微波消化-固相萃取光度法测定生物样品中的钴

Spectrophotometric Determination of Cobalt in Biological Sample by Microwave Digestion and Solid Phase Extraction

根据 2 - (2 -喹啉偶氮 ) - 1,5 -苯二酚 (QADHB)与钴的显色反应及 C18固相萃取小柱对显色络合物的固相萃取 ,建立了一种测定生物样品中痕量钴的新方法。在 p H=4 .0的 HAc- Na Ac缓冲介质中 ,溴化十六烷基三甲基铵 (CTMAB)存在下 ,QADHB与钴反应生成 2∶ 1稳定络合物 ,该络合物可用 C18固相萃取小柱富集 ,小柱上富集的络合物用乙醇 (内含 2 %乙酸 )洗脱后用光度法测定 ,络合物最大吸收波长为5 80 nm,钴含量在 0— 0 .8μg/m L范围内符合比耳定律 ,摩尔吸光系数 ε=5 .6× 10 4L· mol-1·cm-1。本方法用于几种生物样品的分析 ,结果令人满意。

Based on the color reaction of 2-(2-quinolinylazo)-1,5-dihydroxy-benzene(QADHB) with cobalt(Ⅱ) and the solid phase extraction of its colored complex with C 18 cartridge, a new method for the determination of cobalt was studied. In the presence of CTMAB and pH 4.0 buffer solution medium, QADHB can react with cobalt(Ⅱ) to form a stable 2∶1 complex. The colored complex was extracted by C 18 cartridge and eluted by ethanol (containing 2% of acetic acid).Then it was determined by spectrophotometry at 580nm.Beer's law is obeyed in the range of 0-0.8μg/mL. This method can be applied to the determination of cobalt in biological samples with satisfactory results.