Ionic imprinted polymer for nickel recognition by using the bi-functionalized5-vinyl-8-hydroxyquinoline as a monomer: Application as a new solid phaseextraction support

摘要

A new ionic imprinted polymer(IIP)for Ni(II)recognition/pre-concentration was prepared via precipitationpolymerization using 2-(diethylamino)ethyl methacrylate(DEM)and divinylbenzene(DVB)as a crosslinkingagent in the presence of nickel(II)and 5-vynil-8-hydroxyquinoline(5-VHQ)as a bi-functionalizedligand. An important increase on the selectivity of the synthesised IIP for nickel(II)ions was obtained whencomparing to the use of 8-hydroxyquinoline(8-HQ)as a ligand.The synthesised IIP was used as a newsupport for solid phase extraction(SPE)of nickel(II)from seawater before inductively coupled plasmaoptical emission spectrometry(ICP-OES)detection.Variables affecting the SPE process,such as pH,load andelution flow rates, and concentration and volume of the eluting solution,were fully evaluated. The optimisedprocedure consists of a sample loading(100 mL of seawater at a pH of 9.0±0.1)through IIP-SPE cartridgescontaining 300 mg of the synthesised IIP at a flow rate of 3.0 mL min1.Elution was performed by passing2.5 mL of 2.0 M nitric acid at a flow rate of 1.5 mL min1,which gave a pre-concentration factor of 40.Thelimit of detection(LOD)of the method was 0.26 μg L1,while the relative standard deviation(RSD)for eleven replicated measurements was 3%.Accuracy of the method was assessed by analyzing SLEW-3(estuarine water)and TM-23.3(lake water) certified reference materials.In addition to the selectivity of the synthesised material for nickel(II)ions against other transition metal ions and major alkaline and alkalineearthmetals(Na+,K+,Mg2+and Ca2+)in seawater,it can be stated that the salt matrix is efficiently removed by using the proposed IIP-SPE procedure.