Liquid absorbance standards

Burke, R. W.; Deardorff, E.R.; Menis, Oscar

doi:10.6028/jres.076a.041

Cited by 47 publications

(25 citation statements)

References 18 publications

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“…Cr207=' The equilibrium between these two species may be represented as (1) and the corresponding dimerization constant, K v , is given by (2) Although eq. (2) predicts that the formation of CrZ0 7= is strictly a quadratic function of K ZCr Z0 7 concentration, the value of K D =32.9 (mol kg-l)-l obtained previously [3] is of such magnitude that the percentage of total chromium present as the Cr207 = ion is very nearly a linear function of the K2Cr207 concentration for the range of solutions studied. Calculated values of HCrO,-/CrZ07= speciation in this system are given in table III.…”

Section: Discussion and Resultsmentioning

confidence: 85%

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Acidic potassium dichromate solutions as ultraviolet absorbance standards

Burke

Mavrodineanu

1976

J. RES. NATL. BUR. STAN. SECT. A.

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. The absorbances of five concentrations of potassium dichromate in 0.001 ]l.f perchloric aCid have been determined at eight wavelengths in the ultraviolet on the National Bureau of Standards Institute for Materials Research high-accuracy spectrophotometer. Four of the wavelengths-235, 257, 313, and 3.50 nm-correspond to absorbance maxima or minima in the HCrO,-spectrum and are useful wavelengths for checking the accuracy of the absorbance scale of narrow bandpass speetrophotometers. Although partial dimerization of nCrO,-to Cr207-prod~c.e~ small positive deviations from Beer's law at these wayelengths, the apparent absorptlvltles calculated for each concentration arc reproducible to one part in a thousand. The estimated uncertainties in the absorptivity values are ± 0.7 percent at 0.1 absorbance (A) and ± 0.2 percent ncar A = 1. These uncertainties include all known sources of possible systematic error and the 95 percent confidence level for the mean. The remaining four wavelengths used for measurement arc ncar two predicted isosbestie points in the HCrO,~/Cr207-sp~ctra . The absorptivities at 345 nm arc sufficiently independent of concentratIOn that thiS wavelength can be used for checking absorbance linearity to one part in a thousand over the range A = 0.2-1.~cy words: ~bsorbance linearity; accuracy; acidic potassium dichromate solutions; calibratIOn of ultravIOlet speetrophotometers; liquid filters; transfer standards; ultraviolet absorbance standards.

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Section: Discussion and Resultsmentioning

confidence: 85%

“…Of the chemical or liquid-type filters that have been proposed, the weakly acidic potassium dichromate system is considered the best. A critical evaluation of this system, as well as several other candidate materials, was presented in a previous paper [3].…”

Section: Introductionmentioning

confidence: 99%

Acidic potassium dichromate solutions as ultraviolet absorbance standards

Burke

Mavrodineanu

1976

J. RES. NATL. BUR. STAN. SECT. A.

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“…Sulfone reaction spectrum for characterization of wavelength reproducibility of a spectrometer Vol. 37 Ultraviolet and Visible Spectroscopysulfuric acid [127,128]. The Lambert -Beer law requires a linear relationship between the signal and concentration.…”

Section: Photometricmentioning

confidence: 99%

Ultraviolet and Visible Spectroscopy

Gauglitz

2008

Ullmann's Encyclopedia of Industrial Chemistry

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The article contains sections titled: 1. Introduction 1.1. Comparison with Other Spectroscopic Methods 1.2. Development and Uses 2. Theoretical Principles 2.1. Electronic States and Orbitals 2.2. Interaction Between Radiation and Matter 2.2.1. Dispersion 2.2.2. Absorption 2.2.3. Scattering 2.2.4. Reflection 2.2.5. Band Intensity 2.3. The Lambert–BeerLaw 2.3.1. Definitions 2.3.2. Deviations from the Lambert ‐ Beer Law 2.4. Photophysics 2.4.1. Energy Level Diagram 2.4.2. Deactivation Processes 2.4.3. Transition Probability and Fine Structure of the Bands 2.5. Chromophores 2.6. Optical Rotatory Dispersion and Circular Dichroism 2.6.1. Generation of Polarized Radiation 2.6.2. Interaction with Polarized Radiation 2.6.3. Optical Rotatory Dispersion 2.6.4. Circular Dichroism and the Cotton Effect 2.6.5. Magnetooptical Effects 3. Optical Components and Spectrometers 3.1. Principles of Spectrometer Construction 3.1.1. Sequential Measurement of Absorption 3.1.2. Multiplex Methods in Absorption Spectroscopy 3.2. Light Sources 3.2.1. Line Sources 3.2.2. Sources of Continuous Radiation 3.2.3. Lasers 3.3. Selection of Wavelengths 3.3.1. Prism Monochromators 3.3.2. Grating Monochromators 3.3.3. Electro‐Acoustic and Opto‐Acoustic Wavelength Generation 3.4. Polarizers and Analyzers 3.5. Sample Compartments and Cells 3.5.1. Closed Compartments 3.5.2. Modular Arrangements 3.5.3. Open Compartments 3.6. Detectors 3.7. Optical Paths for Special Measuring Requirements 3.7.1. Fluorescence Measurement 3.7.2. Measuring Equipment for Polarimetry, ORD, and CD 3.7.3. Reflection Measurement 3.7.4. Ellipsometry 3.8. Effect of Equipment Parameters 3.9. Connection to Electronic Systems and Computers 4. Uses of UV ‐ VIS Spectroscopy in Absorption, Fluorescence, and Reflection 4.1. Identification of Substances and Determination of Structures 4.2. Quantitative Analysis 4.2.1. Determination of Concentration by Calibration Curves 4.2.2. Classical Multicomponent Analysis 4.2.3. Multivariate Data Analysis 4.2.4. Use in Chromatography 4.3. Fluorimetry 4.3.1. Inner Filter Effects 4.3.2. Fluorescene and Scattering 4.3.3. Excitation Spectra 4.3.4. Applications 4.4. Reflectometry 4.4.1. Diffuse Reflection 4.4.2. Color Measurement 4.4.3. Regular Reflection 4.4.4. Determination of Film Thickness 4.4.5. Ellipsometry 4.5. Resonance Methods 4.5.1. SurfacePlasmon Resonance 4.5.2. Grating Couplers 4.5.3. Other Evanescent Methods 4.5.4. Interferometric Methods 4.6. On‐Line Process Control 4.6.1. Process Analysis 4.6.2. Measurement of Film Thicknesses 4.6.3. Optical Sensors 4.7. Measuring Methods Based on Deviations from the Lambert – Beer Law 5. Special Methods 5.1. Derivative Spectroscopy 5.2. Dual‐Wavelength Spectroscopy 5.3. Scattering 5.3.1. Turbidimetry 5.3.2. Nephelometry 5.3.3. Photon Correlation Spectroscopy 5.4. Luminescence, Excitation, and Depolarization Spectroscopy, and Measurement of Lifetimes 5.5. Polarimetry 5.5.1. Sugar Analysis 5.5.2. Cellulose Determination 5.5.3. Stereochemical StructuralAnalysis 5.5.4. Use of Optical Activity Induced by a Magnetic Field 5.6. Photoacoustic Spectroscopy (PAS)

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“…the relative band width (RBW). Table 2 which is modified from that of Burke et al [4] illustrates the influence of relative band width on the apparent absorbance of a chromophore and shows that the greater the relative band width, the greater the discrepancy between true and observed absorbance. .…”

Section: Naphthol Green Proceduresmentioning

confidence: 99%