Gong Jiadi, Cao Xiaolin, Cao Zhaoyun, Bian Yingfang, Yu Shasha, Chen Mingxue
Se Pu. 2014 Jul;32(7):717-22. doi: 10.3724/sp.j.1123.2014.03015.
A method was developed for the simultaneous determination of arsenic acid [As (V)], arsenious acid [As (III)], arsenobetaine (AsB), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in rice by liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). The extraction reagent was 0.3 mol/L nitric acid with heat-assistant condition for 1.5 h at 95 degrees C. Then, the five arsenic species were separated by an anion exchange column (Dionex IonPac AS19, 250 mm x 4 mm) and detected by ICP-MS. Four kinds of extracted solutions were compared through the extraction efficiency. The concentration of nitric acid, the temperature and the extraction time were optimized. The recoveries of the five arsenic species spiked in rice at two levels ranged from 89.6% to 99.5% with the relative standard deviations (RSDs, n = 5) of 0.6% - 3.6%. The measured values of the arsenic species in standard rice materials were consistent with their standard values. The linear ranges were 0.05 - 200 microg/L for AsB and DMA, 0.10-400 microg/L for As (III) and MMA, 0.15-600 microg/L for As (V). The limits of detection for the five arsenic species were 0.15-0.45 microg/kg. The results showed that the method is much more precise for the risk assessment of the rice. This method is simple, accurate and durable for the determination of arsenic species in rice.
建立了一种液相色谱-电感耦合等离子体质谱法（LC-ICP-MS）同时测定大米中砷酸[As（V）]、亚砷酸[As（III）]、砷甜菜碱（AsB）、一甲基砷酸（MMA）和二甲基砷酸（DMA）的方法。提取试剂为0.3 mol/L硝酸，在95℃热辅助条件下提取1.5 h。然后，通过阴离子交换柱（Dionex IonPac AS19，250 mm×4 mm）分离5种砷形态，并用电感耦合等离子体质谱仪进行检测。通过提取效率比较了4种提取液。对硝酸浓度、温度和提取时间进行了优化。大米中添加的5种砷形态在两个加标水平下的回收率为89.6%～99.5%，相对标准偏差（RSD，n = 5）为0.6%～3.6%。标准大米材料中砷形态的测定值与标准值一致。AsB和DMA的线性范围为0.05 - 200 μg/L，As（III）和MMA为0.10 - 400 μg/L，As（V）为0.15 - 600 μg/L。5种砷形态的检出限为0.15 - 0.45 μg/kg。结果表明，该方法用于大米风险评估更为精确。该方法简单、准确、耐用，可用于大米中砷形态的测定。
