in this research, nanoporous silica (sba-15) was physically functionalized using2-(2-nitrobenzylideneamino) guanidine compound. this functionalized sba-15 was utilized as a new sorbentfor separation and preconcentration of some lanthanide ions. inductively coupled plasma optical emissionspectrometry (icp-oes) was used as a detection technique. the preconcentration factor of the method is 100and...