火焰原子吸收光谱法用于竹筷中铜的形态分析

Species Analysis of Copper in Bamboo Chopsticks by FAAS

利用火焰原子吸收光谱法研究了竹筷中铜的化学形态及其分布。从不同使用阶段(分未用过的,用过10d及用过20d 3个阶段)的竹筷中采样,经预处理后分别称取一定量试样,置于1.0 mol.L-1盐酸溶液中浸泡5 h,过滤。所得滤液调节至pH6.0并使其通过阳离子交换柱,收集柱中流出溶液,用于测定稳定态铜。然后用1.0 mol.L-1盐酸溶液淋洗交换柱,在所得洗脱液中测定可交换态铜。将滤器上的残渣用硝酸-高氯酸(3+1)混合酸处理并蒸发至不再冒白烟,用稀盐酸溶解残渣,所得溶液过滤,在滤液中测定残渣态铜。文中给出了不同使用阶段竹筷中3种不同形态铜的含量和分布以及在使用中不同形态铜的积累规律。

Chemical species of copper and their distribution in bamboo chopsticks were studied with the aid of FAAS analysis.Samples were taken from the bamboo chopsticks of different use stages,i.e.,unused,used after 10d,and used after 20d,and after pretreatment,were soaked in 1.0 mol·L-1 HCl for 5 h.The filtrate from the solution was adjusted to pH 6.0 and passed through cation exchange resin column.The effluent from the column was collected and used for determination of stable species of copper.1.0 mol·L-1 HCl was used to elute the exchangeable species of copper from the ion exchange column,and the eluate was used for the determination.The residue on the filter was treated with HNO3-HClO4（3＋1） and fumed to near dryness.The residue was taken up with dil.HCl and the solution was filtered.Copper in the residual state was then determined in the filtrate.As shown by the results of the study,contents and distribution of copper in the 3 main species,as well as the regularity of their accumulation during time of using were given.