ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 55, Number 3
JKCSEZ 55(3)
June 20, 2011 

The concentration of selenium in grain samples was determined using isotope dilution method in ORC-ICPMS. The experimental conditions were optimized to H2 mode and the flow rate was 4.0 mL min-1. ORC in H2 mode proved to eliminate most of polyatomic interferences except BrH+ when Br is present in sample matrix. Chemical removal of Br was very difficult and the mathematical correction was successfully employed. The fraction of BrH+ generated from Br at the current experimental condition was 14.1%. The signal on m/z 82 was corrected and calculated for isotope dilution. The analytical reliability of the propose method was successfully evaluated by analyzing the certified standard reference material NIST SRM 1566 and 1567. The method was applied to real samples and the results are 0.034±0.001 μg g-1 for white rice, 0.059±0.0025 μg g-1 for brown rice, 0.029±0.0014 μg g-1 for black rice, and 0.034±0.002 μg g-1 for barley. The detection limits (3σ) for Se was 0.012 ng g-1.