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偶氮氯膦Ⅰ分光光度法测定血清蛋白质的效果分析 总被引:1,自引:0,他引:1
在Na2HPO4-柠檬酸酸性缓冲液中,加入非离子表面活性剂聚氧乙烯月桂醚(Brij-35),使偶氮氯膦Ⅰ(CPA—Ⅰ)与牛血清白蛋白形成复合物,复合物的最大吸收波长在570nm,比试剂本身红移了70nm,表观摩尔吸光系数为5.88×10^4L/(mol·cm^-1),线性范围0—166mg/L,采用分光光度法研究该结合反应的最佳反应条件,并据此建立了一种测定血清蛋白质的新方法。结果表明,该法回收率为98.7%~102.2%,批内变异系数为2.4%,血清用量少,线性范围宽,具有操作快速、简便、结果灵敏可靠等优点,与双缩脲法相关性良好。 相似文献
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Zhang J Zhang S Dong K Zhang Y Shen Y Lv X 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(15):4021-4026
A new type of "task specific ionic liquid", tetrabutylphosphonium amino acid [P(C4)4][AA], was synthesized by the reaction of tetrabutylphosphonium hydroxide [P(C4)4][OH] with amino acids, including glycine, L-alanine, L-beta-alanine, L-serine, and L-lysine. The liquids produced were characterized by NMR, IR spectroscopies, and elemental analysis, and their thermal decomposition temperature, glass transition temperature, electrical conductivity, density, and viscosity were recorded in detail. The [P(C4)4][AA] supported on porous silica gel effected fast and reversible CO2 absorption when compared with bubbling CO2 into the bulk of the ionic liquid. No changes in absorption capacity and kinetics were found after four cycles of absorption/desorption. The CO2 absorption capacity at equilibrium was 50 mol % of the ionic liquids. In the presence of water (1 wt %), the ionic liquids could absorb equimolar amounts of CO2. The CO2 absorption mechanisms of the ionic liquids with and without water were different. 相似文献
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Yingqi Mi Qin Miao Jingmin Cui Wenqiang Tan Zhanyong Guo 《Molecules (Basel, Switzerland)》2021,26(14)
Recent years have seen a steady increase in interest and demand for the use of humectants based on biodegradable natural polymers in many fields. The aim of this paper is to investigate the moisture absorption and retention properties of 2-hydroxypropyltrimethyl ammonium chitosan derivatives which were modified by anionic compounds via ion exchange. FTIR, 1H NMR, and 13C NMR spectroscopy were used to demonstrate the specific structures of chitosan derivatives. The degrees of substitution for objective products were calculated by the integral ratio of hydrogen atoms according to 1H NMR spectroscopy. Meanwhile, moisture absorption of specimens was assayed in a desiccator at different relative humidity (RH: 43% and 81%), and all target products exhibited enhanced moisture absorption. Furthermore, moisture retention measurement at different relative humidity (RH: 43%, 81%, and drier silica gel) was estimated, and all target products possessed obviously improved moisture retention property. Specifically, after 48 h later, the moisture retention property of HACBA at 81% RH was 372.34%, which was much higher than HA (180.04%). The present study provided a novel method to synthesize chitosan derivatives with significantly improved moisture absorption and retention properties that would serve as potential humectants in biomedical, food, medicine, and cosmetics fields. 相似文献
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H.-W. Gao Y.-C. Li P.-F. Zhang M. Tao L. Wang 《Journal of Analytical Chemistry》2001,56(11):1007-1010
The reaction between Cd2+and a chromogenic agent, p-acetylbenzenediazoaminoazobenzene (p-ABAA) at pH 12.5 is sensitive and selective in the presence of triethanolamine and citrate. The solubilization and sensitization of the OP emulsifier (nonionic surfactant) was observed in the above reaction. Because the absorption of excess p-ABAA interferes with the absorption of the complex, primary–secondary wavelength spectrophotometry (PSWS) was used instead of the single-wavelength method in the determination of trace amounts of cadmium. Results showed that this method gave out a higher precision and better accuracy than the single-wavelength method, because two wavelengths that are located at the peak absorption and the valley absorption of the reaction solution were used simultaneously. By analyzing samples, the relative standard deviations were less than 8% and the recovery between 96.5 and 111%. 相似文献
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Wu C Wang P Yao X Liu C Chen D Lu GQ Cheng H 《The journal of physical chemistry. B》2005,109(47):22217-22221
The microstructure and absorption/desorption characteristics of composite MgH2 and 5 wt % as-prepared single-walled carbon nanotubes (MgH2-5ap) obtained by the mechanical grinding method were investigated. Experimental results show that the MgH2-5ap sample exhibits faster absorption kinetics and relatively lower desorption temperature than pure MgH2 or MgH2-purified single-walled carbon nanotube composite. Storage capacities of 6.0 and 4.2 wt % hydrogen for the MgH2-5ap composite were achieved in 60 min at 423 and 373 K, respectively. Furthermore, its desorption temperature was reduced by 70 K due to the introduction of as-prepared single-walled carbon nanotubes (SWNTs). In addition, the different effects of SWNTs and metallic catalysts contained in the as-prepared SWNTs were also investigated and a hydrogenation mechanism was proposed. It is suggested that metallic particles may be mainly responsible for the improvement of the hydrogen absorption kinetics, and SWNTs for the enhancement of hydrogen absorption capacity of MgH2. 相似文献
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An X-ray fluorescence method for determining trace elements in silicate rock samples was studied. The procedure focused on the application of the pertinent matrix corrections. Either the Compton peak or the reciprocal of the mass absorption coefficient of the sample was used as internal standard for this purpose. X-ray tubes with W or Cr anodes were employed, and the W Lβ and Cr K Compton intensities scattered by the sample were measured. The mass absorption coefficients at both sides of the absorption edge for Fe (1.658 and 1.936 Å) were calculated. The elements Zr, Y, Rb, Zn, Ni, Cr and V were determined in 15 international reference rocks covering wide ranges of concentration. Relative mean errors were in many cases less than 10%. 相似文献
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Zhengwei Qu Yi Wang Pingan Yang Wei Zheng Nan Li Jingying Bai Youwei Zhang Kailin Li Dashuang Wang Zhaohui Liu Kexin Yao Rui Li Yuxin Zhang 《Molecules (Basel, Switzerland)》2022,27(1)
In this work, spherical flower-shaped composite carbonyl iron powder@MnO2 (CIP@MnO2) with CIP as the core and ultrathin MnO2 nanosheets as the shell was successfully prepared by a simple redox reaction to improve oxidation resistance and electromagnetic wave absorption properties. The microwave-absorbing properties of CIP@MnO2 composites with different filling ratios (mass fractions of 20%, 40%, and 60% after mixing with paraffin) were tested and analyzed. The experimental results show that compared with pure CIP, the CIP@MnO2 composites have smaller minimum reflection loss and a wider effective absorption bandwidth than CIP (RL < −20 dB). The sample filled with 40 wt% has the best comprehensive performance, the minimum reflection loss is −63.87 dB at 6.32 GHz, and the effective absorption bandwidth (RL < −20 dB) reaches 7.28 GHz in the range of 5.92 GHz–9.28 GHz and 11.2 GHz–15.12 GHz, which covers most C and X bands. Such excellent microwave absorption performance of the spherical flower-like CIP@MnO2 composites is attributed to the combined effect of multiple beneficial components and the electromagnetic attenuation ability generated by the special spherical flower-like structure. Furthermore, this spherical flower-like core–shell shape aids in the creation of discontinuous networks, which improve microwave incidence dispersion, polarize more interfacial charges, and allow electromagnetic wave absorption. In theory, this research could lead to a simple and efficient process for producing spherical flower-shaped CIP@MnO2 composites with high absorption, a wide band, and oxidation resistance for a wide range of applications. 相似文献
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Howell SL Gordon KC Waterland MR Leung KH Phillips DL 《The journal of physical chemistry. A》2006,110(38):11194-11199
The lowest energy transition of [Ru(CN)(4)(ppb)](2-) (ppb = dipyrido[2,3-a:3',2'-c]phenazine), a metal-to-ligand charge transfer, has been probed using resonance Raman spectroscopy with excitation wavelengths (488, 514, 530, and 568 nm) spanning the lowest energy absorption band centered at 522 nm. Wave packet modeling was used to simultaneously model this lowest energy absorption band and the cross sections of the resonance Raman bands at the series of excitation wavelengths across this absorption band. A fit to within +/-20% was obtained for the Raman cross sections, close to the experimental uncertainty which is typically 10-20%. Delta values of 0.1-0.4 were obtained for modes which were either localized on the ppb ligand (345-1599 cm(-1)) or the CN modes (2063 and 2097 cm(-1)). DFT calculations reveal that the resonance Raman bands observed are due to modes delocalized over the entire ppb ligand. 相似文献