Diffusion flame, heated quartz tube or dielectric barrier discharge? Comparing the resistance of hydride atomizers towards interferences with detection by atomic absorption spectrometry

Abstract

The resistance of three types of hydride atomizers towards interferences from other hydride forming elements and mercury was comprehensively investigated. Four hydride forming elements (Pb, Bi, Se and Te) were used as model analytes while seven hydride forming elements and mercury were investigated as potential interferents. The atomizers studied were based on a diffusion flame - DF, an externally heated quartz tube (multi)atomizer - (MM)QTA as well as a dielectric barrier discharge plasma - DBD. The performance of even two designs of DBD atomizers was compared. The first configuration (REF-SIN) was realized by a DBD chamber with glued electrodes coupled to a power supply source with sinusoidal modulation of high voltage. The second configuration of the DBD atomizer (SE-SW) comprised of a DBD chamber with the sputtered electrodes powered by a square-wave modulated high voltage source. The DF atomizer was found to be the most robust towards atomization interferences. However, its sensitivity was 30 to 50 times lower compared to (MM)QTA and DBD based atomizers due to its short optical path. The DBD atomizer in REF-SIN arrangement can compete very well with (MM)QTA atomizer in terms of resistence to interferences as well as sensitivity. The resistence of DBD atomizer in SE-SW configuration towards atomization interferences is slightly worse compared to (MM)QTA and DBD in REF-SIN design.