硫代苹果酸功能化的纳米银分光光度法测定面制食品中铝含量

Spectrophotometric Determination of Aluminum in Flour Foods with Silver Nanoparticles Functionalized by Thiomalic Acid

制备了硫代苹果酸功能化的银纳米颗粒(TMA-AgNPs),随着Al3+浓度的增加,TMAAgNPs上的功能基团与Al3+发生相互作用导致TMA-AgNPs的聚集,溶液颜色由黄色逐渐变为橘红色,据此采用分光光度法测定面制食品中铝含量。优化的试验条件如下:①5.0mmol·L^-1硫代苹果酸溶液的用量为2mL;②修饰反应时间为10min;③Al3+与TMA-AgNPs的作用时间为2min。Al3+的线性范围为0.10~5.00μmol·L^-1,检出限(3S/N)为0.031μmol·L^-1。方法用于面制食品样品的分析,加标回收率为97.0%~105%,测定值的相对标准偏差(n=5)为2.1%~3.1%。

Silver nanoparticles(TMA-AgNPs)functionalized by thiomalic acid were prepared.The interaction between the functional groups of the TMA-AgNPs and Al3 +resulted in the aggregation of TMA-AgNPs accompanied by a color change from yellow to orange with increase of Al3 +ion concentration.Based on this fact,spectrophotometry was applied to the determination of aluminum in flour foods.The optimized conditions found were as follows:① amount of 5.0 mmol·L^-1 thiomalic acid solution was 2 mL;② modification reaction time was10 min;③ interaction time of Al3 +and TMA-AgNPs was 2 min.Linearity range of Al3 +was found between0.10μmol·L^-1 and 5.00μmol·L^-1 with detection limit(3 S/N)of 0.031μmol·L^-1.The proposed method was applied to the analysis of samples of flour foods,giving values of recovery found by standard addition method and RSDs(n=5)of determined values in the ranges of 97.0%-105% and 2.1%-3.1%respectively.