2-(2-喹啉偶氮)-5-二乙氨基苯甲酸固相萃取光度法测定环境水样中的镍

Solid Phase Extraction-Spectrophotometric Determination of Nickel Ⅱin Water with 2-(2-Quinolinylazo)-5-Diethylaminobenzoic Acid

用 2 (2 喹啉偶氮 ) 5 二乙氨基苯甲酸 (QADEAB)与镍的显色反应及WatersPorapak Sep Park固相萃取小柱对显色络合物的固相萃取 ,建立了测定水样中 μg/L级镍的新方法。水样中的镍在pH =8.0的硼酸 磷酸二氢钾缓冲介质中和Tween 80存在下与QADEAB反应生成 2∶1稳定有色络合物 ,该络合物可用WatersPorapak Sep Park固相萃取小柱富集 ,用乙醇洗脱后用光度法测定 ,可测定水样中 μg/L级的镍。方法用于几种环境水样分析 。

Based on the color reaction of 2 (2 quinolinylazo) 5 diethylminobenzoic acid (QADEAB) with nickel ? and the solid phase extraction of its colored complex with Waters Porapak  Sep Park C 18 cartradge, a new method for the determination microamount of nickel ? was studied. In the medium of Tween 80 and presence of pH=8.0 buffer solution. QADEAB can react with nickel ? to form a stable 2∶1 complex. The colored complex can be extracted by C 18 column and eluted by ethanol, and then determinated by spectrophotometry. The molar absorptivity is 1.23×10 5 L·mol -1 ·cm -1 at 590 nm. Beer′s law is obeyed in the range of 0～0.4 mg/L. This method has been applied to the determination of microamount of nickel in water with satisfactory results.