Comparison of activated chromatography resins for protein immobilization

The adsorption of bovine serum albumin (BSA) to an immobilized camelid‐derived antibody fragment was investigated using six different activated resins, of which two are prototypes. The resins differed in base material, coupling chemistry and particle size. The adsorption, washing and desorption stage of the affinity chromatography process were taken into account. Dynamic binding capacities at 10% breakthrough ranged between 0.76 and 4.8 mg BSA/mL resin. The washing volume ranged between 2.9 and 10 column volumes. One of the resins did not concentrate BSA, while the highest concentration was 13‐fold. We present a method to rank and weigh the properties of the resins to find the optimal resin to meet specific requirements. For three of the resins the adsorption flow rate was varied, while the washing and desorption flow rate was kept the same. The dynamic binding capacity decreased with increasing flow rate, as expected. For one resin, the washing volume remained constant, but for the others it decreased with increasing adsorption flow rate. The number of column volumes required to purify a given amount of BSA increases with increasing flow rate, which indicates that higher flow rates do not necessarily speed up the process.     

A simple method to ordered mesoporous carbons containing nickel nanoparticles

A series of ordered mesoporous carbons containing magnetic Ni nanoparticles (Ni-OMCs) with a variety of Ni loadings was made by a simple one-pot synthetic procedure through carbonization of phenolic resin-Pluronic block copolymer composites containing various amount of nickel nitrate. Such composite materials were characterized by N₂ sorption, XRD, and STEM. Ni-OMCs exhibited high BET surface area, uniform pore size, and large pore volume without obvious pore blockage with a Ni loading as high as 15 wt%. Ni nanoparticles were crystalline with a face-center-cubic phase and observed mainly in the carbon matrix and on the outer surface as well. The average particle size of Ni nanoparticles was dependent on the preparation (carbonization) temperature and Ni loading; the higher the temperature was used and the more the Ni was incorporated, the larger the Ni nanoparticles were observed. One of the applications of Ni-OMCs was demonstrated as magnetically separable adsorbents. Dedicated to Professor Mietek Jaroniec on the occasion of his 60th birthday.     

Bio-Adsorbent from Carboxymethyl Cellulose and Tannin for Dye Adsorption

A bio-adsorbent was prepared by the crosslinking reaction of a tannin based phenolic resin and carboxymethyl cellulose with epichlorohydrin as crosslinker. The water absorption ratio of the adsorbent decreased due to the introduction of the phenolic resin based on tannin but the adsorption properties of the adsorbent for methylene blue were improved due to the introduction of the phenolic hydroxyl groups from the tannin in comparison with the carboxymethyl cellulose based adsorbent cross-linked with epichlorohydrin. The maximum adsorption capacity of the adsorbent for methylene blue was 1300mg/g and the adsorption process for methylene blue was exothermic. The adsorption ratio of the adsorbent for methylene blue was over 98% for an adsorbent dosage of 2.5 g/L when the concentration of methylene blue in solution was lower than 2000mg/L. The adsorbent can process wastewater containing methylene blue in the pH range of 4–12.     

Effects of textural and surface characteristics of microporous activated carbons on the methane adsorption capacity at high pressures

The objective of this study is to relate textural and surface characteristics of selected microporous activated carbons to their methane storage capacity. In this work, a magnetic suspension balance (Rubotherm, Germany) was used to measure methane adsorption isotherms of several activated carbon samples. Textural characteristics were assessed by nitrogen adsorption on a regular surface area analyzer (Autosorb-MP, by Quantachrome, USA). N₂ adsorption was analysed by conventional models (BET, DR, HK) and by Monte Carlo molecular simulations. Elemental and surface analyses were performed by X-ray photoelectronic spectroscopy (XPS) for the selected samples. A comparative analysis was then carried out with the purpose of defining some correlation among the variables under study. For the system under study, pore size distribution and micropore volume seem to be a determining factor as long as the solid surface is perfectly hydrophobic. It was concluded that the textural parameters per se do not unequivocally determine natural gas storage capacities. Surface chemistry and methane adsorption equilibria must be taken into account in the decision-making process of choosing an adsorbent for gas storage.     

Non-targeted evaluation of selectivity of water-compatible class selective adsorbents for the analysis of steroids in wastewater

Selective adsorbents for solid-phase extraction are needed to meet the low concentration requirements of new environmental quality standard directives, especially for the analysis of estrogens in wastewater. In this work, bulk polymerization procedures were first optimized for the synthesis of non-imprinted polymers (NIP) with low non-specific adsorption of nonpolar compounds in aqueous environments. Water-compatible molecularly imprinted polymers (MIP) were then synthetized by increasing the selectivity of the polymer towards steroids with a testosterone template (average imprinting factor > 10). In addition, the affinity of synthetized entrapped β-cyclodextrin–epichlorohydrin polymers (ECD) towards steroids was clarified. The polymers were applied to the extraction of spiked wastewater effluent samples and their performance compared to commercially available adsorbents. The selectivity of the studied adsorbents was evaluated utilizing liquid chromatography ? mass spectrometry as well as comprehensive two-dimensional gas chromatography ? time-of-flight mass spectrometry. Affinity between adsorbents and steroids as well as matrix removal potential were measured with targeted methodologies, and two novel non-targeted methodologies were proposed to quantitatively measure adsorbent selectivity by utilizing chemometrics. Semi-quantitative selectivity was measured from the ratio of peak areas between steroidal and other compounds. Semi-qualitative selectivity was calculated from the ratio between the number of tentatively identified steroidal and other compounds. The synthetized polymers provided good matrix removal potential (ion suppression 15–30%) and semi-qualitative selectivity (∼4 units) compared to the commercial adsorbents (ion suppression 45–80%, selectivity < 3 units). Simple non-targeted approaches provided a novel method of quantifying the selectivity of extraction.     

Preparation of a polymeric ionic liquid-based adsorbent for stir cake sorptive extraction of preservatives in orange juices and tea drinks

In this study, a new polymeric ionic liquid-based adsorbent was prepared and used as the extraction medium of stir cake sorptive extraction (SCSE) of three organic acid preservatives, namely, p-hydroxybenzoic acid, sorbic acid and cinnamic acid. The adsorbent was synthesized by the copolymerization of 1-ally-3-vinylimidazolium chloride (AV) and divinylbenzene (DVB) in the presence of a porogen solvent containing 1-propanol and 1,4-butanediol. The effect of the content of monomer and the porogen solvent in the polymerization mixture on the extraction performance was investigated thoroughly. The adsorbent was characterized by infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. To obtain the optimal extraction conditions of SCSE/AVDVB for target analytes, key parameters including desorption solvent, adsorption and desorption time, ionic strength and pH value in sample matrix were studied in detail. The results showed that under the optimized conditions, the SCSE/AVDVB could extract the preservatives effectively through multiply interactions. At the same time, a simple and sensitive method by combining SCSE/AVDVB and high-performance liquid chromatography with diode array detection was developed for the simultaneous analysis of the target preservatives in orange juices and tea drinks. Low limits of detection (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target analytes were achieved within the range of 0.012–0.23 μg/L and 0.039–0.42 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation (RSD), and it was found that the values were all below 10%. Finally, the proposed method was used to detect preservatives in different orange juice and tea drink samples successfully. The recoveries were in the range of 71.9–116%, and the RSDs were below 10% in the all cases.     

氨基酸—VT对SLE病理性抗体的吸附

本文研究了用ＶＴ树脂偶联各种氨基酸制备的吸附剂对系统性红斑狼疮患者血清中病理性抗体的吸附作用。实验结果表明，多种氨基酸－ＶＴ对ＳＬＥ患者血清中ＩｇＧ抗体有吸附作用，其中Ｓｅｒ－ＶＴ，Ｇｌｎ－ＶＴ和Ｔｙｒ－ＶＴ选择性吸附抗－ＤＮＡ等致病性抗体的效果比较好，同时，提出评价治疗ＳＬＥ用吸附剂吸除效果的四个指标。     

Improved Synthesis of Chitosan -Bearing boldbeta-Cyclodextrin and Its Adsorption Behavior towards Bisphenol A and 4-Nonylphenol

The synthesis of chitosan-bearing -cyclodextrin (CDC) has been improved by use of an alternative condensing agent, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM). CDC was obtained by the reaction of succinyl chitosan with a small amount of mono-6-amino-mono-6-deoxy--cyclodextrin (ACD) within a shorter reaction time. Under optimal conditions, the CD yields reached to 50%, which were almost the same as those in the reactions using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC). The gelation time suggests that the crosslinking of chitosan and the immobilization of the ACD occur competitively. To test the potential of CDC for selective removal of pollutants, the adsorption of bisphenol A (BPA) and 4-nonylphenol (NP) from aqueous solution onto CDC was investigated. In the case of the equilibrium concentrations more than 10 mg/L, the amounts of both sorbents onto CDC were close to the estimated saturated value of the CDC (85 mg/g for BPA and 81 mg/g for NP).     

吸附法脱除乙烯中少量氮气的研究

采用重量法在电子天平上，研究了C2H4和N2单组分在5A、13X、丝光沸石和炭分子筛不同吸附剂上的吸附平衡性质和扩散动力学性质。单柱模拟变压吸附评价了炭分子筛吸附脱除C2H4-N2（N2为4．7％）混合组分中N2的性能，并对流速和压力的影响进行了考察。研究表明，该炭分子筛是吸附脱除C2H4中少量N2的理想吸附剂。     

Adsorption and deformation phenomena at interaction of N2 and microporous carbon adsorbent

Deformation of activated carbon adsorbent ACC (adsorbent obtained by removing Si from SiC) upon N(2) adsorption has been studied. To solve this problem, a dilatometer was used. Its main part was a line differential transformer, the core of which was connected to the adsorbent by means of a rod. Any changes in the adsorbent height caused a change in the core position in the transformer, which influenced the signal recorded from its secondary winding. These results were compared with the adsorption isotherms. High sensitivity of the dilatometric method has been shown. The dilatometer used allowed the measurement of absolute deformations in the range 1 x 10(-4) to 3 mm.