Analysis of properties of cadmium adsorption onto whisker surface ion-imprinted polymer by inductively coupled plasma atomic emission spectrometry

A new type of surface ion-imprinted polymer was synthesized in aqueous media with sodium trititanate whisker in the presence of Cd(II), chitosan and γ-glycidoxypropyl trimethoxysilane (KH-560). A batch of adsorption experiments were performed to evaluate its adsorption of Cd(II) using inductively coupled plasma atomic emission spectrometry (ICP-AES). The factors affecting adsorption capacity, including pH and sorbent amount, were discussed. The adsorption kinetics and adsorption isothermals were also obtained. The Langmuir isotherm can fit in the experimental equilibrium data. Under the optimum conditions, the value of the adsorption was above 99%, and the maximum adsorption capacity was 52.34 mg·g^-1. In accordance with the parameters distribution coefficient (K_d) and selectivity coefficient (K), the selectivity for Cd(II) of the prepared imprinted polymer was estimated. Finally, the adsorption mechanism was discussed and the detection limit of 0.024 μg·mL^-1 with the relative standard deviation (RSD) of 1.74% (c=1.0 μg·mL^-1, n=13) for Cd(II) was obtained. Results showed that the surface Cd(II)-imprinted polymer was a solid sorbent with high efficiency, low-cost, convenient separation/enrichment for environmental trace Cd(II).