膜富集分光光度法测定微量锌

Study on the Spectrophotometric Determination of Microamount Zinc with Concentration by Means of Soluble Membrance Filter

以５－Ｂｒ－ＰＡＤＡＰ为显色剂，用ＷＸ型混合纤维素滤膜（孔径０．６５μｍ，２５ｍｍ）富集微量锌，用乙醇溶解富集物（Ｚｎ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ），分光光度法测定锌．Ｚｎ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ在乙醇溶液中最大吸收波长为５５５ｎｍ，表观摩尔吸光系数１．０９×１０５Ｌ·ｍｏｌ－１·ｃｍ－１．锌量在０．１～５．０μｇ／５ｍＬ范围内符合比耳定律．本法灵敏度高，操作简便．应用于食品、水样中锌的测定，结果满意．

In this paper, a study on the determination of microamount Zinc using 5 Br PADAP as a colour agent and WX model cellulose membrance filter (pore diameter: 0.65 μm,25mm) as a concentration and separation membrance filter has been reported. Ethanol was used to dissolve the catched complex (Zn(Ⅱ) 5 Br PADAP). The maximum absorption of the complex is at 555nm and the molar absorptivity is 1.09×10 5 L·mol -1 ·cm -1 . Beers law is obeyed in the concentration range for Zn(Ⅱ) of 0.1￣ 5.0 μg/5mL. The proposed method has been applied to the determination of Zn(Ⅱ) in waters and foods with satisfactory results.