浓度直读法快速测定南瓜、莴笋中氟的含量

Rapid determination of fluoride content in pumpkin and lettuce by concentration direct reading method

目的为建立一种快速、简便测定蔬菜中氟含量及其分布的新型分析方法。方法以南瓜、莴笋为样品,利用超声波辅助浸提,氟离子选择性电极浓度直读法测定。结果氟电极的转化系数为90.53%,样品平行测定(n=5)的相对标准偏差RSD【3%,回收率在91.6%~99.4%之间,该方法的检出限和定量限分别为0.83和2.70μg/L。结论氟在莴笋和南瓜不同组织的分布为从外到内依次减少,郑州莴笋尖干基氟含量最高为8.56μg/g。该方法具有快速、方便、实用性强、对环境污染较小等优点,适合现场批量快速测定。

Objective To establish a rapid, simple and new analysis method for determination of fluorine content in vegetables, and to study its distribution.Methods With pumpkin and lettuce as samples, they were extracted with ultrasonic, and the concentration and distribution of fluoride in solution were determined by a direct reading the with fluoride ion selective electrode.Results The conversion coefficient of fluorine electrode was 90.53%, the relative standard deviation (RSD)<3% that based on the samples parallel determination (n=5), standard addition recovery was between 91.6%~99.4%, the method of the detection limit was 0.83μg/L and the quantitation limit was 2.70μg/L.Conclusion The fluorine distribution is reduced in different organizations of pumpkin and lettuce from outside to inside gradually, the maximum fluorine content was 8.56μg/g in Zhengzhou lettuce tip dry. This method is fast, convenient and strong practicability, with a less pollution to the environment, which is suitable for mass rapid determination.