固相萃取-氢化物产生-原子荧光光谱法检测 大米中总砷的含量

Determination of total arsenic in rice by solid-phase extraction-hydride gerneration-atomic fluoerence spectrometry

中文关键词:  UIO66  氢化物发生-原子荧光光谱法  大米  总砷

英文关键词:UIO66  hydride generation - atomic fluorescence spectrometry  rice  total arsenic

中文摘要:

      目的 建立基于UIO66材料分散固相萃取体系的提取大米中总砷, 并采用氢化物产生-原子荧光光谱法检测其含量。方法 以7 mL 0.06 mol/L HNO3+3%H2O2为消解液, 在最大微波功率800 W下, 180 ℃微波消解20 min, 提取大米中的总砷, 通过金属有机骨架材料UIO66实现大米提取液中总砷的分离净化, 最后采用氢化物产生-原子荧光光谱法进行总砷含量测定。结果 在10~80 μg/kg浓度范围内, 总砷的标准曲线方程线性良好(相关性系数r2=0.9997), 最低检出限(limit of detection, LOD)为0.024 μg/kg, 样品加标回收率在93.4%~107.8%之间, 相对标准偏差<2%。7种大米样品中的总砷含量在150~250 μg/kg之间, 其中糙米中总砷含量最高(244.53±4 μg/kg), 东北地区产大米与南方地区产大米的总砷含量存在显著性差异(P<0.05)。结论 基于UIO66分散固相萃取体系的大米中总砷分离分析方法具有高灵敏度、低成本、易操作的特点, 可有效实现大米中总砷的净化和定量分析。

英文摘要:

      Objective To establish UIO66 material dispersive solid-phase extraction system for extraction of the total arsenic in rice and detect its content by chemical generation-atomic fluorescence spectrometry. Methods Using 7 mL 0.06 mol/L HNO3+3%H2O2 as the digestion solution, the total arsenic in the rice was extracted by microwave digestion at 180 °C for 20 min at the maximum microwave power of 800 W, and the total arsenic in rice extract was separated and purified by metal organic framework material UIO66. Finally, the total arsenic content was determined by hydride generation-atomic fluorescence spectrometry. Results The standard curve of total arsenic in the range of 10-80 μg/kg showed a good linearity with the correlation coefficient of 0.9997. The limit of detection (LOD) was 0.024 μg/kg, and the recoveries of sample addition were 93.4%-107.8% with the relative standard deviations (RSDs) below 2.0%. The contents of total arsenic in different kinds of rices were in the range of 150-250 μg/kg, while the brown rice had the highest total arsenic content (244.53±4 μg/kg). There was a significant difference in total arsenic content between rice grown in northeast China and rice grown in south China (P<0.05). Conclusions The method of separating and analyzing total arsenic in rice based on UIO66 dispersive solid-phase extraction system has the characteristics of high sensitivity, low cost and easy operation, which can effectively realize the purification and quantitative analysis of total arsenic in rice.