Evaluation of filter papers as substrates for solid-surface room-temperature fluorimetry and photochemical fluorimetry

Filter papers (Whatman Nos. 1 and 41, S & S 904) and anion-exchange filter paper (Whatman DE-81) have been evaluated for their use as substrates in solid-surface room-temperature fluorescence (RTF) and photochemical fluorescence (RTPF). Several chemical treatments of filter papers are found not to reduce significantly their background fluorescence signal. Analyte fluorescence signals are 2-4 times higher on filter papers than on silica-gel TLC plates. Absolute limits of detection range between 0.6 and 40 ng on the Whatman filter papers, depending on the test compound. Filter papers are proposed as convenient, inexpensive, and easy-to-handle substrates for RTF and RTPF measurements.     

How to write a paper on atomic-absorption spectrometry

The present situation in the preparation of new papers on atomic-absorption spectrometry is discussed. The different types of papers published in this field are reviewed, and details given of the topics that must be dealt with in writing such papers. Particular attention is given to experimental papers dealing with new instrumentation, study of the analytical behaviour of analytes, and new procedures for specific analytical applications.     

Effects of Carbon Nanotube Paper Properties on Enzymatic Bioanodes

Carbon papers are frequent current collectors in fuel cells, but recently carbon nanotube papers have been introduced as new types of carbon paper. They have varying thickness, surface area, density, gas permeability, and conductivity. This paper studies the effect of these properties on electrochemical performance. Electropolymerizing methylene green on each carbon nanotube papers was performed to study the papers’ ability to oxidize NADH. Secondly, glucose bioanodes were formed with carbon nanotube papers to study glucose bioelectrocatalysis. The optimal carbon nanotube paper had a high surface area, low gas permeability, and low sheet resistance. Our results showed a greater than three‐fold increase in sensitivity over commercially available Toray carbon paper.     

Growth of a journal reflects trends in the literature of nuclear analytical methods

The results of a scientometric analysis of 50 volumes of the Journal of Radioanalytical Chemistry (further on JRC) are presented. The investigated items are: growth of the journal, distribution of papers according to countries, language and topics, turnover of papers, distribution and growth of the number of papers published from various countries, doubling times as well as relationship of the JRC to other journals.     

Chromatography of leaf chloroplast pigments on ion-exchange papers

For the separation of leaf carotenoid pigments, some ion-exchange papers are more effective than pure cellulose papers. Separations of the major pigments on ion-exchange paper are superior to those obtained by uni-dimensional paper chromatography. For green-leaf extracts, ion-exchange papers offer no advantage. Ion-exchange columns do not separate the chloroplast pigments. On ion-exchange paper, there is no major yellow pigment in addition to neoxanthin, violaxanthin, lutein, and carotene.     

Ion-Exchange Chromatographic Separation of Anions on Hydrated Bismuth Oxide Impregnated Papers

Abstract

A comparative study of the chromatographic behaviour of anions, iodide, sulphide, phosphate, arsenate, arsenite, vanadate, chroraate, dichromate, thiosulphate, thiocyanate, ferricyanide and ferrocyanide on papers impregnated with hydrated bismuth oxide and untreated Whatman no, 1 papers has been made by employing identical aqueous, non-aqueous and mixed solvent systems. Sharp and compact spots were obtained with impregnated papers whereas the opposite applied to plain papers. Various analytically important binary and ternary separations are reported.     

Analytical Applications of Ion-Exchange Materials. V. Chromatographic Separation of Drugs on Ferric Phosphate Papers

Abstract

Chromatography of 14 drugs is performed on papers impregnated with ferric phosphate. Nine solvent systems are used based on aqueous phosphate buffers and mixed organic solvents. The Rf values on plain papers and impregnated are compared. Some important binary separations are practically achieved.     

Publication activity on radioanalytical chemistry in the German Democratic Republic

The growth of the number of papers on radioanalytical methods and activation analysis, the distribution of the authorship and papers published in various periodicals are determined in the course of a scientometric analysis using the first complete National Bibliography of GDR on Radioanalytical Chemistry as a database.     

原子发射光谱分析

本文是《分析试验室》期刊单年度定期评中关于发射光谱的第四篇综述文章。文中对１９９５－１９９６年期间我国在ＡＥＳ领域所取得的主要进展作了简要的评述，包括概述，会议，综述，基础理论研究，样品引入，生命材料，环境科学分析及不同光源的原子发射光谱研究，引用３００多篇文献。     

以砂纸为模板制作聚合物超疏水表面

报道了一种聚合物材料超疏水表面的简便制备方法. 以不同型号的金相砂纸为模板, 通过浇注成型或热压成型技术, 在聚合物表面形成不同粗糙度的结构. 接触角实验结果证明, 聚合物表面与水的接触角随着所用砂纸模板粗糙度的增加而加大, 其中粒度号为W7和W5砂纸制作的表面与水的接触角可超过150°, 显示出超疏水性质. 多种聚合物使用砂纸为模均可制备不同粗糙度及超疏水的表面, 本征接触角对复制表面浸润性的影响从Wenzel态到Cassie态而变小. 扫描电镜结果表明, 不规则形状的砂纸磨料颗粒构成了超疏水所需要的微纳米结构的模板.     

Electrochemical methods of analysis of inorganic substances. Publications for 1990–1999

The data of the scientometric study of publications in inorganic electrochemical analysis for 1990– 1999 were presented. Most of the published papers (from 60 to 80%) deal with voltammetry and potentiometry. Since 1997, the number of papers on voltammetry has been higher or equal to the number of papers on potentiometry, which is due to the successive development of modified electrodes, the use of ultramicroelectrodes, and the development of stripping voltammetry, including adsorption voltammetry. The role of electrochemical analysis in the development and production of sensors was discussed. The most advantageous methods are potentiometry and conductometry; the role of amperometry is also significant. It was underlined that, although the number of papers on coulometry is low, this method is the most precise absolute method of analytical chemistry. The contribution of conferences on analytical chemistry to the publications on electrochemical methods and the elements leading in the number of publications are considered. Presented at the V All-Russian Conference with the Participation of CIS Countries on Electrochemical Methods of Analysis (EMA-99), Moscow, December 6–8,1999.     

用荧光光谱双总体t检验法鉴别纸张

本文用荧光分光光度法对纸张的荧光特性进行了研究。根据其激发光谱、发射光谱和二阶导数光谱的特性,鉴别了部分外观相近不同种类的纸张。特别将数理统计中的“假设检验”理论对纸张的荧光强度进行ｔ检验处理,提出了分辨率,为纸张的进一步认定提供了科学依据。     

Chromatographic behaviour of 47 metal ions on titanium(IV) arsenate papers

Titanium arsenate papers with As/Ti ratios 0.2-2.2 have been prepared and 47 metal ions chromatographed on these papers in 10(-5)-4M nitric acid. The effect of pH and of the Ti/As ratio on the R(f) values has been studied. A new quantity R(i) (R(i) = R(f) on untreated papers minus R(f) on treated papers) has been defined. The effect of the concentration of the loading reagents on the Ti/As ratio of the ion-exchanger precipitated on the papers has been determined Contrary to Alberti, it is shown that Lederer's equation is obeyed by titanium arsenate papers in the sodium form if the activity of Na(+) ions is considered instead of their concentration. It has also been demonstrated that the selectivity sequence for cations on titanium arsenate papers is not the same as that on titanium arsenate columns.     

卷烟纸中CaCO3的定量方法比较及形貌表征研究

分别采用煅烧法、电位滴定法及络合滴定法定量测定3种卷烟纸中CaCO3的含量,发现煅烧温度和时间对煅烧法的测定结果影响很大,当煅烧温度为900 ℃,煅烧2 h时卷烟纸中的纤维可完全氧化分解;电位滴定法和络合滴定法的结果具有较高的稳定性,但卷烟纸中的金属氧化物和碳酸盐易给电位滴定法带来误差,络合滴定法通过遮蔽剂可消除杂质离子的影响,具有较高的准确性。对3种卷烟纸灰分的XPS分析结果表明,灰分中除CaO外,还含有C、Na2CO3、Na2SiO3、Na3PO4、CaSiO3、Ca3(PO4)2等物质;SEM分析结果表明CaCO3呈纺锤状微晶和团簇状体分布在纤维中。该研究结果提供了一种比较准确的定量测定纸张中CaCO3含量的方法。     

The effect of volatile organic compounds and hypoxia on paper degradation

The possible effects of volatile organic compounds (VOCs) and of hypoxic conditions on the durability of library and archival collections have been investigated. There is growing evidence that particularly in micro-environments, there may be an important contribution of these indoor-generated pollutants to the degradation of paper. However, since the principal source of VOCs in repositories is the collections themselves, there are also significant possibilities for less stable papers, which are net VOC emitters, to promote the degradation of more stable papers, which may be net VOC absorbers.Using a range of model and real historic papers, the influence of acetic acid, formic acid, furfural, toluene, 1,4-diethylbenzene, iso-butylbenzol, 2-pentylfuran, paraformaldehyde, hexanal and vanillin was evaluated by adding them to samples degraded in closed vessels at elevated temperature. Possible protective effects of the use of activated charcoal cloth, oxygen removal, and of various chemisorbents were also investigated.The results strongly suggest that particularly VOCs with acidic or oxidisable functions can have a strong effect on degradation of cellulose. This is less pronounced in lignin-containing and acidic papers and more pronounced in papers with a small alkaline reserve. The removal of VOCs from the immediate environment can have a pronounced beneficial effect on papers emitting VOCs more intensively, in fact, the lifetime expectancy can be doubled.The results have immediate implications for storage of paper-based heritage in enclosures, but also for initiation of long-term VOC monitoring programmes in libraries and archives, where significant development is still needed.     

The first decade of flow injection analysis: from serial assay to diagnostic tool

Some 804 papers on flow injection analysis published to the end of May 1985 are summarized. Past trends are discussed and new developments are briefly outlined.The paper entitled “Flow Injection Analysis. Part 1. A New Concept of Fast Continuous Flow Analysis” [1], which appeared in August 1975, was the first of some 804 papers [1/2-804] published on flow injection analysis (f.i.a.) during the past ten years. In the present contribution, all these papers are collected to record the status quo of the general method and to reveal the present trends in applications of f.i.a. and in the geographical distribution of the research activities. Important concepts and technological innovations are reviewed and the future development of f.i.a. is briefly outlined.     

pitfalls in Using Filter Paper Disks as Standard Supports In X-Ray Fluorescence Spectrometry

Abstract

Standard solutions of dimethylarsinic acid in water and methanol are deposited on Whatman No. 1 and No. 114 filter papers. The arsenic content is measured by X-ray fluorescence spectrometry. The observed specific count depends on the nature of solvents, the volume of spotting solutions, the method of spotting and the type of filter papers.     

Complexation ion-exchange chromatography of some metal ions on papers impregnated with Ti(IV)-based inorganic ion exchangers

The chromatographic behavior of 40 metal ions is studied on titanium (IV) arsenate, titanium (IV) phosphate-, titanium (IV) molybdate-, titanium(IV) tungstate-, and titanium(IV) selenite-impregnated papers in 0.1M oxalic, citric, and tartaric acid as mobile phases. Similar studies are carried out on Whatman No. 1 papers for comparison. The ion-exchange capacity of these papers is determined, and their selectivity for different cations is discussed. The mechanism of migration is explained in terms of ion-exchange, precipitation, and adsorption. The prediction of elution sequence from RF values is also checked. The average Ri is found to be almost linearly dependent on the charge of the metal ions. The effect of the pKa of complexing acids on average RF values of 3d series metal ions is explained. A number of binary and ternary separations are achieved.     

Preface - Pacifichem '95 Meeting(1)

Issues 4 and 5 of Applied Organometallic Chemistry, vol. 11, 1997 consist of papers based on work presented at two Symposia held at the Pacifichem '95 Meeting in Honalulu, Hawaii. The papers published here were reviewed by the normal process of the Journal and are not verbatim accounts of the presentations themselves.