流动注射在线富集-火焰原子吸收光谱法测定环境水样中CrⅢ和CrⅥ

Determination of CrⅢand CrⅥ in environmental water by flame atomic absorption spectrometry with flow injection on-line preconcentration

采用单阀双阳离子交换树脂微柱并联 ,设计了双路采样单一试剂逆向洗脱在线分离富集系统。该系统与原子吸收测量技术相结合 ,实现了在线分离富集 -火焰原子吸收光谱法同时测定水中Cr 和Cr ,富集 1min时 ,分析速度为 60样 /h ,测定Cr的特征浓度分别为 5 0 4μg/L ,线性范围分别为 0～ 90 μg/L ,对浓度分别为 0 1μg/mL的Cr测定 ,相对标准偏差分别为 3 0 2 % ,检出限为 9 0 6μg/L。该法对实际水样加标回收率为 92 0 %～ 10 6 0 %。

A rapid and sensitive methed for the simultaneous determination of Cr*#and Cr*& in water samples based on flow injection on line preconcentration on two microcolumn system-flame atomic absorption spectrometry has been developed The Cr*# and total chromium after appropriate reduction of Cr*&to Cr*#were respectively retained on two microcolumn with cation exchange resin and was eluted directly by 3 mol/L HNO 3 The characteristic concentration(preconcentration time 1 min)for Cr was 5 04μg/L The relative standard deviation at the 0 1 μg/mL level was 3 02% and corresponding detection limit(3σ)was 9 06μg/L The method has been successfully applied for the determination of chromium in water reference material GBW08607 and other water samples