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.     

科技论文关键词撰写探讨

以《低温与超导》为例,探讨关键词写作中的一般规律以及需要注意的事项。还给出一些提高关键词写作质量的建议。     

Electroactive-paper actuator made with cellulose/NaOH/urea and sodium alginate

In an earlier work we reported the discovery of cellulose as a smart material that can be used in sensors and actuators. While the cellulose-based Electro-Active Paper (EAPap) actuator has many merits – lightweight, dry condition, biodegradability, sustainability, large displacement output and low actuation voltage – its performance is sensitive to humidity. We report here on an EAPap made with a cellulose and sodium alginate that produces its maximum displacement at a lower humidity level than the earlier one. To fabricate this EAPap, we dissolved cellulose fibers into a aqueous solution of NaOH/urea. Sodium alginate (0, 5 or 10% by weight) was then added to this cellulose solution. The solution was cast into a sheet and hydrolyzed to form a wet cellulose-sodium alginate blend film. After drying, a bending EAPap actuator was made by depositing thin gold electrodes on both sides of it. The performance of the EAPap actuator was then evaluated in terms of free displacement and blocked force with respect to the actuation frequency, activation voltage and content of sodium alginate. The actuation principle is also discussed.     

Ion-Exchange Chkomatographic Determination of Aming Acids On Impresgnated Papers

Abstract

The modified optical density method of Moore and Stein has been used for the estimation of amino acids present in biological samples. the mixture of amino acids were chromatographad on bismuth oxide impregnated papers, the identified spots were cut out and eluted, the optical densities were measured at 570 nm. With the help of a calibration curve, the amino acids present in the samples were estimated.     

Determination of Fluorescent Whitening Agents in Infant Clothes and Paper Materials by Ion‐Pair Chromatography and Fluorescence Detection

A simple and rapid method was developed to simultaneously determine four stilbene‐type disulfonate and one distyrylbiphenyl‐type fluorescent whitening agents (FWAs) in infant clothes and paper materials by ion‐pair chromatography. FWAs were extracted from cloth and papers samples using a hot‐water extraction. The aqueous extract was then mixed with ion‐pair reagent, extracted with C₁₈‐SPE cartridges and eluted with methanol. The contents of FWAs were determined by an isocratic ion‐pair chromatography with RP‐C₁₈ column and equipped with fluorescence detection. Limits of quantitation were 0.04 to 0.45 ng/g in 10 g of samples. Recovery of FWAs in spiked infant cloth and paper samples was between 76 to 92% and precision (RSD) ranging from 2.0 to 4.0%. Analysis of three infant clothes and six paper materials found concentrations of selected FWAs ranging between n.d. to 24 μg/g and n.d. to 3.8 μg/g, respectively.     

Chromatographic Behaviour of Anions of Zr (IV) Molybdate Papers and Silica Gel ‘G’ Thin Layers

Abstract

Ion exchange potential of Zr (IV) molybdate and silica gel ‘G’ has been explored in paper chromatography and thin layer chromatographic studies for the separation of anions from one another. Several Important and difficult separations of anions have been achieved as a result of these studies. IO^? ₃ - BrO₃ ^?, Br^? - NO₂ ^?, IO₄ ^? - I^?, NO₂ ^? - NO₃ ^?, NO₃ ^? - BO₃ ^?, NO₃ ^? - BrO₃ ^?, PO₄ ^— - F^? and PO₄ ^— - IO₃ ^? are separations of practical Interest.     

Paper Chromatography of 34 Organic Acids on Calcium Carbonate and Calcium Sulphate Impregnated Papers

Abstract

Paper chromatographic separations of 34 organic acids on calcium carbonate and calcium sulphate impregnated paper has been developed. Tricarboxylic acids, dicarboxylic acids, amino acids, and keto acids and their derivatives can be separated in simple solvents such as acetone, ethanol, water, aqueous sodium chloride, ammonium chloride and calcium nitrate. Important separations achieved are: Adipic from maleic and malonic, cis-aconitic from I-cystine and nicotinic, citric or tartaric from ascorbic, gallic, malic and salicylic, I-aspartic from arginine-HCl, fumaric and glutamic, barbituric from hippuric and α-ketoglutaric, benzoic from ρ- & m-nitrobenzoic and cis-aconitic from trans-aconitic.     

Substrate pre-treatment of flexible material for printed electronics with carbon nanotube based ink

In this work, an innovative solution was developed in order to make paper-based material, used traditionally in the packaging and labelling industries, compatible with the printing of functional conductive inks. In order to avoid the deterioration of the ink functionalities due to different paper properties, a UV-curing inkjettable primer layer was developed. This pre-treatment enables homogeneous surface properties such as smoothness, absorption capacity and surface energy to be obtained, for almost all the examined substrates. To confirm the positive impact of such pre-treatment, conductivity has been measured when using a new conductive ink, combining the processability of the PEDOT-PSS conductive polymer with the high electrical properties of carbon nanotubes (CNTs). Significant improvement has been measured for all paper materials and similar conductivity (close to reference PET film) has been obtained whatever the substrate involved. This pre-treatment now makes it possible to consider paper-based material as a potential substrate for printed electronics. In this case, the substrate adaptation technique offers an innovative solution to produce low-cost and flexible electronics.