紫外分光光度法测定紫阳富硒茶中的硒.pdf

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西北农业学报 2009 ,18 (4) :229 232
A cta A griculturae B oreali occi dentalis S inica
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紫外分光光度法测定紫阳富硒茶中的硒
周跃花, 杨菊香, 张娜
(西安文理学院化学系,陕西西安 710065)
摘要: 采用紫外分光光度法,以邻苯二胺为络合剂,室温下,Se4 + 与邻苯二胺生成 3 , 4 苯并 1 , 2 , 5 重氮苤
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硒脑,反应后甲苯萃取,在波长 335 nm 下测定其吸光度。本方法用于研究紫阳富硒茶叶中硒含量的测定。
结果表明,该方法的最佳测定条件为 p H 1. 5~2. 5 ,1 %邻苯二胺和 5 % EDTA 用量均为 2. 0 mL ,反应 60
min ,萃取3 8 min。硒含量在 1~5μg 线性良好,相关系数为 0. 9983 ,相对标准偏差为 1. 13 %。该方法操作简
便,成本低廉,可测定茶叶和食品中的硒含量。
关键词: 紫外分光光度法;富硒茶;硒;测定
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中图分类号:O657. 32 文献标识码: A 文章编号:1004 1389 (2009) 04 0229 04
Determination of Selenium of Enriched Tea in
Ziyang by UV Spectrophotometry
ZHOU Yuehua , YAN G J uxiang and ZHAN G Na
(Department of Chemistry , Xi’an University of Arts and Science , Xi’an Shaanxi 710065 , China)
Abstract : plex reagent using o p henylenediamine and Se4 + was allowed to react at room tem
perat ure , which made t he formation of 3 , 4 benzo 1 , 2 , 5 diazopiazselenole. After extracted by tolu
ene , the solution was used to determine t he absorbance values at 335 nm by UV spectrop hotometry.
The met hod was developed for determination of selenium of enriched tea in Ziyang. The result s is
shown t hat t he optimal conditions is 2. 0 mL of 1 % o p henylenediamine and 2. 0 mL of 5 % ED TA in
p H 1. 5~2. 5 for reacting 60 min , extracting 8 min. This met hod had a good linear