Yun Hongxiao, Zhang Lei, Li Xiaowei, Zhao Yunfeng, Wu Yongning
College of Animal Medicine, China Agriculture University, Beijing 100193, China.
Wei Sheng Yan Jiu. 2010 May;39(3):316-20.
To develop a method for the determination of inorganic arsenic (As(i)) in rice and to provide the basis for revising the national standard method GB/T 5009.11 "Determination of Inorganic Arsenic in Food". To compare the extracting ability of trifluoroacetic acid (TFA) under different concentrations and the different time for extracting samples. To evaluate the pollution of rice sampling from different original production places.
Inorganic arsenic of rice was extracted under heating at 80tC by trifluoroacetic acid. The supernatant was concentrated to dryness by centrifuging, and then dissolved in the solution for mobile phase by ultrasonication. Passed through RP cartridge and filter, the sample solutions were ready for analysis. The mobile phases were 1 mmol/L NH4H2PO4 solution and 20 mmol/L NH4H2PO4 solution. As were separated with an anion exchange column, Hamilton PRPX-100, and detected by liquid chromatography-atomic fluorescence spectrometry (LC-AFS).
Extraction with 3% TFA (v/v) and heating for 2 h were desirable for the pre-treatment of samples. The results meet the reference value of As.
This method is suitable for the analysis of inorganic arsenic in rice. The inorganic arsenic content of samples collected from original production places did not exceed the limit standard.
建立大米中无机砷（As(i)）的测定方法，为修订国家标准方法GB/T 5009.11《食品中无机砷的测定》提供依据。比较不同浓度三氟乙酸（TFA）及不同提取时间对样品的提取能力。评估不同产地大米样本的污染情况。
大米中的无机砷用三氟乙酸在80℃加热提取。上清液经离心浓缩至干，然后超声溶解于流动相溶液中。通过反相柱和过滤后，样品溶液即可进行分析。流动相为1 mmol/L NH4H2PO4溶液和20 mmol/L NH4H2PO4溶液。用阴离子交换柱Hamilton PRPX - 100分离砷，并用液相色谱 - 原子荧光光谱法（LC - AFS）检测。
用3%（v/v）TFA提取并加热2 h对样品预处理较为理想。结果符合砷的参考值。
该方法适用于大米中无机砷的分析。从产地采集的样品中无机砷含量未超过限量标准。
