2-(2-喹啉偶氮)-间苯二酚固相萃取光度法测定镉

Solid Phase Extraction and Spectrophotometric Determination of Cadmium with 2-(2-Quinolinylazo)-Resorcin

在 p H=8.0的硼酸 -氢氧化钠缓冲介质中 ,Triton X- 10 0存在下 ,2 - (2 -喹啉偶氮 ) -间苯二酚 (QAR)与镉反应生成 2∶ 1稳定络合物 ,最大吸收波长为 5 45 nm,摩尔吸光系数ε=6 .88× 10 4L· mol-1· cm-1。样品中的镉用强阴离子交换固相萃取柱固相萃取预分离和富集后 ,光度法测定 。

In the presence of pH=8.0 buffer solution and Triton X-100 medium,2-(2-quinolinylazo)-resorcin(QAR) reacts with cadmium(Ⅱ) and forms a 2∶1 complex(QAR∶Cd(Ⅱ)) with the molar absorptivity of 6.88×10 4L·mol -1·cm -1 at 545nm.Beer's law is obeyed in range of 0—1.0μg/mL.The cadmium ion in samples was enriched and separated by solid phase extraction with anion exchange resin cartridge before determination.This method was applied to the determination of cadmium in water and food with good results.