建立了富硒米中硒含量的紫外分光光度测定方法。在酸性介质中采用S e4＋与邻苯二胺发生络合反应生成3，4‐苯并‐1，2，5‐重氮苤硒脑，以甲苯溶液萃取，测定Se4＋的含量。考察了检测波长、邻苯二胺加入量、还原剂用量、p H、反应时间对测定结果的影响。在最佳测定条件下，其标准曲线在0.15～6.0μg／m L范围内呈线性关系，回归方程为 A＝0.1213 C＋0.0062，线性相关系数 R＝0.9984。方法回收率为98.38％～106.3％，R S D为0.7713％。该方法操作简便，灵敏度高，费用低廉，可用于富硒米中硒含量的分析。%An UV Spectrophotometric method for the determination Se of in the enriched rice was established in this research .The method was based on the fact that Se4+ could react with o‐phe‐nylenediamine to form 3 ,4‐benzo‐1 ,2 ,5‐diazopiazselenole in sulfuric acid medium ,after extracted by toluene ,with which the solution was determined .In order to obtain optimal determination results , 5 crucial determination parameters , including detection wavelength , complex development time , amounts of complex reagent and reducing agent , pH were investigated . Results showed that the optimal values of the above parameters were as follows :detection wavelength 333 nm ,o‐phenylenediamine amount 4.0 mL ,hydroxylamine hydrochloride amount 2.0 mL ,EDTA amount 1.0 mL ,pH 4.0 ,and complex development time 120 min .Under these conditions ,a good liner relationship between absorbance(A) and Se4+ concentration(C) in the range 0.15~6.0μg/mL was observed ,which could be expressed as A=0.121 3C+0.006 2 ,(r=0.998 4) ,recovery rate 98.38% ~106.3% ,RSD 0 .7713% .The method has the merit of easy operation ,good sensitivity ,and low Toxicity ,which could be applied to indirect determination of the Se4+ in the enriched rice .
展开▼
