Quantitative Determination of Iron and Aluminium in Some Alloys and Silicate Rocks After a Cation Exchange Separation on Zirconium(IV) Phospho and Silico Arsenates

Abstract

A rapid and quantitative method has been developed for the analysis of some iron and aluminium based alloys and silicate rocks using zirconium(IV) based arsenophosphate and arsenosilicate cation exchangers. The method is simple, reproducible and precise with a standard deviation <3%, for the direct determination of iron and aluminium in rocks and alloys. The low standard deviation values suggest that the method should be useful for the standardization purposes.     

A Fast Cation Exchange Separation of Iron(II) and Iron(III) on Zirconium(IV) Arsenophosphate Columns Using Potassium Thiocyanate as a Complexing Agent

Abstract

A new quantitative method has been developed for the separation of ferrous and ferric iron on zirconium(IV) arsenophosphate columns using the cation exchange properties of this material and the complex forming ability of potassium thiocyanate. The method is rapid and requires simply water as the eluant, the results obtained being precise and accurate within the experimental error range (±3%).     

Determination of zirconium in zirconium-bearing sands and zirconium concentrates by a nondispersive x-ray fluorescence method

A nondispersive X-ray fluorescence; method for the rapid, nondestructive determination of zirconium in zirconium-bearing sands and zirconium concentrates is described. A ¹⁰⁹Cd source of primary radiation and compact geometry for measurements were used. The matrix effect from iron and titanium in sands was eliminated by measuring the fluorescent radiation of zirconium and the scattered primary radiation, and interpreting the data with nomograms. For concentrates, dilution with pure sand and measurement of the ratio of fluorescence to scattered radiation were used to reduce a matrix effect; a calibration curve was then satisfactory. Particle size effects were avoided by grinding to below 70 μ.     

Use of organic reagents in inorganic analysis

Summary Thorium and zirconium have been determined gravimetrically with phenylglycine-p-carboxylic acid and zirconium alone with phenylglycine-o-carboxylic acid, almost within the same pH range. Better results are obtained when zirconium is precipitated in acetic acid solution in presence of a little ammonium acetate. A number of foreign ions may be separated from thorium and zirconium with these reagents. Iron and titanium cause heavy interference. The interference caused by iron, may however, be eliminated by adding a little ascorbic acid, before precipitation of the metals. The para acid can also extract thorium from a mixture of cerite earths and from monazite sands.Part V: See Z. anal. Chem. 158, 347 (1957).The author likes to thank Dr. B. N. Bose, Principal of the College and Dr. S. K. Sinha, the Head of the Department of Chemistry for their kind advice and encouragements.     

Analytical aspects of some organic acids

Summary Back titrimetric procedures for the estimation of aluminium, zirconium, and thorium have been developed, which involved the adjustment of the concentration of the metallic salts, concentration of EDTA,ph, and temperature, addition of indicator solution (namely, 2-hydroxy3-naphthoic acid and back titration with standard 0.1 M ferric chloride solution. This method is based on the fact that the excess EDTA, which is added to the metal solutions may be back titrated with iron(III), which forms a highly coloured complex with the indicator, when present in slight excess. Quantities of aluminium, zirconium and thorium as small as 10.8, 4.6, 11.6 mg respectively, can be back titrated with in experimental error, when present in a volume of 100 ml.Part IV: See Z. analyt. Chem. 172, 356 (1960).     

Microdetermination of Lead in Water Samples,Preconcentration by Coprecipitation Followed by its Atomic Absorption Spectrophotometric Determination

Abstract

The method incorporates coprecipitation of lead on zirconium hydroxide and its quantitative spectrophotometric determination in natural, polluted and synthetic water samples. The method incorporates coprecipitation of lead on zirconium hydroxide and its quantitative determination by AAS using 283.3 nm wavelength.     

Application of acidic extract of Platanus orientalis tree leaves as a green reagent for selective spectrophotometric determination of zirconium

Abstract

A novel spectrophotometric method for the determination of zirconium by using a new reagent, acidic extract of Platanus orientalis tree leaves is developed. In 6 M hydrochloric acid, zirconium reacts with this reagent to form a yellow product. The formed product shows maximum absorbance at 422 nm with a molar absorptivity value of 0.59×10^? l mol^?1 cm^?1 and the method was linear in the 0.4–8 µg mL^?1 concentration range. The detection limit value was found to be 0.086 µg mL^?1. The proposed method was simple, clean, low cost, selective, and sensitive. It was applied to the determination of zirconium in tap water, wastewater and well water samples with relative standard error of less than 2.5%.     

Complexometric determination of aluminium in iron ore,sinter, concentrates and agglomerates

A method for the complexometric determination of aluminium in iron ore, sinter, concentrates and agglomerates encountered in international trade is described. The sample is fused in a zirconium crucible with a mixed flux of sodium carbonate and sodium peroxide. The fused mass is completely soluble in hydrochloric acid. The R₂O₃ oxides are then precipitated with ammonia and redissolved in hydrochloric acid. Elements such as iron, titanium and zirconium are separated from aluminium by solvent extraction with cupferron and chloroform. After removal of traces of organic matter from the aqueous phase, the solution is treated with an excess of EDTA, which is then back-titrated with zinc solution (Xylenol Orange as indicator). Addition of ammonium fluoride then releases EDTA equivalent to the aluminium and this is titrated with zinc solution. The method is rapid. The precision and accuracy are excellent, and the results comparable with those obtained by the referee method.     

STABILITIES OF IRON(III) COMPLEXES WITH 3- AND 4-HYDROXYPYRIDINE

Abstract

Equilibrium constants for the reaction of 3- or 4-hydroxypyridine with iron(III) were measured in aqueous solution. The experimental method involved the measurement of hydrogen ion concentration and optical absorbance for each of a series of reaction mixtures. The results are consistent with the interpretation that the separate interactions between iron(III) and the hydroxypyridines are of the hard acid-hard base type, with sigma bonding alone being important. Equilibrium constants are reported for both the reactions in which iron(III) displaces a proton in protonated hydroxypyridine and for the direct combination of iron(III) and the hydroxypyridine.     

Analytical aspects of some organic acids

Summary A direct complexometric titration of iron(III) with EDTA using o- and p-cresotic acids indicators is given. The colour change at the end point is from blue-violet to light yellow or colourless [at low concentrations of iron(III)]. The optimum range of pH and temperature for carrying out the titrations is 1.99 to 4.2 and 35° to 55°C and 1.42 to 4.4 and 30° to 60° C, respectively. Iron(III) may easily and accurately be estimated in macro- and micro-gram quantities with the help of these metal indicators. Be, Mg, Ca, Sr, Ba, Cd, UO₂ and Mn are without any interference in the estimation. Back titration procedures for determination of zirconium and thorium with iron(III) and o- and p-cresotic acids are carried out.Part V: See Z. analyt. Chem. 173, 196 (1960).     

The determination of zirconium in fluoride-containing solutions

In the recommended procedure the zirconium is first precipitated from solution as the insoluble barium fluozirconate. After separation, the precipitate is dissolved in a mixture of nitric and boric acids and the zirconium is then precipitated as its hydroxide. This precipitate is separated, dissolved in hydrochloric acid and this solution is evaporated to fumes of perchloric acid to remove completely fluoride ions. The zirconium content is then determined volumetrically by adding a slight excess of a standard solution of ethylenediaminetetra-acetic acid and back titrating with a standard iron solution at pH 2.3 using potassium benzohydroxamate as indicator and the photometric technique for end-point detection. This method is applicable to the determination of milligram amounts of zirconium in fluoride-containing nitric or hydrochloric acid solutions provided that the concentration of these acids is below 3N. It is also suitable for the determination of zirconium in the presence of any of the following elements - uranium, titanium, niobium, tantalum, molybdenum, tungsten, lead, iron, copper and tin.     

Determination of Copper,Cadmium, Zinc And Lead In ArgeŞ River In Romania During Four Seasons By Inductively Coupled Plasma Atomic Emission Spectrometry And Anodic Stripping Voltammetry

ABSTRACT

The paper represents a continued study of selected heavy metals concentration in the Arge? River, the fifth river in length from Romania.

For the determination of metal ion concentration in Arge? river was used Atomic Absorption Spectrometry for sodium, potassium and magnesium; Direct Coupled Plasma Atomic Emission Spectrometry for calcium; Inductively Coupled Plasma Atomic Emission Spectrometry for copper, cadmium, zinc, aluminium, lead, titanium, zirconium, chromium, molybdenum, manganese, iron and nickel.

Copper, cadmium, zinc and lead concentration were determined by ICP–AES and ASV and results were reliable.

By comparison of the results a good agreement between these two techniques is observed.     

Synthesis, characterization, and structural study of K2FeZrP3O12 with the langbeinite structure

A potassium iron zirconium phosphate, K₂FeZrP₃O₁₂, was synthesized by thermal treatment of a material obtained by the sol-gel method, mixing two aqueous solutions, the first containing KCl, FeCl₃ and ZrOCl₂, and the second, H₃PO₄. The crystal structure was refined using powder X-ray diffraction data. The unit cell is cubic, a=10.0554(3) Å, space group P2₁3. This compound is the first iron zirconium phosphate described with a langbeinite-type structure.     

乙烯聚合水杨醛亚胺锆配合物的合成、结构和固定化

合成和表征了2个锆的配合物：Bis[N-(3-tert-butylsalicylidene) allylaminato] zirconium dichloride (4)和Bis[N-(3-tert-butylsali-cylidene)-iso-butylaminato] zirconium dichloride (5)，并且得到了配合物4的单晶结构。在引发剂的作用下，配合物4和苯乙烯进行自由基共聚，得到高分子化催化剂6。在助催化剂MMAO的存在下，4，5和6都可以催化乙烯聚合。最高活性为3.7×10⁶ g PE·(mol Zr)^-1·h^-1。     

Quantitative Separation of Iron from some Multivitamin-Multimineral Formulations using Zirconium (Iv) Arsenophosphate Columns

Abstract

Iron has been separated quantitatively from various multivitamin-multimineral formulations on zirconium(IV) arsenophosphate columns. The method is simple and selective with a high degree of accuracy and precision.     

Solvent Extraction Separation of Zirconium (iv) With Anberlite LA - 1 From Citrate Solutions

Abstract

Zirconium was quantitatively extracted with 8 × 10^?2 M of Amberlite LA-1 or LA-2 xylene from 0.001 M citric acid at pH 3.5 and it was stripped from the organic phase with 2 M hydrochloric acid and was determined spectrophotometrically at 665 nm as its complex with arsenazo III. Zirconium was separated from binary as well as tertiary mixtures by exploiting the difference in the distribution coefficient or by selective extraction or selective stripping. The method was applied for the analysis of zircon.

Zirconium was extracted as its anionic complex with various mineral acids by liquid anion exchanger. The chlorocomplex of zirconium was extracted from 6–10 M hydrochloric acid with trioctylamine^1–5, triisooctylamine⁶ or Aliquat 3365⁷. The sulphotocomplex of zirconium was extracted with Aliquat 3365⁸, Primine JMT⁹, Alamine 336¹⁰. The nitratocomplex was less extensively utilised for the extractive separation of zirconium^{11, 12}.

Zirconium was extracted quantitatively from oxalate^{13, 14} and malonate media¹⁵. These extractions were carried out at low pH and separated zirconium from large number of associated elements. The ion exchange chromatographic behaviour of zirconium on column with cation exchange^16–17 or with anion exchange¹⁸ resin with citric acid as eluent were utilised but extraction studies from citrate solutions were never attempted.

From the critical study of existing methods it was observed that zirconium was extracted at narrow pH range; with high concentration of complexing ligand for extraction with liquid anion exchangers and long period of equilibration for extraction as well as stripping. So also such extractions were possible mostly at milligram concentrations involving use of hazardous diluents like benzene. In order to circumvent these difficulties an attempt was made to develop a better method for the solvent extraction separation of zirconium by ion pair formation.

Therefore this paper presents systematic investigations on the solvent extraction separation of zirconium from citrate media with liquid anion exchangers. From the study of various factors. The optimum conditions for the extraction and the separation of zirconium from associated elements are evaluated. The method has been extended for the analysis of zirconium from zircon.     

Use of organic reagents in inorganic analysis

Summary Eighteen anilic acids have been prepared from maleic anhydride and various aromatic amines and their properties and analytical reactions with various metal ions have been studied. The acid prepared from benzidine was insoluble in all common solvents and, hence, its application could not be studied. Most of these reagents, except those obtained from aniline, o- and p-chloroanilines, nitranilines, p-amino-acetanilide and o-phenylenediamine, produced more or less quantitative precipitations with both thorium and zirconium. Their actions towards thorium and zirconium were very much alike. They also gave precipitations with mercury(I), lead and cerium(IV), but such precipitations were not complete. Ferrous iron showed greyish turbidity with most of the reagents, but ferric iron produced colourations varying from brown to violet, such colours were, however, found to be unstable either on standing for a while or on heating. Gold and platinum underwent reduction in presence of these reagents.Part VIII: See Z. analyt. Chem. 163, 403 (1958).The work has been carried out in the chemical laboratories of Darjeeling Government College, Darjeeling. The author is grateful to the authorities of the College for the laboratory facilities.     

Spectrofluorimetric Determination of Zirconium Based on the Inclusion Complex of 8-Hydroxy 7 Iodo Quinoline Sulfonic Acid with β-Cyclodextrin As Ligand

Abstract

Ferron form inclusion complex with β-cyclodextrin in aqueous media at pH 3.2 with an association constant of 25 M^?1. This ligand has been used for the fluorimetric determination of zirconium at trace levels. The limit of detection is 0.07 μg/ml and the RSD is 5.2%. A significant improvement in selectivity is gained in the β-CD method compared to the method in absence of cyclodextrin.     

Simple UV and visible spectrophotometric methods for the determination of doxycycline hyclate in pharmaceuticals

Doxycycline hyclate (DOX), a broad spectrum antibiotic with activity against a wide range of gram-positive and gram-negative bacteria, is widely used as a pharmacological agent and as an effector molecule in inducible gene expression system. Three simple, selective, rapid, accurate, precise and cost-effective spectrophotometric methods for the determination of DOX in bulk drug and in tablets have been developed and validated. First method (method A) is based on the measurement of absorbance of DOX in 0.1 M HCl at 240 nm. The second method (method B) is based on the measurement of yellow chromogen at 375 nm which is formed in 0.1 M NaOH. The third method is based on the measurement of 2: 1 complex formed between DOX and iron(III) in H₂SO₄ medium, the complex peaking at 420 nm (method C). The optimum conditions for all the three methods are optimized. Beer’s law was obeyed over the ranges 2.5–50.0, 1.50–30.0 and 10–100 g/mL for method A, method B and method C, respectively. The apparent molar absorptivity values are calculated to be 1.03 × 10⁴, 1.73 × 10⁴, and 5.21 × 10³ L mol⁻¹ cm⁻¹ for method A, method B, and method C, respectively. The Sandell sensitivity, limit of detection (LOD) and limit quantification (LOQ) values are also reported. All the methods were validated in accordance with current ICH guidelines. The developed methods were employed with high degree of precision and accuracy for the estimation of total drug content in commercial tablet formulations of DOX.     

Flow-injection spectrophotometric determination of fluoride by using the zirconium/alizarin red S complex

A spectrophotometric flow-injection procedure is described for fluoride in aqueous samples. The method is based on the decrease in absorbance of the zirconium/alizarin red S complex at 520 nm; linear response is obtained for the range 0.1–10 mg l^?1 fluoride at a sampling rate of 100 h^?1. Aluminum(III), iron(III) and phosphate interfere.