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Showing papers in "Applied Spectroscopy in 1967"


Journal ArticleDOI
TL;DR: In this paper, diffuse-reflectance spectra for 11 rare-earth oxides of various structural types over the spectral range of 225-2700 mμ have been reported.
Abstract: Diffuse-reflectance spectra are reported for 11 rare-earth oxides of various structural types over the spectral range of 225–2700 mμ. These spectra, particularly in the near infrared, permit the use of diffuse-reflectance spectroscopy to identify rare-earth ions in solid materials.

47 citations


Journal ArticleDOI
TL;DR: In this article, the spectrum of solid 5-aminotetrazoles and their deuterated derivatives in mulls and KBr disks is presented and regions for NH and ND stretching, bending, and rocking modes; ring N=N and C=N frequencies; and exo CN stretching modes.
Abstract: Spectra of solid 5-aminotetrazoles and their deuterated derivatives in mulls and KBr disks are presented. It has been possible to assign regions for NH and ND stretching, bending, and rocking modes; ring N=N and C=N frequencies; and exo CN stretching modes.

26 citations


Journal ArticleDOI
TL;DR: In this article, the dc-arc method was used for the determination of up to 15 volatile elements in trace amounts in silicates, including Ag, Au, In, and Tl.
Abstract: Details are given of a quantitative dc-arc method for the determination of up to 15 volatile elements in trace amounts in silicates. Twenty milligrams of sample are mixed with an equal weight of an alumina–lime buffer containing 0.1% bismuth trioxide as internal standard and the mixture arced as the anode in a graphite cup. Careful control of arcing conditions allowed the determination of common volatile elements in amounts down to 1 ppm and in the case of several rare elements—notably Ag, Au, In, and Tl—down to 0.1 ppm.

19 citations


Journal ArticleDOI
TL;DR: In this article, the mathematical theories which are applicable to the excitation and ionization of atoms in plasmas at thermal equilibrium are described, which can be applied to practical problems which arise in spectrochemical analysis.
Abstract: The mathematical theories which are applicable to the excitation and ionization of atoms in plasmas at thermal equilibrium are described. These processes are controlled by the temperature and electron density in the plasma; some methods of determining these parameters are given. There have been several measurements of arc and spark temperatures in air, but few determinations of electron densities or of temperatures in gases other than air. It is shown that, even with the limited data available, the theories can be applied to practical problems which arise in spectrochemical analysis.

18 citations


Journal ArticleDOI
TL;DR: In this article, a brief description of the optimization of critical instrumental parameters for achieving maximum sensitivity and precision is given for flame-emission, atomic-absorption, and atomic-fluorescence flame spectrometry.
Abstract: A brief description of the optimization of critical instrumental parameters for achieving maximum sensitivity and precision is given for flame-emission, atomic-absorption, and atomic-fluorescence flame spectrometry. The discussion covers suggested techniques for optimization.

16 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present a review of the early development of the ion detector using photographic emulsions as ion detectors and a more detailed look at the development since 1960.
Abstract: This paper is a review presenting a description of the instrument and method, a brief summary of the early work, and a more detailed look at the development since 1960. Studies on the properties of photographic emulsions as ion detectors and the optimum conditions for their use are reported. Various methods are reported for quantitative data treatment, which include plate calibration, photometry, and corrections. Investigations of the spark source are reviewed, covering the causes and effects of the varying energy spectra and some corrections for the relative volatility and diffusion rates. The contribution of the sample itself to the analytical error is discussed, and the results obtained with rigorous standardization are presented.

13 citations


Journal ArticleDOI
TL;DR: A technique for trapping small gas-chromatographically isolated samples directly in such an all-glass NMR microcell using a modification of a cell first described by Frei and Niklaus is described.
Abstract: The use of a commercially available all-glass spherical sample-chamber microcell in combination with a time-averaging computer for nuclear magnetic resonance (NMK) analyses of microsamples has recently been reported.1 Brame2 has described a technique for trapping small gas-chromatographically isolated samples directly in such an all-glass NMR microcell. A somewhat different, easily fabricated microcell has been constructed and tested in our laboratories with excellent results. The design is a modification of a cell first described by Frei and Niklaus.3

12 citations


Journal ArticleDOI
TL;DR: The mass spectra of some chlorinated copper phthalocyanines have already been reported as discussed by the authors, which indicated that at least two processes were occurring, namely electron-impact-induced dissociation and thermal depolymerization.
Abstract: The mass spectra of some chlorinated copper phthalocyanines have already been reported. These observations suggested that at least two processes were occurring, namely electron-impact-induced dissociation and thermal depolymerization. The combined effect of these yielded the mass spectrum that comprised the parent molecular ion, a composite ion which represents one quarter of the molecule with a copper atom attached, and halogenated phthalonitrile ions together with some fragments corresponding to halogen atoms. Even if the parent molecular ion is absent, as happens with highly substituted compounds, a partial structure may be deduced from a consideration of the phthalonitrile ions produced by the depolymerization. Each molecule of phthalocyanine depolymerizes to yield four phthalonitrile molecules.

11 citations


Journal ArticleDOI
TL;DR: In this article, a new method for the copper determination in complex brasses is described, which is based on the measurement of the intensity ratio between the ZnKα and the CuKβ lines.
Abstract: A review over the current practice in the determination of copper in complex brasses by x-ray-fluorescence spectroscopy is outlined. It is shown that, in close agreement with experimental results, interelement effects may be derived from fundamental considerations based on intensity integrals and primary and secondary absorption effects in brass samples. A new method for the copper determination in complex brasses is described, which is based on the measurement of the intensity ratio between the ZnKα and the CuKβ lines. This method is independent of the absorption or enhancement effects of additivs or impurities of the alloy and is very little influenced by variation in high tension of the x-ray tube or variations of position, preparation, and size of the sample. The counting time can be reduced in comparison with the conventional method. The same principles may be used for the analysis of several other chemical systems.

10 citations


Journal ArticleDOI
TL;DR: In this article, the lead in aqueous solution was complexed as K2PbI6 and the complex extracted into methyl isopropyl ketone, a threefold increase in sensitivity relative to the lead as lead nitrate was obtained using a 178mm-long adapter on the top of a Beckman integral aspirator-burner (oxy-hydrogen).
Abstract: The sensitivities of lead in aqueous and organic media by atomic-absorption spectroscopy using lead lines 2170 A, 2833 A, and 4058 A, and an oxy-hydrogen or oxy-acetylene flame were studied. When lead in aqueous solution was complexed as K2PbI6 and the complex extracted into methyl isopropyl ketone, a threefold increase in sensitivity relative to the aqueous solution of lead (as lead nitrate) was obtained. Using a 178-mm-long adapter on the top of a Beckman integral aspirator-burner (oxy-hydrogen), a sensitivity (in ppm/1% absorption) of 0.007 and a standard deviation of 0.014 ppm were obtained with a sample containing 0.1 ppm lead. Results obtained with oxy-hydrogen and oxy-acetylene flames have been discussed, and the precision and detection limits indicated. A procedure to determine lead in ppb–ppm level by extracting lead as K2PbI6 in methyl isopropyl ketone has been prescribed.

9 citations


Journal ArticleDOI
TL;DR: In this article, a reaction mechanism has been proposed for the isomerization of Palladium complexes of the type cis-PdL2X2 to the corresponding trans isomers.
Abstract: Palladium complexes of the type cis-PdL2X2 have been found to be unstable at room temperature and isomerize to the corresponding trans isomers. Neglecting lattice interactions, symmetry considerations would predict two Pd–N stretching vibrations. These vibrations have been observed at 495 and 476 cm−1 for the cis-chloride isomer and at 480 and 460 cm−1 for the cis-bromide isomer. The trans isomer, by the same considerations, should have but one Pd–N stretching vibration. This vibration was observed for the trans-chloride isomer at 496 cm−1 and for the trans-bromide isomer at 490 cm−1. It has been found that as isomerization proceeds, from the cis to the trans forms, the lower Pd-N stretching vibration decreases in intensity and eventually disappears. The intensity changes for these vibrations over a period of 72 h indicated that the reaction follows a first-order rate law. A reaction mechanism has been proposed.

Journal ArticleDOI
TL;DR: A spectroradiometerluminometer has been constructed, calibrated, and applied to the measurement of fluorescence and chemiluminescence-emission intensity as a function of wavelength and to kinetic decay studies.
Abstract: A spectroradiometerluminometer has been constructed, calibrated, and applied to the measurement of fluorescence- and chemiluminescence-emission intensity as a function of wavelength and to kinetic decay studies. It is also applicable to investigations of phosphorescence, electroluminescence, bioluminescence, and the spectroradiometry of external light sources. A computer program has been set up to take care of wavelength-response corrections and to convert emission intensities into photochemical, radiometric, or luminous units, including total integrated intensities for quantum-yield studies.

Journal ArticleDOI
TL;DR: In this paper, it was shown that as the relative intensity ratio of the doublet changes in different solvents, the phosphoryl doublet probably results from more than inter-molecular hydrogen bonding.
Abstract: The phosphoryl absorption band in the infrared spectra of organic phosphorus compounds appears in the region 1320–1150 cm−1 as a doublet. Goldenson has reported that the phosphoryl doublet may be due to the hydrogen bond formed with impurities that cannot be removed by ordinary purification methods. However, as the relative-intensity ratio of the doublet changes in different solvents, the phosphoryl double probably results from more than inter-molecular hydrogen bonding. Consequently, other fundamental causes must be considered.

Journal ArticleDOI
TL;DR: In this paper, the x-ray emission analysis of noble-metal alloys was investigated critically to determine optimum conditions for accurate analysis, and the analytical curves for the elements Cu, Pd, Pt, and Zn were found to be linear with a deviation of less than ± 0.2%.
Abstract: The x-ray emission analysis of noble-metal alloys was investigated critically to determine optimum conditions for accurate analysis. The analytical curves for the elements Cu, Pd, Pt, and Zn were found to be linear with a deviation of less than ±0.2%. However, a nonlinear relationship existed for gold and for silver. These discrepancies could not be eliminated by variation in sample preparation. An interelement effect due to x-ray absorption and enhancement was found and was corrected to an accuracy of 0.2% by means of a mathematical treatment suggested by Lucas-Tooth and Price. The analysis by x-ray emission can be accomplished in approximately one-tenth of the time necessary for conventional wet chemical methods.

Journal ArticleDOI
TL;DR: In this paper, a hollow-cathode light source of new design has been tested in connection with a vacuum spectrograph, and the limit of detectability under the given conditions was at 0.01 μg iodine.
Abstract: On the basis of some theoretical considerations concerning the analyzability of elements that have their resonance lines in the vacuum ultraviolet, a hollow-cathode light source of new design has been tested in connection with a vacuum spectrograph. The results, which show an improvement over those reported in the literature, are tabulated. The limit of detectability under the given conditions was at 0.01 μg iodine.

Journal ArticleDOI
TL;DR: In this article, a high-temperature all-metal cell suitable for infrared adsorption studies has been described in the literature, which requires a higher operating temperature (>700°C), better vacuum (∼ 10−6 Torr), and a larger aperture.
Abstract: A high-temperature all-metal cell suitable for infrared adsorption studies has been described in the literature.1 Our applications, however, require a higher operating temperature (>700°C), better vacuum (∼ 10−6 Torr), and a larger aperture. The higher operating temperature requires a higher temperature gradient between the inside and outside, so that the surface of the furnace section does not become unreasonably warm. This temperature gradient results from a more efficient furnace design which utilizes reflection principles for confining the heat inside the furnace section. We have also found our method of construction and method of introducing the thermocouple into the system more convenient for this type of study.

Journal ArticleDOI
T. H. Siddall1, C. A. Prohaska1
TL;DR: In this paper, the same authors obtained proton magnetic resonance and infrared spectra for 44 carbamylphosphonates and related compounds, the common structural features being the grouping [Equation] and slow rotation is observed around the carbonyl-to-nitrogen bond, but the chemical shift between nitrogen substituents is three to five times as great.
Abstract: Proton magnetic resonance and infrared spectra were obtained for 44 carbamylphosphonates and related compounds, the common structural features being the grouping [Equation] As with ordinary amides, slow rotation is observed around the carbonyl-to-nitrogen bond, but the chemical shift between nitrogen substituents is three to five times as great. Evidence is presented for long range coupling of phosphorus to protons in N-substituents. Correlations are observed between the carbonyl and phosphoryl stretching frequencies and substituents both on nitrogen and on phosphorus.

Journal ArticleDOI
TL;DR: In this article, an emission-spectrographic method using a plasma arc to determine B, Ba, Fe, Mn, and Sr in oilfield waters was developed and the relative intensities of their emission lines were determined using each of 10 solvent systems.
Abstract: Studies of the concentration and distribution of the mineral content in subsurface oilfield waters aid in locating water-pollution sources, determining water compatibilities, determining the origin and distribution of oilfield waters and petroleum, and exploring for petroleum and other minerals. An emission-spectrographic method using a plasma arc to determine B, Ba, Fe, Mn, and Sr in oilfield waters was developed. Variations in brine composition were reduced by use of a synthetic brine solution. Less than 1 mg/liter of each ion can be detected. Synthetic and natural oilfield waters containing the subject ions were mixed with various organic solvents and the internal standard. Relative intensities of their emission lines were determined using each of 10 solvent systems.

Journal ArticleDOI
TL;DR: In this paper, a 1:2 mixture of BaCO3 or Li2CO3 and graphite powder is used to increase the stability of the dc arc, which is shown to reduce current and voltage fluctuations and arc wandering.
Abstract: The stability of the dc arc can be increased by the use of a cathode that is cored with a material containing an element of an ionization potential lower than carbon. An effective core material developed for spectrochemical analysis is a 1:2 mixture of BaCO3 or Li2CO3 and graphite powder. In the arc, the added element forms a stationary positive-ion cloud at the tip of the cathode and acts as a ballast to electron flow. Arc temperature is not lowered, as is frequently the case when a buffer is added to the anode. Current and voltage fluctuations and arc wandering are reduced, as indicated by recordings during sample consumption. Several hundred sample materials have been tested to determine the usefulness of the cored cathode.

Book ChapterDOI
TL;DR: In this paper, the authors used the vacuum ultraviolet spectral region (VUV) where the nonmetallic elements show their most sensitive spectral lines (i.e., resonance lines) to perform spectroscopic analysis of nonmetals.
Abstract: The development of the spectrochemical analysis of nonmetals progressed much slower than that of the metallic elements. This difference could probably be traced to the following reasons: (1) lack of sensitive spectroscopic lines in the visible or near ultraviolet region; (2) poor spectral sensitivity; (3) excitation difficulties; and (4) materials to be analyzed are often poor conductors and mechanically unworkable as electrodes. Some of these difficulties can be overcome by utilizing the vacuum ultraviolet spectral region (VUV), where the nonmetallic elements show their most sensitive spectral lines (i.e., resonance lines). The remaining difficulties can be ameliorated if an exciting source is provided, which allows these elements to be used as electrodes.

Journal ArticleDOI
TL;DR: In this paper, a detailed study of the visible spectra in solution and the infrared spectrum in the solid state has been made for the following vinylogous series of cyanine dyes.
Abstract: A detailed study of the visible spectra in solution and the infrared spectra in the solid state has been made for the following vinylogous series of cyanine dyes: [2-bis (3-ethylbenzoxazolyl)] cyanine iodides, [2-bis-(1-ethyl-3,3-dimethylindolinyl)] cyanine iodides, and [2-bis-(1-ethylquinolyl)] cyanine iodides. Each dye, to be acceptable for study, had to be chromatographically pure, give a correct microchemical elemental analysis, and be free of electron-spin-resonance (free-radical) signals. The characteristic red shift of the principal absorption maxima was observed for these dyes in the visible range as the number of methine linkages increased. A careful comparison of the visible spectral data of the [2-bis (3-ethylbenzoxazolyl)] cyanine iodides with those of the corresponding [2-bis (3-ethylbenzothiazolyl)] and [2-bis (3-ethylbenzoselenazolyl)] cyanine iodides, [Leifer et al., Appl. Spectry. 20, 289 (1966)] indicates that the electronegativity of the atom S, Se, or O in the heterocyclic rings probably affects the wavelength of the principal absorption maximum. As the electronegativity of the Group VI.A atom increases, the principal absorption maximum shifts slightly toward the blue. Assignments of vibrational modes to separate absorption regions have been made for these vinylogous series of dyes. Each vinylog has a characteristic pattern of resonant-conjugated stretching modes in the region 1600–1400 cm−1. Some of these modes exhibit a low frequency shift as the resonant-conjugated chain increases. Comparison of the benzoxazolyl modes with those of the corresponding benzothiazolyl and benzoselenazolyl modes indicates that they are probably a function of the electronegativity of S, Se, or O in the heterocyclic rings. As the electronegativity of the VI.A atom increases, the resonant-conjugated stretching modes shift to higher frequencies. There are also characteristic bands in the 1600–1400 cm−1 region which are present in all the vinylogs of each series of these dyes. These bands have been assigned to the stretching modes of the fused phenyl rings present in these dyes. It appears that the fused phenyl stretching modes are a function of the groupings C(CH3)2, O, S, Se present in the indolinyl, benzoxazolyl, benzothiazolyl, and benzoselenazolyl heterocyclic rings, respectively. The sulfur and selenium atoms affect these modes the least while the oxygen atom affects these modes the most. Assignments have been made for the aromatic CH out-of-plane bending modes in the region 800–700 cm−1 for these vinylogous series of cyanine dyes. In the spectra of the 2-bis-indolinyl and 2-bis-quinolyl cyanine iodides, there is a band appearing in the region 1000–900 cm−1 which changes systematically with an increase in the number of hydrogens on the bridge. This band has been assigned to the out-of-plane bending vibrations of the hydrogens in a trans configuration on the bridge. No evidence of a cis isomer was observed in the spectra.

Journal ArticleDOI
TL;DR: In this article, a spectrometric method for the direct determination of Dy, Eu, Gd, and Sm in the parts-per-million range in thorium dioxide was described.
Abstract: A spectrometric method is described for the direct determination of Dy, Eu, Gd, and Sm in the parts-per-million range in thorium dioxide. The method, based upon a carrier-distillation technique, utilizes silver chloride as a carrier and neodymium as an internal standard. Direct-current arc excitation in an atmosphere of 80% argon-20% oxygen prevents formation of cyanogen band spectra and thereby permits the use of sensitive lines in the regions normally obscured by cyanogen bands. The method fulfills the requirements of precision and sensitivity for specification analysis of reactor-grade thorium dioxide with a time saving of approximately 60%, as compared to conventional methods involving chemical separation.

Journal ArticleDOI
TL;DR: In this article, the authors describe the performance of a flow-through cathode lamp and illustrate the ease with which stable hollow-cathode discharges can be obtained from a variety of cathode materials.
Abstract: Hollow-cathode lamps have been used almost exclusively as emission sources in atomic-absorption spectrometry. Although the lamps have been mainly the sealed-off type, two reports by Koirtyohann et al. 1,2 refer to an interchangeable cathode lamp constructed from metal with a continuous inert-gas flow. Interchangeable cathode lamps are extremely useful for laboratories engaged in varying types of analysis, particularly of the “one-off” type. This note describes the performance, based on four years of experience, of the flow-through type of lamp shown in Fig. 1, and illustrates the ease with which stable hollow-cathode discharges can be obtained from a variety of cathode materials. The flow-through system avoids the outgassing steps necessary for the preparation of sealed lamps and, therefore, enables cathodes to be quickly interchanged.

Journal ArticleDOI
TL;DR: A quantitative spectrographic method has been developed for the determination of traces of iron in high-purity copper and silver as discussed by the authors, which can be used over a very wide range of concentrations.
Abstract: A quantitative spectrographic method has been developed for the determination of traces of iron in high-purity copper and silver. The use of copper chloride as a spectrographic carrier improves the sensitivity and enables the method to be used over a very wide range of concentrations. Samples containing from 0.004 to more than 150 μg of iron (0.07–2500 ppm) can be determined by the identical procedure. A series of 15 replicate copper samples containing 6.4 ppm iron yielded a coefficient of variation of 5.2%. The intensity of the iron spectrum is apparently independent of the copper or silver matrix, which greatly simplifies the preparation of calibration curves. Methods for the preparation of iron-free copper chloride and for purifying graphite electrodes are also outlined.

Journal ArticleDOI
TL;DR: Combining gas-liquid chromatography and infrared spectrophotometry is an established analytical practice, however, special trapping procedures are required for the collection and successful infrared analysis of microliter samples obtained from GLC instruments.
Abstract: Combining gas-liquid chromatography (GLC) and infrared spectrophotometry is an established analytical practice Special trapping procedures are required, however, for the collection and successful infrared analysis of microliter samples obtained from GLC instruments Procedures designed for the collection of volatile GLC effluents include: (1) Trapping in powdered potassium bromide, followed by pelleting; (2) trapping in thermoelectrically cooled cells, for use with multiple reflection attachments; (3) trapping in capillary tubes containing solvent; and (4) trapping through a special fraction collector into ultramicrocavity cells, which are used with beam-condensing equipment

Journal ArticleDOI
TL;DR: In this article, a procedure for the determination of nitrogen, oxygen, and hydrogen by spark-source mass spectrography is described, and the reduction of instrument blank levels is an important consideration in this analysis.
Abstract: A procedure for the determination of nitrogen, oxygen, and hydrogen by spark-source mass spectrography is described. The reduction of instrument blank levels is an important consideration in this analysis. Factors which influence the blank level include vacuum, choice of sample etch, and baking of the source. A prespark of 100–300 nC is considered an integral part of the procedure, since it apparently removes the last traces of surface impurities. Blanks below 1 at. ppm have been observed. The procedure can also be applied for the determination of carbon.

Journal ArticleDOI
B. T. Cronhjort1
TL;DR: The use of digital computers to improve the efficiency of interpretation of raw data and the concept of the instrument transform will stimulate creative contributions in the analyst's collaboration with computers are discussed.
Abstract: A new problem representation for evaluation of analytical data is offered. The data considered are generated by multicomponent composition analyzers such as ordinary spectrometers, mass spectrometers, and chromatometers. Each instrument defines a transform that relates the output of the instrument to its input. In terms of the instrument transform, we discuss the use of digital computers to improve the efficiency of interpretation of raw data. Special reference is made to optical direct-reading emission spectrometers in process-control applications. It is believed that the concept of the instrument transform will stimulate creative contributions in the analyst's collaboration with computers.

Journal ArticleDOI
TL;DR: In this article, a dc-arc technique is described for the analysis of impurities in tantalum thin films, where films are sputtered directly on ultrapure graphite substrates, heat oxidized, and removed mechanically.
Abstract: A dc-arc technique is described for the analysis of impurities in tantalum thin films. Films are sputtered directly on ultrapure graphite substrates, heat oxidized, and removed mechanically. Graphite is employed as the buffer, and samples are compared to standards of similar composition. The graphite-substrate technique has been applied to films of other metals produced by sputtering, resistance-heating evaporation, and electron-beam evaporation. Only portions of the spectrographic procedure are modified for different metallic films.

Journal ArticleDOI
TL;DR: In this paper, the authors presented strontium values determined by atomic absorption spectrophotometry on six NBS Portland cements, 6 NBS standards, and the wellknown G-1 and W-1.
Abstract: This paper presents strontium values determined by atomic absorption spectrophotometry on six NBS Portland cements, six NBS standards, and the wellknown G-1 and W-1. These samples represent a wide variety of rock or rocklike types with strontium ranging in concentration from about 0.0025% to 0.21%. Values on samples certified by the National Bureau of Standards are limited to six portland cements and one argillaceous limestone.

Journal ArticleDOI
J. M. McCrea1
TL;DR: A treatment similar to that used by Slavin is combined with a logarithmic logistic equation for a spectrographic-emulsion response curve and used to develop conditions for minimizing the propagation of random error in transmittance data into exposure and analytical results as discussed by the authors.
Abstract: A treatment similar to that used by Slavin is combined with a logarithmic-logistic equation for a spectrographic-emulsion response curve and used to develop conditions for minimizing the propagation of random error in transmittance data into exposure and analytical results. In cases without spectral background, the optimum transmittance levels for reduced propagation depend sharply on behavior in the photometric system, but not on the slope or contrast terms in the emulsion equations. Optimum levels with spectral background involve contrast specifically and present prohibitive difficulties for direct algebraic treatment. Such cases can be studied by numerical computation and plotting techniques, and results for selected background situations are compared. A small effect of graininess on results obtained from Ilford Q2 plates is discussed.