Potassium Ferricyanide Solution Research Articles

The preparation of stained acetate peels for the study of carbonate rocks

ABSTRACT A method is described for the preparation of acetate peels of stained carbonate rocks. The stains transferred are: Alizarin red-S (for the detection of calcite), potassium ferricyanide (for the detection of ferrous iron-bearing calcite or dolomite), and Feigl's solution (for the differentiation of aragonite from calcite). The stains may be applied separately or simultaneously. The stained peels preserve textural details and are very simply and rapidly prepared; they are widely applicable to limestones, dolomites, carbonate-cemented sandstones and allied rock types. It should be possible to extend the same staining principle to other compositions.

Reduction Potentials of Vat Dyes and Their Relation to the Ease of Reduction and Tendering Behavior

A method for carrying out potentiometric titration of reduced vat dyes in aqueous alkaline solutions using a potassium ferricyanide solution as the oxidant is described. The standard method is modified on the basis of certain assumptions, and the values of potentials are calculated and termed “Characteristic redox potentials.” An account of the determination of these characterisic redox potential values for a series of purified vat dyes is given. The characteristic redox potential values of vat dyes are compared with the ease of reduction of these dyes and also with their tendering behavior. The effect of substitution on these values is discussed.

Fading phenomena in nuclear emulsions

Eradication of background grains in emulsion plates has been studied with potassium ferricyanide solution in hypo. The special feature of this method is that it can be applied after the processing of the plates. The effect of various parameters like time of treatment, concentration and temperature on reduction has been studied in details.

Paper and plate chromatographic methods for the determination of dichlorophene and hexachlorophene when present together

A simple and rapid method is described for the separation of mixtures of dichlorophene and hexachlorophene. The compounds are resolved by ascending paper and plate chromatography, using n-heptane saturated with glacial acetic acid as the developer, and detecting the spots with a solution of ferric chloride and potassium ferricyanide. After elution from the plates, the isolated compounds are assayed by ultraviolet spectrophotometry.

Sensitivity of Hæmoglobin to Oxidation in Various Conditions

WHEN intact red cells are treated with weak solutions of sodium nitrite in isotonic saline, or haemolysed red cell suspensions are treated with weak solutions of potassium ferricyanide, the red colour changes to brown as the oxyhaemoglobin is oxidized to methaemoglobin. Infants have long been known to be particularly sensitive to this change1–3 ; but it has only recently been shown3,4 that this increased sensitivity is also present in children of both sexes up to the age of puberty.

A spectrophotometric study of ionic association in aqueous solutions

Measurements are reported of the extinction coefficients of aqueous solutions of potassium ferrocyanide, potassium ferricyanide, thallous perchlorate, thallous sulphate, thallous ferrocyanide and mixtures of lanthanum chloride and potassium ferrocyanide. Observed deviations from Beer’s law in the last three cases have been interpreted in terms of the theory of incomplete dissociation, paying particular attention to assumptions about ionic activity coefficients. The formulae of the associated ions in ferrocyanide solutions have been determined by the method of continuous variations and thermodynamic dissociation constants have been obtained at 25, 35 and 50° C for the TlFe(CN) 3- 6 ion and at 25° C for the LaFe(CN) - 6 ion. These dissociation constants are discussed in terms of Bjerrum’s theory of ionic association.

Direct titration of potassium ferricyanide with hydrazine sulphate in presence of zinc sulphate determination of hydrazine

Operative conditions for direct titration of potassium ferricyanide solution with a solution of hydrazine sulphate which contains zinc sulphate are described. The results are comparable with those obtained by the standard iodate procedure. The chief advantages of the present method of estimating hydrazine are (1) titration in slightly acidic medium and (2) no indicator is required. Determination of substituted hydrazines, hydroxylamine and other reducing substances on similar lines is suggested.

Potentiometric determination of potassium ferricyanide

A rapid and accurate electrometric method for the determination of potassium ferricyanide solutions has been investigated. It consists in titrating ferricyanide solutions potentiometrically against standard AgNO 3, using a silver indicator electrode in conjunction with a saturated calomel electrode connected by a KNO 3 bridge. Either of the reagents may be used as the titrant. A marked change in e.m.f is observed at thc end-point corresponding to the formation and precipitation of Ag 3[Fe(CN) 6]. The curves have a regular form, a pronounced maximum in d E/d V occurs at the end-point and the results are very accurate and reproducible. The reaction, though simple, affords a quantitative method for the determination of ferricyanide or silver. The effect of neutral salts and ethanol on the accuracy of the end-point has been studied.

ニトロプルシッドナトリウムとフェリシアン化カリウムとによるジエチルアミンの呈色反応について

Specific color reaction for diethylamine (I) is to mix 1 drop of (I) or its hydrochloride solution with 1 drop of 5% sodium nitroprusside (II) solution, 1 drop of 5% potassium ferricyanide (III) solution, and 1 drop of 2N Na2CO3 solution, and warming the mixture in a water bath (90°) for about 15 seconds by which the reaction mixture acquires a pale brownish yellow color which turns from indigo blue, through purple, to purplish red on cooling in air or water. The mechanism of this coloration may be assumed as the oxidation of (I) by (II) and (III) to form acetaldehyde which reacts with (I) and (II) to give the color reaction peculiar to aliphatic secondary amines.

A rapid iodometric method for the determination of copper and zinc

A method has been described for the iodometric simultaneous determination of zinc and copper. Copper is determined in the presence of sufficient KCNS and a small amount of KI. This is followed by the titration of the iodine equivalent to the zinc, which is liberated by the addition of potassium ferricyanide solution. Interference is eliminated completely by keeping the solution neutral or just acid with phosphoric acid. Within the range under investgation, results are obtained which are accurate to ± 0.7%.

光電分光光度計による比色法の研究（第6報）赤血塩による鋼中のCoの定量

An addition of K3 [Fe(CN)6] to an ammoniacal solution of cobalt causes a brownish red coloration. When the solution was left standing for some time, brownish black precipitate were separated out. When (NH4)2SO4, (NH4)3PO4 or NH4-citrate was present, a reddish clear solution was obtained. Thus the solution changed its hue and color intensity with anions present. But when the concentration of (NH4)3PO4 and NH4-citrate was kept at about 2 and 2N respectively, no effects on the color intensity of SO4″, Cl′ ions and the amount of K3 [Fe(CN)6] added was observed. In visible range, the cobalt complex showed an absorption below 650 mμ having absorption maximum at about 445 mμ. From 480 to 520 mμ, it showed a shoulder. Potassium ferricyanide solution showed a deep absorption below 500 mμ and the above transmittancy reading was 100%. Therefore, when wavelength within the range between 500 and 650 mμ is used, the absorption due to an excess of the reagent does not interfere the determination of cobalt. At the wavelengths, for example, of 500, 510, 520 and 540 mμ, it obeyed the Beer’s law. There was no difference in absorbancy whether cobalt was present alone or iron salt was coexistent. Chromate and tungstate ions must be removed.

Detection of some precursors of adrenaline by paper chromatography.

DURING studies on the biosynthesis of adrenaline, both para- and meta-hydroxyphenylethanolamine have been found to form noradrenaline following ultraviolet irradiation in the presence of air1. Whereas the para compound has been identified in Octopus vulgaris2, the meta compound has not hitherto been found occurring naturally. Their detection in biological materials is a major problem. With the aid of paper chromatography, using a solvent of butanol (4 vol.), glacial acetic acid (1 vol.) and water (5 vol.), we have found that the meta compound exhibits an intense violet fluorescence under ultra-violet light when the developing agent is a mixture of 9 vol. of a solution of either potassium ferricyanide or dichromate (0.66 per cent) and 1 vol. of formaldehyde (40 per cent), followed by exposure to heat (100° C.) for 5 min. As little as 0.5 µgm. (RF value 0.56) can be identified by this test. Development with the p-nitraniline reagent3 results in a dark red spot (similar to that produced with the para compound), but this test is only sensitive to 5 µgm.

The Electrochemical Behavior of Aluminum: III . In Buffered and Alkaline Solutions of Potassium Ferricyanide and in Sodium Hydroxide

A study has been made of the reactivity and polarization characteristics of pure aluminum in buffered and alkaline solutions of potassium ferricyanide and in sodium hydroxide. Electrode potentials, weight loss data, and polarization curves are presented; it is shown that the reaction of aluminum with these electrolytes may be interpreted from an electrochemical point of view. The analysis of the polarization behavior is based on the theory of the “mixed potential.”

The occurrence of a diphenyl isatin in california prunes

A commercial water concentrate of California prunes was extracted with chloroform-ethanol solutions which were washed with water to remove dispersed impurities. Evaporation of chloroform revealed a mixture of amorphous and crystalline materials that yielded negative tests for hydroxyanthraquinones and their derivatives, but positive reactions for a diphenyl isatin. A quantitative estimation for dihenyl isa-tins was devised using di(acetylhydroxyphenyl)isatin as a reference stansard based on photometric determinations of color development when diphenyl isatins are treated with sodium hydroxide and potassium ferricyanide solutions.

Further application of potassium ferricyanide method in the estimation of organic carbon in soils

1. Potassium permanganate in acid medium is found to decompose on heating and the rate of decomposition increases with the period of boiling. 2. A method for estimation of organic carbon in soil by oxidation with alkaline potassium ferricyanide solution is outlined. 3. The results obtained by the potassium ferricyanide method are shown to agree more closely in calcareous soils than other methods with those obtained by the standard dry combustion method. Besides the method is more exact in view of its very sharp end-point.

Application of potassium ferricyanide method for the estimation of carbohydrate in cane leaves

1. A method for the quick estimation of carbohydrates in cane leaves is described and it consists in the direct use of lead oxlate filtrate for the titration of glucose with 1% alkaline potassium ferricyanide solution. 2. This method is shown to be simpler, quicker and more economical than the standard methods of Bertrand and Schaffer and Hartmann. 3. The three methods are shown to give excellent comparable results for glucose in cane leaves while the new method gives the least observational error thus adding to the precision of results.

Permanent Color Standards for Folin’s Ferricyanide Sugar Method

Permanent Color Standards for Folin’s Ferricyanide Sugar Method Get access W. D. Stovall, W. D. Stovall Wisconsin State Laboratory of Hygiene, University of Wisconsin Medical School, Madison, Wisconsin Search for other works by this author on: Oxford Academic Google Scholar Marian Foote, Marian Foote Wisconsin State Laboratory of Hygiene, University of Wisconsin Medical School, Madison, Wisconsin Search for other works by this author on: Oxford Academic Google Scholar M. Starr Nichols M. Starr Nichols Wisconsin State Laboratory of Hygiene, University of Wisconsin Medical School, Madison, Wisconsin Search for other works by this author on: Oxford Academic Google Scholar American Journal of Clinical Pathology, Volume 3, Issue 4, 1 July 1933, Pages 299–304, https://doi.org/10.1093/ajcp/3.4.299 Published: 01 July 1933

Reducing and Intensifying Solutions for Motion Picture Film

The properties of a large number of known intensifying and reducing solutions have been studied in detail to determine formulas suitable for use with motion picture film. — For intensification, the chromium, Monckhoven (mercury), and silver intensifiers were the most satisfactory. The Monckhoven intensifier is useful for extreme intensification where permanence is not essential and the chromium intensifier is suitable for negatives where a medium increase in contrast is desirable. The degree of intensification with the chromium method may be controlled within limits by a variation of the time of redevelopment. For negatives and projection prints, intensification with silver has been found to give strictly neutral images and the process permits of easy control of the degree of intensification. So far as is known, both the chromium and silver intensified images are stable. — For subtractive reduction, such as in the case of overexposures or fogged images, the use of either (1) a two-bath formula comprising separate solutions of potassium ferricyanide and sodium thiosulfate, or (2) a modification of the Belitzski reducer is suitable. Where proportional reduction is required, a solution containing ferric ammonium sulfate with sulfuric acid is recommended. — It has been found that the above methods of intensification and reduction are applicable to sound film with the possible exception of subtractive reduction which, by virtue of the lowering of resolving power, causes a loss of high frequencies.

The Determination of Guanidine Bases in the Blood.

Recently, Pfiffner and Myers, in a preliminary report, gave a tentative procedure for the determination of the guanidine bases in blood. In an attempt to apply this method it was found that recoveries of added guanidine in amounts as small as 1 mg. per 100 cc. of blood could not be made. The main difficulty in the determination of these small amounts is the fact that the reagent proposed by Marston does not give a sufficient color production with guanidine in amounts smaller than 0.05 mg. per 5 cc. of solution. It was found that by replacing potassium ferrocyanide with ferricyanide, and eliminating the hydrogen peroxide, a reagent is produced which retains practically all the advantages of Marston's reagent, and in addition gives almost twice as much color with guanidine. The reagent is made by mixing equal volumes of 10 per cent solutions of sodium nitroprusside, potassium ferricyanide, and sodium hydroxide and diluting the mixture with three volumes of water. The color changes from a dark red to a pale yellow in about 20 minutes and is then ready for use. This prepared reagent will usually keep for 12 hours, but if turbidity develops a fresh reagent should be made up. It is used in the proportion of 1 cc. of the reagent to every 5 cc. of the solution to be tested. Equal amounts of guanidine or methyl guanidine give the same color value with the reagent, whereas dimethyl guanidine gives only two-thirds as much color. The color is an orange red, which develops to its maximum in 2 minutes. Creatine gives 1/10 as much color as does guanidine, and the color develops to its maximum in about 5 minutes.

8. On Ferric Ferricyanide as a Reagent for Detecting Traces of Reducing Gases

The brown solution obtained when solutions of ferric chloride and potassium ferricyanide are mixed, which may be regarded as containing ferric ferricyanide, is, as is well known, very readily turned blue by reducing agents, Prussian blue or Turnbull's blue being formed. The author uses strips of filter paper dipped in the freshly prepared solution to test for traces of reducing gases, such as sulphuretted hydrogen, sulphurous acid, &c. As nitrous fumes also blue the brown solution, reducing it, traces of them can be detected by using together a piece of paper prepared as above and a piece of iodised starch paper.