Quantitative chemical analysis on paper: Micro-determination of copper and a mixture of copper and silver

Summary A method has been suggested for the determination of small amounts of copper and of mixtures of copper and silver using filter paper impregnated with silver chloride and sodium carbonate. The method depends on competition between copper and silver ions to form complexes with cyanide added to the paper. The area of the spot produced by conversion of AgCl into Ag(CN)₂ ^– is measured by weight, and is inversely proportional to the amount of copper present, since the Cu(CN)₄ ^3– complex is preferentially formed. The silver present is determined separately, and the amount of copper calculated.The determination is possible in the presence of Bi³⁺, C³⁺, Mn²⁺, Pb²⁺, K⁺, Na⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mg²⁺, NH₄ ⁺, Al³⁺, Sn²⁺, Hg²⁺, Ag⁺, Fe²⁺, Fe³⁺, NO₃ ^–, SO₄ ^2–, CO₃ ^2–, CrO₄ ^2–, Cl^–, Br^–, and SCN^–.The determination is impossible in the presence of I^–, I₂, Zn²⁺, Cd²⁺, Hg₂ ²⁺, Co²⁺, or Ni²⁺.The method permits the determination of 4–30g of copper and 8–60g of silver with an accuracy of 2%.

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Zusammenfassung Eine Methode zur Bestimmung kleiner Kupfermengen und von Kupfer-Silber-Gemischen mit Hilfe von Filtrierpapier wird vorgeschlagen, das mit Silberchlorid und Natriumcarbonat imprägniert ist. Sie beruht auf der Konkurrenz zwischen Kupfer und Silber bei der Komplexbildung mit Cyanid, das man auf das Papier aufbringt. Das Flächenausmaß des durch Komplexierung des Silbers gebildeten Fleckens wird gravimetrisch bestimmt. Es ist umgekehrt proportional zur Menge anwesenden Kupfers, da [Cu(CN)₄]^3– bevorzugt gebildet wird. Das Silber wird getrennt bestimmt und so die Kupfermenge berechnet.Die Bestimmung ist möglich in Gegenwart von Bi³⁺, Cr³⁺, Mn²⁺, Pb²⁺, K⁺, Na⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mg²⁺, NH₄ ⁺, A1³⁺, Sn²⁺, Hg²⁺, Ag⁺, Fe²⁺, Fe³⁺, NO₃ ^–, SO₄ ^2–, CO₃ ^2–, CrO₄ ^2–, Cl^–, Br^– und SCN^– und nicht möglich in Gegenwart von J^–, J₂, Zn²⁺, Cd²⁺, Hg₂ ²⁺, Co²⁺ oder Ni²⁺.4 bis 30g Kupfer sowie 8 bis 60g Silber können mit einer Genauigkeit von 2% bestimmt werden.

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Résumé On propose une méthode pour doser de petites quantités de cuivre et de mélanges de cuivre et d'argent, à l'aide de papier-filtre imprégné de chlorure d'argent et de carbonate de sodium. La méthode dépend de l'effet compétitif entre les ions cuivre et argent pour former les complexes avec le cyanure déposé sur le papier. La surface de la tache formée en transformant le chlorure d'argent en Ag(CN)₂ ^– est mesurée par pesée et est inversement proportionnelle à la quantité de cuivre présent, puisque le complexe Cu(CN)₄ ^3– se forme préférentiellement. L'argent présent est dosé séparément et la quantité de cuivre s'en déduit par calcul.Le dosage est possible en présence de Bi³⁺, Cr³⁺, Mn²⁺, Pb²⁺, K⁺, Na⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mg²⁺, NH₄ ⁺, Al³⁺, Sc³⁺, Hg²⁺, Ag⁺, Fe²⁺, Fe³⁺, NO₃ ^–, SO₄ ^2–, CO₃ ^2–, CrO₄ ^2–, Cl^–, Br^– et SCN^–.Le dosage est impossible en présence de I^–, I₂ ^–, Zn²⁺, Cd²⁺, Hg²⁺, Co²⁺ ou Ni²⁺. La méthode permet le dosage de 4 à 30g de cuivre et de 8 à 60g d'argent avec une précision de 2%.

     

Quantitative chemical analysis on paper: Determination of phosphate in the presence of large quantities of other ions

Summary A rapid method has been developed for the determination of phosphate by means of filter paper impregnated with lead iodide. A sample is added to the impregnated filter paper by means of a capillary, and after irrigation to cause migration of the ions a white spot is obtained as the lead iodide is converted into the phosphate. The weight of the spot is dependent on the p_H and the quantity of phosphate present.The determination is possible in the presence of SCN^–, Cl^–, Br^–, NO₃ ^–, CO₃ ^–, I^–, IO₃ ^–, CH₃COO^–, B₄O₇ ^2–, F^–, Sb₂O₇ ^4–, K⁺, Na⁺, NH₄ ⁺, OH^–, H⁺, succinic, citric and tartaric acids. The determination is impossible in the presence of C₂O₄ ^2–, SO₄ ^2–, MoO₄ ^2–, NO₂ ^–, SO₃ ^2–, S^2–, CrO₄ ^2–, or CO₃ ^2–.The method permits the determination of 7–100g of phosphate with an accuracy of 2%.

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Zusammenfassung Ein schnelles Verfahren zur Phosphatbestimmung wird besehrieben, bei dem man sich eines mit Bleijodid imprägnierten Filterpapiers bedient. Die Probe wird mit einer Kapillare auf das Papier aufgebracht. Man erleichtert die Ionenbewegung durch geeignete Befeuchtung und erhält einen weißen Fleck infolge Umsetzung des Bleijodids in -phosphat. Das Gewicht des Fleckens hängt vom p_H und von der Phosphatmenge ab.Die Bestimmung ist möglich in Gegenwart von SCN^–, Cl^–, Br^–, NO₃ ^–, CO₃ ^–, J^–, JO₃ ^–, CH₃COO^–, B₄O₇ ^2–, F^–, Sb₂O₇ ^4–, K⁺, Na⁺, NH₄ ⁺, OH^–, H⁺, Bernsteinsäure, Zitronensäure und Weinsäure; sie ist nicht möglich bei Gegenwart von C₂O₄ ^2–, SO₄ ^2–, MoO₄ ^2–, NO₂ ^–, SO₃ ^2–, S^2–, CrO₄ ^2– oder CO₃ ^2–. 7 bis 100g Phosphat können mit einer Genauigkeit von 2% bestimmt werden.

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Résumé On a développé une méthode rapide pour le dosage des phosphates sur papier-filtre imprégné d'iodure de plomb. On dépose l'échantillon sur le papier-filtre imprégné, à l'aide d'un capillaire, et, après humidification pour provoquer la migration des ions, on obtient une tache blanche quand l'iodure de plomb est converti en phosphate. Le poids de la tache dépend du p_H et de la quantité de phosphate présent.Le dosage est possible en présence de SCN^–, Cl^–, Br^–, NO₃ ^–, CO₃ ^–, I^–, IO₃ ^–, CH₃COO^–, B₄O₇ ^2–, F^–, Sb₂O₇ ^4–, K⁺, Na⁺, NH₄ ⁺, OH^–, H⁺, et des acides succinique, citrique et tartrique. Il est impossible en présence de C₂O₄ ^2–, SO₄ ^2–, MoO₄ ^2–, NO₂ ^–, SO₃ ^2–, S^2–, CrO₄ ^2– ou CO₃ ^2–.La méthode permet le dosage de 7 à 100g de phosphate avec une précision de 2%.

     

Properties and treatments of pulps from recycled paper. Part I. Physical and chemical properties of pulps

The mechanical, physical, and chemical properties of recycled pulps were evaluated after a series of treatments designed to improve and/or modify the pulp characteristics. Tensile strength, bursting strength, and apparent density of the pulps decreased with recycling. However, the tear strength, in most cases, increased after the first recycle and then decreased after the second recycle. Carboxyl content and WRV of pulps also decreased with recycling. Chemical treatments did not increase the bonding ability of recycled pulps and, in most cases, decreased the physical properties of the pulps. Altering the physical state of the cellulose microstructure through additional swelling did not appear to be a significant factor for strength restoration. It may be that the hemicelluloses plan a greater role in recycling than originally thought.     

Quantitative LAMMA analysis of biological specimens I. Standards. II. Isotope labeling

Summary Besides a remarkably high sensitivity for light elements, laser microprobe mass spectroscopy offers two main advantages for microprobe analysis: 1) the possibility to obtain data of relatively high precision and 2) the ability to discriminate isotopes. This opens the possibility to use cold isotopes as atomic labels to study cellular or subcellular kinetics of ions or labelled organic compounds. In this study photoreceptor cells were labelled with ⁴⁴Ca²⁺ prior to LAMMA analysis to monitor Ca²⁺ uptake and/or Ca²⁺ accumulation from extracellular sources into intracellular compartments such as the various pigment granula present in these photoreceptors.As in other microprobe techniques also LAMMA analysis requires internal standards for quantitative work. For this purpose thin films of inorganic material were shown to be useful standards when deposited (in vacuum) directly onto the specimen to be analyzed. Some metals and dielectrica have been tested for their possible suitability for standardisation procedures. Even though metals like Pt, Ag, Au, Al are excellent for thin film production, they seem to be less useful for the present purpose because their threshold for laser induced perforation and ion production is rather different from that of the specimen material. However, thin film deposits of some dielectric materials such as MgF₂ turned out to be more suitable to serve as an internal standard for plastic embedded biological material in LAMMA analysis.

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Quantitative LAMMA-Analyse biologischer Proben. I. Standards. II. Isotopenmarkierung

     

Quantitative analysis by electro-chromatography on paper : The separation and gravimetric determination of copper

Up to 20 mg of copper can be quantitatively separated from small quantities of gold, platinum and palladium, by ionophoresis on strips of paper pulp, 6 mm thick, 25 mm wide and 250 mm long. One millilitre of the hydrochloric acid solution of the metallic salts is placed on the paper, the ends of which are placed in cells containing 50 ml N HC1 and 25 ml N KC1. The paper is then moistened with N HC1. Carbon electrodes are used and are connected to a 12 volt D.C. supply, a current of about 200 milliamperes being recorded. The copper travels towards the cathode and after about 18 hours separates completely from the noble metals as a blue band about 75 mm in length. This band is cut out and used for the determination of the copper by electrodeposition, after decomposition of the organic matter by means of concentrated nitric and sulphuric acids.     

Prediction of paper permanence by accelerated aging I. Kinetic analysis of the aging process

The validity of accelerated aging tests to predict and rank papers on their permanence has been under question, preventing the development of performance-based standards for permanent paper. We conducted a general kinetic analysis to investigate the aging process of paper. A general kinetic model is proposed to describe the depolymerization of cellulose. Experimentally it was shown that in the case of aging, cellulose degradation follows classic first-order kinetics as a special case of our general kinetic model. The Arrhenius equation was critically re-examined for the case of a multiple reaction system. It was shown analytically that the Arrhenius equation is still applicable when certain conditions are met. This was convincingly supported by experimental results. We also analysed the dependence of the degradation rate on the moisture content and hydrogen ion concentration. By conducting systematic experiments on these two factors, a general and quantitative relationship was established to explain the contribution of each factor and their interactions. Finally, based on this kinetic analysis, the effects of storage conditions on the life expectancy of paper were estimated.     

Quantitative estimation of halogenated organic acids on paper chromatograms

A quantitative method is described for the estimation of the ammonium salts of the halogenated organic acids after they have been separated on a paper chromatogram. The recovery of the added acid is better than 98%.     

Quantitative gas chromatographic analysis on support-coated open tubular capillary columns : I. Analysis of isomeric ethylphenols

Gas chromatographic methodology has been developed for quantitative analysis of samples of o-, m-, and p-ethylphenols. Samples are dissolved in a dichloromethane solution of the internal standard, anisole, and are then derivatized with N-trimethylsilylimidazole to form the silyl ethers. The samples are chromatographed with similarly prepared standards on a stainless-steel OV-17 support-coated open tubular (SCOT) column.Specificity, linearity, precision and stability of the samples are discussed, and chromatograms obtained on the SCOT column are compared to those obtained on a packed analytical column.This report describes one of the first quantitative gas chromatographic analytical methods to use a SCOT (capillary) column.     

Quantitative analysis of deuterium using the isotopic effect on quaternary C NMR chemical shifts

Quantitative analysis of specifically deuterated compounds can be achieved by a number of conventional methods, such as mass spectroscopy, or by quantifying the residual ¹H NMR signals compared to signals from internal standards. However, site specific quantification using these methods becomes challenging when dealing with non-specifically or randomly deuterated compounds that are produced by metal catalyzed hydrothermal reactions in D₂O, one of the most convenient deuteration methods. In this study, deuterium-induced NMR isotope shifts of quaternary ¹³C resonances neighboring deuterated sites have been utilized to quantify the degree of isotope labeling of molecular sites in non-specifically deuterated molecules. By probing ¹³C NMR signals while decoupling both proton and deuterium nuclei, it is possible to resolve ¹³C resonances of the different isotopologues based on the isotopic shifts and the degree of deuteration of the carbon atoms. We demonstrate that in different isotopologues, the same quaternary carbon, neighboring partially deuterated carbon atoms, are affected to an equal extent by relaxation. Decoupling both nuclei (¹H, ²H) resolves closely separated quaternary ¹³C signals of the different isotopologues, and allows their accurate integration and quantification under short relaxation delays (D1 = 1 s) and hence fast accumulative spectral acquisition. We have performed a number of approaches to quantify the deuterium content at different specific sites to demonstrate a convenient and generic analysis method for use in randomly deuterated molecules, or in cases of specifically deuterated molecules where back-exchange processes may take place during work up.     

Quantitative thermal analysis,I Mathematical problems of quantitative differential thermal analysis

A highly simplified method for calculating heat of phase transitions from DTA data is presented. Two DTA curves are needed to calculate the heat of transition and the specific heat of the sample: one is for the original sample and one is for a sample prepared by mixing the original sample with some unreactive diluent the specific heat of which is known. The data of the DTA curves used in the calculations are the peak area, the rate of heating and the deviation of the DTA curve from the base line.

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Zusammenfassung Eine einfache Methode zur Errechnung der Werte der Phasenübergangswärme aus den DTA Daten wird besprochen. Die Kenntnis der spezifischen Wärme der betreffenden Substanz und zwei Thermogramme sind hierzu nötig, jenes der Originalprobe und jenes einer Mischung der zu prüfenden Substanz mit einem indifferenten Stoff von bekannter spezifischer Wärme. Die notwendigen DTA Daten sind die Spitzenflächen, die Erhitzungsgeschwindigkeit und die Abweichung der DTA Kurve von der Nullinie.

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Résumé On décrit une méthode simple pour caIculer les chaleurs des transitions de phase à l'aide des données d'analyse thermique différentielle. Il est nécessaire de connaître la chaleur spécifique et les thermogrammes de l'échantillon pur et en mélange avec une substance indifférente, de chaleur spécific connue. Pour les calculs, on se sert des données suivantes: surface des pics d'A. T. D., vitesse de chauffage et déviation de la courbe d'A. T. D. par rapport à la ligne de base.

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Quantitative theory of iniferter polymerization. I. Kinetics

On the basis of a rather general scheme of elementary reactions of radical polymerization conducted in the presence of iniferters, kinetic equations have been derived describing this process over the whole range of monomer conversion. Proceeding from thorough analysis of these equations, different regimes of polymerization have been found that differ in values of order with respect to the iniferter and monomer of the initial rate of polymerization. Conditions for kinetic parameters have been formulated whose fulfillment predetermines that radical polymerization occurs according to the iniferter mechanism. © 1994 John Wiley & Sons. Inc.     

Faecal lipid chromatography. I. Quantitative determination with chromarods

A new and original method is proposed for the qualitative and quantitative analysis of faecal lipids by thin-layer chromatography and detection through the flame ionization detector of an analyser (the Iatroscan TH 10). This method enables the rapid quantification of the different faecal lipid classes, including cholesterol, with great accuracy and reproducibility. In-series operations are possible with easy manipulation.