In atomic absorption spectroscopy, which lamp provides a line source for UV and visible?

In atomic absorption spectroscopy, which lamp provides a line source for UV and visible?

• A. Tungsten Lamp
• B. Deuterium Lamp
• C. Hollow Cathode Lamp
• D. Mercury Lamp

Answer: (C)

In atomic absorption spectroscopy, the lamp used as a line source emits photons at specific wavelengths that match the element’s atomic transitions. A hollow cathode lamp achieves this by using the element of interest as the cathode; when energized, it sputters atoms of that element into the discharge, producing sharp, element-specific emission lines in the UV–visible range. These narrow lines align with the absorption wavelengths of the same element in the sample, enabling precise, selective measurement with high sensitivity. Broad-spectrum sources like tungsten emit across a wide range without sharp lines, deuterium lamps provide UV continuum rather than discrete lines, and while mercury lamps have lines, they are not tailored to the analyte in use. Therefore, the hollow cathode lamp is the best choice for producing the needed line source.

In atomic absorption spectroscopy, the lamp used as a line source emits photons at specific wavelengths that match the element’s atomic transitions. A hollow cathode lamp achieves this by using the element of interest as the cathode; when energized, it sputters atoms of that element into the discharge, producing sharp, element-specific emission lines in the UV–visible range. These narrow lines align with the absorption wavelengths of the same element in the sample, enabling precise, selective measurement with high sensitivity.

Broad-spectrum sources like tungsten emit across a wide range without sharp lines, deuterium lamps provide UV continuum rather than discrete lines, and while mercury lamps have lines, they are not tailored to the analyte in use. Therefore, the hollow cathode lamp is the best choice for producing the needed line source.