高效液相色谱等离子质谱联用分析食品中的主要有机砷和无机砷(英文)

Speciation Analysis of Arsenic in Food Samples with High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry

应用液相色谱 等离子质谱联用的方法分析食品样品中的主要有机砷 (一甲基砷和二甲基砷 )和无机砷 (三价砷和五价砷 )。采用 5 0 % (体积分数 )甲醇水溶液作为萃取剂 ,将食品样品进行预处理 ,再以 5mmol/L四丁氢铵 ,2mmol/L丙二酸和 5 % (体积分数 )甲醇水溶液作为流动相 (pH 5 9) ,C18色谱柱 (15 0mm× 4mmi d ,5 μm)将样品萃取液进行液相色谱分离 ,最后进入等离子质谱仪定性分析。经测定发现 ,新鲜蔬菜和水果样品中主要含有的无机砷为三价砷和五价砷 ,有机砷为二甲基砷。一甲基砷在个别样品中也有发现。该法的检出限分别为 :三价砷 0 2μg/kg,五价砷 0 6 μg/kg和二甲基砷 0 3μg/kg。

The speciation of arsenic in food samples was analyzed. The methods used for sample preparation include: the extraction of arsenic from food samples using a 1∶1 (v/v) methanol/water, and high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC ICP MS) determination of the speciation of arsenic in food samples. A C18 column was used to separate the arsenic species. The mobile phase consists of 5 mmol/L tetrabutylammonium hydride, 2 mmol/L malonic acid and 5% (v/v) methanol solution with the pH adjusted to 5 9. The mobile phase flow rate was 1 2 mL/min . The chemical species of arsenic present in the foodstuffs were found mainly As (Ⅲ), As (Ⅴ), dimethylarsinic (Ⅴ) (DMA (Ⅴ)). Detection limit was based on signal to noise ratio of 3. As to apple samples, the detection limits were 0 2, 0 6 and 0 3 μg/kg for As (Ⅲ), As (Ⅴ) and DMA (Ⅴ), respectively. The concentrations of arsenic in raw apple samples were calculated.