Porous organic polymers for selective enrichment of trace Cu(<scp>ii</scp>) 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%.