Quantitative determination by the Stallwood Air-Jet DC Arc Technique 4. trace impurities in aluminum, magnesium, tin and zinc

A method has been developed to permit the quantitative determination of trace metals in polypropylene and other organic materials in which the total ash content ranges from 0.10 per cent to less than 0.001 per cent by weight. A small sample of the material is ashed directly in the electrode. A fixed amount of germanium internal standard solution is added to the electrode and dried Standards are prepared by adding weighed amounts of a plastic dispersion containing known amounts of the elements to be determined to specially prepared electrodes. Using a controlled atmosphere chamber the prepared electrodes are excited with a dc arc in an atmosphere of argon and oxygen and the spectra recorded photographically.

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Controlled-Atmosphere dc Arc for the Quantitative Determination of Rare Earths in Calcium Fluoride

Applied Spectroscopy ◽

10.1366/000370266774386579 ◽

1966 ◽

Vol 20 (6) ◽

pp. 392-394 ◽

Cited By ~ 7

Author(s):

D. L. Nash

Keyword(s):

Quantitative Determination ◽

Rare Earths ◽

Calcium Fluoride ◽

Controlled Atmosphere ◽

Specific Technique ◽

Limits Of Detection ◽

Dc Arc

This paper discusses the investigation of optimum controlled-atmosphere conditions for the analysis of rare earths in calcium fluoride and describes the specific technique evolved for the determination of terbium and holmium. The limits of detection and precision of the method are given.

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A Spectrochemical Method for the Determination of Trace Impurities in Metallurgical Materials

Applied Spectroscopy ◽

10.1366/000370266774386128 ◽

1966 ◽

Vol 20 (3) ◽

pp. 168-171 ◽

Cited By ~ 17

Author(s):

B. E. Balfour ◽

D. Jukes ◽

K. Thornton

Keyword(s):

Trace Impurities ◽

Dc Arc ◽

Single Set

A method is described in which Ag, As, Au, Bi, Cd, Ge, In, Mo, Pb, Sb, Sn, and Tl are simultaneously determined in a variety of metallurgical materials. Preconcentration and separation are achieved by coprecipitation with copper as mixed sulphides, and excitation is by means of the dc arc. Provision is made for the analysis of a wide variety of materials using a single set of synthetic standards.

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Electrodes for Trace Impurity Analysis and Determination of Traces in Gallium

Applied Spectroscopy ◽

10.1366/000370270774372083 ◽

1970 ◽

Vol 24 (1) ◽

pp. 60-67 ◽

Cited By ~ 5

Author(s):

M. S. Wang

Keyword(s):

Signal To Noise Ratio ◽

Sampling Technique ◽

Trace Determination ◽

Trace Impurities ◽

Graphite Electrodes ◽

Impurity Analysis ◽

Gallium Metal ◽

Ultra Trace ◽

Dc Arc

Electrodes of several graphite makers have been evaluated and compared for weight consistency and impurities for the purpose of developing techniques to determine trace impurities in material which can take advantage of preferential volatilization. A technique suitable for pre-arcing graphite electrodes in an argon atmosphere has been developed for minimizing the impurity background in the electrode cup so that ultra-trace determination is possible. The purified and selected electrodes are used in development of a spectrochemical method for determining trace impurities in gallium metal. The technique takes advantage of strong preferential volatilization of the metals in a dc arc with sequential exposures used for improvement of signal-to-noise ratio. A new sampling technique and standardization method are discussed. Special problems related to the analysis of gallium are investigated, and analytical results are shown.

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Direct Nebulization of Metal Samples for Flame Atomic-Emission and Absorption Spectroscopy

Applied Spectroscopy ◽

10.1366/000370271779951066 ◽

1971 ◽

Vol 25 (6) ◽

pp. 636-642 ◽

Cited By ~ 27

Author(s):

Royce K. Winge ◽

Velmer A. Fassel ◽

Richard N. Kniseley

Keyword(s):

Arc Discharge ◽

Spectroscopic Method ◽

Atomic Emission ◽

Metal Particles ◽

Large Area ◽

Trace Impurities ◽

Uniform Sampling ◽

Aerosol Generator ◽

Dc Arc

A device for transforming solid-metal samples into an aerosol of fine metal particles has been combined with a flame spectroscopic method for the determination of trace impurities and alloying elements in steels. The aerosol generator is a simple apparatus in which the sample serves as the cathode of a low-current dc-arc discharge. Constant movement of the cathode spot results in uniform sampling of a relatively large area. A flowing gas stream transports the aerosol particles from the arc discharge to the nitrous oxide–acetylene flame. Analytical curves for the determination of chromium, manganese, and nickel in steel are shown. The method provides a very rapid means of determining trace elements and alloy constituents in metals without the complications attendant to dissolution procedures.

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Porous-Core Electrode for Emission Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702884430254 ◽

1988 ◽

Vol 42 (6) ◽

pp. 1090-1096 ◽

Cited By ~ 1

Author(s):

M. S. Wang

Keyword(s):

Graphite Powder ◽

Trace Impurities ◽

Porous Core ◽

Porous Graphite ◽

New Instrumentation ◽

Ultra Trace ◽

The Cost ◽

Dc Arc ◽

Metallic Impurities

A core was made of porous graphite to fit a preformed electrode. This porous-core electrode replaces old popular methods using graphite powder as an absorbent to accomplish concentration of liquid samples, but without causing contamination problems of Teflon® ware. When the amount of sample solution is not limited, a concentration of several thousand times is possible, to extend detection limits required by the modern electronics industry. High-purity water, solvents, volatile acids, and alkali were concentrated, and ultra trace impurities were determined. Some organic material can be ashed at 400°C on the electrode for arcing. Boron in trichlorosilane was separated with an addition of mannitol and routinely determined in low ppba range. The cost of this operation is a small fraction of that for new instrumentation required for achieving these sensitivities. The old spectrograph with a dc arc source unit and photographic detection has found some applications to meet new stringent requirements. The technique should be able to be easily applied to the determination of metallic impurities in trichlorosilane, dichlorosilane, hydrogen chloride, and others.

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Atomic force microscopy (AFM) of the topography of silicon surfaces exposed to ion beams

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130298 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1132-1133

Author(s):

Mark Denker ◽

Jennifer Wall ◽

Mark Ray ◽

Richard Linton

Keyword(s):

Secondary Ion Mass Spectrometry ◽

Incidence Angle ◽

Ion Beam ◽

Depth Profiling ◽

Depth Resolution ◽

Ion Beams ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Trace Impurities ◽

Energy Dose

Reactive ion beams such as O2+ and Cs+ are used in Secondary Ion Mass Spectrometry (SIMS) to analyze solids for trace impurities. Primary beam properties such as energy, dose, and incidence angle can be systematically varied to optimize depth resolution versus sensitivity tradeoffs for a given SIMS depth profiling application. However, it is generally observed that the sputtering process causes surface roughening, typically represented by nanometer-sized features such as cones, pits, pyramids, and ripples. A roughened surface will degrade the depth resolution of the SIMS data. The purpose of this study is to examine the relationship of the roughness of the surface to the primary ion beam energy, dose, and incidence angle. AFM offers the ability to quantitatively probe this surface roughness. For the initial investigations, the sample chosen was <100> silicon, and the ion beam was O2+.Work to date by other researchers typically employed Scanning Tunneling Microscopy (STM) to probe the surface topography.

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