Off-axis imaging for improved resolution and spectral intensities

Salmon, S. G.; Holcombe, James A.

doi:10.1021/ac50034a040

Cited by 43 publications

(18 citation statements)

References 3 publications

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“…Similar to Cu, equilibrium or 'pseudo-equilibrium' may exist at the interface for Au Au ads CCA desorption Au (g) (6) during vaporization. Smets plots for gold may show evidence of a 'pseudo-equilibrium' as has been proposed for copper, but rationalization requires the mechanistic stage of a sticking Au ads CCCCA surface diffusion Au (l) CCA desorption Au (g) (7) coefficient near unity for Au-graphite and mobile surface atoms to explain fully how equilibrium could be achieved. If the first process dominated early in time or if gold was Finally, while even small irregularities in the time-dependent forced to hit the droplets to stick, then the absorbance signal heating program do not impact peak areas or Arrhenius-type would be larger than that observed during cooling owing to plots (if actual temperatures are used), they can easily produce the small probability of colliding with a droplet and an shoulders or secondary peaks on the absorbance profile which increased residence time in the gas phase.…”

Section: Effect Of Non-linear Temperature On Analysismentioning

confidence: 92%

Impact of non-linear heating on electrothermal atomic absorption spectrometry

Histen¹,

Holcombe²

1998

J. Anal. At. Spectrom.

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Section: Effect Of Non-linear Temperature On Analysismentioning

confidence: 92%

Impact of non-linear heating on electrothermal atomic absorption spectrometry

Histen¹,

Holcombe²

1998

J. Anal. At. Spectrom.

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“…Oxygen has been used to aid in the charring process (14). This causes a delay of analyte atomization due to chemisorbed O2 on the active carbon sites of the graphite furnace as determined by Holcombe's group (15). Chemical modification has helped to minimize matrix effects, but not to the extent that the need for standard additions has been removed.…”

Section: Methods For Reducing Matrix Effectsmentioning

confidence: 99%

Operating Principles

1982

Anal. Chem.

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“…A 200-µ horizontal slit was positioned 6 mm behind the entrance slit for spatially resolved studies. This arrangement produced maximum light transfer (12) and provided the spatial resolution vital to these experiments. Two 1-m focal length spherical mirrors in an over-and-under configuration were used to direct the hollow cathode radiation through the laser plume and spectrometer entrance optics.…”

mentioning

confidence: 99%

Time and spatially resolved atomic absorption measurements with a dye laser plume atomizer and pulsed hollow cathode lamps

Manabe¹,

Piepmeier²

1979

Anal. Chem.

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Time and spatially resolved atomic absorption measurements were made using a -µß dye laser beam to atomize solid samples of Cu, Al, and Pb alloys, steel, and graphite. Pulsed hollow cathode lamps with pulses as short as 1 ps were used as primary sources for the atomic absorption measurements. The Influences of sample chamber pressure were studied. The time-integrated, absorption spectral line profile of Cu In the plume was observed during the first 60 ps of the plume.Intense focused laser beams have been used as atomizers for atomic absorption spectroscopic analysis of solid samples by several investigators (1-7). Mossotti et al. (1) and Piepmeier (2) used Q-switched lasers to atomize the sample, and flash lamps as the primary light source. Karyakin and Kaigorodov (3) took advantage of the intense radiation emitted from the laser plume itself as the primary source and used the widths of self-reversed lines produced on film as an analytical signal. Osten and Piepmeier (4) and Vul'fson et al. (5) used pulsed hollow cathode lamps as primary sources. Hollow cathode lamps operated in the dc mode have been used as primary light sources by Matousek and Orr (6), who used a graphite furnace to aid atomization by a C02 TEA laser, and by Ishizuka et al. (7), who swept the atomized sample into an auxiliary observation chamber by a rapid flow of argon gas. The graphite furnace (6) and the auxiliary observation chamber (7) were designed to mask emission signals from the plume, which interfere with the observation of the absorption signal. The masking effectively reduced the plume emission signals relative to the dc hollow primary source signals, but did not entirely eliminate sample emission in all cases.Piepmeier and Osten (8) predicted from theoretical considerations that the intense continuum emission from the plume could be reduced by using a long laser pulse [of the same energy], and by using a laser with a shorter wavelength to reduce inverse Bremsstrahlung absorption of the laser energy in the plume, which tends to result in intense plasma emission. This study reports the results of using such a laser to atomize solid samples, and using long and short-pulse hollow cathode lamps as primary sources. The influence of the pressure of the gas in the sample chamber is studied. EXPERIMENTAL Laser Microprobe. The laser used in these experiments was a Chromabeam 1070 dye laser (Synergetics Research, Inc.). The lasing dye solution (1 X 10"4 M Rhodamine 6B in 95% ethanol) was circulated through the 1-cm bore of a coaxial flash lamp. The maximum energy for the l-µß laser pulse was 0.1 J. The maximum repetition rate was 3 pulses per min.The original laser trigger used an electromechanical relay in the primary circuit of a high voltage pulse transformer, similar to that used in a conventional automobile ignition system. The secondary circuit of the transformer was connected to the trigger

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Off-axis imaging for improved resolution and spectral intensities

Cited by 43 publications

References 3 publications

Impact of non-linear heating on electrothermal atomic absorption spectrometry

Impact of non-linear heating on electrothermal atomic absorption spectrometry

Operating Principles

Time and spatially resolved atomic absorption measurements with a dye laser plume atomizer and pulsed hollow cathode lamps

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