Heterometric microtitration of aluminium with oxine

The reaction of aluminium with oxine was studied by a new heterometric method. The composition, of the intermediate compounds which are formed at room temperature are given. A method is presented for the determination of aluminium with oxine. ? 0.5 mg Al in 20 ml of solution may be determined in 5–15 minutes with an error between zero and 0.5 microgram per ml.     

Titrages “thermochimiques” par formation de fluorures complexes de fer,aluminium, antimoine,etain et plomb

A thermochemical study of the titration of aluminium, iron, copper, lead, tin and antimony salts with sodium fluoride is described. The destruction of fluoride cumplexes by boric acid has been studied. The measurement apparatus consists of two thermistors and a bridge. Clear breaks were obtained for iron, aluminium, copper and lead but no separation of iron and aluminium was possible. The action of boric acid also gave clear breaks in the curves.     

Synthesis of 2,4-Dihydroxybenzaldehyde-Isonicotinylhydrazone and Its Fluorescence Reaction with Aluminium

A new fluorescent reagent, 2,4-dihydroxybenzaldehyde-isonicotinylhydrazone (DHBI), is synthesized and characterized by elemental analysis and infrared spectra (KBr disks). The fluorescent reaction of aluminium(III) with the new reagent has been studied. The fluorescent excitation and emission wavelengths of the complex are at 394 and 484 nm, respectively. The optimum pH range is 4.2–4.6; hence the pH is controlled in the optimum interval with a buffer solution (sodium formate–formic acid) of pH 3.3. The linear range of the method is 0–6 μg/25 ml. The molar ratio of aluminium to reagent is found to be 1:1. The proposed method has been used for the determination of trace aluminium in drinking water and edible bicarbonate of sodium with satisfactory results.     

The determination of aluminium by the ammonium benzoate method : An investigation into factors affecting the separation and estimation of aluminium and beryllium

An investigation has been made into the separation of aluminium from beryllium by the ammonium benzoate method. It has been shown (a) that over a wide range of concentrations aluminium can be determined with a maximum error of 2 %, (b) that the beryllium can be estimated after the removal of the aluminium with an error of not more than 2 % if the proportion of alumina, to beryllia is not more than 1 : 1. If the proportion of alumina to beryllia is greater than 1 : 1 considerable inaccuracy in the beryllium determination will result due to the co-precipitation of the beryllium with the aluminium benzoate; (c) that a double precipitation is required to obtain a satisfactory separation of aluminium and beryllium, (d) that although KoLTOFF el al. reported partial precipitation of beryllium with ammonium benzoate, this does not occur if tlie PH is carefully controlled between 3.5–4.0, and (e) it has been confirmed that ammonium benzoate precipitates aluminium quantitatively at PH 3.5ú4.0 wlilst beryllium does not commence to precipitate until about PH 6.5.     

Die Bestimmung des Elastizitätsmoduls viskoelastischer Systeme aus rheologischen Messungen

Summary In this paper the best available inorganic insecticides were chosen as emulsifying agents. While preparing the emulsions it was kept in mind to take minimum of the substance as an economical measure. The ratio of water to oil was so kept, as to have the most stable and mobile emulsion, in order that it could be easily-used for practical purposes. It was found that the percentage of 0.5 and 0.25 of the emulsifying agent with a ratio of oil to water as 20∶80, best stable emulsions are produced. The substances taken were copper arsenate and arsenite, lead, calcium and aluminium arsenates. With the addition of natural colloids, the stability is increased to a great extent. The natural colloids easily formed a highly solvated membrane which envelops the oil globules, thereby making the emulsions very stable. The addition of soaps deteriorates or breaks the emulsions in all cases, but with aluminium arsenate. The addition of soaps instead of having an antagonistic effect, re-inforces aluminium arsenates. The aluminium arsenate is hydrolysed producing aluminium hydroxide. It has already been seen by previous workers that aluminium hydroxide and sodium or potassium oleate act as very good emulsifying agents.

---

Zusammenfassung Die erreichbaren anorganischen Insektizide werden als emulgierende Agentien untersucht. Es wurde bei der Emulsion angestrebt, als m?gliches ?konomisches Ma? mit einem Minimum an Substanzen auszukommen. Das Verh?ltnis von Wasser zu ?l wurde so gew?hlt, da? m?glichst stabilste und flüssige Emulsionen erreicht wurden, so da? leichte Anwendbarkeit für praktische Zwecke besteht. Ein Gehalt an 0,5 und 0,25% und ein Verh?ltnis ?l zu Wasser wie 20 zu 80 ergab die stabilsten Emulsionen. Es wurden Kupferarsenat und -arsenit Blei-, Calzium- und Aluminiumarsenate verwendet. Zufügung von natürlichen Kolloiden verst?rkte die Stabilit?t au?erordentlich. Die natürlichen Kolloide bilden hochsolvatisierte Membranen, die die ?ltr?pfchen einhüllen und so die Stabilit?tserh?hung bedingen. Die Zufügung von Seifen zerst?rt oder bricht die Emulsionen, au?er im Falle von Aluminiumarsenat. In diesem Falle wird der Effekt statt dessen verst?rkt. Al-Arsenat wird hydrolysiert, es entsteht Al-Hydroxyd. Schon von anderer Seite wurde gezeigt, da? Al-Hydroxyd mit Na- oder K-Oleat sehr gut emulgierend wirkt.

     

Determination of aluminium and sodium in tungsten by non-destructive activation analysis

The sodium and aluminium content of tungsten has been measured by thermal neutron activation analysis. The concentration of aluminium was evaluated from the 1.78 MeV, and that of sodium from the 2.76 MeV full energy peaks. The minimum detectable concentrations of impurities were 0.04 microg of aluminium and 0.07 microg of sodium per 100 mg of tungsten.     

恒电位氟-铝配位滴定法测定铝的研究

以氟离子溶液作滴定剂,氟离子选择性电极作指示电极,对恒电位配位滴定法测定铝进行了研究,导出了该测定法的计算模型。测定结果的准确度受电位的控制误差对滴定剂体积误差的影响及滴定剂体积的相对误差两个因素影响。在滴定的中间位置,准确度比较高。随着滴定剂体积的增加,测定的灵敏度增加。方法可用于金属铝及锌一铝合金中铝的测定。     

Fluorimetric kinetic studies and sub-muM determination of aluminium with 2-hydroxy-1-naphthaldehyde p-methoxybenzoylhydrazone

A fluorimetric study has been made of the kinetics of the reaction of 2-hydroxy-1-naphthaldehyde p-methoxybenzoylhydrazone with aluminium, and a rate equation and a possible kinetic scheme are proposed. Experimental conditions are defined under which 0.020-10.0muM aluminium can be determined with an average error of 3.7% and a coefficient of variation of about 4.6%.     

A study of the titrimetric potassium silicofluoride method for determination of silica in aluminosilicate materials

A critical study of the titrimetric potassium silicofluoride method for determination of silica reveals that quantitative precipitation of the sificofluoride is possible in 3.5-7.5N acid containing 1% sodium fluoride and >/ 12% potassium chloride. An aqueous wash solution (pH approximately 5.3) containing 0.1% sodium fluoride and 12% potassium chloride has been found ideal for washing the precipitate without significant hydrolysis even at 35 degrees C. The interference of large amounts of aluminium (up to 160 mg of Al(2)O(3)) is eliminated by precipitating the silicofluoride in 6-7.5N acid solution, the aluminium then forming practically no fluoro-complex, because of extensive protonation of fluoride. Interference by large amounts of boron (up to 160 mg of B(2)O(3)) is eliminated by precipitating silicofluoride with the minimum permissible potassium chloride concentration (12%) and washing with the aqueous wash solution at room temperature. Nitrazene Yellow has been used as a more sensitive indicator.     

Estimation of sodium in aluminium using the flame photometer

A flame photometric method of estmating sodium in aluminium has been developed. It was found that the concentration of aluminium altered the intensity of the sodium flame. This necessitated using standerd conditions.     

Gelation and conductometric and potentiometric studies during the formation of aluminium succinate

Summary The addition of sodium succinate solution to aluminium chloride solution produces a gel at a suitable concentration, where aluminium chloride remains in excess. The gradual addition of sodium succinate up to the equivalent point of the reactants has been studied to find the nature of the precipitate that separates out.It has been shown that the precipitate consists mainly of aluminium succinate contaminated with a little of hydrous oxide and there is very little chance of formation of any soluble complex ions.

---

Zusammenfassung Zufügen von Natriumsuccinatlösung zu Aluminiumchloridlösung erzeugt bei geeigneter Konzentration ein Gel, wobei Aluminiumchlorid im Überfluß verbleibt. Die graduelle Zufügung von Natriumsuccinat bis zum Äquivalenzpunkt der reagierenden Stoffe wurde untersucht, um die Natur der gefällten Substanz, die sich abscheidet, herauszufinden.Das Fällprodukt besteht in der Hauptsache aus Aluminiumsuccinat verunreinigt mit etwas Hydroxyd, und es besteht sehr wenig Wahrscheinlichkeit für die Bildung irgend eines Komplexions.

     

The Inhibition of the Dissolution of Aluminium in Sodium Hydroxide by Some Organic Phosphorus Compounds

The inhibition of the corrosion of aluminium in 1M sodium hydroxide solution by some cyclodiphosphazane derivatives has been studied using hydrogen evolution technique. The results indicate that the additives reduce the corrosion rate. The inhibitory character of these compounds depends upon the concentration of the inhibitor, as well as on its chemical composition.     

Kinetic Study of the Hydrolysis of Schiff Bases Derived from 2-Aminothiophenol

The kinetics of the hydrolysis of Schiff bases derived from 2-aminothiophenol have been studied in aqueous sodium hydroxide media containing 40?% (v/v) methanol in the temperature range 22?C45?°C. The Schiff base molecular structure-hydrolysis reactivity relationship has been investigated and discussed. Suitable reaction mechanisms have been suggested. From the effect of temperature on the rate constant, various activation parameters have been evaluated. The work has been extended to study the hydrolysis mechanism in buffer solutions of pH?=?2?C13 at 22?°C for Schiff base I (H). A rate profile diagram of pH-rate constant has been proposed.     

Evaluation of Matrix Effects in a Pulsed Electrolyte Cathode Atmospheric Pressure Discharge Source for Atomic Emission

In sample measurements, matrix effects are unavoidable. The matrix effects are one of the main factors affecting the accuracy of the pulsed electrolyte cathode atmospheric pressure discharge detection system. The stability of sodium, potassium, and magnesium, under optimized parameters is measured; the relative standard deviation of spectral intensity is found to be no more than 2%; and the relative standard deviation of background intensity is less than 2%. The matrix effects on the elements potassium, sodium, and magnesium were studied, and the experiments showed that high concentrations of sodium and potassium interfere with each other. A concentration of 200?mg?L^?1 K⁺ affected the sodium signal with an enhancement of more than 120%; and the K⁺ intensity increased 20% in the presence of a high concentration of 200?mL^?1 Na⁺. In high concentrations of sodium or potassium, the elemental signal for magnesium enhancement was approximately 8%. Sodium, potassium, and magnesium were quantitatively determined using a mixed calibration sample. When sodium, potassium, and magnesium are present at low concentrations in solution, there were no obvious matrix effects. The sodium, potassium, and magnesium in the calibration samples are quantitatively determined. The relative error and precision are less than 3%, and the recoveries are less than 105%. The detection limits for sodium, potassium, and magnesium were found to be 2.1, 3.4, and 92.6?µg?L^?1, respectively.     

用氢化物—原子荧光法测定水处理剂中微量铅

对氢化物－原子荧光法测定水处理剂聚合氯化铝和硫酸铝中铅的测定介质、测定条件及干扰元素进行了探讨,拟定了简便,快速,准确测定两种水处理剂中微量铅的方法。在测定条件下,方法的线性范围为０￣５０ｎｇ·ｍｌ＾－１,检出限为０．４ｎｇ·ｍｌ＾－１,回收率在９０％￣１１０％之间。     

Mechanism of adhesion promotion between aluminium sheet and polypropylene with maleic anhydride‐grafted polypropylene by γ‐aminopropyltriethoxy silane

The effect of concentration of γ‐aminopropyltriethoxy (γ‐APS) solution on shear strength of adhesive bonding between aluminium sheet and polypropylene (PP) with addition of a certain amount of maleic anhydride‐grafted polypropylene (PP‐g‐MAH) has been investigated. It is shown that the lap shear strength is promoted obviously with pre‐treatment of aluminium sheet by γ‐APS. The maximum strength is obtained at a concentration of 3% γ‐APS solution. With further high concentration of γ‐APS, the lap shear strength decreases. The examination of the separated surfaces by X‐ray photoelectron spectroscopy (XPS) shows that (C?O)₂? O? Al and C(?O)? O? Al are formed for adhesive bonding between PP with the addition of 20 wt% PP‐g‐MAH and aluminium sheet without pre‐treatment by γ‐APS, and that the area ratio of C related to oxygen on the separated aluminium side is 33.28%, which is obviously higher than 14% on the polymer side. As for adhesive bonding between PP with the addition of 20% PP‐g‐MAH and 3% γ‐APS pre‐treated aluminium sheet, C(?O)? N? C(?O) and C(?O)? NH are formed. The area ratio of C related to oxygen on the separated polymer side increases to 24.99%. It is proposed that γ‐APS pre‐treatment improves the distribution and shape of PP‐g‐MAH chains in the region adsorbed on the substrate and the region adjacent to this region. The chemical interactions at the interface are also proposed. Copyright © 2008 John Wiley & Sons, Ltd.     

Direct determination of fluoride in aluminium reduction materials by using an ion-selective electrode

Macro amounts of fluoride in aluminium reduction materials are successfully determined with a fluoride electrode. Except for anhydrous aluminium fluoride, which requires fusion with sodium hydroxide, samples are dissolved in aqueous media. Cryolite and sodium fluorosilicatc are dissolved in boiling sodium hydroxide solution. Other materials containing fluoride, such as fluorspar and the reduction cell bath and pot-lining, require dissolution in a hydrochloric acid solution of aluminium chloride. Potential interference from large amounts of aluminium (and calcium, if present) is eliminated and pH control attained by using ammoniacal sulphosalicylate (and EDTA). The procedures are reasonably rapid. Relative errors of less than 2% and a relative standard deviation of 1% are achieved.     

Inhibitive Effect of Butyltin Trichloride on Dissolution and Localized Corrosion of Aluminium in Sodium Hydroxide and Hydrochloric Acid

The dissolution of aluminium in sodium hydroxide and hydrochloric acid in the presence of butyltin trichloride as corrosion inhibitor has been studied by hydrogen evolution and thermometric methods. Experimental findings indicate that the inhibition effect of butyltin trichloride takes place through an adsorption mechanism following the Frumkin's isotherm. Butyltin trichloride acts as a weakly adsorbed inhibitor in NaOH and as a strongly adsorbed inhibitor in hydrochloric acid medium.     

Size fractionation of metals in wine using ultrafiltration

Ultrafiltration has been used to examine the size fractionation of lead, copper, iron, aluminium, calcium, potassium and sodium in white and red wines. Fractionation patterns demonstrated that the behaviour of lead is significantly diferent to the other metals considered. In red wine, there was a sudden decrease for lead between 100 000 and 30 000 nominal molecular weight cut off (NMWCO) and in white wine, a gradual decrease in the lead concentration was observed from 100 000 NMWCO. Iron was the only other metal which showed, for red wine, a size distribution pattern with a reduction in the iron concentration between 30 and 50% from 100 000 to 1000 NMWCO. Potential binding agents for lead and iron are discussed. The absence of any fractionation pattern for the other metals examined has been interpreted in terms of the metals existing as aquated cations (potassium and sodium), metal tartrate complexes (aluminium, copper and calcium) and either tartrate or phosphate for iron in white wine. The possibility of ultrafiltration disturbing kinetically facile processes, particularly for copper and calcium, is identified.     

Verfolgung der Verbrennungsreaktionen exothermer Massen auf Basis von Aluminium,Fluoriden und Kaliumnitrat mit Differentialthermoanalyse

DTA was applied to investigate the course of combustion of exothermic mixtures composed of aluminium, fluorides and potassium nitrate, and the results obtained were compared with the simultaneous results of X-ray investigations. The combustion of exothermic mixtures composed of aluminium, fluorides and potassium nitrate is similar to the combustion of mixtures where the potassium nitrate is substituted by sodium nitrate. Two exothermic reactions occur: between 400 and 520?, and between 800 and 1130?, in mixtures with sodium fluoride and between 450? and 650? and 850 and 1130? in mixtures with calcium fluoride. The reaction in the lower temperature range initiates the combustion of the mixture. In sodium fluoride mixtures this reaction takes place at lower temperature and seems to be more intense, since these mixtures inflame earlier than those with calcium fluoride. The reaction in the higher temperature range, which occurs at approximately the same temperature in the two cases, liberates the main part of the useful heat of the exothermic mixtures.