Kinetic Model of Batch Sorption Processes: Comparing Calculated and Experimental Data

Russian Journal of Physical Chemistry A - The possibility of deriving a model of the kinetics of batch sorption processes is considered by transforming a nonlinear difference kinetic equation with...     

A Pseudo-Second Order Kinetic Equation for Sorption Processes

Russian Journal of Physical Chemistry A - The problem of substantiating a pseudo-second order equation in the kinetics of sorption processes is considered. A simple way is presented of transforming...     

高效液相色谱法直接测定血浆中的丝裂霉素C

本实验采用两根反相柱串联而形成的高效液相色谱柱切换装置，直接进样测定血浆中抗癌药物丝裂霉素Ｃ。第一根柱利用胶束流动相进行样品的纯化和富集，第二根柱对药物进行分析。紫外检测波长为３６５ｎｍ。药物的回收率在９５．９％～１００．３％之间，相对标准偏差为２．７６％。用该法对人和狗的局部和全身注射药物的血浆样品进行了测定。     

热脱附/冷阱聚焦/气相色谱/质谱法卷烟香气分析

利用热脱附装置(TDS)对烟丝粉末进行快速升温,模拟卷烟燃吸过程中蒸馏区的部分反应,用冷阱收集所脱附的物质,以GC/MS对进行定性分析.成功的分离出了有机酸、饱和烃、芳香烃、烯烃以及含氮、氧杂原子的化合物等系列超过100种有机化合物,并且还发现了典型的存在于环境中的化学污染物——邻苯二甲酸二丁酯.     

Direct Determination of Azathioprine in Human Fluids and Pharmaceutical Formulation Using Flow Injection Chemiluminescence Analysis

A simple, sensitive and inexpensive flow injection chemiluminescence method for the determination of azathioprine had been discovered. It was based on the fact that the weak chemiluminescent reaction of cerium(IV) with azathioprine in acidic medium, which was enhanced by the addition of rhodamine 6G. A lot of optimized experimental conditions had been studied in detail. The CL intensity was linearly related to the concentration of azathioprine in the range of 0.1–10.0 μM and the detection limit was 45.0 nM (3σ). The relative standard deviation (RSD) for the technique was 2.1% (n = 11). The method had high selectivity, sensitivity and good repeatability. The proposed method had been triumphantly applied to the determination of azathioprine in human fluids and pharmaceutical formulation with satisfactory results.     

Targeted Manipulation of Metal–Organic Frameworks To Direct Sorption Properties

Metal–organic frameworks are promising materials for manifold applications. This Minireview highlights approaches for the fine‐tuning of specific sorption properties (e.g. capacity, selectivity, and breathing behavior) of this interesting class of materials. Central aspects covered are the control over the crystal morphology, the targeted tuning of sorption properties by judicious choice of metal centers and linkers, and the preparation of host–guest systems. We want to introduce the reader to these topics on the basis of the manipulation of a handful of outstanding prototypical metal–organic frameworks.     

In situ Fluorescence Study of Swelling,Sorption and Desorption Processes in and out of PAAm Gels

Summary: Small molecule sorption and desorption in and out of polyacrylamide (PAAm) gels were studied at various temperatures. Pyranine (P_y) dissolved in water used as a probe. Fluorescence emission intensity, I_p from P_y was monitored for studying sorption and desorption processes. Scattered light intensities, I_sc from PAAm gel was also monitored to observed structural variations during sorption and desorption process. Li-Tanaka model was applied to produce the swelling time constants, τ_c and sorption coefficients, D_c for the swelling processes. On the other hand, sorption and desorption processes were studied and coefficients were produced by using Fickian model. Related activation energies were also calculated from the corresponding physical processes.     

荧光分光光度法直接测定盐酸异丙嗪片剂及注射液的含量

以０．０００１ｍｏｌ／Ｌ盐酸的溶剂,３０３ｎｍ为激发波和ｎｍ为发射波和散荧光分光光度法直接测定盐酸异丙嗪片剂及注射液中盐酸异丙嗪的含量。盐酸异丙嗪在０．１～１０．０μｇ／ｍＬ浓度范围呈良好线性。片剂及注射液的测定平均变异系数分别为０．３１％和０．４５％,回收率分别为９９．９％和９９．６％。     

直接进样电喷雾质谱分析烷基苯磺酸盐

采用直接进样法，电喷雾质谱分析三次采油用烷基苯磺酸盐，可以得到定性结果，定出该表面活性剂中各组分的分子式，操作简单易行．     

Direct Formation of Cycloadducts Between Fullerenes and Amino Acids Through Electron-Transfer Processes

Abstract

The reactions of [60]fullerene and amino acids in the absence of aldehyde in o-dichlorobenzene (ODCB) at 150 °C have been investigated. Fulleropyrrolidines 1 [C₆₀(CH₂N(CH₃)CHC₆H₂(NO₂)₃)], 2 [C₆₀(CH₂N(CH₃)CH₂)], 3 [C₆₀(CH₂NHCH₂)], and 5a–b [C₆₀(RCHNHCHR), R?CH₃ (5a), R?CH₂Ph (5b)] were obtained in moderate yields from the reactions of C₆₀ and corresponding amino acids. The reaction of C₇₀ and N-methylglycine in the absence of aldehyde was also studied and was found to give the positional isomers of N-methyl[70]fulleropyrrolidines 6 (1,9-isomer) and 7(7,8-isomer). All products were fully characterized by ultraviolet–visible, Fourier transform–infrared (FT-IR), NMR, and mass spectrometry. The reactions were also carried out in the dark to exclude the possible interference of the photoinduced reactions, and almost the same yields of products were obtained.     

Particle Injection in Direct Current Air Plasma Spray: Salient Observations and Optimization Strategies

External injection of high-melting point low thermal conductivity ceramics orthogonal to a typical direct current thermal plasma jet plays a vital role in determining the in-flight state of the particles and the process downstream. The interactions between low density ceramic particles and high temperature plasma jet is quite complex, which influences the spray process and associated deposition. Detailed in-flight particle diagnostics as well as spray stream visualization have significantly enhanced our capability to diagnose and control the process. In this paper we present some salient observations on the role of key variables on particle injection. A number of experiments were conducted using a 7MB torch (Sulzer Metco, Westbury, NY) with both Ar–H₂ and N₂–H₂ plasma gases, where the carrier gas flow to inject Yttria Stabilized Zirconia (YSZ) was varied systematically and the resulting in-flight particle state was captured using an array of particle and spray stream sensors arranged in a 3D set-up. A notable observation is the existence of a “sweet-spot” in the plasma jet where the particle temperatures and velocities achieved a maximum. This sweet-spot can be characterized by the plume position (location of centroid of the spray stream) rather than carrier gas flow rate and is independent of primary gas flows and other process/material conditions. This result suggests a possible approach to optimize particle injection independent of plasma-forming-torch-parameters. Controlling particle injection at this sweet-spot has shown to benefit the overall process efficiency (in terms of melting) and process reliability (both in-flight measurement and coating build-up) with concomitant application benefits.     

毛细管气相色谱直接柱内进样技术的研究

发展了一种新型进样技术，使样品直接进入位于炉箱内的色谱柱内，样品的汽化，溶质聚焦和分离过程都在炉箱里一次控制完成，不再需要对进样器的温度和其它流量进行控制，极大地简化了进样器的设计和制作 ，改善了定量重复精度，减少了沸点歧视效应在炉箱里一次汽化     

Control of the Sorption Properties and Wettability of a Nonwoven Polypropylene Material by Direct Gas Fluorination

The effect of direct gas fluorination on the surface properties of a nonwoven polypropylene material was studied. Direct gas fluorination with mixtures of different compositions allows directional variation of the surface properties of the nonwoven polypropylene material. The surface becomes more hydrophobic when using a mixture of fluorine and nitrogen but less hydrophobic when using a mixture of fluorine, oxygen, and nitrogen. The modification leads to changes in the chemical composition of the surface and in the roughness of the material. The nonwoven polypropylene materials thus obtained exhibit increased sorption capacity for spent oil or water, respectively. Variation of the properties of the nonwoven polypropylene material allows expansion of its applications.

     

Study of Sorption Processes of Selected Pesticides on Soils and Ceramic Porous Cups used For Soil Solution Sampling

Abstract

Soil sorption constants of four organochlorine (lindane, dicofol, chlorfenson and tetradifon) and three organophos-phorus pesticides (dimethoate, fenitrothion and methidathion) were measured using two different soils at six concentrations.

Soil samples were collected at depths of 0-20 cm and around 100 cm from an experimental citrus crop field. Effects of soil properties (organic matter, moisture content, pH and texture) on the sorption processes were also investigated.

Partitioning of pesticides between soil and solution was investigated after batch equilibration, using pesticide concentrations ranging from 10 to 200 μg1^?1. The equilibration time was estimated in 2 h for organochlorine, and 72 h for organophosphorus pesticides. Data fitted to Freundlich types adsorption isotherms.

Analytical determinations were carried out by gas chromatography with ECD and NPD detectors, after liquid-liquid extraction with dichloromethane of the water supernatant.

Moreover, a validation of the use of suction samplers used to collect soil solution samples from the vadose zone, based on a short term study in the laboratory was determined.     

Sorption of Ion Associates on Polyurethane Foams and Its Application to Sorption–Spectroscopic and Test Methods of Analysis

The results of studying the sorption of various ion associates on polyurethane foams were generalized. The main sorption-affecting factors were found to be the nature, hydrophobicity, and charge of the associate ion; the nature and concentration of the counter ion; the composition of the polymer unit of the polyurethane foam; and the pH and salt composition of the aqueous phase. Correlation equations were proposed to relate the partition coefficients with the hydration energy of counter ions in the ion associates of cationic dyes and metal complexes of 1,10-phenanthroline and with the number of carbon atoms in the alkyl fragment of cationic alkyltrimethylammonium surfactants. A sorption scheme was proposed and substantiated. Examples were given of the practical use of sorption for determining anionic and cationic surfactants, phenols, 1-naphthol, Fe(III), and Ru(IV).     

体液直接进样固定相的研究进展

评述了生物体液直接进样主效液相色谱固定相的制备、结构性能及应用。其特点可概括为：只允许生物体液中蛋白质等大分子物质与亲水的生物相容的固定相表现接触、使其在柱中无保留地洗脱、而小分子物质可获得保留、达到直接进样分析的目的。