Effect of Selenium-enriched Organic Fertilizers on Selenium and its Form in Garlic

An effective method was developed for determination of selenium of different forms in selenium-enriched garlic by high resolution-continuum source graphite furnace atomic absorption spectrophotometry（HR-CS GFAAS）.Effect of selenium-enriched organic fertilizers on selenium and its form in garlic was studied.The mixture of Pd（NO3）2（1 g/L）and Mg（NO3）2（0.5 g/L）was selected as the matrix modifier with the best volume of 5 μL for determination of selenium by single factor experiments.The samples were pretreated according to the standard of DBS 42/002—2014，and further determination of selenium by HR-CS GFAAS，results showed that the total selenium in selenium-enriched garlic was 8.933～9.476 μg/g，and inorganic selenium in selenium-enriched garlic was 5.784～6.021 μg/g.The organic selenium in selenium-enriched garlic was 3.124～3.491 μg/g by calculating，and had reached 34.16%～36.84% of total selenium.These indicated that total selenium and organic selenium in garlic were increased effectively by using selenium-enriched organic fertilizers as garlic grow.The relative standard deviations were from 3.0% to 5.2%，and the recoveries for total selenium and inorganic selenium were 96.3% and 93.7% respectively，indicating that selenium and its form in selenium-enriched garlic by the standard of DBS 42/002—2014 could get accurate and reliable results，moreover，the added prototype（inorganic selenium）was almost all in the inorganic selenium sample.Therefore，the proposed method was rapid，accurate and stable with a high practical value.It provided scientific basis for analysis of many trace elements and their forms in food.