ABSTRACT
Selenium (Se) is an essential trace element in humans and animals. Se content in the crust of the Earth is unevenly distributed, and it can be divided into available and unavailable Se. Se was determined by using hydride generation–atomic fluorescence spectrometry. All acids used in pre-treatment were of excellent grade, and the reliability of the results was verified by the National Standards substance. Ten of 19 tested samples were Se-deficient, whereas eight samples had medium Se content. Only one region has Se-rich soil, but its Se content was close to the lower limit value. However, the percentage of water-soluble Se in total Se in different soil types was 0.70–7.18%. Exchangeable Se was similar to water-soluble Se. The total Se content of soils represented the potential level of Se available. The total Se content in soil in Heilongjiang Province was generally low. Residual Se and organic Se were the main Se fractions in low Se soils, followed by acid-soluble Se.
