Diethylenetriamine ion-imprinted silica gel for copper determination in tap water

Abstract

This paper proposes the preparation of a hybrid adsorbent material organically modified with N1-[3-(trimethoxysilyl)propyl]diethylenetriamine and imprinted ionically with Cu(II) ions. The structure of functionalized silica matrix with an organic group containing electron-donating nitrogen atoms allows several applications such as adsorption of metal ions, electrocatalytic studies, and development of electrochemical sensors. The electrochemical behavior of the hybrid material was investigated using a carbon paste electrode in different electrochemical techniques: cyclic voltammetry, differential pulse voltammetry, differential pulse anodic stripping voltammetry, and chronoamperometry. DPASV yielded the best results and linear response to Cu(II) in the concentration range of 6.0 × 10−4 to 5.4 × 10−3 mmol L−1 (R2 = 0.999; n = 9) using a pre-concentration time (tpc) of 1800 s at a reduction potential (Ered) of − 0.51 V versus SCE and a scan rate of 20 mV s−1, with a detection limit estimated at 1.82 × 10−7 mmol L−1. The samples were evaluated using the proposed sensor and a good recovery of Cu(II) was obtained in the range from 92.88 to 110.89%. The proposed method for DPASV was used for Cu(II) determination in samples of tap water, and the results from literature and that of flame atomic absorption spectrometry.