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目的建立以0.3 mol/L硝酸为提取剂提取大米中4种砷形态(亚砷酸根AsⅢ、砷酸根AsⅤ、一甲基砷MMA和二甲基砷DMA)的液相色谱-原子荧光(liquid chromatography-atomic fluorescence spectrometry,LC-AFS)分析方法。方法在60℃条件下,超声40 min提取大米样品,上清液供LC-AFS测。比较2种提取方法对稻米中4种砷形态的提取效率,并对提取温度和提取时间等条件进行优化。结果 4种砷形态化合物的检出限为0.002~0.01μg/mL,加标回收率为89.03%~100.70%,RSD不大于4.36%(n=5)。结论此方法可以在1h时内完全分离大米样品中的四种砷形态,操作简单、灵敏,适用于大米中重金属砷的风险评估。
OBJECTIVE To establish a liquid chromatography - atomic fluorescence spectrometry (HPLC) system for the extraction of four arsenic species (As Ⅲ, As Ⅲ, MMA and DMA) in rice with 0.3 mol / L nitric acid as extractant -atomic fluorescence spectrometry, LC-AFS) method of analysis. Methods The rice samples were extracted by ultrasonic for 40 min at 60 ℃. The supernatant was collected for LC-AFS. The extraction efficiency of four kinds of arsenic species in rice was compared by two kinds of extraction methods. The extraction temperature and extraction time were optimized. Results The detection limits of four arsenic compounds ranged from 0.002 to 0.01 μg / mL. The spiked recoveries ranged from 89.03% to 100.70% with a RSD not greater than 4.36% (n = 5). Conclusion This method can completely separate four kinds of arsenic speciation in rice samples within 1h. The method is simple and sensitive, and is suitable for the risk assessment of heavy metal arsenic in rice.