Porous organic polymers for selective enrichment of trace Cu(ii) in food and water samples

Porous organic polymers (POPs) were synthesized by polymerization of benzene triamine and trimesoyl chloride. The POP material is water-stable and shows selective extraction of Cu(ii) due to its intrinsic nitrogen-rich surface, which forms a chelate with Cu(ii) ions. The prepared polymeric material was characterized through Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray elemental mapping, and scanning electron microscopy for surface group analysis and structural morphology studies. A microcolumn was developed using POPs for the preconcentration of trace Cu(ii) from complex real samples. The proposed method shows a high enrichment factor of 900 and a quantification limit of 1.1 ppb for Cu(ii) ions. The accuracy of the developed method was confirmed by analyzing standard reference materials (NIES 8 and NIES 10c) and the standard addition method. The method shows good precision with an RSD value of less than 5%.