Potassium Bromide Disk Research Articles

The Infrared Spectrophotometric Determination of Ethisterone by the Potassium Bromide Disk Technique

The Infrared Spectrophotometric Determination of Ethisterone by the Potassium Bromide Disk Technique

Spectrophotometric studies of the 2:4-dinitrophenylhydrazones of n-alka-2-enals and n-alka-2:4-dienals

Abstract Wavelength maxima and molar absorption coefficients in the ultraviolet-visible region are reported for chloroform solutions and for alkaline ethanol solutions of the 2:4-dinitrophenylhydrazones of the n-alka-2-enals containing from three to eleven carbon atoms and of the n-alka-2:4-dienals containing from five to twelve carbon atoms. Infrared spectra from 2 to 15 μ are reported for these compounds dispersed in potassium bromide disks. Correlations of u.v. and i.r. spectral features with degree of conjugated unsaturation are discussed. Although the infrared spectra of the individual members of each homologous series are similar, those examined can be differentiated. Characteristic spectral differences between the stable and unstable polymorphic forms of the 2-enal derivatives are reported.

STRUCTURE OF BRIDGMAN'S BLACK CARBON DISULPHIDE

The infrared spectrum of black carbon disulphide dispersed in a potassium bromide disk has been examined. The blackness and the infrared spectrum are consistent with its being a linear polymer, —(C==S.S)n.

INFRARED AND ULTRAVIOLET ABSORPTION SPECTRA OF SOME SALTS AND METAL CHELATES OF ANTHRANILIC ACID

Absorption maxima in the 3000 and 1550 cm-/sup 1/ regions in potassium bromide disks, in the 300 m mu region in potassium bromide disks, and in ethanol solutions are reported i for anthranilic acid; its sodium, potassium, calcium, strontium, and barium salts; and its chelates with magnesium, zinc, cadmium, nickel, and copper. Chelation shifts the 320 m mu band of the anthranilate ion to shorter wave lengths, decreases the frequencies of the N - H stretching vibrations, causes an inversion of the relative intensities of the 1615 and 1580 cm-/sup 1/ peaks and effects small shifts to higher frequencies of the band attributed to the antisymmetric COO/sup -/ stretching vibration. The spectra indicates a trans planar square comfiguration for all complexes. The chelates are appreciably dissociated in ethanol. (auth)

Infrared Analysis of Pharmaceuticals I : Application of the Potassium Bromide Disk Technique to Some Steroids, Alkaloids, Barbiturates, and Other Drugs

The quantitative potassium bromide disk technique has been investigated and methods have been adopted for its application to some pharmaceuticals. Average deviations from linearity within ±4.0 per cent were obtained with some crystalline compounds. Analyses of pharmaceutical preparations, by hand-grinding or vibrator-grinding methods, resulted in average agreement within ±3 to ±4.5 per cent with ultraviolet spectrophotometric or gravimetric determinations.

Infrared Analysis of Pharmaceuticals II : A Study of the Cinchona Alkaloids in Potassium Bromide Disks

In the course of an investigation into the applicability of a quantitative potassium bromide disk method to various drugs and chemicals, the cinchona alkaloids, quinidine, quinine, cinchonine, and cinchonidine were studied. Under certain experimental conditions, possibly due to the formation of dimorphous and amorphous forms, anomalous spectra were obtained for quinidine and quinine. Cinchonine and cinchonidine did not exhibit significant variations in spectra under the conditions investigated.

Digitalis X. The Infrared Absorption Spectra of Some Digitalis Glycosides and Aglycones

The infrared absorption spectra of commercial samples of the three lanatosides, their aglycones and their three intermediate glycosides, digitoxin, gitoxin, and digoxin, have been scanned between 2.5 μ and 15 μ using the potassium bromide disk technique. Some of the more pronounced characteristics of these spectra have been noted and their possible significance in the identification and differentiation of these highly important cardiotonic substances has been indicated.

Analysis of Milk Phospholipids by Chromatography and Infrared Spectrophotometry

Summary Milk phospholipids were fractionated into the major phospholipid classes by successive elution from a silicic acid column with chloroform, acetone, methanol (20% and 40%) in chloroform, and methanol. Each fraction was analyzed by infrared spectrophotometry as well as by chemical methods. Potassium bromide disk spectra of milk cerebrosides, cephalins, lecithins, and sphingomyelins are presented and compared with pure reference compounds. Concentrations of each class were calculated from specific bands measured either in chloroform or in carbon disulfide solutions. Respective weight percentages of cerebrosides, cephalins, lecithins, and sphingomyelins were: 6, 35, 32, and 24. Evidence is given for the presence of minor amounts of other constituents, including carbohydrate-containing phospholipids, lysolecithins, and unidentified lipids. Advantages and limitations of the method at its present state of development are discussed.

Quantitative Analysis of Mono- and Polybasic Benzene Carboxylic Acids in Potassium Bromide Disks by Infrared Spectroscopy

Quantitative Analysis of Mono- and Polybasic Benzene Carboxylic Acids in Potassium Bromide Disks by Infrared Spectroscopy

Applications of Infrared Absorption Spectroscopy to Investigations of Cotton and Modified Cottons

The potassium bromide disc technique is being used for rapid, simple, and reproducible measurement of the infrared spectra, of modified cotton fibers, yarns, and fabrics. Ap plications of the procedure have demonstrated that chemical modification can be readily detected and identified and that the extent of treatment can be quantitatively estimated. Experiments have been designed to select bands most useful in investigations of cotton modified by esterification. etherification, or replacement reactions. The examples cited illustrate the potential usefulness of infrared absorption spectra to studies in this field. A list has been prepared of 50 infrared absorption bands (and correlations with vibrating groups which give rise to them) which summarize the spectral characteristics which have been found most useful in investigations of cottons modified by esterification, etherifica tion, and replacement reactions.

KBr Disk Technique for Infrared Microanalysis with Freeze Drying of Samples Soluble in Organic Solvents but Insoluble in Water

The potassium bromide disk technique has been adapted for quantitative microanalysis of compounds which are soluble in organic solvents, but insoluble in water. The principal improvements of the technique comprise exclusive use of freeze drying for preparation of suspensions of samples in solid potassium bromide, avoidance of contamination during the sample preparation, and lubrication of the die with graphite The present experimental data indicate that the disk technique can be used for quantitative infrared microanalysis of binary mixtures of complex organic compounds.

Radiation-Induced Reactions of Potassium Bromide with Air

When a pressed potassium bromide disc was irradiated in ordinary laboratory air, new bands appeared in the infrared absorption spectrum, with maxima at 1260, 1260, 830, phere of dry oxygen produced, in addition to the peak at 1440 K, an infrared absorption band with a maximum at 790 K. The possibility of the presence of potassium nitrate, potassium nitrite, potassium bromate, and carbon dioxide arising from the radiolysis of organic impurities is discussed.

A simplified method for the preparation of α‐ and β‐eleostearic acids and a revised spectrophotometric procedure for their determination

SummarySimplified methods for the preparation of pure α‐ and β‐eleostearic acids are described. These procedures involve saponification of α‐ and β‐tung oils under mild conditions, followed by direct crystallization of the liberated acids at −20°C. from ethanolic solution. Only one recrystallization from ethanolic solution at +5°C. was required to produce the pure acids.Absorptivities obtained from measurements of the ultraviolet absorption revealed α‐eleostearic acids of from 3–4% higher purity than those used in obtaining the equations previously recommended for the simultaneous determination of α‐ and β‐eleostearic acids. This has necessitated a revision of these equations. Equations for the determination of each isomer from both cyclohexane and ethanol are reported. Equations are also given for an independent determination of total eleostearic acid, and for the determination of one isomer in the absence of the other.Infrared absorption spectra in the rock salt region from 2–15 microns have been measured from potassium bromide discs. These solid‐state or crystalline spectra reveal, in addition to the prominent bands assigned to characteristic groupings of the eleostearic acid molecule, the progression bands by means of which carbon chain length can be computed.

Spectrochemical Study of Microscopic Crystals. XIV. Absorption Spectra and Structure of Dibenzene-chromium(I) Iodide

Abstract Polarized absorption spectra of [Cr(C6H6)2]I in the visible and the ultraviolet region were quantitatively determined by Tsuchida-Kobayashi’s microscopic method using a single crystal. Visible and ultraviolet absorption spectra in solution and an infra-red spectrum in potassium bromide disks were also determined. From the results of the measurements, it was concluded that the electronic state of the benzene rings in [Cr(C6H6)2]I deviates greatly from the state of free benzene and that the π-electrons of the benzene rings are attracted remarkably toward the chromium ion to form firm linkages.

Infrared Determination of Tetramethylthiuram Disulfide in Commercial Dithiocarbamate Formulations by the Potassium Bromide Disk Technique

Infrared Determination of Tetramethylthiuram Disulfide in Commercial Dithiocarbamate Formulations by the Potassium Bromide Disk Technique

Adaptation of Potassium Bromide Disk Press for Microdisk in Pressing in Vacuo

Adaptation of Potassium Bromide Disk Press for Microdisk in Pressing in Vacuo

Difficulties in the Infrared-Spectrophotometric Identification and Estimation of Pure Compounds and Mixtures by Use of the Potassium Bromide Disk Technique.

Difficulties in the Infrared-Spectrophotometric Identification and Estimation of Pure Compounds and Mixtures by Use of the Potassium Bromide Disk Technique.

Potassium Bromide Disk Method for the Infrared Studies of Coördination Compounds

The infrared absorption of tetrakis(ethylenethiocarbamide)copper(I) nitrate, ethylenethiocarbamide, and potassium nitrate have been measured by the potassium bromide disk method. The assignment of the frequencies of ethylenethiocarbamide explains that part of the spectrum (the wavelength region between 7 and 13 microns) in which various CH2 deformation frequencies are expected to appear. Generally speaking the infrared spectrum of tetrakis(ethylenethiocarbamide)copper(I) nitrate can be regarded as the superposition of the spectra of ethylenethiocarbamide and potassium nitrate, except for the absorption peaks at 9.6 and 14 microns, which do not appear in the infrared spectra of ethylenethiocarbamide and potassium nitrate. It is interesting to note that these wavelengths correspond to the Raman frequencies (1050 cm—1 and 720 cm—1) of potassium nitrate, which should be infrared-inactive. The appearance of these frequencies in the absorption spectrum is explained by the distortion of the nitrate ion in tetrakis(ethylenethiocarbamide)copper(I) nitrate.

Die for Preparation of Potassium Bromide Disks under Vacuum

Die for Preparation of Potassium Bromide Disks under Vacuum

New Infrared Sampling Technique Using Pressed Potassium Bromide Disks

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text , "New Infrared Sampling Technique Using Pressed Potassium Bromide Disks," J. Opt. Soc. Am. 43, 712-712 (1953) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article