Chlorpromazine hydrochloride as an analytical reagent : Part 1. Spot tests for inorganic ions

Chlorpromazine hydrochloride is proposed as a spot test reagent for the detection of gold, cerium, iron, chromate, manganate, bromate, iodate, nitrite, bromide, iodide, platinum and palladium. Conditions for the suppression of certain interfering substances are also given.     

Chlorpromazine hydrochloride as an analytical reagent : Colorimetric determination of micro quantities of gold

Chlorpromazine hydrochloride is proposed for the colorimetric determination of gold in acidic medium at 530 mμ. Comparatively large amounts of copper, silver, iron, lead, etc. can be tolerated. The colour is stable; Beer's law is obeyed over the range 0.5–8 mμ of gold per ml.     

Chlorpromazine hydrochloride as a new redox indicator in vanadametry

Chlorpromazine hydrochloride is proposed as an indicator in the vanadametric titration of iron(II) and molybdenum(V). It gives a sharp, reversible colour change from green to violet at the equivalence point. It has advantages over the diphenylamine class of indicators. Its redox and transition potentials are reported.     

Methyl orange as a redox indicator in titrations with ceric ammonium nitrate in perchloric acid

Summary Conditions for the use of methyl orange as a redox indicator for the titration of iron(II), hydroquinone and oxalate with cerio ammonium nitrate dissolved in perchloric acid, have been established. It is found that methyl orange behaves as a reversible indicator with a transition potential of 955±10 mV. Nitric acid as a medium of titration is not satisfactory.

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Zusammenfassung Methylorange kann als Redoxindicator bei der Titration von Eisen(II), Hydrochinon und Oxalat mit Cer(IV)-ammoniumnitrat in perchlorsaurer Lösung verwendet werden. Der Indicator hat ein Umschlagspotential von 955±10 mV. In salptersaurem Medium erhält man keine befriedigenden Werte.

     

Fast grey as a new indicator in titrations with EDTA

An acqueous solution of the Solochromate Fast Grey RA dye has proved a suitable indicator for the direct determination of thorium, ferric iron, bismuth and zinc, or the analysis of binary mixtures, thorium-iron, zinc-calcium, zinc-magnesium or zinc-thorium, with EDTA. Thorium can be determined in present of U, Fe, Zn, Ba, Be, Mg, and comparatively large amounts of rare carths. Ferric iron and zinc can be estimated in presence of U, Mg, Ca, Ba and Be. Cations of the rare and the alkaline carths can do not interfere with the determination of bismuth.     

Eriochrome black a as an indicator for chelatometric titrations

The use of Eriochrome Black A for the EDTA titrations of Zn, Mn, Ni, Pb and Cu ions is described. Spot tests for the determination of the sensitivity limits of detection have been made     

4-amino-4'-chlorodiphenyl as analytical reagent for sulphate

The acidic dissociation constant and the solubility of 4-amino-4'-chlorodiphenyl have been determined. The solubility of the amine sulphate has been redetermined and found to be ten times greater than reported earlier. The reason for the discrepancy is revealed, and the use of the amine as a reagent in the micro-analytical determination of sulphate is discussed in the light of the experimental results.     

2'-hydroxychalcone as an analytical reagent for beryllium

Several o-hydroxychalcones were examined to develop specific reagents for the precipitation of beryllium in the presence of elements such as aluminium and iron, which occur in its ores. All these reagents showed specificity only in the presence of EDTA. Among them, the readily obtainable 2'-hydroxychalcone is proposed as a new specific reagent for beryllium. The chalcone complex can be dried to constant weight at 105-110 degrees and the conversion factor is 0.01978. A probable structure for the complex has been suggested. Quantitative separation of beryllium from aluminium and iron carried out by this method gave good results. This method was applied for the gravimetric determination of beryllium in beryl and the results were in good agreement with those obtained by the oxide and pyrophosphate methods.     

Some new applications of ferroin as redox indicator in titrations with dichromate

Working conditions for the titration of arsenic(III), hydroquinone, ferrocyanide, uranium(IV) and molybdenum(V) with dichromate in sulphuric acid and hydrochloric acid media have been established, with ferroin as the redox indicator.     

Omega chrome green BLL: A new analytical reagent

Summary Omega Chrome Green BLL was used as a metal indicator for the direct complexometric titration of copper, lead, thorium and for the back titration of aluminium using thorium as a back titrant. It was also used as a colorimetric reagent for the microdetermination of copper and vanadium. A large number of anions and cations do not interfere in such a determination even if they are present in 10 folds the amount of copper or vanadium. Interference due to ferric iron is simply eliminated by the addition of few crystals of ascorbic acid to reduce it to the ferrous state.     

Omega Chrome Fast Blue 2G: A new metal indicator for EDTA titrations

Summary Omega Chrome Fast Blue 2G was used as an indicator for the direct titration of calcium, magnesium, manganese and nickel. A displacement reaction was described for the titration of lead and cadmium. Fenugreek mucilage which is a colourless polysaccharide was used as medium for spot tests. The method is illustrated by spot tests for Ca, Mg, Mn, Ni, and Co. It has the advantage of sensitivity and simplicity.     

Salicylaldehyde guanylhydrazone as an analytical reagent for spectrophotometric estimation of iron

The properties and analytical possibilities of salicylaldehyde guanylhydrazone as spectrophotometric reagent have been examined. A new method for the determination of iron has been developed. Iron can be determined in the presence of the oxalate, tartrate, citrate, aluminum, and others.     

Resorcinol as an analytical reagent for the spectrophotometric determination of uranium

A spectrophotometric study of the reaction of uranyl acetate and resorcinol shows that an orange-red coloured resorcinolate of composition 1:2 is formed. This colour reaction can be conveniently used for the spectrophotometric estimation of uranium at PH 4.72.     

Acenaphthenequinonedioxime as an analytical reagent: Determination of nickel in mixtures

Summary The titled reagent (ANDO) has been used as a reagent for gravimetric determination of nickel and for its separation from common cations and anions. Nickel (II) precipitates quantitatively by ANDO within the pH range 6.8–8.4. After drying the precipitate at 110°, its composition corresponds to the formula Ni(C₁₂H₇O₂N₂)₂. Many commonly associated ions, except Fe(III), Co(II) and Cu(II), do not interfere. Solvent-extraction techniques have been utilized to separate Cu(II) and Co (II) from the binary mixture. For masking Fe(III) excess citrate ion has been used. Elemental analysis confirms 12 metal-ligand ratio. The complex is approximately diamagnetic ( _eff=0.95 B. M.) and gives typical d-d spectral bands as generally observed in square planar complexes involving d⁸ electronic configuration. Electronic spectra of the metal chelate in pyridine are discussed and results of thermo gravimetric analysis are also presented. I. R. and far I. R. spectral analysis indicate the involvement of strong hydrogen bridges and metal-nitrogen bond.

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Acenaphthenchinondioxim als analytisches Reagens: Bestimmung von Nickel in Gemischen

Zusammenfassung Acenaphthenchinondioxim (ANDO) wurde für die gravimetrische Bestimmung von Nickel und für dessen Trennung von üblichen Kationen und Anionen verwendet. Ni(II) wird mit diesem Reagens quantitativ ausgefällt innerhalb des pH-Bereiches 6,8–8,4. Getrocknet bei 110° entspricht der Niederschlag der Zusammensetzung Ni(C₁₃H₇O₂N₂)₂. Viele üblicherweise anwesende Ionen, ausgenommen Fe(III), Co(II) und Cu(II), stören nicht. Die beiden letztgenannten lassen sich durch Extraktionen abtrennen, Fe(III) wird mit Citrat maskiert. Das Metall-Ligand-Verhältnis beträgt 12. Die Komplexverbindung ist nahezu diamagnetisch ( _eff=0,95 B. M.) und gibt typische d-d-Spektralbanden, wie sie üblicherweise von planar-quadratischen Komplexen mit d⁸-Elektronenkonfiguration gezeigt werden. Die Elektronenspektren des Metallchelates in Pyridin wurden diskutiert und die Ergebnisse der thermogravimetrischen Untersuchung angeführt. IR- und ferne IR-Analyse weisen auf die Anwesenheit starker Wasserstoffbrücken und auf eine Metall-Stickstoff-Bindung hin.

     

Potassium hexacyanoruthenate(II) as an analytical reagent for iron

Fe(III) undergoes a reaction with colourless Ru(CN)(4-)(6) to produce an intensely violet-blue complex that absorbs at 550 nm and obeys Beer's law over the iron concentration range 0.04-2 mug/ml in acidic medium. Some common cations and anions are tolerable at low concentrations. The procedure is applicable for determination of total iron in potable water. Destruction of organic matter is required for contaminated surface waters or soil samples.     

Spectrophotometric determination of palladium : Bismuthiol ii as an analytical reagent

A method for the spectrophotometric determination of palladium with bismuthiol 11 is described. The colour reaction is instantaneous and at 20–30° the system is stable for about 24 hours when maintained at a pH between 3 and 10. The colour system shows no sharp peak of maximum absorption but measurements can be made at any wavelength between 410 mμ and 430 mμ, preferably at 420 mμ. In this region the system obeys Beer's law at a palladium concentration of 0.4 μg to 80μg per ml. The sensitivity of the reaction is 0.0t6μg palladium per cm² (practical) or o 01 μg and 0.012μg of palladium per cm² at 410 mμ and 420 mμ respectively (Sandell). Acetone and methyl cellosolve stabilize the system. Excess of reagent and a large number of cations and anions are completely without effect. The composition of the complex in solution, which agrees well with that of the isolated compound, is Pd(C₈H₅N₂S₃)₂ with an average dissociation constant of 2.8$\text{.}\text{?}$10^-12 at 25°.     

Polypyrrole-calcion film as a membrane and solid-contact in an indicator electrode for potentiometric titrations

This paper shows the application of conducting polymers (CPs) for constructing potentiometric indicator electrodes. Two types of polypyrrole (PPy)-based calcium sensors are presented, one sensor with PPy-calcion film as the active part and the other sensor with PPy-calcion as a solid-state contact coated with a conventional membrane selective towards calcium ions. It is shown that the PPy-calcion film, due to the complexing properties of calcion ensuring high loading of the film with calcium, is sufficiently selective to be used as the active part or as a mediating layer of the indicator electrode. The electrode, with PPy-calcion film as the active part, was used as the indicator electrode in potentiometric titrations of calcium in mixed solvents, where conventional PVC-based electrode can not be used. For the first time, the practical applicability of PPy-based electrodes in titrations is demonstrated.     

A contribution to the use of thorin as an analytical reagent: spectrophotometric study of its complexation with barium and application to sulphate determination in atmospheric particulates

The complexation of Ba(2+) by Thorin in the pH range 2-9 in aqueous ethanol medium has been investigated. The dissociation constants of Thorin in the ethanolic medium have been determined spectrophotometrically and the distribution of the protonated species has been used to explain the behaviour of the apparent complexation constant. On the basis of the apparent constants found, and mass-balances, the effect of sulphate on the absorbance has been calculated, and the best conditions for determination of sulphate have been established. Cation and anion interferences have been studied and means of overcoming them are proposed. The method developed has been applied to sulphate determination in atmospheric particulates. As little as 1 mug of sulphate can be measured.