In-situ preconcentration of volatile Se and Cd species in the dielectric barrier discharge (DBD) atomizer for subsequent analyte detection by atomic absorption spectrometry (AAS) was investigated. Quantitative trapping of selenium hydride in the DBD atomizer, followed by incomplete volatilization of trapped analyte species, was previously described in the simplest apparatus arrangement. In this work, two advanced constructions of both the DBD atomizer and its high voltage power supply source were tested to improve the preconcentration efficiency by increasing the volatilization efficiency of trapped Se species. Unfortunately, no significant improvement was found. The overall preconcentration efficiency ranged between 60 and 70% regardless of the apparatus set-up. In contrast to Se, in-situ trapping of volatile Cd species in the DBD atomizer for AAS was optimized for the first time in this work. Quantitative Cd trapping was observed at 17.5 kV with 3.5 mL min-1 O2 admixed to 300 mL min-1 Ar, while complete analyte release was achieved at 25.2 kV with 75 mL min-1 Ar. The preconcentration efficiency was quantified to 98 ± 7%. The sample loop volume was optimized to 0.15 mL, as higher sample volumes unfortunately led to a significant decrease in preconcentration efficiency due to analyte loss during the prolonged trapping step.