The challenges of Se quantification in bean samples using line and continuum sources atomic absorption spectrometry

This work demonstrates the challenges for selenium (Se) determination in bean samples using high-resolution continuum source Graphite Furnace Atomic Absorption Spectrometry (HR-CS-GF-AAS) and line source Graphite Furnace Atomic Absorption Spectrometry (LS-GF-AAS). Different chemical modifiers were optimized namely; Ir, Ru, and Pd/Mg nitrates. At selenium contents < 5 ng g(-1), it cannot be quantified accurately. Spectral interferences of the molecular bands of PO and NO as well as the iron lines with Se line at 196.026 were demonstrated. The noticeable low energy of the continuum source of the HR-CS-GF-AAS at 196.026 nm gives high values of the limits of detection and quantification. The Se limits of detection were found to be 24, 33, and 29 ng g(-1) for Ir, Ru, and Pd/Mg modifiers, respectively. In situ trapping hydride generation LS-GF-AAS gives better limits of detection and it reached 30 pg g(-1) with Ir modifier.