膜富集-可见漫反射光谱法测定池塘水和维生素B_(12)药片中痕量钴

Determination of Trace Amount of Cobalt in Pond Water and Vitamin B_(12) Tablets by Visible Diffuse Reflectance Spectrometry with Membrane Filtration Enrichment

1-(2-吡啶偶氮)-2-萘酚与钴离子生成暗绿色的络合物,反应后将其过滤到膜上,测得膜表面漫反射光谱,据此提出了膜富集-可见漫反射光谱法测定池塘水和维生素B12药片中痕量钴的方法。钴的质量浓度在0.2~3.0μg·L-1和3.0~10.0μg·L-1范围内与其吸光度呈线性关系,检出限(3s/k)为0.093μg·L-1。方法用于池塘水和维生素B12药片的分析,加标回收率在96.7%~105%之间,测定值的相对标准偏差在1.4%~2.9%之间。

Co-PAN complex was formed by the reaction of 1-(2-Pyridylazo)-2-naphthol and cobalt(Ⅱ)ion.The mixture was filtered with membrane,then visible diffuse reflectance spectra of the membrane filters were acquired.Based on the fact,a method for the determination of trace amount of cobalt in pond water and vitamin B12 tablets by visible diffuse reflectance spectrometry with membrane filtration enrichment was proposed.Linear relationship between values of absorbance and mass concentration of cobalt was obtained in the ranges of 0.2-3.0μg·L-1 and 3.0-10.0μg·L-1,with detection limit(3s/k)of 0.093μg·L-1.The proposed method was applied to the analysis of samples of pond water and vitamin B12 tablets,giving values of recovery and RSD′s in the ranges of 96.7%-105% and 1.4%-2.9%,respectively.