8/27/2023 0 Comments Modulation of hollow cathode lamp![]() High-frequency modulation of the hollow-cathode lamp was applied to eliminate the influence of furnace emission on Zeeman-effect AAS signals. components of the radiation emitted by the furnace wall cause systematic errors in the ZAA signal and also contribute to the noise. The enhancement is much more pronounced in integrated absorbance than in peak absorbance. Under the optimum condition, the laser frequency at 399 nm can be stabilized. The error signal for frequency locking is optimized by measuring the dependences of its slope, linewidth and magnitude on various parameters. When furnace emission is present, the ZAA:AAS ratio is increased. The modulation transfer spectroscopy in an ytterbium hollow cathode lamp at 399 nm is measured. The ratio of the absorbances, ZAA:AAS, is equal in peak height and in integrated absorbance in the absence of furnace emission. The ratio of the signals measured with Zeeman-effect background-corrected atomic absorption spectrometry (ZAA) and atomic absorption spectrometry without Zeeman-effect background correction (AAS), depends on the contribution of the furnace emission intensity to the measured intensities. continuum-source or deuterium lamp background correction, Zeeman background correction, pulsed lamp or SmithHieftje background correction and wavelength-modulation correction methods. components, independent of the total amount of furnace emission that reaches the detector. The total or gross absorbance is measured at the wavelength of the resonance line emitted by the hollow cathode lamp. Hollow cathode lamps (HCL) are discharge lamps designed for use in Atomic Absorption (AA) instruments. A lamp is required for each element, although. The emission line selected must avoid wavelength overlaps, and have good intensity with low noise. AAS lamps utilize the hollow cathode effect to generate light at wavelengths for the element of interest. The metal in the lamp is subjected to an electric current, causing it to emit. A hollow cathode lamp is used as a spectral line source for Atomic Absorption (AA) instruments. About 8% of the radiation emitted by the wall of the graphite furnace consists of a.c. The method involves using hollow cathode lamps containing the metal of interest.
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