中文摘要：

利用甲醇．水（1：1，V／V）超声萃取、微波辅助HNO，萃取和磷酸盐缓冲液（PBS）超声萃取等3种前处理方法对大米、海藻和苹果汁等3种样品中不同形态砷进行萃取．结果表明，低砷含量大米（砷含量〈15μg．kg^-1）应选用甲醇-水进行砷萃取，萃取率达85％-94％，砷形态不发生变化．高砷含量大米（砷含量〉150μg．kg^-1）应选用微波辅助HNO3进行砷萃取，其萃取率可达78％．海藻样品应选微波辅助HNO3法，萃取率高达87％．苹果汁应选用微波辅助HNO3或PBS溶液萃取法．实验结果与41个国际实验室对相同样品的分析数据基本一致，说明本实验所得结论可信度较高．高砷含量大米（砷含量〉150μg．kg^-1）萃取过程中砷形态易发生变化，海藻及苹果汁砷形态基本保持稳定，三者砷形态分析应优先选用微波辅助HNO3法．

英文摘要：

Arsenic （As） species in rice, kelp and apple juice were analyzed by methanol-water （1：1, V/V） ultrasonic extraction, microwave assisted HNO3, and phosphate buffer saline （PBS） method, respectively. Results indicated that when As content was less than 150μg.kg^-1 in rice, 85%-94% extraction efficiency was achieved using methanol-water ultrasonic extraction method, and the As speciation remained unchanged after extraction. HNO3 method should be chosen for rice sample containing high As （〉150μg.kg^-1）, and the extraction efficiency was 78%. The As extraction efficiency reached 87% for kelp samples using HNO3 extraction method. Both HNO3 and PBS method could be used for As extraction in apple juice. The data obtained in this study are in accordance with those collected from 41 international laboratories for the same samples, which demonstrats the reliability of our conclusions. In conclusion, arsenic species is easy to change in high arsenic content rice but nearly stable in kelp method of microwave assisted HNO3 extraction analysis of rice, kelp and apple juice. and apple juice through the extraction process. The should be preferentially applied to arsenic speciation