FIA-安培法测定水中的Cr(Ⅲ)和Cr(Ⅵ)

FLOW-INJECTION AMPEROMETRIC DETERMINATION OF CHROMIUM(Ⅲ)AND CHROMIUM(Ⅵ)IN WATER

流动注射分析(FIA)测定铬的主要方法有FIA-AAS、FIA-AES和FIA-VIS。Pratt等用铂和金电极流通池、Hwang等用玻璃碳和金电极流通池分别建立了测定Cr(Ⅲ)和Cr(Ⅵ)的FIA安培法,检出限依次是5ng/mL和0.5ng/mL。鉴于Cr(Ⅵ)在负电位下能被还原的性质,我们用廉价的碳作电极材料,用FIA安培法测定了天然水中的痕量铬,结果亦令人满意。 FIA安培法测定系统见图1.TRB-8蠕动泵、注射阀均系东北电力学院仪器仪表厂产品,

A flow-injection amperometric method for the determination of Cr(Ⅲ) and (Ⅵ) in water is established,using a carbon tube flow-through detector. The method is simple,rapid and of low cost.The effects of interfering ions are eliminated with a line-on separation column with strong acid-cation resin. Detection limit under optimized conditions was 0.2ng/mL for Cr (Ⅵ). The determination resuits of trace Cr (Ⅲ) and (Ⅵ) in water were in accordance with those obtained by atomic absorption spectrophotometry in graphite tube furnace.