The two commonly used light sources in Atomic Absorption Spectroscopy are Hollow Cathode Lamps and Electrodeless Discharge Lamps . In most laboratories hollow cathode lamps are in predominance due to their lower cost and convenience of use. However, electrode-less lamps provide improved sensitivities in analysis of several volatile elements.
As an analyst your main expectation is high accuracy and precision of results. This is possible through rigorous maintenance and calibration routines of laboratory equipments and volumetric glassware. A consistent light source which provides intense narrow width light is essential for any trace metal analysis using AAS technique. Several reputed manufacturers are there but Photron Pty Limited , an Australian manufacturer, provides lamps which meet the expectations of analysts and leave little to be desired.
Photron manufactures Hollow cathode lamps under the trade name-Super Hollow Cathode lamps which offer several desirable benefits over other conventional hollow cathode lamps which are briefly covered in the article.
Cost of Super lamps is in the same range as other popular hollow cathode lamps but at same time sensitivities upto 5-10 times better. The cost is lower than most electrodeless discharge lamps.
Adaptability with different makes of AAS
Super lamps can be conveniently used on different makes of AAS systems such as Perkin Elmer, Agilent, GBC, Analytical Jena,etc with affordable adaptor kits and Photron power supplies.
Long shelf life
Super lamps can be used for periods extending upto 5 years without observable drop in sensitivities.
Narrow line widths with low background interferences
Flexibility to use higher currents permits intense narrow lines with minimal background interference. A selection of slit widths can offer a wider linear range of analysis.
Short warm-up times
The design of Super lamps incorporates a secondary cathode which permits complete ionization of atoms. This helps in reduction of warm-up time and simultaneously lamp’s performance. When using double beam instrument it helps reduce warm up time and smaller warm- up is sufficient.
The only disadvantage of such lamps is that the useful life of some elements can get shortened as higher current can be passed but this single disadvantage far outweighs the advantages over conventional lamps.