流动注射在线萃取-火焰原子吸收法测定食用盐中的锌

Determination of zinc in edible salt by atomic absorption spectrometry combined with on-line liquid-liquid extraction

基于锌与 1 (2 吡啶偶氮 ) 2 萘酚 (简称PAN)形成的配合物可被氯仿萃取 ,从高盐基体样品中分离富集锌 ,利用自行设计的分相器 ,实验确定了最佳的流动注射在线萃取 火焰原子吸收光度法测定锌的流路系统和化学反应条件。在选定的工作条件下 ,其RSD和检出限分别为 4 3 % (c=0 6 μg/mL ,n =1 1 )和0 0 3 μg/mL ,测定速度为 2 5样 /h。用于实际样品的测定 ,加标回收率为 97%～1 0 6 %。

A method was developed for determination of zinc in edible salt by atomic absorption spectrometry combined with on-line liquid-liquid extraction. The zinc was complexed with PAN and subsequently extracted into CHCl_3. The optimum experimental conditions and manifold parameters were investigated. The proposed method had a detection limit of 0.03 μg/mL, the precision of 4.3% RSD for 0.6 μg/mL of Zn 2+ ( n =11), and a sampling rate of 25 samples per hour. Recoveries of Zn 2+ in edible salts are 97%～106%.