磁性纳米四氧化三铁选择性富集-电感耦合等离子体原子发射光谱测定砷

Nanomagnetic Material Ferriferrous Oxide Separation/Enrichment and Inductively Coupled Plasma-Atomic Emission Spectrometry for Determination of Arsenic

基于磁性纳米Fe3O4对砷的选择性富集作用,建立了电感耦合等离子体原子发射光谱(ICP-OES)测定水溶液中砷的方法。考察了溶液酸度、吸附时间、吸附剂用量、试液体积和共存离子等因素对不同形态砷分离富集效率的影响。结果表明,在pH2～10范围内,选用6.0 mg纳米Fe3O4定量富集,振荡2 min后,三价砷、五价砷、一甲基砷以及二甲基砷等均可被磁性纳米Fe3O4定量富集。线性范围为0.063～20 mg/L;检出限(3σ)为0.0189 mg/L;对砷标准溶液测定的相对标准偏差为1.27%(n=6)。用本方法对自来水中加入的砷标准溶液进行了测定,回收率为100.3%～104.8%。本方法简便快速,可用于复杂基体中低含量砷的富集分离和测定。

Using a magnetic separation teehnique, the novel separation and preeoneentration technique for the determination of trace As in water samples was established. Arsenic levels can be determined by ICP-AES. The adsorption behavior of arsenic speciation on nanomagnetic material Fe3O4 was investigated, pH values for solution, time of adsorption, amounts of adsorbent, volumes of solutions and the co-existent ions were considered. At pH 2 - 10, As （Ⅲ） , As （ Ⅴ ） , monomethylarsenie （MMA） and dimethylarsenie （DMA） were retained on 6.0 mg nanomagnetic Fe3O4 after shaking 2 min. Extractions were performed in test tubes eontaining 10 g arsenic ions at pH 5, using 6.0 mg nanomagnetie material Fe3O4. They are attraeted to a magnetie field and can be separated from solution within a minute with a magnet. The detection limit （3σ） was 0. 0189 mg/L with relative standard deviations of 1.3%. It was obtained a wide linear range of 0. 063 - 20 mg/L and the recovery is 100.3% - 104.8%.