【摘要】 在2.4 mol/L HCl介质中,Se(Ⅳ)与过量的硫氰酸铵反应析出单质硒,并形成稳定的悬浊液,据此建立了比浊法测定硒的新方法。实验了酸度、还原剂用量、温度和时间的影响,确定了最佳测定条件。选择测定波长为320 nm,线性范围为0~0.25μg/mL,检出限为0.0294μg/mL。方法用于测定硒强化营养盐和健康平衡盐中硒含量,结果与荧光法一致,相对标准偏差小于1.6%(n=5),平均回收率为100.0%~101.4%。更多还原

【Abstract】 A new nephelometric method was developed for the determination of selenium.The proposed method is based on the reaction of Se(Ⅳ) with excess ammonium thiocyanate in 2.4 mol/L HCl medium to liberate elemental selenium,and form stable suspension.The optimal conditions of measurements of Se(Ⅳ) including acidity,reductant concentration,temperature and time were studied.The detection wavelength was chosen at 320 nm.The linear range for determination of selenium was 0～0.25 μg/mL.The detection limit was 0.0294 μg/mL.The proposed method was applied to determining selenium in salt fortified with selenium and health balance salt.The results are in good agreement with those obtained using the fluorometric method.RSD was less than 1.59%(n=5),and average recoveries varied from 100.0% to 101.4%.更多还原