在线流动注射共沉淀预浓集火焰原子吸收法测定痕量钴

Determination of Trace Cobaltby On-Line Flow Injection Analysis Coprecipitation Precocentration Atomic Absorption Spectrometry

用流动注射分析与原子吸收光谱联用的方法对环境水样及动物组织牛肝中痕量钴进行了测定。并对钴离子与吡咯烷二硫代氨基甲酸铵铁(APDC-Fe^(2+))产生共沉淀的最佳条件进行了选择试验。分析速度为72次/h,样品消耗量为1.1 ml,火焰原子吸收测定钴的灵敏度提高42倍。最低检出限为1μg/1。20μg/l 含量水平钴测定的相对标准偏差为2.3％(n=11)。测定河水、自来水中钴的回收率为97.9％和101.0％。测定动物组织牛肝标准参考物(NBS1577a)中钴的测定结果与标准值一致。

An efficient on-line co-precipitation preco- centration system was developed for flame at- omic absorption spectrometry (FAAS) using a flow-injection technique.Cobalt was co-preci- pitated with ammonium pyrrolidinedithiocarba- mate (APDC)-Fe^(2+)complex,and the precipitate was collected on Knotted Reactor(KR)made of 250cm long 0.5mm i.d.PTFE tube without filter.The precipitate was dissloved by MIBK and directly introduced into FAAS.Eehancem- ent factor of 42 was obtained by using 30s sa- mpling time.The detection limit was 1μg/l and the precision was 2.3%(n=11)at 20 μg/l Co level.Recveries obtained using tap water and river water samples were 97.9% and 101.0%. Result obtained for the determination of Co in standard reference bovine liver (NBS 1577a) agreed well with the recommened value.