首次制备了Fe(Ⅲ)改性修饰的海藻酸钠微球作为固相微萃取材料, 用该微球装载的微柱能够在不同形态砷化物共存时选择性富集水样中As(Ⅴ)。 结合氢化物发生-原子荧光光谱法, 可以实现实际水体样中无机As(Ⅲ)和As(Ⅴ)的形态分析。 具体过程为: (1)以0.1 mol·L-1柠檬酸为介质, 在填充柱后流出液中选择性测定As(Ⅲ); (2)以20 g·L-1硫脲-10 g·L-1抗坏血酸溶液为预还原剂, 5%盐酸为介质, 测定不经过微萃取柱分离的原始水体样品中无机总砷(As(Ⅲ)和As(Ⅴ)), 然后以差减法计算As(Ⅴ)的量。 Fe(Ⅲ)改性海藻酸钠微球制备过程简便, 成本低廉、 绿色环保, 相应基于Fe(Ⅲ) 改性海藻酸钠微球微萃取过程的砷形态分离分析微萃取柱及其光谱联用技术, 可以有效、 快速地测定自然水体中As(Ⅲ)和As(Ⅴ), 具有实际意义。

Fe(III) modified sodium alginate beads (Fe(Ⅲ) modified Na) were firstly adopted as solid phase for micro-extraction of inorganic arsenic species from water samples. In combination with hydride generation-atomic fluorescent spectrometry (HG-AFS), speciation analysis of inorganic As(Ⅲ) and As(Ⅴ) in water samples could be accomplished because Fe(Ⅲ) modified Na had various micro-extraction behavior for inorganic As(Ⅲ) and As(Ⅴ) respectively. As a result, Fe(Ⅲ) modified Na could be developed into a practical solid phase for speciation analysis of inorganic As(Ⅲ) and As(Ⅴ), with the advantages of being efficient, simple, and environmental-friendly.