bluuebunny/crossref_metadata_2025 huggingface dataset:
The Fluorescence of Diamond and Raman Spectroscopy at High Pressures Using a New Design of Diamond Anvil Cell
Authors: Adams D. M. , Payne S. J. , Martin K.
Published: September 2005

A new design of diamond anvil high pressure cell suitable for use in infrared and Raman spectroscopy is described. Its performance is demonstrated with particular reference to the pressure dependence of the infrared spectrum of K2PtCl6 and the Raman spectrum of W(CO)6. In contrast to earlier reports, in which forward scattering geometry was used, this design of cell is shown to be very suitable for Raman use in the 180° excitation mode. However, severe limitations are imposed by the fluorescence emission of diamond and of sapphire. Conditions under which the cell can be used for Raman work are summarized. New fluorescence and Raman features are reported for diamond. In particular, a band at 1730 cm−1 is characteristic of type I stones and may be due to C to N bond stretching at defect centers.
Optimization of Instrumental Parameters in an Automated Nonflame Atomic Fluorescence Spectrometer
Authors: Goode S. R. , Montaser Akbar , Crouch S. R.
Published: September 2005

A fully automated nonflame atomic fluorescence (AF) spectrometer has been constructed to facilitate a critical study of how the atomization process is affected by varying the experimental parameters. A hot wire loop atomizer is evaluated and fully optimized for atomic fluorescence spectrometry. A laboratory minicomputer or a hardware logic control system directs the spectrometer operation, including sample delivery to the atomizer, application of electrical current to heat the atomizer, data acquisition, and mathematical analysis of the data. The relative standard deviation of the data is 4 to 7%. Under most conditions on-line data processing allows variation and optimization of the parameters in real time. The optimum parameters for a platinum loop AF spectrometer are presented along with typical analytical data.
The Analysis of Polyester-Wool Mixtures by Attenuated Total Reflectance Infrared Spectroscopy
Authors: Basch A. , Tepper E.
Published: September 2005

The composition of polyester-wool mixtures is determined by infrared spectroscopy utilizing attentuated total reflectance. An accuracy of 1% is realized for mixtures containing between 25 and 75% polyester.
Vibrational Spectra and Force Constants of MoO42− and MoS42− Containing 92Mo and 100Mo Isotopes
Authors: Müller A. , Weinstock N. , Mohan N. , Schläpfer C. W. , Nakamoto K.
Published: September 2005

The Raman and infrared spectra of Na2MoO4, K2MoS4, and Cs2MoS4 with 92Mo and 100Mo have been measured. The exact force field has been determined from these spectra. The results are compared with those obtained by using various approximation methods.
Raman Difference Spectroscopy with the Rotating Cell
Authors: Kiefer W.
Published: September 2005

A simple technique is described which makes it possible to record Raman difference spectra of binary liquid systems. The main feature is a divided rotating Raman cell for liquids and a gated electronic system. The cancellation of solvent lines in the Raman spectrum of a solution is demonstrated on a 1:1 mixture of CCl4 and CHCl3 and on an MnO4−-H2O solution. Further advantages of this technique are accurate wavenumber shift measurements (e.g., the isotopic lines of ν1 in CHCl3) and correction of the intensity error of Raman lines obtained from highly absorbing solutions (e.g., I2-CHCl3).
An On-Line Spectrophotometer for Collection and Manipulation of Absorbance Spectra
Authors: DeSa Richard J. , Wampler John E.
Published: September 2005

A uv-visible recording spectrophotometer has been developed which uses an on-line general purpose digital computer and the optical train of a conventional double beam recording spectrophotometer. The computer controls all functions of the instrument and permits the collection and manipulation of high quality absorption spectra without the use of electronic or optical correction devices. Spectra are represented by a series of up to 500 individual data points. Spectra can be manipulated in a variety of ways to meet particular experimental situations and can be displayed or plotted on an arbitrary absorbance scale. A spectrum can be added to, or substracted from, any other spectrum, differentiated, converted to log absorbance, or multiplied by an arbitrary factor. Data can be preserved on paper tape or presented graphically as a high quality labeled plot of variable size on either a wave-length or a wave number scale. The complete system can scan a full spectrum at a maximum rate of 30 nm/sec over any part of a range from 230 to 700 nm. Details of the system are presented with examples of its performance.
Radiation Exposure Considerations When Employing Microwave-Excited Spectroscopic Sources
Authors: Stanley J. L. , Bentley H. W. , Denton M. B.
Published: September 2005

Studies are described which demonstrate the presence of microwave radiation levels exceeding the present national safety standards in the vicinity of several common microwave-excited source configurations. Since the various pathological effects of microwave energy are not fully understood, shielding considerations and on-site radiation surveys are recommended.
Far Ultraviolet Solution Spectrophotometry
Authors: Fox Malcolm F.
Published: September 2005

Techniques and apparatus for extending conventional solution absorption spectrophotometry into the far uv region are discussed. The principal difficulties of spectroscopy in this region are reviewed. Applications and examples are given in inorganic, organic, and biological chemistry.
Improved Discriminant Training and Feature Extraction for the Generation of Simulated Mass Spectra of Small Organic Molecules
Authors: Schechter Joseph , Jurs Peter C.
Published: September 2005

An empirical method employing computerized pattern recognition techniques has been applied previously to the generation of simulated mass spectra of small organic molecules. The techniques have been improved in two ways to yield superior performance. First, a method for training adaptive binary pattern classifiers using an iterative least squares approach is used. Second, a feature extraction technique known as an attribute inclusion algorithm is used to investigate the importance of multiple features in the molecular descriptions.
Atomic Fluorescence Spectrometry with a Graphite Rod Atomizer and Thermostated Electrodeless Discharge Lamps
Authors: Patel B. M. , Reeves R. D. , Browner R. F. , Molnar C. J. , Winefordner J. D.
Published: September 2005

Atomic fluorescence investigations with a graphite rod atomizer and thermostated multiple element electrodeless discharge lamps (EDL's) are reported for Ag, Cd, Cu, Hg, Pb, Sn, Tl, and Zn. Detection limits in the range 10−10 to 10−14 g have been obtained for these elements using a sample volume of 0.5 µl. The detection limits are better than, or close to, the lowest reported values obtained by other workers using atomic spectrometric methods. No spectral or chemical interferences have been observed when using multiple element EDL's or standard multielement solutions.

The atomic fluorescence signal obtained using argon and argon-hydrogen atmospheres has been studied as a function of the gas flow rates and as a function of height above the graphite rod atomizer. Except for Hg, better fluorescence signals are obtained with argon-hydrogen.
Metal Isotope Effect on Metal-Ligand Vibrations. IX. Far Infrared Spectra of Octahedral Nickel Halide Complexes of Pyridine and γ-Picoline
Authors: Saito Y. , Schläpfer C. W. , Cordes M. , Nakamoto K.
Published: September 2005

The far infrared spectra of Ni (pyridine)4X2 and Ni(γ-picoline)4X2 (X = CI, Br and I) have been measured. The Ni-X and Ni-N stretching bands have been assigned based on isotopic shifts due to the 58Ni-62Ni, pyridine-pyridine-d5, and Cl-37Cl substitutions.
Infrared Emission Spectra of Molten Salts
Authors: Bates John B. , Boyd G. E.
Published: September 2005

Infrared emission spectra of molten alkali metal nitrates and chlorates were recorded over the frequency interval from 50 to 3000 cm−1 employing a Fourier transform spectrometer. Emission spectra of molten mixtures of NaNO3 and NaClO3 also were measured, and the ν3 mode of NO−3 ion was observed with solutions containing about 0.1 mole % NaNO3. Far infrared spectra of the melts revealed a broad band which progressively shifted to a lower frequency as the mass of the cation increased. The emission spectrum of each salt at a given temperature was recorded in fewer than 2 min and was of comparable or of better quality than previously reported infrared spectra.
In-Depth Compositional Profile Analysis of Alloys Using Optical Emission Glow Discharge Spectrography
Authors: Belle C. J. , Johnson J. D.
Published: September 2005

Sequential analysis of metal alloys in depths of 0.1 to 40 µm are made with a glow discharge source for optical emission spectrography. The alloys examined have compositional variations in depth due to mass transfer in liquid sodium tests for materials studied in the fast breeder reactor program. The ion-sputtering action of the source produces progressive and discrete sampling of a defined area with concurrent excitation of the analytes in the negative glow region of the discharge. Integrated exposures of successive layers of attack are spectrographically recorded. The total weight loss is measured gravimetrically. Weight loss is assigned per exposure layer, and the depth of each attack is calculated. With more than 98% of the elemental composition measured, the sum of all elements is used as the internal standard. The precision approaches that of the photographic measurement process and does not indicate the ultimate precision of the source.
Emission Spectrographic Analysis of Iron in Lithium Niobate
Authors: Nash D. L.
Published: September 2005

Emission spectrographic studies of lithium niobate, both as starting material and as undoped single crystals, have confirmed the presence of iron in all samples. A quantitative procedure for the determination of this impurity has been developed, and iron contents of the order of 10 ppm and greater are reported for the samples analyzed.
Compositional and Texture Analysis of Tantalum Thin Films by Energy Dispersive X-Ray Analysis
Authors: deBen H. S. , Broyde Barret
Published: September 2005

Quantitative measurements of concentrations are given for the phases present in undoped tantalum thin films by the use of energy-dispersive x-ray detectors. This diffraction method can also yield the extent of preferred orientation.
The Relationship of Spectral Line Intensity to the Weight of Sample Vaporized with the Laser Microprobe
Authors: Morton Kim L. , Nohe James D. , Madsen Bruce S.
Published: September 2005

Emission spectra excited by the laser microprobe are less subject to the influence of the matrix than when excitation is by conventional modes such as a dc arc. Statistical correlations show that the measured spectral line intensity is a function of the weight of material vaporized when the laser is used. Several important factors must be considered to obtain such results with the laser. The size and dimensions of the laser craters (pits) must be carefully measured to determine concentrations since the crater sizes vary from material to material. Crater dimensions may be determined relatively easily by optical microscopy and serve as a method of standardization among materials. The laser energy must be carefully focused to produce a crater which is essentially conical. This not only facilitates microscopic measurements but insures complete sample vaporization. Also, the amount of material deposited around the crater (and probably not reaching the spark discharge) is shown to be minimal in most cases.
A Study of the Effect of pH on the Determination of Zinc by Atomic Absorption Spectrophotometry
Authors: Dong Alex E.
Published: September 2005

Substantial errors in the determination of zinc by atomic absorption spectrophotometry can be caused by differences in pH among samples and standards. Zinc absorption is constant in the pH range of about 2 to 5. Between pH 5 and 10, a sharp decrease in absorption is observed. With an increase above pH 10, zinc absorption levels off to a constant value. Experimental data suggested that pH variation rather than chemical interferences is primarily responsible for the variation of absorption in zinc analysis. Several possibilities, such as sorption of zinc to container walls, zinc hydroxide formation, zinc complex formation, and zinc oxide formation in flame subsequently attacked by hydrogen atoms, have been considered in an attempt to understand the cause of pH-dependent zinc absorption.
The Quantitative Determination of Surface Oxide Thickness on Deposited Metal Films by Combination Auger Spectroscopy and Inert Gas Ion Bombardment
Authors: Holloway D. M.
Published: September 2005

A technique combining Auger spectroscopy and inert gas ion bombardment has been employed for the determination of “surface oxide” thickness on deposited metal films. The quantitative limitation on the technique depends on knowing accurately the sputtering rate for the material under study. Using x-ray fluorescence and atomic absorption spectroscopy as independent analytical methods, an empirical value for the net sputtering rate for the material may be determined. In addition, the technique allows the elemental composition of the film as a function of depth to be determined. Surface oxide thickness on electron beam-deposited erbium films, followed by air exposure, ranged from 170 to 190 Å, whereas hydrided erbium films that were vacuum annealed at 1 × 10−8 Torr over a range of temperatures up to 500°C had oxide thicknesses from 110 to 350 Å.
Emission Spectrographic Determination of Hafnium in Zirconium Dioxide
Authors: Stempel G. D.
Published: September 2005

An emission spectrographic method of analysis is described in which trace quantities of hafnium are determined in zirconium dioxide. The sample preparation, starting with zirconium metal sheet or zirconium dioxide, is discussed in detail. The excitation source used is an ac spark. Quantitation was achieved with a dual grating emission spectrograph. The analytical range of the method for the analysis of hafnium is 5 to 1000 ppm with a relative standard deviation of 9.7%.
X-Ray Photoelectron Spectra of Aluminum Oxides: Structural Effects on the “Chemical Shift”
Authors: Lindsay James R. , Rose Harry J. , Swartz William E. , Watts Plato H. , Rayburn Kenneth A.
Published: September 2005

The aluminum (2p) electron spectra of several anhydrous and “hydrous” aluminum oxides have been recorded, and the binding energies have been measured. A simple electrostatic model is employed to explain the observed shift in binding energy and relate it to differences in structure and hydrogen bonding. Two conclusions can be drawn: structural differences must be considered when interpreting photoelectron spectra for inorganic crystalline substances; and hydrogen bonding with anions may have a measurable effect on the binding energy of core electrons of the cations.
Far Infrared Group Frequencies. V. Oximes and Aldoximes
Authors: Craven S. M. , Bentley F. F. , Pensenstadler D. F.
Published: September 2005

The low frequency infrared spectra from 450 to 75 cm−1 of seven oximes and five aldoximes have been recorded for pure samples and for dilute solutions in cyclohexane. An intense characteristic band is present in the solution spectra at 367 ± 10 cm−1. This characteristic band shifts to 275 ± 10 cm−1 in the spectra of the OD compounds. The 367 ± 10 cm−1 and 275 ± 10 cm−1 bands are assigned to OH and OD torsional vibrations. A comparison of the solution spectra with spectra of the solid samples indicated that the OH … N hydrogen bond stretch of oximes and aldoximes occurs in 300 to 200 cm−1 region. Strong bands also are present in 140 to 100 cm−1 region which are due to OH … N bending modes or perhaps lattice vibrations.
Vibrational Spectra and Assignments for Series of Mono- and Dihalonaphthalenes
Authors: Michaelian Kirk H. , Ziegler Stanley M.
Published: September 2005

Infrared and Raman spectra have been measured, and a complete vibrational assignment has been made for the following molecules: α-C10H7X and β-C10H7X where X = F, Cl, Br and I, 2,3-dibromonaphthalene, 2,3-dichloroquinoxaline, 1,4-dichloronaphthalene, and 1,4-dibromonaphthalene. The very low energy in-plane and out-of-plane halogen bending modes for these molecules were identified and assigned based on a comparison and correlation of halogen mass effect, band shapes and intensities, infrared and Raman selection rules, and Raman depolarization data. These vibrations were found to be relatively free from coupling with other vibrational modes of the molecule. The halogen stretching modes, on the other hand, were found to be strongly coupled with naphthalene skeletal modes to the extent that in several compounds no predominant halogen stretching mode could be identified. In several instances, supporting evidence is given which favors a particular assignment of a disputed vibrational assignment in naphthalene.
A Raman Spectroscopy Study of the Chloromethyl Group Attached to an Aliphatic Hydrocarbon Chain
Authors: Wang T. S. , Mannion J. J.
Published: September 2005

The chloromethyl group (—CH2Cl) attached to a normal hydrocarbon chain gives rise to two characteristic Raman bands near 660 and 730 cm−1. The band at 660 cm−1, which is very intense, is assigned to a stretching mode of the C-Cl linkage when the chlorine atom is trans to a hydrogen atom. The less intense peak at 730 cm−1 is assigned to the same mode of the rotational isomer with the chlorine atom trans to a carbon atom. These assignments are consistent with those reported in infrared studies. In contrast to almost equal intensities for both bands in the infrared, the band at 660 cm−1 proved to be the strongest by far in Raman spectra.
Radiative and Electrical Properties of Exploding Silver Wires
Authors: Sacks R. D. , Holcombe J. A.
Published: September 2005

The radiative properties of silver wires exploded by capacitive discharge are studied using time-integrated and time-resolved spectroscopy. Discharge current measurements are obtained from a calibrated current shunt and are correlated with time-resolved spectra to obtain a model for the current conduction processes during wire explosions. Two basic explosion mechanisms are described, both of which begin with the conversion of the wire from a conducting solid to a rapidly expanding dielectric cylinder of metal vapor. This results in a rapid reduction of discharge current. Current then may resume in one of two ways. In He at atmospheric and reduced pressure and in air at reduced pressure dielectric breakdown of the gas surrounding the wire occurs with current conduction peripheral to the expanding metal vapor cylinder. In air at atmospheric pressure, dielectric breakdown occurs through the metal vapor. This results in current conduction along the vapor cylinder axis. The advantages of peripheral current conduction for the analysis of metals electroplated on the surface of silver wires are discussed. Parametric studies with Cd-plated silver wires indicate that the intensity of the background continuum can be reduced by nearly 2 orders of magnitude with little effect on Cd line intensities by reducing the pressure from 730 Torr to 50 Torr in He where peripheral current conduction occurs.
Resolution and Frequency Calibration Performance of Beckman IR-9 Infrared Spectrophotometer
Authors: Kirk R. M. , Wilt P. M.
Published: September 2005

Modifications affecting the resolution and frequency calibration capability of the Beckman IR-9 infrared spectrophotometer are described and discussed. Under favorable conditions these modifications enable the instrument to be calibrated with an absolute accuracy of 0.03 cm−1 or better; resolution is also improved so that spectral slitwidths may be reduced by approximately √2 over normal specifications. These results are illustrated with vibration-rotation spectra from NH3, CH4, and HBr.
A Direct Carrier Distillation Procedure for the spectrographic Determination of Impurities in Uranium Tetrafluoride
Authors: Dale L. S.
Published: September 2005

A direct carrier distillation procedure for the determination of a wide range of impurities in uranium tetrafluoride is described. The method is based on the use of lead chloride as carrier with yttrium oxide to suppress uranium spectral interference. A deep crater electrode further aids in the reduction of spectral interference. Germanium and cobalt are used as internal standards. The method has been adopted for the simultaneous determination of Ag, l, B, Cd, Cr, Cu, Fe, Mg, Mn, Mo, Na, Ni, Si, Sn, Ti, V, and Zn with detection limits in the range 0.1 to 20 ppm and coefficients of variation ranging from 4 to 15%.
Studies of Gaseous Flame Combustion Products by Raman Spectroscopy
Authors: Arden William M. , Hirschfeld Tomas B. , Klainer Stanley M. , Mueller William A.
Published: September 2005

Combustion products from various hydrocarbon-oxygen flames have been examined in the laboratory using the techniques of laser Raman spectroscopy and phase-sensitive detection. Instrumentation, techniques, and spectral results are described.
Spectroscopy at High Pressures—Status Report and Update of Instrumental Techniques
Authors: Ferraro John R. , Basile Louis J.
Published: September 2005

A status report and update of the instrumentation necessary to obtain spectra of molecules at high pressures are presented. The optical pressure cells used, the spectrophotometer needed to obtain the spectra, the optical link between the two, high pressure spectroscopic windows, pressure calibration methods, and future outlook of the technique will be determined. The use of the high pressure cells with the interferometric technique and for Raman spectroscopy is outlined.
Effect of Atomic Level Width on Ge(Li) X-ray Spectra
Authors: Pathak B. P. , Makherjee S. K.
Published: September 2005

The shapes of x-ray and γ-ray peaks have been studied with the use of a high resolution Ge(Li) spectrometer. The Kα x-ray peaks of high Z elements have been found to exhibit larger width compared to the width of γ-ray peaks of same energy. This excess width has been assigned to the natural energy width of characteristic x-ray lines. An analytical study of the variation of the observed width with the natural width of the incident radiation has been made. The computed results are in excellent agreement with the experimental observation.
Studies of Polymeric Bond Failure on Aluminum Surfaces by X-ray Photoelectron Spectroscopy (ESCA)
Authors: Wyatt David M. , Gray Robert C. , Carver James C. , Hercules David M. , Masters Larry W.
Published: September 2005

X-ray photoelectron spectroscopy (ESCA) has been used to identify very thin layers of polymeric species remaining on aluminum plates after the polymer was cured and stripped from the aluminum. Two polymers were studied. In one, the residual polymeric carbon was used as the tracing signal; in the other, the polymeric silicon was used. In both cases, the polymeric species was partially sputtered from the aluminum surface by an argon ion gun. A reduction in the polymeric signal relative to a standard signal was noted. The results of this study show that, when the polymers studied were mechanically pulled from the aluminum substrate, the failure was a cohesive separation within the polymer, rather than failure at the polymer-aluminum interface. Scanning electron microscopy was used to show that the residual polymer does not remain on the surface as “clumps” or “islands,” but rather as a smooth surface a few atomic layers thick.
Infrared Spectra of Trimethylamine-Carbon Monoxide-Borane and its Deuterated Derivatives
Authors: Carter James C. , Luther George W. , Moyé Alfred L.
Published: September 2005

Low temperature infrared spectral data are given for the adducts H3BC(O)N(CH3)3, D3BC(O)N(CH3)3, H3BC(O)N(CD)3)3)D3BC(O)N(CD3)3 over the range 3000 to 300 cm−1. Boron-11 NMR data are given for H3BCO and H3BC(O)N(CH3)3. The spectra allow the assignment of the structure of the adducts as [Formula: see text]
Emission Spectrographic Determination of Trace Elements in Airborne Particulate Matter Collected on Silver Membrane Filter
Authors: Sugimae Akiyoshi
Published: September 2005

An emission spectrographic method is described to determine the concentrations of aluminum, bismuth, cadmium, chromium, iron, lead, manganese, molybdenum, nickel, tin, vanadium, and zinc in airborne particulate matter collected on a silver membrane filter. The sample filter is dissolved with dilute nitric acid. Hydrochloric acid is added to precipitate silver ion as silver chloride. After the solution is evaporated to dryness, the residue is subjected to dc arc excitation. The precision of the method is better than ±18%.
Nondestructive Determination of Tritium Content of Erbium Tritide Thin Films
Authors: Pearson John E.
Published: September 2005

The x-ray spectrum resulting from beta decay of an erbium tritide film is used to measure tritium content of the film. The areal density of the film is measured using differential emission techniques and is used to correct the measured x-ray intensity for self-absorption. The corrected intensity is linearly related to tritium content through an empirically derived calibration curve. The technique will measure tritium contents from less than one to several hundred micron liters. Repeatability is generally determined by counting errors and is typically 0.3% for a 5-min count while accuracy depends upon the empirical calibration technique. In principle, the technique is not limited to erbium tritide but can be extended to many uniformly radiating thin films.
Emission Spectrographic Analysis of Boron in 40% NH4F Solution
Authors: Grilletto Carlo
Published: September 2005

This paper describes a reliable emission spectrographic method capable of quantitatively determining boron in the 0.5 to 50 ppm range. The detection limit for the method is 0.1 ppm. Previous to this report no reliable method was available for the accurate determination of boron in reagent 40% ammonium fluoride solution in the ppm range; consequently, no incoming inspection or manufacturer's certification was available for boron content. Analysis of representative ammonium fluoride samples shows that the boron level is less than 0.1 ppm, suggesting that this element may not be a major problem in ammonium fluoride reagent.
Absorption Corrections and Concentration Optimization for Absorbing Samples in Resonance Raman Spectroscopy
Authors: Strekas Thomas C. , Adams David H. , Packer Andrew , Spiro Thomas G.
Published: September 2005

For Raman scattering studies of absorbing samples, e.g., in resonance Raman spectroscopy, it is frequently important to optimize the concentration and to correct for self-absorption effects on the observed intensities. These question are explored for 90° “transverse” scattering in a 0.1-cm capillary through intensity measurements of resonance Raman bands of ferro-cytochrome c and tris(1,10-phenanthroline) iron (II). It is found that a simple log intensity vs concentration plot provides the extrapolation needed to eliminate self-absorption effects. The optimum concentration is found to correspond to an absorbance per 1 cm of path length of 13 (average of values for the incident and scattered wavelengths) and is independent of absorptivity and of refractive index of the medium. The data are adequately reproduced by a point-scattering model, although different values of the effective light path through the sample are required to fit the self-absorption and intensity vs concentration curves.
Emission Spectrometric Determination of Isotopic Concentrations of Lithium
Authors: Lichte F. E. , Skogerboe R. K.
Published: September 2005

Isotopic concentrations of lithium have been determined by emission spectrometry using an optical scanning method. Results indicate that the method provides results with a precision of 1%, relative standard deviation.
The Backscattering Geometry for Raman Spectroscopy of Colored Materials
Authors: Shriver D. F. , Dunn J. B. R.
Published: September 2005

Quantitative laser Raman spectroscopy on colored substances is considered, and it is shown that sample positioning and concentration are less critical when 180° illumination is used in place of the more common 90° illumination. In addition, the correction of Raman intensities for sample absorption is easily accomplished for data collected via backscattering (180° geometry), and the appropriate equations are presented. A spinning sample cell and holder are described for 180° illumination. The design utilizes simple and inexpensive sample tubes which are conveniently employed with standard liquids and solids as well as volatile, air-sensitive, and corrosive compounds. Provision for sample heating and cooling is described.
A Method for the Chemical Analysis of Intimal Surfaces of Arteries and Veins with Potassium Bromide Infrared Spectroscopy: Preliminary Results
Authors: Johnson W. T. M. , Penneys Raymond
Published: September 2005

We report a method to determine the chemical composition of the first few layers of molecules making up the intimal surface of the bovine aorta. We gently and uniformly spray-abrade the opened, flat surface of the aorta with fine, dry potassium bromide (KBr) powder. Surface molecules are rubbed off and collected with the KBr powder. This powder is pressed into a disk and analyzed by infrared spectroscopy. The thickness of the surface sample is estimated from the density-mass-volume (area times thickness) relationship. We designed and constructed a mechanical spray abrader to analyze blood vessel surfaces. The uniformity and depth of abrasion are controlled by the angle of spray, pressure, distance, and rate of traverse of sample drum. Several successive surface samples may be removed from one blood vessel. In complementary work, a method was developed for the physical removal and mounting of the intima of arteries and veins as intact films for infrared analysis. Preliminary experiments on bovine aortas gave surface samples as thin as 57 Å (estimated) and with an infrared spectrum markedly different from that of the total aortic intimal film. The major infrared bands found in the surface samples were: NH (3300 cm−1); CH (lipid) (2920 cm−1); amides I and II (1650 and 1540 cm−1); and, as a tentative assignment, sulfate (1050 cm−1). Comparison of surface spectra with intimal film spectra suggests that the surface protein is different from intimal protein. The surface spectra resemble chondroitin sulfate, but not heparin. Possibly the first few molecular layers of intimal surface contain chondroitin sulfate. These methods may prove to be of value in determining the role of the intima and intimal surface in cardiovascular disease.
Precise Measurements of Cesium in the Ocean by Flame Emission Spectrometry
Authors: Folsom T. R. , Hansen N. , Parks G. J. , Weitz W. E.
Published: September 2005

An automatic flame emission spectrometer has been developed for measuring traces of cesium in sea water samples with precision enough to demonstrate for the first time some significant concentration variations of this element in the ocean. Extremely reproducible comparisons of standard and unknown solutions are effected by a programmed sample changer employing a novel distribution valve. Temperature effects and influences of gas flow and draft fluctuation are suppressed by carrying out repeated comparisons of small portions of the extracted sample concentrate and of the standard, computing a concentration after each comparison and then averaging the results. Following each recording of the peak emission, the emission from a nearby spectral baseline also is automatically recorded by using a simple accessory added to the monochromator. A Plexiglas refractor slab mounted on an axis in front of the exit slit is rotated a few degrees by pulses from a programmer that is under command of a standard desktop calculator. Analyses of test samples containing about 0.3 µg of cesium replicated better than 0.3%. Surface cesium concentrations in the North Pacific were shown to vary less than 0.5%; however, typically deep water contained about 1.4% lower average concentrations than surface water.
Temperature Distribution in a dc Free Burning Arc in Nitrogen with and without Addition of Li2CO3
Authors: Rekalić M. , Vukanović V.
Published: September 2005

The investigation of the lithium effect on the temperature distribution of the arc is presented. Measurements were carried out by the Schlieren interference method to about 4000°K. The arc free burning in nitrogen was observed and the results of temperature measurements, carried out with and without lithium addition, were presented. Lithium was added to the arc by anode evaporation. Temperature measurements in outer areas were connected to previously presented spectroscopical measurements in the central part of the arc. The lithium addition affects the increase of the electroconductive central part of the arc.
Excitation of Spectra of Multiply Ionized Atoms by Capacitor Discharges
Authors: Van Deurzen Cornelius H. H. , Conway John G.
Published: September 2005

Spectra of vanadium have been produced in a vacuum sliding spark, and their relative line intensities have been measured as parameters of the electrical circuit were varied. Intensity maxima of the spectral lines are interpreted as representing excitation energies and have been found to depend in a definitive manner on the power delivered to the source and on the duration of the discharge. The differential equation of the circuit is solved for the charge and energy transfer rates from the capacitor to the source, and two functions of the continuous circuit parameter

[Formula: see text]

are defined which greatly assist in interpreting the effect of the circuit parameters on the excitation in the source. A relationship was found between the excitation in the source and the electrical circuit parameters. By means of this relationship one may obtain a good estimate of the excitation gained in the spark source. It is shown that by exercising careful control over the circuit parameters it is possible to separate spectra of neighboring ionization stages through either total pulse or time-resolved observations.
Electron Impact-Induced Fragmentation of 4-Aminoazobenzene Dyes and Relationship with Photochemical Stability
Authors: Mehta Himanshu P. , Peters Arnold T.
Published: September 2005

Relative abundance of daughter ions resulting from cleavage of 4-aminoazobenzene dyes across the C-Nα and C-Nβ bonds of the azo group can be related to the photochemical stability of these dyes on synthetic fibres.
A Study of Na2O-TiO2-SiO2 Glasses by Infrared Spectroscopy
Authors: Manghnani Murli H. , Ferraro John R. , Basile L. J.
Published: September 2005

The infrared absorption spectra of six Na2O-TiO2-SiO2 glasses in the frequency range of 1600 to 200 cm−1 are reported. These glasses, having a SiO2/Na2O molar ratio of 1.07 to 3.54, and containing 20 or 25 mole % TiO2, demonstrate two main absorptions at ∼950 cm−1 and at ∼450 cm−1. A weak absorption at ∼790 cm−1 becomes progressively weaker in intensity, and a weak shoulder at 1050 cm−1 appears with increasing Na2O content. The frequency of the absorption band at ∼950 cm−1 is found to decrease markedly and systematically with a decrease in the SiO2/Na2O molar ratio, whereas the frequency of the band at ∼450cm−1 shows a slight increase. The infrared results may be interpreted in terms of a lowering of symmetry occurring for the SiO4 units. The effect of TiO2 content on the relationship between vibrational frequency is discussed. The frequency composition curves for glasses containing 20 and 25 mole % of TiO2 intersect at SiO2/Na2O ratio ∼2. A reversal in the frequency vs SiO2/Na2O ratio relation was also found at SiO2/Na2O ∼2 for the sodium silicate glasses.
Jet Engine Oil Analysis by Atomic Absorption Spectrometry with Graphite Filament
Authors: Chuang F. S. , Winefordner J. D.
Published: September 2005

Aqueous standards of Ag, Cu, Fe, Mg, Ni, Pb, and Sn were used for the measurement of these elements in jet engine and reciprocating engine oils by the graphite rod atomizer atomic absorption spectrometric method. The graphite rod atomizer method resulted in speed and ease of measurement, in excellent precision, and in good correlation between aqueous and organometallic standards. Excellent agreement between results obtained on Air Force SOAP correlation samples using aqueous and organometallic standards resulted for all of the elements determined.
Quantitative Analysis of Glass Structure with the Use of Infrared Reflection Spectra
Authors: Sanders D. M. , Person W. B. , Hench L. L.
Published: September 2005

It is predicted theoretically and justified experimentally that infrared reflectances are proportional to the concentrations of the vibrational species causing them. In the binary Li2O-, Na2O-, and K2O-SiO2 glasses used in this study, the reflection peaks have been assigned to vibrations of single silicon-oxygen tetrahedra in different symmetry environments caused by the presence of alkali ions. Care has been taken here in recording the spectra of high alkali glasses to prevent chemical reactions with water vapor in the atmosphere. The influence of phase separation on reflection spectra is also discussed.
Solvent Effects in the Nuclear Magnetic Resonance Spectra of Benzal Compounds
Authors: Weinberger M. A. , Meppelder F. H. , Nicholson G. G. , Holmes H. L.
Published: September 2005

Nuclear magnetic resonance spectra of benzal compounds, Z—C6H4—CH=C(X)Y, have been determined in carbon tetrachloride, chloroform, acetone, and benzene solutions. Group X, trans to the ring, was one of NO2, COOEt, COCH3, CONH2, the series comprising mostly para-substituted (Z=NO2, Cl, H, Me, OMe, NMe2) β-nitrostyrenes, β-alkyl-β-nitrostyrenes, cinnamates, cyanocinnamates, malonates, acetoacetates, acetylacetones, and cyanocinnamides. The ambiguity in the assignments to the olefinic protons in the β-nitrostyrenes was resolved by studying deuterated compounds. The solvent shifts for the aromatic protons are shown to be additive, the olefinic side chains and the ring substituents making characteristic contributions. The solvent effect for the aromatic protons ortho to the side chain is most affected by variation of the latter and, when large, may contribute to the effect at the olefinic protons. The β-nitrostyrenes show the largest solvent shifts for the olefinic protons, and the reasons for the more marked effects at the β-proton are discussed.
X-ray Spectrographic Microanalysis of Human Urine for Arsenic
Authors: Mathies James C.
Published: September 2005

A rapid, precise, and interference-free x-ray spectrographic procedure for the determination of arsenic in human body fluids and tissues has been devised. The organic material in the sample is oxidized, and the arsenic is released by a simplified rapid wet-washing technique using nitric-sulfuric-perchloric acids. The arsenic in the digestion mixture is converted to arsine and collected quantitatively on a silver nitrate-impregnated filter paper disk using a new and convenient sub-micro modification of the Gutzeit arsine generator. The arsenic in the test paper is rapidly and nondestructively quantitated to the nearest 0.1 µg in the x-ray spectrograph. The method is relatively free of the interferences usually associated with Gutzeit and colorimetric techniques for arsenic. The precision of the method is indicated by the fact that 5 µg of arsenic can be quantitated with a relative standard deviation of 2.5% or less. Normal levels of arsenic in human urine have been redetermined.
An Inexpensive Vacuum Ultraviolet Spectrograph
Authors: Dreher G. B. , Frank C. W.
Published: September 2005

The description of an inexpensive vacuum ultraviolet spectrograph is presented. A representative spectrum used in the qualitative identification of arsenic is shown for the region of 1890 Å.
The Determination of HF, HCl, SiF4, and HCF3 in WF6 Gas
Authors: Chaney C. L. , Chin J.
Published: September 2005

An infrared absorption method in the 1- to 15-µ range has been developed for determining HF, HCl, HCF3, and SiF4 in WF6, gas. Because of the reactivity and corrosiveness of WF6, a special gas absorption cell and gas-sampling apparatus were designed and built. Calibration curves were generated for a 10-cm cell. Sensitivity values were 100 wppm for HF and HCl, and 10 wppm for HCF3 and SiF4.
Matrix Effects in the Emission Spectrometric Analysis of Trace Metals in Biological Specimens
Authors: Niedermeier William , Griggs James H. , Webb John
Published: September 2005

A study was made of the effect of metals that appear in animal tissues in the mg% range on the spectrochemical determination of certain trace metals in a NaCl matrix. The presence of as little as 1 mg% of iron, magnesium, calcium, potassium, or phosphorus had a marked influence on the spectral response of the trace metals (Cu, Fe, Al, Ba, Mn, Ni, Ca, Sn, Sr, Cr, Zn, Pb, Mo, and Cd) studied. Matrix effects in this medium did not appear to be concentration-dependent or additive. It was concluded that unless the matrix compositions of standard and specimen were closely matched, serious analytical errors would result.
Internal Reflection Spectra of Several Tetracyclines
Authors: Schlecht K. D. , Dix R. B. , Tamul M. J.
Published: September 2005

The infrared internal reflection spectra of the hydrochloride salts of tetracycline, chlortetracycline, oxytetracycline, 6-deoxyoxytetracycline, and 6-methylene-oxytetracycline as well as tetracycline base and oxytetracycline base are reported from 1700 to 300 cm−1. This technique yielded sharp, well defined spectra with numerous strong absorption peaks.
A Method for Automatic Scanning of the Depolarization Ratio in Raman Spectroscopy
Authors: Kiefer W. , Topp J. A.
Published: September 2005

A simple technique and an electronic system are described which allow an automatic scanning of the depolarization ratio in Raman spectroscopy. As a check the “parallel” and “perpendicular” spectra of the scattered Raman light can be recorded simultaneously with the depolarization ratio. The system performance is demonstrated for liquid carbon tetrachloride and carbon disulfide and the Q branch of nitrogen in air.
Mass Spectrometry of Methyl and Alkyl Phenols
Authors: Sellier N. , Maume B. F. , Guiochon G.
Published: September 2005

Mass spectra of a series of alkyl phenols have been determined by using a conventional combination of gas chromatography and mass spectrometry to check the purity of the analyzed compounds.
Spectrographic Determination of Trace Elements in Ferrous Materials
Authors: Morello B. , De Gregorio P. , Savastano G.
Published: September 2005

A method is described for the spectrographic determination of trace elements in ferrous materials. The powdered sample is first mixed with PTFE (polytetrafluoroethylene) and graphite in the ratio 100:10:25. This mixture is then submitted to direct excitation in a 10 A dc arc, utilizing a capped supporting electrode of the Scribner-Mullin type, with reverse polarity (sample: negative; counter electrode: positive), the spectrum being taken from the central-cathodic region of the arc.

The method may be used to determine Al, As, B, Co, Cr, Cu, Mn, Mo, Nb, Ni, Pb, Sb, Sn, Ti, V, Zn, and Zr. The detection limits are indicated, as are data on the precision and accuracy obtainable.
The Elimination of Interference Fringes from Infrared Spectra
Authors: Clark F. R. S. , Moffatt D. J.
Published: September 2005

A method is described to remove interference fringes from infrared spectra by a computer-assisted spectral subtraction technique. The method does not involve degradation of spectral quality in regions of low absorption.
A Photoacoustic Spectroscopy Study of Some Thallium Iodide Powders
Authors: Fernelius Nils C.
Published: September 2005

Photoacoustic spectroscopy has been used to study TlI powders used in thin film coating applications. The spectra obtained show differences between what was regarded as good coating material from that which was unacceptable. Good material displayed a sharp absorption edge at 440 nm and no tailing off at the transparent side of the edge. The ratio of signals on the opaque side of the edge divided by that on the transparent side was largest for good material. Much of the poorer material contained absorbed I2 within the material. It was found that material exposed to the atmosphere would evolve I2 gas. Differenence spectra between freshly mounted TlI and evolved materials closely resemble absorption spectra of I2 gas.
Resolution of Complex Band Shapes by Infrared Polarization Measurements
Authors: Krishnan K.
Published: September 2005

Complex band shapes in the infrared spectra of crystalline films will, in general, be different for different orientations of the sample when examined in polarized radiation. Absorbance subtraction of these differently polarized spectra can lead to the resolution of the individual bands in the complex band profile. Weak shoulders accompanying strong bands and weak features buried under stronger bands can be examined by this technique. This method can also be used to enhance the resolution in the spectrum effectively.
Evaluation of the Analytical Capabilities of a dc Plasma-Echelle Spectrometer System
Authors: Skogerboe R. K. , Urasa I. T.
Published: September 2005

The analytical capabilities of a dc plasma used in combination with an echelle spectrometer have been evaluated. Measurements of the spectrometer resolution capabilities have demonstrated that they closely approximate the high values theoretically predicted but are ultimately limited by Doppler broadening effects occurring in the plasma. Investigations of possible ionization interference effects have shown that enhancements due to the addition of easily ionized elements are generally observed for elements having ionization potentials below approximately 8.5 eV; these may be compensated for by the addition of an excess of an easily ionized element. Evaluation of solute vaporization interference effects indicates that they also occur but can be negated by proper choice of operational conditions and/or the addition of releasing agents. Comparison of the detection capabilities of the system with those reported for other techniques shows that they are equivalent or superior to those characteristic of flame atomic absorption and often competitive with those obtained with the inductively coupled plasma, atomic emission system.
Raman Spectra of Possible Corrosion Products of Iron
Authors: Thibeau Richard J. , Brown Chris W. , Heidersbach Robert H.
Published: September 2005

Raman spectra of FeO, Fe3O4, α-Fe2O3, α-FeOOH, and γ-FeOOH, the common products of iron oxidation, have been measured. The spectra of FeO and Fe3O4 appear to be identical. Armco iron oxidized in air at 250°C was examined by Raman spectroscopy after varying periods of exposure and the surface film was found to contain Fe3O4 and α-Fe2O3.
Use of a Roll Film Back for Photographic Spectral Detection
Authors: Scheeline Alexander , Walters John P.
Published: September 2005

Use of a film back designed for size 120 or 220 film is presented as an alternative to photographic plates for detection of emission spectra. Spectral quality and cost comparisons are made.
A Raman Spectroscopic Investigation of Heteropolymolybdate Species in Aqueous Solution
Authors: Kasprzak Melody Starr , Crouch S. R. , Leroi G. E.
Published: September 2005

Raman spectroscopy has been applied to the study of the pH-dependent decomposition of 12-molybdophosphoric acid, H3(PMo12O40), and 12-molybdosilicic acid, H4(SiMo12O40), in aqueous solution. The decomposition schemes involving several smaller polymeric molybdate species, proposed from indirect techniques such as electrochemistry, are confirmed. Identification of the species present in solution is made by comparison of the Raman spectra to the spectra of known species, except in the case of (PMo11O39)7-, for which the spectrum is reported for the first time.