The identification of some inorganic anions on the micro-scale using a slotted oven

Summary A slotted oven has been devised for the separation and identification of anions (ferrocyanide, ferricyanide, cobalticyanide, tungstate, molybdate, iodate, bromate, chromate, periodate, chlorate and nitrite) using 2–5l of solution. The anions are separated into four groups within which individual anions may be identified.

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Zusammenfassung Für die Trennung und Identifizierung von Anionen [Cyanoferrat(II), Cyanoferrat(III), Cyanokobaltat, Wolframat, Molybdat, Jodat, Bromat, Chromat, Perjodat, Chlorat und Nitrit] unter Verwendung von 2 bis 5l Lösung eignet sieh ein von den Autoren beschriebener, mit einem Schlitz versehener Ofen. Die Anionen werden in vier Gruppen aufgeteilt und dann identifiziert.

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Résumé On a cherché à réaliser un four à baïonnette pour la séparation et l'identification d'anions (ferrocyanure, ferricyanure, cobalticyanure, tungstate, molybdate, iodate, bromate, chromate, periodate, chlorate et nitrite) sur 2–5l de solution. On sépare les anions en quatre groupes sur lesquels on peut identifier les anions individuels.

     

Identification of some polyatomic inorganic anions as their diphenyliodonium salts by infrared spectroscopy and interpretation of the spectra

The main features of infrared spectra of the diphenyliodonium salts of some polyatomic anions are reported and interpreted, and their application in qualitative analysis discussed.     

Infrared spectra of some alkylfurans

The possibility of using the region of the C=C and C-H vibrations of the furan ring for the analysis of the structure of substituted furans and the possibility of determining the structure of the side chain in alkylfurans and alkylbenzofurans have been shown.     

Infrared spectra of some organophosphorus extractants

The infrared spectra of a group of organo-phosphorus compounds useful for extraction of metals from acidic aqueous solutions are presented and discussed. The spectra of a few organophosphorus degradation products or probable impurities are also included. Many of the organic groups responsible for some of the absorption bands are identified.     

Heterometric microdetermination of cobalt using nitron as titrant

Small amounts of cobalt (0.1–0.25 mg in 15 ml solution) were determined heterometrically in the presence of potassium thiocyanate by titration with nitron acetate solution. A strong electrolyte (Na₂SO₄) must be added to obtain a clear end point. The titration can be carried out in the presence of a number of diverse ions e.g., Cd²⁺, Ni²⁺, Pb²⁺, Mn²⁺, Cr³⁺, MoO₄^2?, WO₄², CrO₄^2?, NO₃^?, Au³⁺, Pt⁴⁺ without interference; Fe³⁺ can be masked with NaF. Copper and zinc interfere and must be absent. The titration takes about 2–3 min. and the maximum error was 1.5%.     

Interpretation of solute retention of some monovalent inorganic anions in anion-exchange chromatography using a dicarboxylic Acid as an eluent.

In single-column anion-exchange chromatography, the retention volume of some monovalent inorganic anions (Cl(-), Br(-), NO(3)(-), NCS(-) and NO(2)(-)) were observed as a function of the pH of a mobile phase at a fixed concentration of 2-phenylmalonic acid or 1,4-benzenediacetic acid used as an eluent. The experimental retention volume of such an anion was decreased with an increase in the pH of a mobile phase, and was able to be described by the following equation taking account of anion-exchange equilibria of a sample anion with a hydrogen dicarboxylate ion (HE(-)) and with a dicarboxylate ion (E(2-)): alpha(1s)/V(R)'[HE(-)] = 1/m(T)wK(ex1) + (2K(a2)/m(T)w(2)K(ex2))(V(R)'/alpha(1s)[H(+)]), where V(R)', m(T), w, K(a2), K(ex1) and K(ex2) are the adjusted retention volume of a given sample anion, the capacity for the anion-exchange of column packings and the weight of column packings packed into a separating column, the second acid-dissociation constant of the dicarboxylic acid used as an eluent, and equilibrium constants for the anion exchange of a sample anion with a monovalent hydrogen dicarboxylate ion and with a divalent dicarboxylate ion, respectively. The term alpha(1s), defined as K(as)/([H(+)] + K(as)), where K(as) is the acid-dissociation constant of HX, is the mole fraction of a sample anion, X(-), and is equal to 1 when using a strong acid anion as a sample anion.     

稀土丙酸盐的红外光谱研究

本文研究了La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y十三种稀土丙酸盐的FT-IR光谱, 对1800-100cm^-^1的主要红外吸收谱带进行了归属, 指认316-349cm^-^1的强吸收带为Ln-O键的伸缩振动带. 稀土丙酸盐红外光谱表明存在两种不同的羧基配位形式. 从La到Tm以及Y等十一种丙酸配合物的配位羧基具有对称的螯合双齿形式, 而对稀土Yb和Lu, 与中心离子配位的三个羧基中, 至少有一个羧基具有螯合桥式三齿配位形式. 结果还表明稀土丙酸盐Ln-O键基本上是离子键.     

Indirect spectrophotometric determination of borate using nitron as reagent

An indirect method is outlined for the spectrophotometric determination of small amounts of borate. Borate is quantitatively precipitated as nitron tetrafluoborate in the presence of excess nitron. After separating off the precipitate, the excess of reagent is determined in the supernatant liquid as nitron cobaltothiocyanate.     

Ion chromatographic separation of some aminopolycarboxylic acids and inorganic anions

Microchimica Acta - An ion Chromatographie method of separating polyaminocarboxylic acids is described. A mixture of EDTA, NTA, HEIDA, and IDA is separated. A small amount of phosphate can be...     

Indirect spectrophotometric determination of perchlorate using nitron as reagent

An indirect method is outlined for the spectrophotometric determination of small amounts of perchlorate. Perchlorate is quantitatively precipitated as nitron perchlorate in the presence of excess nitron. After separating off the precipitate, the excess reagent is determined in the supernatant liquid as nitron cobaltothiocyanate. The latter compound is extracted in 30% cyclohexanone in carbon tetrachloride and the absorbance of the extract measured at 625 nm. The method is simple, reproducible, and accurate to ±1%. The interferences of other anions were also investigated.     

Simple electrooptical sensors for inorganic anions

[reaction: see text] Electrooptical sensors consisting of a conjugated chromophore undergoing a change in color and a redox-active moiety such as quinone fused to the chromophore were synthesized. Strong changes in colorimetric and electrochemical properties were observed in the presence of inorganic anions. A unique anion-specific response was observed for fluoride, pyrophosphate, and acetate. DFT (B3LYP/6-31G) calculations performed for both "on/off" states of a sensor-fluoride model are in good agreement with the observed electrochemical and spectroscopic data.     

Indirect photometric detection of inorganic anions by microcolumn liquid chromatography using anthraquinone-disulfonate as visualization agent

Summary Disodium salts of several anthraquinone-disulfonic acids, which possess large molar absorptivity, were employed as the visualization agent for microcolumn ion chromatography with indirect photometric detection. Detection limits of inorganic anions were improved, e.g., concentration detection limits of chloride, nitrate and sulfate were 0.91–1.6 mol L^–1 at S/N=3, corresponding to mass detection limits of 18–32 fmol. The present system was applied to the determination of inorganic anions in tap water.     

Cationic diazacrown ethers as selectors for the separation of inorganic anions by capillary electrophoresis

Two types of positively charged diazacrown ether derivatives involving two quaternary ammonium ions in the 12- and 18-membered rings have been investigated as selectors for the separation of inorganic anions by capillary electrophoresis. Both the cationic macrocycles largely affected the electrophoretic mobilities of analyte anions, and a group of seven inorganic anions examined in this study was completely separated in less than 2.2 min by the use of the low concentration of the additives. From the determination of ion association constants, the cationic diazacrowns were found to show greater electrostatic interaction with divalent anions than with monovalent ones.     

Separation of inorganic anions using a series of sulfobetaine exchangers

A set of five new sulfobetaine exchangers with inner quaternary amines and outer sulfonic acids have been prepared. A series of zwitterionic precursors was attached to highly porous divinylbenzene polymer using a grafting reaction, which allows a flexible adjustment of the degree of functionalisation. The resulting materials have identical spacers to the polymeric backbone and differ only in chain length between the charged functional groups. Capacities of the stationary phases were analysed by two different methods based on elemental analysis and the results obtained were found to correlate. The application of combustion elemental analysis proved an identical molar content of sulfur and nitrogen. The distance between the charged functional groups is varied from one to five methylene groups for a better understanding of the retention behaviour of inorganic anions on zwitterionic stationary phases. Inorganic anions were separated using sodium acetate eluents with varying ionic strength and pH and the behaviour of all columns has been compared to each other and to ZIC-HILIC and ZIC-pHILIC columns from Merck SeQuant. The exchangers with two and five methylene groups between the charges showed the highest retention factors. Polarity and accessibility of the anion exchange sites are dependent on the distance between the charged groups and the flexibility of the chains. These properties have a strong influence on anion separations. The exchanger with two methylene groups between the charged functional groups showed the biggest difference as compared to the commercially available ZIC-HILIC and ZIC-pHILIC exchangers.     

Infrared spectra of some polybasic acid triphenyltin IV derivatives

Triphenyltin IV polybasic acid derivatives have been synthesized, and structures suggested on the basis of their IR spectra. Tetrahedral oxoanions behave as polydentate ligands giving infinite type structures. The cleavage of these infinite type structures occurs when the derivatives react with strong Lewis bases giving discrete structure adducts. A particular type of coordination of the selenite (tetradentate) has been established.