An electronic, adjustable-waveform spark source for basic and applied emission spectrometry

Coleman, David; Walters, John P.

doi:10.1016/0584-8547(76)80055-9

Cited by 48 publications

(6 citation statements)

References 9 publications

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“…The timing diagram for this circuit is shown in Figure 6. A zero-crossing detector circuit generates clock pulses at 120 Hz, synchronized to the zero-crossing of the 60 Hz power line (47).…”

Section: Methodsmentioning

confidence: 99%

Theta pinch discharge designed for emission spectrochemical analysis: design and electrical characterization

Kamla¹,

Scheeline²

1986

Anal. Chem.

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Section: Methodsmentioning

confidence: 99%

Theta pinch discharge designed for emission spectrochemical analysis: design and electrical characterization

Kamla¹,

Scheeline²

1986

Anal. Chem.

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“…The type of spark source used in these studies has been described elsewhere in detail (17). The spark current waveform employed is shown in Figure 5.…”

Section: Methodsmentioning

confidence: 99%

“…Concomitantly, sampled material, in the form of a vapor plume, expands linearly and crosses the gas at predictable velocities. The physical and chemical interaction of these two systems significantly in- It should be noted that since the spark sampling current is pulsed unidirectional (16)(17)(18), only the cathode is sampled. Significant radiation corresponding to anode material (thoriated tungsten) is not observed.…”

Section: Literature Citedmentioning

confidence: 99%

High frequency excitation of spark-sampled metal vapor

Coleman¹,

Sainz²,

Butler³

1980

Anal. Chem.

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standard atomic absorption sensitivities. Even more important, the linearity of the analytical curves should be improved.-. .Apart from the technical problems associated with modulating the field, it must also be shown that in such a system the background does not change when the field is modulated. In considering overall performance for a Zeeman-effect atomic absorption spectrophotometer, it would appear that this approach may retain the improved background correction capability with minimum sacrifice in sensitivity and analytical range. (8) Koizumi, H.; Yasuda, K.First results are presented of a new analytical discharge system wherein the normal processes of samp/ing and spectral excifaflon are temporally and spatially segregated into Independently optlmlzable events. Specifically, a high voltage spark Is first used as a sampling device to create a toroidally-shaped reservoir of species sampled from a metallic electrode surface. Later in time, after the spark sampling current has ceased, thls material is inductively re-excited, at high frequency, utilizing critical coupling Conditions. This approach results in dmpliflcatlon of observed emission spectra with most energy seemingly concentrated in the atom and ion resonance lines (speclation). Further, one observes relatively sharp spectral emitting lines and nearly total elimination of spectral background continuum. Because of the optical thinness of the re-exclted torus, Increased freedom from physlcal matrix effects and Increased dynamic range are anticipated, but have not been experimentally verified.The major goal in this laboratory has centered around the development and understanding of new luminous electrical discharges which allow separation of sampling and of spectral excitation phenomena which are normally integrated in direct spectrochemical analysis of metal surfaces. The long term goal is to provide control and optimization of each step to analytical advantage.We report here first results of a new approach to direct spectrochemical analysis of a metallic electrode surface. This approach involves direct metallic vapor introduction, with spatial integrity, into an observation region via controlled high voltage spark sampling of discrete electrode surfaces. The properties of the spark discharge process serve to locate this vaporized metal (ions and atoms) in space with well-defined toroidal geometry. Time-delayed re-excitation of this resident vapor, with a triggered high frequency pulsed energy train, is then caused to occur at a time corresponding to critical

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“…This lens (L2) was placed on a stage which could be translated along the optical axis without opening the enclosure between the monochromator and the detector housing. Lens LI was mounted on an optical rider (39,40) which was easily and precisely translated along the optical axis. The slit widths were set depending on the signal intensity and desired spectral resolution.…”

mentioning

confidence: 99%

Optical imaging spectrometers

Olesik¹,

Hieftje²

1985

Anal. Chem.

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Two optical systems for acquisition of two-dimensional Images are described. The systems, respectively, an electronic slitless spectrograph and a monochromatic Imaging spectrometer, both usé a Czerny-Turner monochromator for spectral discrimination. A silicon Intensified target vidicon detector provides quantitative Images In time-integrated or timé-resolved modes. By use of simple single-lens Imagetransfer optics with a monochromator, spatial resolution on the order Of 0.3 mm Is attainable. Applications of the Imaging spectrometers for spatial mapping of Inductively coupled plasmas and flames are Illustrated.

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An electronic, adjustable-waveform spark source for basic and applied emission spectrometry

Cited by 48 publications

References 9 publications

Theta pinch discharge designed for emission spectrochemical analysis: design and electrical characterization

Theta pinch discharge designed for emission spectrochemical analysis: design and electrical characterization

High frequency excitation of spark-sampled metal vapor

Optical imaging spectrometers

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