Microchim Acta 150, 1–8 (2005) DOI 10.1007/s00604-005-0330-y Original Paper Determination of Total Selenium Content in Cereals and Bakery Products by Flow Injection Hydride Generation Graphite Furnace Atomic Absorption Spectrometry Applying in-situ Trapping on Iridium-Treated Graphite Platforms Zsolt Ajtony 1 , Norbert Szoboszlai 2 , Zsuzsanna Bella 1 , Szilvia Bolla 1 , Pa ´l Szaka ´l 1 , and La ´szlo ´ Bencs 3;4; 1 Department of Food Quality Assurance, University of West Hungary, Lucsony u. 15-17., H-9200 Mosonmagyaro ´va ´r, Hungary 2 Department of Inorganic and Analytical Chemistry, Lora ´nd E€ otv€ os University of Sciences, P.O. Box 32, H-1518 Budapest, Hungary 3 Department of Chemistry, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, B-2610 Antwerp, Belgium 4 Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest, Hungary Received August 25, 2004; accepted November 19, 2004; published online March 31, 2005 # Springer-Verlag 2005 Abstract. A flow injection hydride generation graph- ite furnace atomic absorption spectrometric (FI-HG- GFAAS) method was applied to the determination of Se in Se-doped and undoped cereals and bakery pro- ducts. For the purpose of doping, the soils used for the cultivation of the cereals were dosed with Se-doped foliar fertilizers. The samples were dissolved in a mix- ture of HNO 3 and H 2 O 2 solutions using microwave- assisted digestion. The decomposition of H 2 Se generated from the sample solutions and the trapping of elemental Se were performed at a temperature of 300  C on an Ir-pretreated integrated graphite platform of a transversally heated graphite atomizer (THGA). For release of the trapped Se within a fairly short atomiza- tion time (5 s), an atomization temperature of 2200  C was observed to be optimal. The overall efficiency of hydride generation, transport and trapping was 86%. The upper limit of the linear dynamic range of cali- bration was 10 mgL 1 , which corresponds to 0.5 mgg 1 for solid samples. Recovery of the samples spiked with Se VI solutions was found to be 93  6% on average. The relative standard deviation of the determinations was less than 8%. The limit of detection was found to be 0.06 mgL 1 , corresponding to 3 ng g 1 for solid samples. The accuracy of the method was verified with the use of IAEA-155 (whey powder) certified reference material. End-capped THGA tubes resulted in an ex- tension of the linear calibration range compared to that of standard THGAs. The Se content in bakery products made of undoped cereals ranged from 7.7 to 68 ng g 1 (wet weight) in 18 samples, whereas the Se content of the corresponding cereals was found to be below 100 ng g 1 (wet weight). The Se level of cereals grown on soils treated with Se-doped fertilizers ranged from 128 to 1046 ng g 1 (wet weight), and it depended linearly on the Se con- centration of the corresponding foliar fertilizer. Key words: Se determination; hydride generation; electrothermal atomic absorption spectrometry; in atomizer trapping; permanent modifier; food analysis; nutrients. Selenium is an essential trace element of the human body [1]. It is incorporated in a number of active selenoproteins, including the glutathione peroxidase  Author for correspondence. E-mail: bencs@szfki.hu