bluuebunny/crossref_metadata_2025 huggingface dataset:
Instrumental Factors and Figure of Merit in the Detection of Low Concentrations by X-Ray Spectrochemical Analysis
Authors: Spielberg N. , Bradenstein Mechtilde
Published: November 2005

Detection of low concentrations in x-ray spectrochemical analysis depends upon the degree of correlation between concentration and spectral line intensity. Various factors causing deviations of points from a calibration curve are mentioned with particular emphasis on deviations due to inadequate spectral resolution and to x-ray counting statistics, both of which are affected by various instrumental parameters. The effects of various choices of instrumental parameters on the counting statistical deviations may be measured in terms of a figure of merit z=A/√ B, where A is the slope of the calibration curve (intensity vs. concentration) and B is the background or intensity at zero concentration. The statistical deviations are inversely proportional to z. Values of z obtained in the analysis of some of the constituents in the NBS low alloy steel standards for several different combinations of instrumental parameters and experimental conditions are presented. It is shown that the use of higher resolution optics or greater dispersion crystals does not always reduce z drastically and in some cases actually increases z The effects on B and hence on z, of spectral purity of the exciting x-ray tube, of pulse height analysis techniques, and of monochromators having no second order reflection, are also examined and are shown to depend upon the spectral nature of B, which in turn depends upon the type of specimen under analysis.
Spectrographic Determination of Trace Amounts of Rare Earths. I. Analysis of Lanthanum and Yttrium by the Powder Sifting Method
Authors: Radwan Z. , Strzyzewska B. , Minczewski J.
Published: November 2005

A new simplified method for the determination of trace amounts of rare earths in HCl and sodium versenate solutions has been developed. The solutions of the rare earths, La and Y, and of the internal standard (palladium chloride) were evaporated on graphite powder, and this was mixed with NH4NO3. Vertically arranged copper electrodes were used with the sifter electrode as the cathode and a flat surfaced copper rod as the anode. A generator was used as excitation source which combines a dc arc with a Feussner spark. The excitation was effected in an atmosphere of 20% argon and 80% oxygen. The detection limit obtained for the two elements, La and Y, as chlorides and as versenates was 0 2 and 0.1 μg per sample respectively. The usual range of the method was from 0.5 to 10 μg/ml for either solution and element. The average coefficient of variation for this method was ±13 7%. The mutual interferences of both elements have been considered as negligible for this range of concentration investigated
A Direct-Reading Spectrochemical Procedure for the Measurement of Nineteen Minor Elements in Natural Water
Authors: Kopp John F. , Kroner Robert C.
Published: November 2005

A method employing a direct reading spectrochemical procedure for the quantitative determination of 19 minor elements in water is presented. Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Mo, Mn, Ni, P, Pb, Sr, V, and Zn are determined in concentrated water samples by the rotating disc-high-voltage spark technique. Using background as the internal standard, concentrations in the order of 0 01 to 100 mg/l in the processed sample are determined in a matter of minutes by converting the “counts” from a sequential read-out system on a drum calculator. Recoveries of the elements from known solutions varied from 80 to 113 percent at the 90 percent confidence level.
The Use of ATR Techniques to Evaluate UV Degradation of Plastics
Authors: Gedemer Thomas J.
Published: November 2005

The ultraviolet degradation rates of inhibited and uninhibited polycarbonates were determined using attenuated total reflectance techniques of infrared analysis. The changes which occurred are related to possible structural transformations. The degree of degradation was determined as a function of penetration thickness.
Optical Emission Spectrographic Determination of Tantalum and Tungsten in Plutonium
Authors: Barton H. N.
Published: November 2005

A spectrochemical method for the determination of 10–1000 ppm tantalum and 20–1000 ppm tungsten in plutonium metal is described. Chemical separation by precipitation of the plutonium as insoluble plutonium trifluoride, centrifuging, and sampling the supernatant solution is well suited to the glove box operation necessary in handling plutonium. Excitation is by graphite spark; spectra are recorded photographically; and concentrations are determined by standard photometry practices using an emulsion calibration-analytical curve technique with a molybdenum internal standard.
A Direct-Reading Spectrometric Solution Method for the Partial Analysis of High-Silica Materials
Authors: Eardley R. P. , Clarke H. S.
Published: November 2005

The development of a direct-reading spectrometric method for the determination of Al2O3, CaO, Fe2O3, T1O2, MgO and Mn2O3 in high silica (> 92 per cent S1O2) is described. Once the effect of silica on the spectral intensities has been evaluated it has proved possible to ‘set up’ the instrument on silica-free standards without loss of accuracy. The results for Al2O3, T1O2, MgO and Mn2O3 are at least as accurate as existing chemical procedures; the results for CaO and Fe2O3 are of routine control level
The Infrared Spectra of Monoterpenes and Related Compounds
Authors: Mitzner B. M. , Theimer E. T. , Freeman S. K.
Published: November 2005

The infrared spectra of 72 highly purified acyclic, monocyclic and bicyclic terpenes and their hydrogenated derivatives are presented. These spectra provide a broad basis for the correlation of structure and spectra.
Data-Reduction and -Search System for Digital Absorbance Spectra
Authors: Reid James C. , Wong Elizabeth C.
Published: November 2005

Cross-correlation technique is effective as an alternative to coding procedures for systematizing the manipulation of a large file of digital spectral data. As a search method, it is reliable in the recognition of matching spectra and yields a low incidence of false identifications. Precision is governed by the purity of specimens rather than instrumental factors. The utility of a file is augmented by treatment of the spectra as vectors that are normalized to unit length before storage. Such reduction minimizes computer time required for the determination of correlation coefficients; in addition, proportionality factors are eliminated and plots can be superposed on a concentration-independent basis to supplement correlation searches.
Apparatus for Absorption Spectroscopy of Liquids under Gas Pressures up to 300 Atm at Temperatures up to 600°C
Authors: James David W. , Smith G. Pedro
Published: November 2005

A pressure vessel and furnace for measuring absorption spectra of liquid systems at elevated temperatures and pressures is described. At 600°C, the assembly will operate at 300 atm. This apparatus was designed for use with either the Cary model 11 or the Cary model 14H spectrophotometer. The liquid sample is held in a standard 1-cm square absorption cell with a wide neck attached.
Investigation of Spectral Sensitization IV. A Study of Visible and Infrared Spectra of Some Very Pure Bis—Benzothiazolyl and Bis—Benzoselenazolyl Cyanine Iodides
Authors: Leifer A. , Bonis D. , Boedner M. , Dougherty P. , Koral M. , LuValle J. E.
Published: November 2005

A detailed study of the visible spectra in solution and the infrared spectra in the solid state have been made for the following vinylogous series of dyes: [2-bis(3-ethylbenzothiazolyl)] cyanine iodides and [2-bis(3-ethylbenzoselenazolyl)] cyanine iodides. Each dye, to be acceptable for study, had to be chromatographically pure, give a correct microchemical elemental analysis, and be free of electron-spin resonance (free radical) signals. The characteristic red shift of the principal absorption maxima was observed for these dyes in the visible as the number of methine linkages increased. Assignments of vibrational modes to separate absorption regions have been made for these vinylogous series of dyes. Each vinylog has a characteristic pattern of resonant-conjugated stretching modes in the region 1600–1400 cm−1. These modes exhibit a low-frequency shift as the resonant-conjugated chain length increases. There are bands absorbing in the regions 1594–1572 cm−1 and 1470–1453 cm−1 which are present in all the vinylogs and which have been assigned to the aromatic stretching vibrations of the fused phenyl rings present in all these dyes. There is a band appearing in the region 1000–900 cm−1 which changes systematically with an increase in the number of hydrogens on the bridge and with substitution on the bridge. This band has been assigned to the out-of-plane bending vibrations of the hydrogens in a trans configuration on the bridge. No evidence of a cis isomer was observed in the spectra. There is a band near 760 cm−1 which is split into a doublet and has been assigned to the aromatic CH out-of-plane bending vibrations of the four adjacent hydrogens on the fused phenyl rings. This splitting has been attributed to a crystal field effect which gives rise to in-phase and out-of-phase vibrations of the same groups in two different molecules.
Simultaneous Determination of Several Elements by Spectrochemical Addition Method
Authors: Masuda Isoo , Onishi Yamato
Published: November 2005

A new addition method that may be useful for quantitative spectrochemical analysis of several elements was investigated. Though an exact solution of the problem was not possible, some approximate solutions were obtained by abolishing the extrapolation technique that is customarily employed in the usual addition method and taking into account the slopes of two analytical curves belonging to an added and an unadded series, respectively. The experiment shows that this new method may be useful in selected instances even though it sometimes gives a considerably large error of about 30%.
Rapid Flame Photometric Determination of Sodium and Potassium in Silicate Rocks
Authors: Govindaraju K.
Published: November 2005

A rapid and accurate flame photometric determination of sodium and potassium in silicate rocks is described. The sample is fused with a suitable fusion agent (H3BO3+Li2CO3) and the ground-fusion product is dissolved completely in dilute citric acid. The analysis of this solution for alkalies does not indicate any matrix effects. Comparison of results with available rock standards shows good accuracy and reproducibility. This method is used to supplement spectrographic determination of major constituents in silicate rocks, using borate fusion techniques and has been used for the analysis of more than 5000 rock samples.
Quantitative Analysis of Ethylene—Propylene Copolymers by Infrared Spectrometry
Authors: Key L. C. , Trent F. M. , Lewis M. E.
Published: November 2005

An infrared solution method for the determination of the propylene content of ethylene—propylene copolymers is described using carbon tetrachloride as a solvent and hydrogenated polyisoprene for calibration. Precision data are presented and the results are compared to those obtained by a newly developed nmr method.
Elemental Analysis of Chemically Modified Cotton Textiles
Authors: Piccolo Biagio , Mitcham Donald , Tripp Verne W. , O'Connor Robert T.
Published: November 2005

X-ray fluorescence has been applied to the analysis of a wide variety of chemically treated cotton textiles. Sample-preparation techniques suitable for the determination of elements heavier than Na have been developed, and the effect of fabric structure on counting rate has been investigated. Selected examples of results obtained in the analysis of some 20 elements applied to cotton fabrics are given. The problem of particle size when the element is in the form of pigment is discussed.
Comparison of dc Arc and Plasma Arc Excitation to Determine Rhenium in Molybdenite
Authors: Schrenk W. G. , Ho Show-Jy , Lehman D. A.
Published: November 2005

The dc arc is considerably more sensitive than the plasma are in determining rhenium, using the rhenium emission line at 3460.5 Å and cobalt at 3453.5 Å as the internal standard. The plasma arc is twice as precise as the dc arc. The internal standard technique does not increase precision of the plasma arc for rhenium but is useful to indicate proper functioning of the arc aspirator assembly. Use of a 1:1 alcohol—ethanol solvent for rhenium increases sensitivity of plasma arc determinations by a factor or two. The extracting solvent used to remove rhenium from molybdenite, 4-methyl-2-pentanone, is not spectrographically useful in the plasma arc at the wavelengths used for rhenium determination.
Optimum Density in Emission Spectrography
Authors: Svoboda Vratislav
Published: November 2005

The relation of optimum density of developed photographic plates to characteristic curve constants has been studied for two extreme cases: spectrographic estimation with high absolute sensitivity and with high relative sensitivity. While the values calculated for absolute sensitivities agree well with those obtained experimentally, the calculated values are slightly lower in the case of contrast sensitivity than experimental ones.
Infrared Spectra of Some Chloro Derivatives of s-Triazine
Authors: Herman T. S.
Published: November 2005

The effects of chlorine atoms on the fundamental frequencies of the s-triazine ring are discussed and the vibrational assignments in the region 1600–700 cm−1 are extended. The variation in the position of the C3N3-ring bending mode in the region near 810 cm−1 is discussed.
Application of Atomic Absorption in the Study of Na, K, Mg, and Ca Binding by Cellular Membranes
Authors: Sanui Hisashi , Pace Nello
Published: November 2005

Atomic-absorption spectrophotometry is applied in the analysis of biological membrane materials for micromolar levels of the physiologically important cations, Na, K, Mg, and Ca. Instrumental parameters and chemical interferences are investigated and a method for the measurement of all four cations in a single sample of ashed membrane material is formulated, tested, and applied. Results are highly satisfactory, and demonstrate that atomic-absorption spectrophotometry affords biologists a powerful and sensitive tool for the study of the important rôle played by inorganic ions in living systems.
Relationship of Serum Magnesium Levels to Serum Cholesterol and Triglyceride Levels and to Myocardial Infarction
Authors: Hyatt Kenneth H. , Levy Louis , Nichaman Milton , Oscherwitz Mark
Published: November 2005

A comparison of 47 patients having proven myocardial infarction with a group of 50 patients having no evidence of coronary disease failed to show a difference in serum Mg levels between the two groups. Further analysis showed no correlation between the levels of serum magnesium and serum cholesterol or triglyceride. The literature is reviewed and apparent conflicts in results are considered. There is some basis for believing that a relationship exists between Mg and atherogenesis, but it would appear that approaches to the question to date have not been sufficiently thorough. The advent of atomic-absorption spectrophotometry should make possible more-accurate and -dependable Mg determinations in the future.
Spectroscopic Investigations of Some Halide Reactions in Plasma-Generating Devices
Authors: Kana'an Adli S. , Beguin Claude P. , Margrave John L.
Published: November 2005

The behaviors of some halides of carbon (CF4, CCl4, CF3Cl, and Teflon), silicon (SiF4 and SiCl4), and boron (BF3) in plasma reactors have been investigated by emission spectroscopy. The emission spectra from these compounds have been identified and arise from excited diatomic molecules SiF, SiO, BO, C2, and CN and excited atoms of Si, B, and C. On the basis of the observed spectra and energetic and thermodynamic arguments, it is concluded that dissociation, excitation, and/or ionization processes requiring 25–30 eV are predominant in the plasma reactors under the experimental conditions of these studies.
Temperature and Self-Absorption in an Atmospheric Chromium Arc, and f Values for Near-Infrared Lines of Chromium I, from Spectrometric Measurements with Refrigerated Photomultiplier Tubes
Authors: Hutcherson Joseph W. , Mundy Bill C. , Hefferlin Ray
Published: November 2005

A 5-A dc are was struck between pure chromium electrodes in nitrogen at 1 atm. The chromium I excitation temperature, averaged over atoms in the center of the arc image, determined by relative emission-line intensities in the near infrared, was found to be (4893 ± 190) °K. The extent of self-absorption was determined from the same lines. Relative f values for 63 lines of chromium I, including the 21 used initially, were determined with precision of 0.33 in log gf. Existing instrumentation and current improvements to the experiment are described.
Infrared Spectra of Cyclic Phosphonate Esters
Authors: Siddall T. H. , Wilhite R. N.
Published: November 2005

A number of medium to strong bands were found in the infrared spectra of heterocyclic esters of 1,3 and 1,4 glycols with phosphonic acids. A set of such bands appears to be characteristic of the esters of a given glycol with all the phosphonic acids. Some of the bands of each set were also observed for esters of phenylphosphoric acid. Such sets of bands do not appear to have been reported for other organophosphorus compounds.
Photographic Indexing Technique for Evaluation of Ion-Sensitive Plates
Authors: McCrea J. M.
Published: November 2005

Emulsion variations on special-purpose spectrographic plates for detection of ions or invisible radiation greatly complicate use of these plates in quantitative analysis. Indexing by visible light is a useful technique for investigating emulsions, and a convenient apparatus has been constructed for exposing bands of full plate width to light under controlled conditions in such a manner that they do not overlap mass spectral lines. Plates with major emulsion irregularities can be identified by darkroom inspection prior to use, but index bands offer a means of permanent identification of the more important nonuniformities. Indexing techniques are also useful for mass marking, for comparing “in-batch„ and “batch-to-batch„ variations of plates, and as an aid in evaluating plate characteristics and processing variables.
Spectroscopy of Plasmajets and Electric Arcs
Authors: Tourin Richard H.
Published: November 2005

Spectroscopy is a useful means to study the ways in which energy is transferred within and from plasmajets and electric arcs. For this purpose, measurements of spectral intensities and line widths are applied to measure thermodynamic properties of the hot ionized gases. Methods, apparatus, and applications are illustrated by examples from the author's laboratory.
Sequential Sample Changer for Surface-Ionization Mass Spectrometer
Authors: Lubin M. D. , Hamby K. O. , Rosenlof K. D. , Gieszelmann E.
Published: November 2005

A three-station sequential sample changer has been built for a surface-ionization mass spectrometer used in the analysis of nanogram-sized samples. During the analysis of a sample, the previously analyzed sample is replaced and the next sample to be analyzed is preheated. The delay between completion of one analysis and start of the next is reduced to 1 min or less.
Use of Large Graphite Beakers in Double-Arc Analysis
Authors: Schroll E. , Sauer D.
Published: November 2005

Large graphite beakers have been developed for analysis using the double-are technique. A two-chamber system prohibits the spraying of sample powder. The new beaker can be filled with more than 10 g of sample. The larger sample gives the advantage of better detection limits (to parts per billion). A new excitation and heating source, called “mixed source,” consisting of an exciting-spark or ac source and a separately controlled heating de arc, is described.
General Method for Analyzing Refractory-Metal Alloys Using the Vacuum-Cup Electrode
Authors: Leao Elizabeth C. , Hobart E. W. , Fornwalt D. E.
Published: November 2005

The application of the vacuum-cup electrode to the spectrographs analysis of solutions of refractory-metal alloys is described. Both citric and oxalic acids in 5% sulfuric acid solution served as suitable completing agents. The absence of interelement effects is demonstrated. Alternate sets of excitation parameters and variation of sample weight and aliquot sizes permit application of the technique to a broad range of element concentrations. Typical coefficients of variation of results obtained by the method are between 3% and 4%.
Infrared Spectra of Some α,ω-Dinitroxy Alkanes
Authors: Barefoot R. D. , Lawrence A. R.
Published: November 2005

The infrared spectra of eight α, ω-dinitroxy alkanes are examined, and frequency shifts and related intensities of characteristic absorption bands are discussed.
X-Ray Fluorescent Analysis of Beryllium for Vanadium through Copper in the Periodic Table
Authors: Carpenter L. , Nishi J. M. , Fehler R. H.
Published: November 2005

Elements in the periodic table from atomic number 23 through 29, vanadium through copper, are determined from 0.0025% to 10.00% in beryllium metal and compounds convertible to beryllium oxide. Metal samples are dissolved in hydrochloric acid, evaporated to dryness, and oxidized at 900° O. The beryllium oxide is combined in equal portions with boric acid and pelletized. A fixed-time-variable-count method is used to obtain values for establishing analytical curves from which concentrations of samples are read.
Infrared Spectra of Carbohydrates (700–250 cm−1) Determined by both Attenuated Total Reflectance and Transmission Techniques
Authors: Parker Frank S. , Ans Roy
Published: November 2005

Infrared transmission and attenuated total reflectance spectra (ATR) of 20 carbohydrates are presented in the range 700 to 250 cm−1. Good ATR spectra can be obtained in this region of the spectrum, and the region is useful for the identification of the various carbohydrates. Among other compounds, α and β sugars and their derivatives can be distinguished from each other by the transmission or ATR techniques.
Application of the Stallwood Jet and dc Arc to the Analysis of Air Contamination in Inert Gases
Authors: Raziunas V. , Loseke W. A. , Grove E. L.
Published: November 2005

This exploratory paper demonstrates the quantitative response of H2, N2, and O2 in 50% argon-50% helium to a 20-A dc arc and 1% thoriated-tungsten electrodes. This work also illustrates the feasibility of exciting the spectra of these gases, as well as chlorine, at atmospheric pressure and at other relatively simple conditions with a minimum of special facilities.
Background Reduction in Photographs of Mass Spectra
Authors: Ahearn A. J. , Malm D. L.
Published: November 2005

Under favorable conditions, impurities in solids can be detected at a part-per-billion atomic fraction in a mass-spectrographic analysis using photographic recording. An important factor limiting the concentration that can be thus detected is the diffuse background against which a faint mass line must be detected. The billionfold excess incidence of major-component ions produces secondary effects of sufficient magnitude to appreciably fog certain regions of the plate, thereby substantially increasing the concentration needed for detection of elements in these fogged regions. This fogging in an MS-7 mass spectrograph is substantially reduced on the high-mass side of the incident ions by removing that segment of the photographic plate on which the major components are incident and trapping these ions and their secondary products by an appropriate collector. The most likely mechanism for fogging is thought to be scattering of positive ions from the point of impact.
Spectroradiometer—Luminometer for Chemiluminescence and Fluorescence Quantum-Yield Studies
Authors: Roberts B. G. , Hirt R. C.
Published: November 2005

A spectroradiometer–luminometer has been constructed, calibrated, and applied to the measurement of fluorescence- and chemiluminescence-emission intensity as a function of wavelength and to kinetic decay studies. It is also applicable to investigations of phosphorescence, electroluminescence, bioluminescence, and the spectroradiometry of external light sources. A computer program has been set up to take care of wavelength-response corrections and to convert emission intensities into photochemical, radiometric, or luminous units, including total integrated intensities for quantum-yield studies.
Physico-Chemical Characterization of Some 5,5-Disubstituted-1,3-Dixanthyl Barbituric Acids
Authors: Flann B. C. , Cloutier J. A. R.
Published: November 2005

The dixanthyl derivatives of 21 clinically important barbituric acids have been prepared. Melting points, infrared spectra, and x-ray powder-diffraction patterns of the purified compounds are presented. Infrared evidence is used to discuss the position of the linkage between the xanthyl and barbiturate portions of the derivatives. The experimental data should prove of particular value for the microchemical identification of barbiturates.
Infrared Studies of the Isomerization of Cis-Pd(NH3)2X2
Authors: Durig J. R. , Mitchell B. R.
Published: November 2005

Palladium complexes of the type cis-PdL2X2 have been found to be unstable at room temperature and isomerize to the corresponding trans isomers. Neglecting lattice interactions, symmetry considerations would predict two Pd–N stretching vibrations. These vibrations have been observed at 495 and 476 cm−1 for the cis-chloride isomer and at 480 and 460 cm−1 for the cis-bromide isomer. The trans isomer, by the same considerations, should have but one Pd–N stretching vibration. This vibration was observed for the trans-chloride isomer at 496 cm−1 and for the trans-bromide isomer at 490 cm−1. It has been found that as isomerization proceeds, from the cis to the trans forms, the lower Pd–N stretching vibration decreases in intensity and eventually disappears. The intensity changes for these vibrations over a period of 72 h indicated that the reaction follows a first-order rate law. A reaction mechanism has been proposed.
Unified Approach to the Evaluation of Analytical Data in Control Applications
Authors: Cronhjort B. T.
Published: November 2005

A new problem representation for evaluation of analytical data is offered. The data considered are generated by multicomponent composition analyzers such as ordinary spectrometers, mass spectrometers, and chromatometers. Each instrument defines a transform that relates the output of the instrument to its input. In terms of the instrument transform, we discuss the use of digital computers to improve the efficiency of interpretation of raw data. Special reference is made to optical direct-reading emission spectrometers in process-control applications. It is believed that the concept of the instrument transform will stimulate creative contributions in the analyst's collaboration with computers.
Atomic-Absorption Characteristics of Bismuth Using a Turbulent-Flow Total-Consumption Burner
Authors: Marshall Delbert , Schrenk W. G.
Published: November 2005

An investigation of the atomic-absorption behavior of bismuth was undrtaken, using the 3067.72-Å line of bismuth. Optimum operating condiions were determined, then a flameintensity profile was obtained, and analytical curve prepared, the sensitivity and limit of detection determined, and interference studies were caried out. The instrument used was an 0.5-m Ebert-mounted monochromator using ac electronics with a Sargent model S-72150 multirange recorder for readout. A bsimuth hollow cathode and a Beckman medium-bore oxy-acetylence burner were used. Optimum flow rate of the oxygen was 2.22 liter/min and the acetylene flow rate was 4.10 liter/min. These flow rates were quite critical. With a single burner and a single optical pass throught the Flame, the analytically useful range was 1-400 μg Bi/ml (in two steps) using a 1: 1 (volume/volume) acetone-water solvent system. The sensitivity was found to be 2.0 μ/ml and the limit of detection was approximately 1 μg/ml. Interference studies were conducted with the metals Ag, As, Cd, Cu, Hg, Ni, Pb, Sb, Sn, and Zn, all of which are commonly found associated with bismuth in ores and alloys. None of these metals were found to interfere with the Bi determination.
Spectrochemical Analysis in the Vacuum Ultraviolet with the Hollow-Cathode Light Source—Part I. Qualitative Analysis
Authors: Milazzo Giulio , Sopranzi Nello
Published: November 2005

On the basis of some theoretical considerations concerning the analyzability of elements that have their resonance lines in the vacuum ultraviolet, a hollow-cathode light source of new design has been tested in connection with a vacuum spectrograph. The results, which show an improvement over those reported in the literature, are tabulated. The limit of detectability under the given conditions was at 0.01 μg iodine.
Spark-Source Mass Spectra of Several Aromatic Hydrocarbons Using a Spinning Electrode
Authors: Kessler T. , Sharkey A. G. , Hickam W. M. , Sweeney G. G.
Published: November 2005

The purpose of this investigation was to evaluate the application of a spark-source mass spectrograph equipped with a spinning-electrode system for the study of various high molecular-weight materials derived from coal. Eight structural types having molecular weights from 178 to 252 corresponding to those substances previously seen in an electron-impact mass spectrum of the coal-tar pitch were affirmed by this technique. Easily interpreted mass spectra of phenanthrene, anthracene, and chrysene were obtained by the spinning-electrode system. Mass spectra obtained from synthetic mixtures of anthracene and chrysene demonstrated that the technique is applicable for semiquanitative analysis.
Developments in Apparatus and Techniques for Time-Resolved Spectroscopy
Authors: Bardócz Á.
Published: November 2005

Spectra dispersed only according to wavelength have a limited physical meaning since they fail to reveal the changes in the light source in time. Electronically controlled spectroscopic light sources operating with high precision in time make possible the production of time-resolved spectra, which can be represented as a function of wavelength and time. Resolution in time is accomplished with the aid of rotating mirrors and disks, fitted in the optical system of conventional spectrographs. The time-revolving element and the light source are synchronized magnetically or by means of a photocell. The light source is controlled by a trigger signal generator driven by a photocell or a magnetic coil. The rotating mirror or disk, driven by a synchronous motor from the mains voltage, is incorporated in a mechanical apparatus, making possible electric phase adjustments. Several details of time-resolved spectra of high- and low-voltage sparks and of ac arcs are demonstrated.
Emission Spectrometric Determination of Barium, Boron, Iron, Manganese, and Strontium in Oilfield Waters Using a Plasma Arc
Authors: Collins A. Gene
Published: November 2005

Studies of the concentration and distribution of the mineral content in subsurface oilfield waters aid in locating water-pollution sources, determining water compatibilities, determining the origin and distribution of oilfield waters and petroleum, and exploring for petroleum and other minerals. An emission-spectrographic method using a plasma arc to determine B, Ba, Fe, Mn, and Sr in oilfield waters was developed. Variations in brine composition were reduced by use of a synthetic brine solution. Less than 1 mg/liter of each ion can be detected. Synthetic and natural oilfield waters containing the subject ions were mixed with various organic solvents and the internal standard. Relative intensities of their emission lines were determined using each of 10 solvent systems.
Detection and Estimation of Some Trace Elements by dc-Arc Excitation Using the Vacuum-Cup Technique
Authors: Bevege Eleanor E. , Gallion Robert E.
Published: November 2005

The dc-arc excitation of aqueous hydrochloric acid solutions of various elements has been studied. Teflon cups of the Zink type were employed. By using the 3089-Å line of the OH band or gallium as an internal standard, boron, mercury, tin, chromium, iron, aluminum, manganese, copper, and zinc in the part-per-million range have been determined.
Emission Spectrographic Analysis of Tantalum Thin Films
Authors: Nohe J. D.
Published: November 2005

A dc-arc technique is described for the analysis of impurities in tantalum thin films. Films are sputtered directly on ultrapure graphite substrates, heat oxidized, and removed mechanically. Graphite is employed as the buffer, and samples are compared to standards of similar composition.

The graphite-substrate technique has been applied to films of other metals produced by sputtering, resistance-heating evaporation, and electron-beam evaporation. Only portions of the spectrographic procedure are modified for different metallic films.
Atomic Absorption Studies with a Bandpass Filter
Authors: Goleb Joseph A.
Published: November 2005

Atomic absorption studies were performed with a simple bandpass filter. Results of these studies for lithium indicated that the sensitivity and detectability obtained were comparable to existing atomic absorption techniques that employ a monochromator to isolate a waveband. The main advantages of using a bandpass filter in place of a monochromator are the relatively low cost of the filter and the ease of operation.
Quantitative Determination of Impurities in Solids by Mass Spectrometry
Authors: Elliott R. M. , Swift P.
Published: November 2005

The reliability of quantitative impurity analysis of solids by spark-source mass spectrometry has been improved as a result of recent investigations. In the past, the technique has been highly successful for quantitative estimation of extremely low impurity levels and for direct comparison of impurity levels in two similar materials. However, improvements in reproducibility and the establishment of reliable relative-sensitivity factors were required for accurate determination of absolute concentrations. It has now been shown that the ion-accelerating voltage and the level of rf spark excitation can have marked effects on relative-sensitivity factors. It is, therefore, extremely important to maintain these parameters constant. The influence of sample inhomogeneity on reproducibility has also been investigated, and here the very low sample consumption of the rf spark can be a disadvantage. The alternative method of excitation by low-voltage dc arc can be less affected by inhomogeneity because a larger amount of sample is involved in an analysis. Following the improvements in reliability of relative-sensitivity measurements, more systematic determinations of these factors have been carried out. It is shown that, when these correction factors are applied, quantitative accuracy of the order of 10% is achieved.
Demountable Water-Cooled Hollow-Cathode Lamp for Atomic-Absorption Spectroscopy
Authors: Rossi G. , Omenetto N.
Published: November 2005

A demountable water-cooled hollow-cathode lamp for general use as a sharp-line source in atomic-absorption spectroscopy is described. The effective removal of the atomic vapors from the mouth of the cathode and the consequent possibility of raising the discharge current are stressed. The lamp has worked satisfactorily for 1 yr for 13 elements. Sensitivities either comparable to or exceeding those obtained with conventional tubes were observed.
General Spectrographic Technique for the Determination of Volatile Trace Elements in Silicates
Authors: Tennant W. C.
Published: November 2005

Details are given of a quantitative dc-arc method for the determination of up to 15 volatile elements in trace amounts in silicates. Twenty milligrams of sample are mixed with an equal weight of an alumina-lime buffer containing 0.1% bismuth trioxide as internal standard and the mixture arced as the anode in a graphite cup. Careful control of arcing conditions allowed the determination of common volatile elements in amounts down to 1 ppm and in the case of several rare elements—notably Ag, Au, In, and Tl—down to 0.1 ppm.
Plasma-Arc Studies for Alloy Analysis
Authors: Muntz James H.
Published: November 2005

An evaluation of the plasma-arc spectrochemical technique for alloy analysis was made. Matrix effects were studied and found to be present at all concentrations investigated, but were not significant enough to preclude the use of one set of standards for any one particular base metal. The application of the technique for the analysis of aluminum, iron, nickel, and possibly cobalt base alloys has been demonstrated using identical operating conditions and with only three sets of standards. Tungsten was determined with a graphite cap covering the plasma's tungsten transfer electrode to prevent spectral lines from this source. The maintenance required by the nebulizer is the main disadvantage of the technique.
Analysis of Gold and Platinum Group Alloys by X-Ray Emission with Corrections for Interelement Effects
Authors: Eick J. D. , Caul H. J. , Smith D. L. , Rasberry S. D.
Published: November 2005

The x-ray emission analysis of noble-metal alloys was investigated critically to determine optimum conditions for accurate analysis. The analytical curves for the elements Cu, Pd, Pt, and Zn were found to be linear with a deviation of less than ±0.2%. However, a nonlinear relationship existed for gold and for silver. These discrepancies could not be eliminated by variation in sample preparation. An interelement effect due to x-ray absorption and enhancement was found and was corrected to an accuracy of 0.2% by means of a mathematical treatment suggested by Lucas-Tooth and Price. The analysis by x-ray emission can be accomplished in approximately one-tenth of the time necessary for conventional wet chemical methods.
X-Ray Fluorescence Determination of Composition and Thickness of Nickel—Iron—Cobalt Thin Films: Application of Solution Techniques
Authors: Cocozza E. P. , Ferguson A.
Published: November 2005

In computer-memory technology, it is important to know the composition and thickness of nickel—iron—cobalt thin films. These parameters affect the magnetic properties of the films and must be determined accurately for evaluation purposes. An x-ray fluorescence procedure was used in this work. Nickel—iron—cobalt thin-film standards were developed by a solution technique. Thin films in the approximate composition range of 79% Ni, 18% Fe, and 3% Co and thickness range of 600–1300 Å were analyzed. Precision of the thin-film compositional analysis yields coefficients of variation of ±0.02% for Ni, ±0.12% for Fe, and ±0.43% for Co. Accuracy is 0.04% for Ni, and 0.17% for Fe, and 0.34% for Co. Precision of the thickness measurement yields a coefficient of variation of ± 0.2%. Accuracy, checked against optical interferometric data, is ±10 to 20 Å (∼1%–2% at the 1000-Å level).
Characteristics of Ion-Sensitive Emulsions for Mass Spectrography. II
Authors: McCrea J. M.
Published: November 2005

An earlier investigation of the properties of ion-sensitive plates has been extended to include additional types of spectrographic emulsions and to obtain more extensive data on the widely used Ilford Type Q2 emulsion. Log-probability response plots are used to compare the different emulsions and emulsion batches. The effects of variations in exposure and processing conditions on the Type Q2 plates have been investigated. These effects are correlated, where possible, with the coating analyses and microstructuro of the plate emulsion.
Slope-Ratio Technique for the Determination of Trace Elements by X-Ray Spectroscopy: A New Approach to Matrix Problems
Authors: Cuttitta Frank , Rose Harry J.
Published: November 2005

A new approach to solving matrix problems in x-ray fluorescence analysis of trace elements has been applied to the determination of bromine in saline waters and zinc in silicates. The method requires no prior knowledge of the chemical composition of the sample. Marked matrix effects are minimized by dilution, and the problem of variable backgrounds due to residual matrix effects is solved by using a slope-ratio technique. In this proposed technique, the slope of a standard curve prepared from pure solutions is compared with that of spiked samples. The ratio of the slopes of these two curves permits the calculation of an adjusted background which does not significantly differ from that of an absorbent impregnated with the sample matrix free of the element sought. Experimental parameters concerning the technique are presented. The excellent agreement of the zinc and bromine data with analytical results obtained by more conventional methods suggests that the technique can be used for the determination of other trace constituents in geologic materials. Application of the slope-ratio technique to other modes of instrumental analysis appears feasible.
Improved Microsecond-Response Electromechanical Spectrograph Shutter
Authors: Kendall Paul A.
Published: November 2005

An improved microsecond-response electromechanical shutter using a rigid body electromagnetic induction driver has been developed for obtaining time-resolved spectra of short duration, transient phenomena with an ordinary time-integrating spectrograph. The shutter, with simple translational closed-open-closed action, is event triggered. It is currently used for spectral line broadening studies that presently require a range of shutter open times from 40 to 1800 μsec. The shutter's ease of use, a nonrepeatability of generally less than one percent, and the high maximum velocity in excess of 5000 cm/sec are its salient features.
Quantitative Infrared Analysis of Styrene-Acrylic-Melamine Resins
Authors: Vandeberg John T.
Published: November 2005

This paper presents a method for rapid and accurate determination of individual components in modified thermosetting acrylic-coating resins. This technique is based on infrared-absorbance measurements at 1733 cm−1, 816 cm−1, and 700 cm−1 for the acrylate, melamine-formaldehyde, and styrene components, respectively. The accuracy and precision obtained on typical system of known composition have been found to be better than ±2% absolute for any one component. Furthermore, the analysis can be performed in minutes after the initial calibration work has been completed.
Determination of Aluminum in the Presence of Fluoride by Emission Spectroscopy
Authors: Kurtz L. T. , Tandon H. L. S. , Marcusiu E. C.
Published: November 2005

Fluoride greater than 0.1 N interfered negatively in the determination of Al by the rotatingdisk-electrode technique. Fluoride interference was eliminated by the addition of H3BO3. Aluminum in the 1–100 ppm range was successfully determined in the presence of 0.25 N fluoride by making the solutions 2.5% in H3BO3. The coefficients of variation among six determinations for solutions containing 10 and 100 ppm Al were 3.0% and 0.9%, respectively. Recovery of known amounts of Al added to fluoride-extracts of soils ranged from 98.4% to 102.2%. The proposed method thus gave acceptable accuracy and precision. The method is simple and rapid since it does not require the removal of fluoride by distillation as H2SiF0 nor does it prevent the determination of Si in the same sample.
Spectrochemical Analysis of Trace Impurities in Copper Using Copper Fluoride as a Carrier-Distillation Agent
Authors: Tymchuk P. , Mykytiuk A. , Russell D. S.
Published: November 2005

A comprehensive study has been made of the efficiency of copper fluoride as a carrier for the quantitative determination of more than thirty impurities in high purity metallic copper. Although other halides of copper and silver have been shown to improve the sensitivity of their detection, copper fluoride was found to be by far the most versatile and effective. The carrier is added directly to the metallic sample, making the method both simple and unusual. The line intensities of the impurities are apparently independent of the size of the copper sample and dependent only on the quantity of impurities present, a fact which greatly simplifies both calibration and analysis. The limits of detection range down to 10 ppb and are lower than those reported by other spectrographic methods in a number of cases. The results obtained for 15 different elements gave a coefficient of variation of 6.5% on 15 replicate samples. Since extremely pure copper fluoride is vital, a simple method for its preparation is described.
Spectrochemical Determinations in Garnets Using a Laser Microprobe
Authors: Blackburn W. H. , Pelletier Y. J. A. , Dennen W. H.
Published: November 2005

Spectrochemical determinations of Fe, Mg, Mn, and Ca in garnets by use of a laser micro-probe were performed in matrix. Standards were prepared by fusion of chemically analyzed mineral powders and these standard glasses were excited in the same manner as the mineral unknowns. Comparison of results with the rock standard W-1 showed good accuracy and reproducibility. The precision and accuracy of the method as a whole deems it suitable for most mineralogic investigations where analysis in matrix is desirable.
Study of N—H Frequencies in Some Metal-Halide Chelates of O-Phenylenediamine
Authors: Coakley Mary P.
Published: November 2005

The infrared studies in connection with the bidentate complexes of o-phenylenediamine were directed toward the study of N–H vibrations. Similar investigations have been undertaken with regard to the N–H stretching and bending vibrations of aniline and α-naphthylamine. Deuteration studies were made. As a result of these studies and by comparison with the assignment of frequencies made in the above mentioned investigations, stretching, scissors, and wagging frequencies are assigned to the chelates of o-phenylenediamine. The absorption in the region of ND2 wagging vibrations of the deuterated palladium complex failed to show splitting and therefore coupling with the C–H out-of-plane vibrations, as was evident in the spectra of the corresponding complexes of α-napthylamine and aniline.
Infrared Spectra of Polysubstituted Pyrimidines in the 700–200 cm−1 Region
Authors: Netzel D. A. , Hermann T. S. , Bentley F. F.
Published: November 2005

The infrared spectra of 28 substituted pyrimidines are presented in the 700–200 cm−1 region. These compounds are characterized by the in-plane ring deformation mode near 500 cm−1, and the out-of-plane ring deformation near 450 cm−1. The resonance, inductive, and mass effects on these and on other fundamental modes are also presented.
Spectrochemical Determination of Nanogram Amounts of Cobalt in Blood Using the Copper-Spark Method
Authors: Kabiel A. M. , Hanna Z. G. , Youssif Y. S.
Published: November 2005

The superiority of spectrographic methods in the estimation of cobalt, the minor constituent in human blood, is pointed out. The main advantages are speed, sensitivity, and certainty in the identification of the trace elements being determined. The analysis is carried out using an ion-exchange concentration method to separate nanograms of cobalt ions from the interfering extraneous elements, followed by a copper spark method which proved to be valuable in reducing the limit of detection. Illustrated examples are given of the kinds of work to which the method is applied.
Technique for Microspark Emission Spectroscopy
Authors: Garbini Leo J. , Mooney John B. , Schoder Carl E.
Published: November 2005

The analyst is frequently confronted with the problem of analyzing a microscopic local area in a heterogeneous sample. A rapid, inexpensive technique has been developed to analyze a spot as small as 50 μ in diameter with an emission spectrograph. The only accessories required are a microscope, some transparent tape, and a sharp needle. The tape is placed on the sample surface and a hole is punctured at the spot to be analyzed while viewing the sample through the microscope. The sample is then excited with a very short spark in the spectrograph. Using a very fast film it has been possible to make qualitative analyses for both major and minor constituents of a spot as small as 50 μ in diameter on a conducting sample.