extractant was carried out. Hemoglobin at the level of 100 ng μL⁻¹ could readily be quantitatively extracted into ionic liquid (IL) 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate (BtmsimPF₆) in the absence of any co-existing extractants/additives at pH 7, at the same time; however, the other protein species do not interfere and remain in the aqueous phase. A back extraction efficiency of ca. 80% for 20 ng μL⁻¹ hemoglobin in ionic liquid phase was achieved with sodium dodecyl sulfate (SDS) solution as stripping reagent. ⁵⁷Fe Mossbauer spectra and circular dichroism (CD) spectra indicated that the penta-coordinated ferrous atom in hemoglobin provide a vacant or free coordinating position, which could be occupied by the cationic Btmsim⁺ moiety. The interaction/coordination reaction between the iron atom in the heme group of hemoglobin and the cationic ionic liquid moiety furnishes the driving force for facilitating fast transfer of hemoglobin into BtmsimPF₆. The present system was applied for selective isolation of heme-protein, i.e., hemoglobin from human whole blood without any pretreatment, giving rise to satisfactory results.     

Selective separation of yttrium(III) through a liquid membrane system using 2-thenoyltrifluoroacetone as an extractant carrier

2-Thenoyltrifluoroacetone has been offered as a mobile carrier in organic phase for the transport and selective separation of yttrium from aqueous media using a liquid membrane system. Perceivably, the use of n-propylamine (PA) in the source phase enhances the transport of yttrium ions. The extraction and stripping conditions have entirely been evaluated and explained. The suggested method has been utilized for the separation of yttrium(III) from its binary mixtures with strontium(II) and some other cations such as Ni²⁺, Co²⁺, Ag⁺, Fe²⁺, Al³⁺, Cu²⁺, Hg²⁺and Cs⁺ in aqueous solutions of pH 5.4 in the presence of PA, while 1 M nitric acid was acting as a stripping agent in the receiving division. Cyanide ion and 5-sulfosalicylic acid have been used as masking agents to minimize the interferences from different transition metal ions and Al³⁺ in the source phase, respectively. ⁹⁰Y in secular equilibrium with ⁹⁰Sr in the source phase, was transferred to receiving phase and separated completely from its long-lived parent isotope. The activity of the transported ⁹⁰Y was found to decay with a half-life 64.17 ± 0.05 h. The purity of yttrium-90 was comparable or better than the other applied liquid membrane systems for purification of yttrium-90.     

"Substituent on benzenesulfonyl group" effect in use of 8-benzenesulfonamidoquinoline derivatives as chelate extractant.

"Substituent on benzenesulfonyl group" effect of 8-benzenesulfonamidoquinoline [N-(8-quinolyl)benzenesulfonamide, Hbsq] as bidentate chelate extractant for divalent metal cations was investigated with using Hbsq and its eight derivatives. Introduction of electron-withdrawing substituent on the benzenesulfonyl group in Hbsq enhanced the extractability that originated from its inductive effect. Furthermore, a bulky substituent on an ortho-position of the benzenesulfonyl group resulted in no steric effect in extraction, whereas the existence of two substituents on each ortho-position caused lower extraction performance due to steric hindrance.     

Combustion experiments of polystyrene by use of a modified bayer-ICI-shell apparatus

The combustion of polystyrene by use of a quartz tube modified Bayer-ICI-Shell apparatus yields, beside the main component styrene, a lot of other products known as biological hazards like benzene, naphthalene and biphenyl. The experiments have been performed in air atmosphere. According to DIN 4102, technical polystyrene mainly used in the building industry has been burnt and the composition of the resulting combustion products has been compared with that produced from the Bayer-ICI-Shell (BIS) experiments. The fire gases adsorbed on charcoal XAD 4 and XAD 2 have been desorbed in carbon disulfide as a solvent.It is concluded that a combination of XAD 4 and charcoal is the most efficient adsorbent. In addition, a method for quantitative determination of fire gas containing decomposition products is discussed.     

Preparation of novel bovine hemoglobin surface-imprinted polystyrene nanoparticles with magnetic susceptibility

In this research, a surface imprinting strategy has been adopted in protein imprinting. Bovine hemoglobin surface-imprinted polystyrene (PS) nanoparticles with magnetic susceptibility have been synthesized through multistage core-shell polymerization system using 3-aminophenylboronic acid (APBA) as functional and cross-linking monomers. Superparamagnetic molecularly imprinted polystyrene nanospheres with poly(APBA) thin films have been synthesized and used for the first time for protein molecular imprinting in an aqueous solution. The magnetic susceptibility is imparted through the successful encapsulation of Fe₃O₄ nanoparticles. The morphology, adsorption, and recognition properties of superparamagnetic molecularly imprinted polymers (MIPs) have been investigated using transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and vibrating sample magnetometer. Rebinding experimental results show that poly(APBA) MIPs-coated superparamagnetic PS nanoparticles have high adsorption capacity for template protein bovine hemoglobin and comparatively low nonspecific adsorption. The imprinted superparamagnetic nanoparticles could easily reach the adsorption equilibrium and achieve magnetic separation in an external magnetic field, thus avoiding some problems of the bulk polymer.     

Investigation of the use of diphenyl-2-pyridylmethane in benzene as an extractant for palladium from aqueous thiocyanate-nitrate solutions

The extraction of palladium/II/ with diphenyl-2-pyridylmethane /DPPM/ in benzene has been investigated from thiocyanate-nitrate media and optimized. Thiosulphate ions showed strong interference and reduced the extraction below 1%. Separation factors determined for most of the elements were better than 10³. This extraction method affords palladium preconcentration and its separation from Sc/III/, Co/II/, Cu/II/, Zn/II/, Se/IV/, Sr/II/, Ru/III/, Cd/II/, Cs/I/ and Eu/III/. Few possible applications of such separations have been cited.     

n-octylphenyl hydrogen phosphate as an extractant for some lanthanides

n-Octylphenyl hydrogen phosphate (OPHP) is examined for the extraction of neodynium, gadolinium and terbium. The effects of pH and metal ion and extractant concentrations are reported. The extraction constants are 39.5, 40.7 and 43.4 for Nd, Gd and Tb, respectively. The extraction efficiency of OPHP for these lanthanides is bettter than that of commoner alkylphosphorus acids.     

Synthesis and modification of low-molecular-weight polybutadiene and polystyrene for use as adhesive additive to asphalt

Russian Journal of Applied Chemistry - Low-molecular-weight butadiene and styrene polymers with narrow molecular-weight distribution were prepared by the mechanism of living polymerization with...     

π-complexes of polystyrene with silver salts and their use as facilitated olefin transport membranes

π-Complexes of silver salts with polystyrene (PS) were prepared and tested in the separation of propylene/propane mixtures. After the incorporation of silver ions into the PS matrix, both the pure propylene gas permeance of the membrane and its olefin selectivity with respect to the propylene/propane mixtures were remarkably higher than those of the pure PS membrane, demonstrating facilitated propylene transport through the solid-state membrane. The remarkable separation performance of the PS/silver salt membranes was attributable to the unusually high solubility of the silver salts in the PS matrix, which was possibly due to the formation of π-complexes between the silver ion and aromatic CC bond of PS. The coordination properties and dissolution behavior of the silver salts in PS were investigated with Fourier transform infrared, Fourier transform Raman, and X-ray photoelectron spectroscopy. The values for the intersegmental d-spacing, determined by wide-angle X-ray scattering, also showed that significant transient crosslinks arose between the PS chains when the silver salts were added to the PS matrix. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2263–2269, 2004     

Selective surface modification of syndiotactic polystyrene films: A study by Fourier transform- and confocal-Raman spectroscopy

A helical crystalline modification of syndiotactic polystyrene (sPS), the δ-form, was employed to prepare solution-cast films selectively sulfonated on the surface. This result was achieved because of the unusual transport characteristics of the δ-form, exhibiting comparatively large diffusivity and solubility values for low-molecular weight compounds such as chloroform, which can be effectively used as a carrier solvent. The results of sulfonation of the δ-form are compared with those obtained with a trans-planar crystalline modification of sPS (β-form). The latter was found unsuitable for selective surface modification. The analysis of the sulfonated films was carried out by FT-Raman and confocal-Raman spectroscopy. The first technique was used to investigate the average composition of the samples in terms of sulfonation degree and crystalline structure. It also allowed us to construct calibration curves to be used in connection with the confocal-Raman data. The latter technique was employed to generate images with spectroscopic contrast and to quantitatively characterize the depth-profiles of the investigated films.     

Selective catalytic transformation of polystyrene into ethylbenzene over Fe-Cu-Co/Alumina

FeCuCo over aluminum oxide catalyst was prepared to catalytically degrade polystyrene (PS) into ethylbenzene (EB) under mild conditions. This catalyst was characterized by XRD, SEM, STEM-EELS, STEM-EDS, XPS, and physical properties. A significant selectivity toward EB formation at 250 °C was achieved in the absence of hydrogen with 82% liquid yield. End-chain session and cross-linking reactions are proposed to be the dominant pathways in the degradation of PS over FeCuCo to form EB.     

Synthesis of branched polystyrene by ATRP exploiting divinylbenzene as branching comonomer

Branched polystyrenes have been synthesized using atom transfer radical polymerization (ATRP) of styrene in the presence of divinyllbenzene (DVB) as branching comonomer. The synthesis was completed via facile one pot approach. Mole ratio of styrene to DVB in range of 5:1-30:1 was employed to obtain soluble polymers. The kinetics of the polymerization and evolution of polymer compositions were revealed by determining the conversions of reactants by gas chromatography (GC). The growth of molecular weight was monitored by GPC and the results indicate that the branched polymers were formed by self-condensing vinyl polymerization (SCVP) of AB^∗ monomer or macromonomers. The branched structure of the resulting polymers was confirmed by the remarkable discrepancies of the weight average molecular weights determined by GPC and multi angle laser light scattering (MALLS). The specific viscosity of the resulting polymer is also much lower compared with that of linear analogues. The influence of dosage of initiator and catalyst on the yield and molecular weights of the resulting polymers was also investigated.     

Role of Cyanex-272 as an extractant for uranium in the determination of rare earths by ICP-AES

A chemical separation procedure has been developed for the extraction of uranium from some of the crucially important rare earths using a novel extractant viz. Cyanex-272 (2,4,4-trimethyl pentyl phosphinic acid). The near total extraction of uranium and quantitative separation of rare earth elements has been validated using inductively coupled argon plasma - atomic emission spectrometry (ICP-AES). The recovery of some of the representative elements has been confirmed by radioactive tracer studies. The back extraction of uranium from the organic phase was carried out using a solution of 0.5M Na₂CO₃ which resulted in a near total recovery of uranium into the organic phase. These studies have enabled determination of sub ppm amounts of the analyte elements with a precision of 5% RSD utilizing prior chemical separation of rare earths from 1 g uranium samples in just three extractions with Cyanex-272.     

Simple method for the isolation and purification of hemoglobin components.

A simple method for the isolation and purification of hemoglobin components from starch gel by electrophoresis is described. An inverted bottle with a cut off bottom is used. Pieces of gel containing the hemoglobin are embedded in potato starch, wetted with buffer, and placed in the neck of the inverted bottle, the mouth of which has been closed with filter paper and tape. Connection with the negative tank buffer is achieved by inserting a layer of starch gel between the potato starch and the negative tank buffer. By electrophoresis, the hemoglobin migrates and accumulates in a dialysing tube tied around the mouth of the bottle and hanging into the positive tank buffer.     

The isolation of radio-manganese by distillation as permanganic acid

The selective isolation of manganese by distillation as permanganic acid was investigated. Contamination from Fe, Cr and Co was negligible. It was found possible to isolate carrier-free ⁵⁴Mn from cyclotron-irradiated iron targets. The time needed for the distillation was about 15 min with yields of 85–90%.     

Investigations on the use of 4-(5-Nonyl) pyridine as an extractant for chlorocomplexes of gallium(III)

A study of the distribution of gallium(III) between hydrochloric acid solutions and 0.1M 4-(5-nonyl)-pyridine in benzene has been undertaken. Gallium can be quantitatively extracted from moderate to concentrated acid solutions and also from dilute acid solutions containing high concentrations of neutral cations of high charge density. The effects of acidity, the solvent concentration and diverse ions on the extraction have been investigated. An attempt has been made to elucidate the stoichiometry of the extracted species. The formulation of (NP_y H)⁺ GaCl ₄ ⁻ ) and (NP_y−H−NP_y)⁺ GaCl ₄ ⁻ is expected at macro and trace concentrations of the metal. The extraction coefficients of several elements have been recorded under conditions optional for the extraction of gallium; and their factors for separations are estimated.     

螯合-螯合-中性萃取剂三元协萃UO~2(NO~3)~2的研究

自从Blake发现协萃效应以来,协萃效应已得到广泛深入的研究,并已有专著予以评述,但对三元协萃体系的研究工作并不多,特别是两种螯合萃取剂与一种中性萃取剂的三元协萃体系未见报道.本文对UO_2~(2+)针/0.5mol·dm~(-3)HNO_3/PMBP-TTA-TBP-CHCl_3三元协萃体系进行了研究,测定了协萃配合物(四元混合配合物)的组成,并求得它们的协萃平衡常数。     

Polymer grafting onto carbon black by use of TEMPO-terminated polystyrene with controlled molecular weight

The grafting of polystyrene with controlled molecular weight and narrow molecular weight distribution onto the carbon black surface through the trapping of polymer radicals formed by the thermal dissociation of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-terminated polystyrene (PSt-TEMPO) by the carbon black surface was investigated. PSt-TEMPO was prepared by living radical polymerization of St with the benzoyl peroxide/TEMPO system. When PSt having no terminal TEMPO moiety was heated with carbon black, no grafting of PSt onto the surface was observed. On the contrary, by the heating of PSt-TEMPO with carbon black in m-xylene at 125°C, PSt with controlled molecular weight and narrow molecular weight distribution was grafted onto the surface: the percentage grafting of PSt (M_n = 3.2 × 10³;M_w/M_n = 1.07) onto furnace black was determined to be 16.0%. On the basis of the above results, it is concluded that PSt radicals formed by the thermal dissociation of the C ON bond between PSt and TEMPO are trapped by polycondensed aromatic rings of carbon black. The mole number of grafted PSt chains on the carbon black surface decreased with increasing molecular weight of PSt-TEMPO. PSt-grafted carbon black gave a stable colloidal dispersion in THF. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3165–3172, 1998