Study on Solid Phase Extraction Spectrophotometric Determination of Copper(II) with 2-(2-Quinolinylazo)-1,5-Dihydroxidebenzene

Based on the color reaction of 2-(2-quinolinylazo)-1,5-dihydroxidebenzene (QADHB) with copper (Ⅱ) and the solid phase extraction of its colored complex with Waters Porapak ○R Sep-Park-C 18 cartridge, a new method for the determination of trace copper (Ⅱ) is studied. In the medium of CTMAB and presence of pH=4.0 buffer solution, QADHB can reacts with copper (Ⅱ) to form a stable 2∶1 complex. The colored complex can be extracted by C 18 cartridge, eluted by ethanol, and then determined by spectrophotometry at 560 nm. Beer's law is obeyed in range of 0~1.0 μg/mL. This method can be applied to the determination microamount of copper in water with satisfactory results.