bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectrochemical Analysis in the Vacuum Ultraviolet (VUV) with the Hollow-Cathode Light Source—II. Quantitative Analysis
Authors: Milazzo Giuiio , Sopranzit Nello
Published: November 2005

The use of a cooled hollow-cathode light source of new design was investigated for quantitative spectrochemical analysis of iodine in the vacuum ultraviolet (VUV). The conditions of the discharge and all prerequisites were tested, taking into account many possible sources of error. The results, shown in Tables and in graphs, indicate that this kind of light source gives good results for spectrochemical analysis in the VUV, for elements having the most sensitive lines in this spectral region. The range covered in this investigation lies between 1 and 100 μg iodine in a 1-mg potassium chloride matrix.
Propagation of Error from Densitometer Data to Spectrographic Results
Authors: McCrea J. M.
Published: November 2005

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.
Direct Spectrometric Determination of Dy, Eu, Gd, and Sm in High-Purity Thorium Dioxide
Authors: Nelms J. R. , Vogel R. S.
Published: November 2005

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.
Direct-Current Arc Determination of Strontium in Calcites
Authors: Schalge A. L. , McCarty B. D.
Published: November 2005

The method described herein employs low-current de-arc excitation, short exposure times, and a selected portion of the analytical gap to analyze small amounts (0.33–1.0 mg) of carbonate samples mixed with graphite for their strontium content. Repeatability of the method is 6%.
Determination of Lead in Aqueous and Organic Media by Atomic-Absorption Spectroscopy
Authors: Chakrabarti Chuni L.
Published: November 2005

The sensitivities of lead in aqueous and organic media by atomic-absorption spectroscopy using lead lines 2170 Å, 2833 A, and 4058 Å, 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.
Spectrochemical Determination of Water in Minerals and Rocks
Authors: Quesada Antonio , Dennen William H.
Published: November 2005

The direct determination of water in minerals and rocks using dc-arc emission spectrography is described. A precision of ±8% or better is attained over a concentration range of ∼1%–20% H2O. Electrodes of a special design are used and careful control of absorbed moisture is required.
Diffuse-Reflectance Spectra of Rare-Earth Oxides
Authors: White William B.
Published: November 2005

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.
Spectrographic Determination of Traces of Iron in Copper and Silver by Carrier Distillation
Authors: Tymchuk P. , Desaulniers J. A. H. , Russell D. S. , Berman S. S.
Published: November 2005

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.
Spectrochemical Study on the Thermal History of Fatty-Acid Aluminum Salts
Authors: Gordon J. M. , Berger R. S.
Published: November 2005

The chemistry of fatty-acid aluminum salts, particularly stearates, was studied in polypropylene, liquid hydrocarbons, and fluorocarbons. Heating results in a series of related events. The distearate carboxylate coordination bonds are altered from crosslinked to intramolecular, and the Al—O—Al bond is weakened or broken. Stearic acid, which is formed as the aluminum distearate decomposes, changes rapidly from the dimer to the less stable monomer form, with a heat of conversion of 4.9 kcal/mole. The conversion of stearic acid dimer to monomer is unaffected by the presence of the aluminum coordination bonds.
Total-Burn Spectrographic Determination of Silicon in Plutonium
Authors: Ko Roy
Published: November 2005

A total-burn spectrographic method has been applied to the determination of trace concentrations of silicon in plutonium. The sample is oxidized to plutonium dioxide, mixed with a germanium dioxide—graphite mixture containing tin internal standard, packed into cupped graphite electrodes, and burned to completion in a high-amperage dc arc. Plutonium spectral interference is avoided by using the less sensitive Si 2506.90-Å line. The lower limit of the determination is 25 ppm of silicon in plutonium. The precision of the method is estimated to be ±8% (coefficient of variation) at the 270-ppm level and ±14% at 40 ppm.
Infrared Spectra of Some 5-Aminotetrazoles and Their Deuterated Derivatives
Authors: Jonassen Hans B. , Paukert Thomas , Henry Ronald A.
Published: November 2005

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.
Cored Cathode for Stabilization of the dc Arc
Authors: Mellichamp J. W.
Published: November 2005

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.
Spark-Source Mass Spectroscopy
Authors: Owens Edward B.
Published: November 2005

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.
Optimization of the Critical Instrumental Parameters for Achieving Maximum Sensitivity and Precision in Flame-Spectrometric Methods of Analysis
Authors: Parsons M. L. , Winefordner J. D.
Published: November 2005

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.
Infrared Identification of Thermosetting Resin Type in Fiberglass-Reinforced Articles
Authors: Bly R. M. , Parker P. Harold
Published: November 2005

Qualitative determination of resin type in articles from fiberglass-reinforced polymerized thermosetting resins is possible by the use of infrared spectroscopy. The technique involves grinding the resin and glass to a fine powder and measuring the spectrum in a potassium bromide pellet. Three types of thermosetting resins can be easily distinguished in the presence of high (60%–70%) concentration of fiberglass. These are (1) unsaturated polyester styrene, (2) anhydride-cured epoxy, and (3) amine-cured epoxy.
Time-Resolved Spectroscopic Studies of Exploding Wires in Controlled Atmospheres
Authors: Cassidy Esther C. , Abramowitz Stanley
Published: November 2005

A spectroscopic technique for continuous and time-resolved study of the atomic and molecular species produced by electrically exploded wires is described. A high-speed drum camera is utilized to record the time history of the explosion spectrum. More detailed studies (from photographic plates) of the spectrum at selected times are then conducted by use of a rotating shutter. Results are presented from experiments with aluminum wires exploded in various controlled atmospheres.
Determination of Nickel and Iron in Nickel—Iron Alloys and Solutions: X-Ray Emission Spectroscopic, and Chemical Methods
Authors: Chow E. T-K. , Cocozza E. P.
Published: November 2005

In magnetic thin-film work, nickel—iron alloys (approximately 80% Ni) and solutions of such alloys must be analyzed for nickel and iron in low-milligram quantities accurately, precisely, and rapidly. A precise, rapid x-ray-emission spectroscopic technique for the analysis of nickel-iron and an accurate, precise, analytical method for calibration of the x-ray data are presented. The methods provide an effective analysis of evaporated nickel-iron thin film in the 500–2500-Å region. Preparation of standard solutions for the x-ray method, interference effects of impurities, accuracy and precision of the method, and comparison of it with other analytical methods are discussed. The precision is shown to be ±0.1%; accuracy is a function of the calibration method. The investigation and evaluation of various analytical calibration methods are described. The results indicate that dimethylglyoxime precipitation of nickel and cerate potentiometric titration of iron meet the requisite of ±0.2% relative accuracy. Relative accuracy and precision of ±0.1% for iron and ±0.2% for nickel were obtained.
Spectrographic Determination of Boron in Carbon and Alloy Steels
Authors: Hines C. R. , Hurwitz J. K.
Published: November 2005

A new spectrographic method for the determination of boron in carbon and alloy steels has been developed by which accurate, precise, and rapid determinations of boron in the range 5–90 ppm are obtained. In this new procedure, a condensed overdamped discharge is used to excite the spectrum, the sample's electrical polarity is negative, and the graphite counter electrode has a pointed tip with an included angle of 15°. The repeatability of the method expressed as the coefficient of variation is ±5.8%; and at a 95% confidence interval, the spectrographic results agree with chemical determinations within ±22% of the amount present in the sample.
Infrared and Raman Studies of Arsenic Compounds
Authors: Szymanski H. A. , Marabella L. , Hoke J. , Harter J.
Published: November 2005

It was found that water solutions of arsenic oxide contain the compounds As4O6-XH2O and As (OH)3. The acid OAsOH is not present in these solutions. The presence of alkali halide in arsenic oxide solutions results in the formation of an ortho arsenite. Oxyarsenic halides and AsCl4 are not present in solutions of AsCl3. The stability of these ions is questioned.
Direct Current Arc in Emission Spectrography II: Influence of Selected Buffer Compounds on the Properties of the Arc
Authors: Decker R. J. , Eve D. J.
Published: November 2005

The results of a series of experiments are reported in which a number of selected buffer compounds were mixed with a synthetic sample containing elements of a wide range of volatilities. The mixtures were burned in a dc arc and measurements were taken of the anode temperature, arc temperature, and spectrum line intensities throughout the life time of the burn. From these results conclusions are drawn regarding the effect of the buffer cation and buffer anion on the arc and anode temperature, vaporization rates, and arc wandering. Some general rules for the selection of buffer compounds are suggested.
Mass Spectrographic Technique for the Determination of Molybdenum Additive in Tantalum Oxide Capacitor Films
Authors: Malm D. L.
Published: November 2005

Recent analytical demands in thin-film technology require a means for quantitative measurements of intentionally added impurities in sputtered tantalum capacitor films. The inherent high sensitivity and surface-sensing ability of the rf vacuum spark source mass spectograph suggest its usefulness for this study [A. J. Ahearn, “Sixth National Symposium on Vacuum Technology Transactions” (Pergamon Press, Inc., New York, 1960)]. It has been demonstrated that with the aid of an internal standard and a sample-scanning technique that samples the film on the substrate, thus eliminating any chemical separations, quantitative estimates of molybdenum additive in films 4000 Å thick can be made with an average deviation of ±23%. A concentration range of 0.02% to 3.1% atomic fraction of molybdenum in tantalum films was studied. Because adequate sensitivity is attained without consuming the entire available sample, it is reasonable to predict that sensitivities of 10 ppm atomic or less may be reached. Results show a linear increase in the molybdenum concentration as the molybdenum-to-tantalum sputtering-surface ratio increases. Once this relationship has been established, films with the desired molybdenum concentration can be produced without the need for further chemical analysis. Mass spectrographic results also indicate that the molybdenum additive is homogeneously distributed in the tantalum film.
Spectrographic Determination of Boron in Clay Shales
Authors: Cody R. D.
Published: November 2005

Cobalt has been found to be an acceptable internal standard for the spectrographic determination of boron in shale. Its use leads to acceptable agreement between spectrochemical and wet-chemical analyses, and has given an average coefficient of varation of ±3.57% for 57 clay samples.
Qualitative Applications of the NMR Spectra of Alkylpyridines: Part I. Chemical Shifts of the Ring Protons
Authors: McDonald F. R. , Decora A. W. , Cook G. L.
Published: November 2005

Spectroscopic identification of pyridine compounds isolated from complex substances such as shale oil is greatly aided by NMR chemical-shift data on the pyridine-ring protons. Chemical shifts of the ring protons in CCl4 and C6H6 solution and the differential shift of the protons in these two solvents are reported. A paramagnetic shift is observed in the directional character of the proton alpha to the nitrogen in the pyridine ring. These data are used to determine structural information from the spectrum of a mixture of pyridine homologs.
Low-Frequency Infrared Spectra of Aliphatic Monocarboxylic Acids
Authors: Saunders J. E. , Bentley F. F. , Katon J. E.
Published: November 2005

The infrared spectra of a number of aliphatic monocarboxylic acids in the 350–50 cm−1 range are reported and several consistencies in band frequencies noted. An attempt to assign the low frequency vibrational modes of some of the simpler acids has been made based on infrared and Raman intensities. It is concluded that these molecules consist of relatively strongly coupled dimer molecules in the pure liquid and that the spectra reflect this dimer structure.
Qualitative Applications of the NMR Spectra of Alkylpyridines: Part II. Chemical Shifts of the Protons of the Alkyl Substituents
Authors: McDonald F. R. , Decora A. W. , Cook G. L.
Published: November 2005

The NMR chemical shifts of protons on alkyl groups attached to pyridine rings are discussed. Data on 31 alkylpyridines are included. The spectra and tabulated differential shifts of 15 monosubstituted pyridines in carbon tetrachloride (CCl4) and hexadeuterobenzene (Bz- d6) are given; and the data on the chemical shifts and the differential shifts in the solvents CCl4 and C6H6 or Bz- d6 for the di-, tri-, and tetrasubstituted pyridines are tabulated. A paramagnetic shift is noted for some protons on alkyl groups attached alpha to the pyridine nitrogen. The use of the data in a qualitative identification of two pyridine homologs is demonstrated on a fraction from shale oil.
Infrared Determination of Stearlymethacrylate-Cetylmethacrylate Copolymer in Waxes
Authors: Martin J. M. , Heaton R. C.
Published: November 2005

A differential infrared absorption method has been developed for the determination of stearylmethacrylate-cetylmethacrylate copolymer in waxes at concentrations as low as 0.003 wt% without prior concentration. The method is based upon differential absorption measurements of the ester-carbonyl stretching vibration at 1735 cm−1. Specialized sampling techniques are discussed, and application to products from dewaxing and deoiling operations are illustrated.
Simple Demountable Hollow Cathode for Atomic Absorption Spectroscopy
Authors: Popham R. E. , Schrenk W. G.
Published: November 2005

A simple demountable hollow cathode for atomic absorption spectroscopy has been developed which involves very little cost and is simple to construct. The performance of the demountable lamp was compared with commercial lamps for the elements zinc, chromium, and nickel. The lamps were found to be almost identical with respect to stability, precision of data, detection limits, and analytically useful ranges for these three elements. It is felt that use of this demountable hollow cathode can greatly extend the number of elements which can be determined by atomic absorption for a laboratory unable to invest in commercial hollow cathodes.
Nuclear Magnetic Resonance and Infrared Spectroscopic Study of N-Vinyl Compounds
Authors: Landis William R. , Perrine Theodore D.
Published: November 2005

The nuclear magnetic resonance and infrared spectra of five N-vinyl compounds and the corresponding N-ethyl compounds have been observed in order to obtain detailed information about the N-vinyl group. Resultant data indicate that one might prove the presence of N-vinyl by two characteristic infrared maxima in the region of 1390 to 1300 cm−1. The NMR spectra of the N-vinyl protons conform to the expected ABX pattern. The chemical shifts do not permit differentiation from other vinyl types.
Improved Performance of a Plasma Jet Equipped with an Inexpensive Atomizer
Authors: Szivek John , Jones Cyril , Paulson Eleanor J. , Valberg Leslie S.
Published: November 2005

The erratic performance of the plasma jet in the analysis of magnesium in blood plasma was found to arise from the accumulation of residue in the atomization annulus. This problem was circumvented by the use of an inexpensive Zeiss atomizer which was easily dismantled and cleaned. The plasma jet, equipped with this atomizer, was successfully applied to the routine analysis of magnesium in blood plasma. Compared to both medium- and large-bore Beckman atomizers the Zeiss atomizer provided similar sensitivity and greatly improved repeatability. The plasma jet, equipped with a Zeiss atomizer, may be universally applicable to the analysis of many solutions, particularly those containing salts in high concentration.
Determination of Trace Amounts of Rare-Earth Impurities in Yttrium Oxide
Authors: Nash D. L.
Published: November 2005

This paper discusses investigations conducted to achieve optimum sensitivity for the determination of rare earths in yttrium oxide and describes a specific technique evolved for the above analysis. A dc arc burning in a controlled atmosphere of argon and oxygen is used together with a spectrograph of very high dispersion in order to provide optimum signal-to-noise ratio. Because the excitation efficiency is not uniform along the entire height of the arc column, only the most efficient portion is transmitted to the slit. Without any treatment or concentration of the sample other than dilution with graphite powder, the above method achieves sensitivities for the rare earths in yttrium oxide ranging from about 50 ppm for the least sensitive rare earths (Pr, Ce) to about 0.5 ppm for the most sensitive rare earths (Lu, Sc, Yb).
Analysis of Solders by X-Ray Spectrometry
Authors: Zanin S. J. , Hooser G. E.
Published: November 2005

The determination of several percent of Au, Ag, and Cu in various Sn/Pb solder compositions used in the manufacture of microelectronic circuits is described. Details of the preparation of standards and x-ray procedure are given. The Au calibration curve can be prepared from any Sn/Pb composition. The Ag and Cu calibration curves must be prepared for each solder composition.
Separation and Identification of Bridgehead-Substituted Methyl and Ethyl Adamantanes
Authors: Warren R. W. , Schneider Abraham , Janoski E. J.
Published: November 2005

A combination of gas chromatography, infrared and nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry was used to characterize the products obtained from aluminum halide-catalyzed isomerizations of tricyclic saturated hydrocarbons. Six compounds were isolated and identified as methyl and ethyl bridgehead-substituted adamantane derivatives. In addition to supplying evidence pertinent to the structural proof of these derivatives, the data provide useful correlations between infrared, NMR, and mass spectra and methyl and ethyl bridgehead substitution of the adamantane nucleus. A complex splitting pattern which was observed in the NMR spectra of the ethyl-substituted derivatives was shown to be due to the unique A2B3 splitting of the bridgehead-ethyl group.
Infrared Spectra of Monoterpenes and Related Compounds. II. Terpene Alcohols
Authors: Mitzner B. M. , Mancini V. J. , Lemberg S. , Theimer E. T.
Published: November 2005

The infrared spectra of 141 highly purified acyclic, monocyclic and bicyclic terpene alcohols, their reduced derivatives, and related compounds are presented. The majority of these spectra are new to the literature. These spectra provide a broad basis for the correlation of structure and infrared absorption.
Line Interferences in the Spectrochemical Determination of Silicon in Steel
Authors: Bryan F. R. , Runge E. F.
Published: November 2005

The two silicon lines 2881.58 and 2516.12 Å commonly used for steel analysis are measured in the presence of known quantities of interfering elements—chromium, vanadium, and molybdenum. The 2881.58-Å silicon measurements at 5.25-Å/mm dispersion are subject to error when chromium exceeds 0.6%, but at 2.6-Å/mm dispersion chromium does not interfere in amounts as high as 2.4%. The 2516.12-Å silicon measurements at 5.2-Å/mm dispersion are subject to error when vanadium exceeds 0.1%, and at 2.6-Å/mm dispersion, essentially the same errors exists. The 2516.12-Å silicon measurements at 5.2-Å/mm dispersion are also subject to error when molybdenum exceeds 0.2%, but at 2.6-Å/mm dispersion the molybdenum does not interfere in amounts as high as 0.9%.
Supplemental Measurements in Probing Electron Impact-Induced Decompositions via Mass Spectra of Labeled Compounds
Authors: Meyerson Seymour
Published: November 2005

The value of isotope labeling in probing the chemistry underlying mass spectra is well established. The usefulness of this approach and the reliability of conclusions reached thereby can be greatly increased by checking dependence of label retentions in fragment ions on operating conditions. For example, varying the ionizing voltage, source temperature, or repeller potential alters the relative contributions of the two competing processes by which methylcyclopentane loses a methyl radical to form isomeric C5H9+ ions. The ions resulting from the two processes are derived from different parts of the original molecule and so can be distinguished by appropriate labeling.
Laser-Spark Excitation of Homogeneous Powdered Materials
Authors: Whitehead A. B. , Heady H. H.
Published: November 2005

The laser microprobe has been applied to the excitation of trace elements homogeneously distributed in powdered materials. Precision of intensity ratios is about ±11% (coefficient of variation), and detection levels are comparable to those of the dc arc. Matrix effects were studied for four different materials and found to be significantly less than in the dc arc. Use of the probe as the source in a “universal” method is suggested.
A Comparison of Five Spectrochemical Methods for the Analysis of High-Purity Zinc
Authors: Gabler R. C. , Peterson M. J.
Published: November 2005

A comparison was made of five optical spectrographic methods for the analysis of high-purity zinc. Analytical capability was required for the determination of Ag, Al, Cd, Cu, Fe, Hg, Mg, Pb, and Sn in the range from 1 to 100 ppm. The factors considered were: sensitivity of detection, handling ease, possible sources of contamination, analysis time, and precision and accuracy. The data show that a metal-direct arcing procedure is rapid, has high sensitivity of detection, and requires a minimum of sample handling. Solution-residue dc arc, point-to-plane ignited ac arc, and zinc oxide dc-arc procedures gave better reproducibility, but lacked the required sensitivity of detection.
DC Arc in Emission Spectrography: I. Some Observations on the Influence of Lithium Compounds as Buffers
Authors: Decker R. J. , Eve D. J.
Published: November 2005

The results of a series of experiments are reported in which buffers, consisting of a range of concentrations of various lithium compounds in graphite, were mixed with synthetic samples containing suitable concentrations of selected elements and the mixtures were then burned in the anode of a dc arc. Anode temperatures during the lifetime of the arc have been observed with the help of a thermistor bolometer and chart recorder. Arc-column temperatures were calculated from the relative intensities of the Mg lines 2783.6 and 3336.7 Å. From these observations, and the measured intensities of spectrum lines, conclusions are drawn regarding the effect of each buffer compound on arc and electrode temperature, vaporization rates, arc wandering, and general efficiency of the arc source.
Characterization of Arsenic by Atomic Absorption Spectroscopy in Oxy-Acetylene Flames
Authors: Smith Kenneth E. , Frank C. W.
Published: November 2005

This study, investigating the absorption characteristics of arsenic, included the sensitivities of the resonance lines suitable for analytical use, interferences, and the effect of solvents on absorption. Of the lines investigated, three proved to be analytically useful: 1972 Å and 3944 Å (1972 Å second order) having sensitivities of 1 ppm and 1937 Å with a sensitivity of approximately 2 ppm. Interferences from alkali, alkaline earth, and transition-metal ions as well as several common anions were investigated at these three wavelengths. It was found that organic solvent—water mixtures generally enhanced the arsenic absorption. The initial stage of the study was the establishment of optimum operating conditions through manipulation of various parameters. At 1937 Å, and to a lesser degree at 1972 Å, problems were encountered stemming from increased scattering of radiation and absorption by molecular oxygen and acetylene.
Direct Method for Determination of Microquantities of Molybdenum, Iron, and Copper in Milk Xanthine Oxidase Fractions by Atomic Absorption Spectroscopy
Authors: Roussos G. G. , Morrow B. H.
Published: November 2005

Microgram and submicrogram quantities of molybdenum, iron, and copper in bovine milk and intestinal xanthine oxidase fractions were determined by atomic absorption spectroscopy using the standard addition method. Dialysis fluids consisting of 0.1–10 m M potassium phosphate buffer, pH 7.4, containing 0.01–1 m M ethylenediaminetetraacetate served as blanks and diluents for both samples and standards. The sensitivities of the method for iron, molybdenum, and copper were 0.02–0.05, 0.01–0.02, and 0.01–0.02 (μg/ml)/1% absorption, respectively. Coefficients of variation of 8.2, 6.6, and 4.2% were obtained with samples containing 0.11, 0.056, and 0.021 μg/ml of iron, molybdenum, and copper, respectively. Occasional interferences encountered with either concentrated or partially purified fractions could be completely eliminated by direct dilution of the sample. Known quantities of all three metals added to various enzyme preparations were quantitatively recoverable. Dry ashing prior to analysis had no effect on the analytical results.
Laboratory Experience with In Situ Detection of Beryllium in Biological Specimens
Authors: Brokeshoulder Solomon F. , Robinson Farrel R.
Published: November 2005

Suitable microspectrochemical techniques have been devised for the laser microprobe made by the Jarrell—Ash Co. to detect beryllium in histologic structures. Density and type of tissue, thickness of the specimen, character of the embedding medium, concentration and localization of the element, and the penetrability of the laser beam must be considered in preparing biological specimens for chemical analysis by the microspectrochemical technique. Advantages of this technique are the identification of specific elements in situ and the correlation of the presence of the element with a specific histologic structure.
Alterations in the Infrared Spectrum (2–15 μ) of Some Ketones at the Transition Liquid—Solid in the Low-Temperature Range
Authors: Caspary R.
Published: November 2005

In this work characteristic alterations in the spectrum of some ketones are described resulting from the transition liquid—solid and from the influence of further lowering of the temperature.
Elemental Analysis of Cracking Catalysts by X-Ray Fluorescence
Authors: Rayburn Kenneth A.
Published: November 2005

X-ray fluorescence analysis has been applied to the routine determination of Al, Si, K, Ca, Ti, Fe, Ni, V, and light rare earths (e.g., La, Ce, Pr, Nd, and Sm) found in petroleum refining catalysts. Two different fusion techniques, using lithium tetraborate, are utilized to cover the elements desired over the necessary concentration ranges. A straight fusion technique can be used for rare earths, Fe, Ni, V, and Al and Ti in used catalysts. A heavy absorber fusion technique is necessary to determine Si and Al in fresh catalysts, clays, or other materials with wide matrix variations.
Neutron Spectroscopy: A Comparison with Raman and Infrared
Authors: Treviño S. F.
Published: November 2005

The technique of neutron scattering has in recent years been applied with success to the study of molecular spectroscopy. The theoretical basis and experimental procedures of this technique are reviewed. Particular attention is paid to those aspects that clarify the role of neutron scattering as a complementary tool to the well-established methods of Raman and ir spectroscopy. Measurements on a variety of systems are presented as examples of its applicability. These various systems include (a) polymers, (b) torsional oscillators, (c) metal hydrides, (d) hydrogen-bonded crystals, and (e) dispersion curves of molecular crystals.
Comprehensive Abbreviated Expression for Dynamic Ranges in Atomic-Absorption Flame Photometry
Authors: Ramírez-Muñoz Juan , Brace Robert O.
Published: November 2005

Different abbreviated expressions for concentration dynamic ranges are proposed and discussed. These expressions are also intended to give information on percentual sensitivity (related to slope of analytical calibration curves) and noise level. Use of logarithmic terms permits calculation of total dynamic range ratios when using instruments which allow wide variation of instrumental sensitivity.
Ultra-Trace Determination of Rare Earths in Gallium Arsenide
Authors: Wang M. S.
Published: November 2005

The determination of rare-earth elements in gallium arsenide by a dc arc was studied. An argon and oxygen atmosphere was carefully selected to enhance the selective volatilization of rare earths which comes at the very end of arcing in this matrix. The controlled atmosphere also contributed to the suppression of the CN band and allowed the use of this region. A commercially available standard was used to mix with the matrix for preparation of synthetic standards. The recovery means were within 30% of the amount added and relative coefficients of variations are within 16%. The range of determinations, below the 1 ppm levels, were reported.
Some Comments on the Infrared Spectra of Vapors
Authors: Welti David , Stephany Rainer
Published: November 2005

The bands in ir vapor spectra shift from their frequency positions in liquid, solution, or solid spectra according to the extent of the interaction of the sample with the solvent or other solute or condensed molecules. The most noticeable differences occur with hydrogen bonding compounds, where the vapor spectra are analogous to the spectra of very dilute solutions and can be correlated with the presence of free monomers, particularly at higher vapor temperatures. The spectra of alcohols, phenols, acids, amines, and amides have been obtained at temperatures ranging from 80°–190°C. The frequencies of the typical bands are tabulated. The carbonyl band frequencies of a selection of carbonyl compounds are also tabulated.
Spectrochemical Determination of Rare Earths in Calcium Fluoride
Authors: Weisberger Sol
Published: November 2005

This paper reports the development of a spectrochemical method for the determination of type 4f rare earths (except lanthanum and cerium) in amounts usually employed in the activation of calcium fluoride. The method converts the fluoride sample to a common matrix, calcium sulfate, thereby eliminating the possibility of errors in the subsequent arcing of the sample due to previous physical and chemical treatment. Since the “burn” is made in air and recorded in the so-called “metallurgical region,” no elaborate apparatus is needed for analysis.
Application of Spherically Curved Crystals for X-Ray Fluorescence
Authors: Ehrhardt C. H. , Banas E. M. , Janik J. L.
Published: November 2005

A general purpose x-ray fluorescence spectrometer has been constructed that employs the focusing properties of large spherically curved crystals. The 10 cm X 10 cm single crystals are bent to a 63.5-cm radius of curvature, and ground to the 31.75 radius of curvature of the focal circle. A motor-driven remotely controlled interchange mechanism has positions for four of these crystals. Also provided are: interchange of gas flow proportional counter or scintillation counter, and of chromium or tungsten target x-ray tubes, and a wide range of entrance and detector slitwidth combinations. Resolution and sensitivity are greatly superior to those of flat crystal optics.
Application of the Graphite Monochromator to Light Element X-Ray Spectroscopy
Authors: Gould R. W. , Bates S. R. , Sparks C. J.
Published: November 2005

The use of highly oriented graphite as a monochromator was recently discussed by Sparks, and has been found to be highly suitable for light-element ( Z⩾15) x-ray spectroscopy. This paper compares the diffracting power of the graphite monochromator with ethylenediamine- d-tantrate and LiF.
X-Ray Diffraction Analysis Techniques to Monitor Composition Fluctuations within the Mineral Group: Apatite
Authors: Skinner H. C. W.
Published: November 2005

Hydrothermal synthesis studies in portions of the system CaO—P2O5–H2O—CO2–F have produced apatites with composition variations. The lattice constants of the apatites have been determined using computer analyses of x-ray powder diffraction data. By this method compositional fluctuations of a phase within a mixture containing several phases can be monitored. Lattice characteristics of hydroxyapatite (molar CaO/P2O5=3.3) synthesized at pressures of 2000 bars and temperatures from 300° to 800°C from bulk compositions over the range 2.0 to 5.0 CaO/P2O5 are discussed.
Fluorescence Spectra of Homogeneous and Mixed Europium Complexes
Authors: Filipescu Nicolae , Moorjani K. , McAvoy N. , Bjorklund S. , Hurt C. R. , Zumoff J.
Published: November 2005

High-resolution emission spectra of several europium complexes with β-diketones, dipyridyl, and phenanthroline have been examined at 77°K in microcrystals. The Stark splitting of the 7 F levels in the ground multiplet and the relative intensities of the individual 5 D0→7 F transitions can be used for theoretical correlation with the ligand field parameters, transition probabilities, molecular structure, and Eu-ligand bonding. The fluorescence spectra of the bis-aqua, tris, tris-aqua, tetrakis, and mixed chelates with the bidentate ligands are discussed in relation to molecular configuration.
Spectrochemical Analysis of Aluminum Alloys Using Nitrogen Gas Shielding and Point-to-Plane Spark Excitation
Authors: Matocha Charles K. , Petit John
Published: November 2005

Improvements in the spectrochemical analysis of aluminum with point-to-plane, high-voltage spark excitation are obtained by using nitrogen shielding of the discharge zone. The improvements, relative to excitation in air, include: increased spectral line intensity; decrease in the concentration equivalent of background; reduction of the influence of sample composition on background; reduction of the influence of the graphite counter electrode structure on spectral intensity; increased precision; and minimized interelement effects as judged by a reduction in the number of analytical curves required for analysis. Variables investigated in establishing the method are discussed and control parameters for consistency of operation are described. A bibliography on the development of gaseous shielding for spark discharges is included.
Carrier Distillation Method for the Determination of Impurities in Niobium Oxide
Authors: Laib R. D. , Lykins J. D.
Published: November 2005

A carrier distillation technique is described for the analysis of trace impurities in niobium oxide. The carrier used is a 1: 1 mixture of AgCl and AgF. Separation of the carrier and sample charge along with the use of a boiler cap on the electrode cup greatly reduces the background and yet allows the impurities to be distilled into the arc within 90 sec. Sensitivity and precision data are included for 13 impurity elements.
Applications of Multiple-Scan Interferometry to the Measurement of Infrared Spectra
Authors: Low M. J. D.
Published: November 2005

An interferometer can be used to measure infrared spectra. The instrument has no slits, and therefore has a relatively high light-gathering ability. It is also not necessary to disperse polychromatic radiation. The signal-to-noise ratio obtained is consequently high and can be further increased by multiple scanning and coherent addition of information, so that a highly sensitive instrument is available for the measurement of infrared spectra. The interference spectrometer is particularly well suited for the examination of infrared radiation of very low intensity, and has been used to measure infrared absorption, reflection, and emission spectra of a wide variety of materials. Some examples of applications are presented and discussed, including the measurement of infrared emission spectra of minerals and rock specimens and the analysis of the effluent stream of a gas chromatograph.
Routine Determination of Major Constituents in Geologic Samples by Atomic Absorption
Authors: Galle O. Karmie
Published: November 2005

A method for the determination of Al2O3, Fe2O3, TiO2, MnO, CaO, and MgO by atomic absorption is described. A 0.5 to 1.0 g sample is put into solution by treatment with HF, followed by fusion of the HF residue with K2S2Oτ and solution of the fused material with HCl. Determination of the various elements is then made using an acetylene—nitrous oxide flame and a premix type burner. The method was developed to eliminate the necessity of changing flame parameters because of the refractory and nonrefractory elements involved. National Bureau of Standards 1-A, G-1, W-1, and U. S. Geological Survey standards BRC-1 and PCC-1 were analyzed by the methods described herein and the results obtained agree within 0.1% or less of the listed values. Standard deviations and coefficients of variation were also calculated for all elements determined on each sample and found to be within acceptable limits.
Spectrophotometry of Aqueous HNO3, H2SO4, and DCIO4 from 25° to 250°C
Authors: Waggener W. C. , Weinberger A. J. , Stoughton R. W.
Published: November 2005

Dilute nitric, sulfuric, and perchloric acids are applicable as solvents for spectrophotometry up to 250°C over the following ranges: 0 to 1.0 f HNO3 from 0.6 to 1.2 μ; 0 to 0.2 f H2SO4 from 0.25 to 1.2 μ; and 0 to 1.0 f DClO4 from 0.25 to 1.8 μ. Each of these acids reacts measurably with the titanium cell wall and the sapphire windows at rates which increase with acidity and temperature. This corrosion affects the spectral measurements as a function of time and is associated with deterioration of cell window surfaces and the presence in the sample of dissolved and suspended corrosion products. These results are part of our more general program for the development of equipment and technique for routine spectrophotometry of pure liquids and solutions over a wide range of temperature and pressure.
Nuclear Magnetic Resonance of Compounds Related to DDT: Part II. Aromatic Protons
Authors: Sharpless Norman E. , Bradley Robert B.
Published: November 2005

The nuclear magnetic resonance spectra of the aromatic protons of DDT and 31 of its analogs and derivatives have been analyzed. Chemical shifts of these molecules are functions of the electronegativities of the substituents on the ring, as well as those in the aliphatic portion, although substitution of the ring chlorine in DDT by either a nitro or a t-butyl group leads to anomalous values. Molecular orbital calculations show that the chemical shift of the proton ortho to the ring substituent depends upon the π electron density at the corresponding carbon, but the chemical shift of the proton meta to this substituent is independent of the π electron density at the corresponding carbon. The data also indicate that the two aromatic rings in DDT are independent of each other.
New Developments in Raman Spectroscopy with Lasers: Electronic Transitions
Authors: Koningstein J. A.
Published: November 2005

A discussion is given of the Raman spectra of single crystals of yttrium gallium garnet (YGaG), of ytterbrium gallium garnet (YbGaG), and of Yb:YGaG. From a comparison of the spectra it has been possible to separate the phonon spectra of the host lattices from that of an electronic Raman effect which occurs between the crystal field levels of the 2F7/2 manifold of Yb3+ in the garnet crystals. Information with respect to the selection rules governing both types of spectra is given.
Electron Probe Microanalysis: A Review
Authors: Heinrich Kurt F. J.
Published: November 2005

This review covers the development of electron microprobe analysis in the last ten years. After a brief decription of the instrument, the following subjects are discussed: progress and instrumentation; progress in the theory of quantitative analysis; and the future development of microprobe analysis.
Detection of Trace Quantities of Organophosphorus Compounds in Air by Frustrated Multiple Internal Reflectance Spectroscopy
Authors: Prager Manfred J. , LaRosa Charles N.
Published: November 2005

Submicrogram quantities of organic phosphorous compounds in air were monitored by frustrated multiple internal reflectance (FMIR) spectroscopy. Vapor detection at these concentrations required the use of adsorptive films on the germanium FMIR cells. Of the various materials tried, platinum films gave the highest sensitivity. The effects of film thickness, temperature and organophosphorus compound concentrations were investigated. Adsorption was found to be reversible, permitting repeated use of detector probes. At optimum thickness and temperature 0.1 μg of dimethylmethylphosphonate per liter of air is detectable in 30 sec.
Anomalies in the Infrared Spectra of Mixed Carbonate Precipitates
Authors: Kalbus Gene E. , Berg Eugene A. , Kalbus Lee H.
Published: November 2005

When a mixture of cations in solution is precipitated by the addition of carbonate, the resulting mixed carbonate precipitate, when subjected to infrared examination, does not usually exhibit the individually characteristic absorption bands due to each of the carbonates constituting the mixture. Instead, various interesting anomalies such as blending of bands, shifting of positions, and changing of intensities are observed. Such anomalous behavior may hamper any qualitative or quantitative measurements on such samples. Representative spectra and possible explanations for some of these anomalies are presented.
X-Ray Fluorescence Analysis of Individual Rare Earths in Complex Minerals
Authors: Rose Harry J. , Cuttitta Frank
Published: November 2005

A combined chemical x-ray fluorescence method is described for determining rare-earth elements in small amounts of complex rare-earth minerals. These elements yield a complex x-ray spectrum in which many of the analytical emission Lα lines of a given element coincide with the Lβ and/or Lγ lines of a lighter rare-earth element several atomic numbers removed. The proposed analytical scheme corrects for these interferences. Sixteen elements consisting of the lanthanides, yttrium, and scandium can be determined on as little as a 1-mg portion of the separated oxides. The oxides are dissolved in 1 ml of dilute acid, absorbed onto cellulose powder and pressed into a pellet for x-ray excitation. Chemically analyzed geologic standards are not required for calibration.