富硒农产品中有机硒的分离与测定

Separation and determination of organic selenium in selenium-enriched agricultural products

目的建立富硒农产品中总有机硒的分离与测定方法。方法通过粉碎、均质、离心及环已烷萃取将富硒农产品中的有机硒与无机硒分离,分离后的试样经消解、赶酸后在最隹仪器条件下用原子荧光光谱法测定总硒和无机硒,差减法计算出总有机硒的含量。结果均质离心分离后,环已烷对水溶性有机硒的萃取率为96%,测定方法回收率为86.68%~113.48%,检出限为0.02 ng/mL,相对标准偏差(relative standard deviation,RSD)为5.14%。结论方法操作简单、无需有机硒标准品、检测周期短、样品普适性强,适用于初级农产品、加工农产品、保健品、发酵产品等4类富硒农产品的中总有机硒的测定。

Objective To establish a method for the separation and determination of total organic selenium in selenium-enriched agricultural products. Methods The organic selenium and inorganic selenium in selenium-rich agricultural products were separated by crushing, homogenizing, centrifugation and cyclohexane extraction. The total selenium and inorganic selenium were determined by atomic fluorescence spectrometry in the best instrument conditions after digestion and acid driving, and the total organic selenium content was calculated by subtraction method. Results After the homogeneous and centrifugation, the extraction rate of cyclohexane to water-soluble organic selenium was 96%, the recovery rates of the method were 86.68%?113.48%, the limit of detection was 0.02 ng/mL and the relative standard deviation (RSD) was 5.14%. Conclusion This method is simple to operate, no need of organic selenium standard substances, short detection period, and strong universality of samples, which is suitable for the determination of total organic selenium in 4 kinds of selenium-rich agricultural products, such as primary agricultural products, processed agricultural products, health products, fermented products and so on.