火焰原子吸收法快速测定安康紫阳富硒茶中的微量硒

目的]为获得生物态有机硒提供依据。方法]建立火焰原子吸收法测定安康紫阳富硒茶中微量硒含量的新方法。结果]紫阳富硒茶中硒含量为2.033~2.885 mg/kg,高于普通茶叶,但其分布不均匀。以硫酸为空白对照,吸取不同浓度的样品溶液,在波长196.09nm处测定其吸光度,其回归方程为y=0.004x+0.002(R=0.997 8),其线性范围为0~40.00 mg/L。直接添加100 ml混酸HNO3-HClO4作为分解剂,湿法硝化分解安康市紫阳地区富硒茶叶效果显著。在样品中加入基体改进剂Ni(NO3)2,可使吸光度和稳定性明显提高,并排除Fe、Mg、K、NaS、O42-的干扰。结论]使用该方法测定茶叶中的硒含硒量,结果准确可靠,对其在生产中的应用具有指导作用。

Rapid Determination of Se in Se-enriched Tea in Ziyang area of Ankang City by Using Flame Atomic Absorption Spectrometry

Objective] The aim of the research was to provide basis for obtaining biological state of organic Se.Method] The new method of flame atomic absorption spectrometry(FAAS) for determining Se content in Se-enriched tea in Ziyang area of Ankang city was established.Result] Se content in Se-enriched tea in Ziyang area was 2.033～2.885 mg/kg,higher than that in common tea.But its distribution was not even.With sulfuric acid as blank control,sample solution at different concn.were absorbed to determine its absorbance at the wavelength of 196.09 nm and its regression equation was y=0.004x+0.002(R=0.997 8)with its linear range of 0～40.00 mg/L.Adding 100 ml mixed acid with HNO3 and HClO4 as resolvent reagent,the effect of discomposing Seenriched tea in Ziyang area of Ankang city was significant.Adding matrix modifier Ni(NO3)2 to samples could make the absorbance and stability obviously increase and get rid of the disturbance of Fe,Mg,K,Na and SO42-.Conclusion] Determining Se content in the tea by this method,the results were exact and credible,which had the guiding action on its application in the production.