Tripyridyltriazine, a reagent for the determination of iron in sea water

Iron, in the parts per billion range in which it occurs in sea water, can be determined spectro-photometrically with 2, 4, 6-tripyridyl-s-triazine (TPTZ). The intense violet compound formed by TPTZ and the ferrous ion is extractable into nitrobenzene if sodium perchlorate be added to the solution. The extraction affords a means of concentrating the iron from a large sample into a small volume of nitrobenzene for spectrophotometric measurement...

A New Method Utilizing Versene for Determination of the Calcite-Dolomite Ratio in Carbonate Rocks

The sedimentary petrologists have long been concerned with the determination of the calcite-dolomite ratio of carbonate rocks. The ratio is difficult to determine in thin section with any accuracy; the minerals are very similar optically and at best only a fair approximation can be obtained by a thin section traverse. The Lemberg staining procedure, which utilizes a silver nitrate-potassium chromate reagent, is rather involved and not too reliable. The differential thermal analysis and thermoluminescence methods are fairly rapid and accurate but involve elaborate equipment

Can Chromatography Occur in Nature?

Adsorption of calcium and magnesium on a sandstone from a bicarbonate solution has been demonstrated. On elution with water saturated with carbon dioxide, the magnesium passes off first. The chromatographic separation of magnesium from calcium can thus occur under conditions which can prevail in nature

5,8-Dihydroxyquinoline and Its Nickel Derivatives

Many derivatives of 8-hydroxyquinoline have been prepared and examined, some looking toward increased specificity as precipitating reagents, others toward an increase in the intensity of the color of the metal derivatives. Of the derivatives which have been studied, attention has been centered principally on the alkyl and halogen derivatives on the one hand and on the aromatic azo derivatives on the other. This paper deals with the preparation and properties of an 8-hydroxyquinoline bearing a second hydroxyl group, 5,8-dihydroxyquinoline. In this substance are combined the properties of chelate ring formation with metals and the oxidation-reduction behavior characteristic of the hydroquinones

Studies on the Duff Reaction for the Preparation of O-Hydroxaldehydes

Moderate quantities of a large number of o-hydroxyaldehydes were required for certain investigations being conducted in this laboratory. Numerous attempts to modify and improve the classical Reimer-Tiemann reaction were uniformly unsuccessful either in minimizing the undue time required for the synthesis or in sensibly increasing the meager yields obtained. Of the other reactions which were also employed for the synthesis of these aldehydes the method recently described by Duff was found the most fruitful and expedient

Formation Constants of the Copper(II) Compounds of Pyridylalpyridylhydrazine

Bivalent copper and the Schiff\u27s base pyridylalpydidylhydrazine form two compounds, composed respectively of one molecule and of two molecules of the organic compound to one atom of copper, and having ultra violet absorption spectra differing only in the value of the molar extinction coefficients at the absorption maxima, 15,100 and 22,450, respectively at 345 mμ. The respective formation constants are 2.4 x 105 and 2.8 x 105 as determined from spectrophotometric data, the method used being unusual in that the ultra violet absorption data provided a direct measure of the free ligand present

Schiff\u27s Bases of Pyridylhydrazine as Analytical Reagents for Cobalt

Schiff s bases having functioned groups adjacent to the carbon-nitrogen bond so that chelation (ring formation) can occur with metal atoms are of interest because of the intense colors of the metal derivatives. Thus, the compound l,3-bis(2\u27-pyridyl)-2,3- diaza-l-propene (I) abbreviated PDP reported by Lions and Martin (1) and Geldard and Lions (2) forms a compound with cobalt so intensely colored as to offer promise of use in the analytical chemistry of cobalt. We have now investigated the cobalt, iron and nickel derivatives of PDP in detail and have investigated also certain similar Schiff\u27s bases such as 1-(2\u27 - hydrozyphenyl)-3-pyridyl-2,3-diaza-l-propene (II) , designated later at HPDP

Sulfonation of Bathophenanthroline and Bathocuproine

Diphenyl-l, 10-phenanthroline, introduced in 1952 as a spectrophotometric reagent for iron by Smith, McCurdy and Diehl (1) , has proved useful and popular; some twenty papers (2) have now appeared detailing its application to the determination of iron in sea water, wine, serum, urine, various metals, and other materials. This reagent was given the common name Bathophenanthroline. The great sensitivity of the reagent is made peculiarly useful by virtue of the solubility of its red, ferrous derivative in isoamyl alcohol, for extraction of the red compound from water into the immiscible solvent provides a concentration method making possible the determination of iron in concentrations as low as 0.002 parts per million, and even more important, provides a method of removing the iron contaminants from the various reagents used in the analysis

The Colorimetric Determination of Cobalt with Dimethylglyoxime and Benzidine

Compounds of cobalt and dimethylglyoxime were first prepared by Tschugaeff during the course of his classical researches on the α-dioximes (1). The simplest of these compounds corresponded to the formula [Co (NH3)2 (DH2)2] X2, DH2 representing a molecule of dimethylglyoxime and X a univalent anion. Tschugaeff prepared other compounds in which one or more of the ammonia groups were replaced by aniline or pyridine

The Pyrite and Marcasite Electrodes

Pyrite and marcasite may be used as the indicating electrode in neutralization reactions. In acid solution the pyrite and marcasite electrodes behave almost identically with the platinum electrode with differences arising (1) in the presence of strong oxidizing agents where the attack on the pyrite and marcasite alters the potential, and (2) long standing where changes result from the dissolution of a little pyrite even under non-oxidizing conditions. Pyrite and marcasite can thus be used as indicator electrodes in oxidation-reduction titrations. A pyrite-platinum pair gives a differential titration curve. In alkaline solution pyrite, marcasite and platinum respond almost identically to changes in the concentration of sulfide, the single electrode potentials being shifted 120 mv. negative for each ten-fold increase in sulfide concentration