Polymerisation of dopamine on the carbon graphite nitride nanosheets as an effective adsorbent in determination of metal ions using effervescent-assisted dispersive micro solid-phase extraction method

Abstract

ABSTRACT A new nanocomposite was successfully synthesised by modifying nanosheets of graphitic carbon nitride with polydopamine (g-C3N4-PDA) and used for the extraction and preconcentration of the Pb(II) and Cu(II) ions, using the effervescent-assisted dispersive micro solid-phase method, before their determination by micro sampling-flame atomic absorption spectrometry. The structure of the g-C3N4-PDA composite was corroborated by the Fourier-transform infrared spectroscopy, X-Ray diffraction and scanning electron microscopy analyses. Due to the effervescence of carbon dioxide in the sample solution, dispersion of the adsorbent occurred in a very short time and led to an increase in the interactions between the composite and the analytes. As a result, the extraction recoveries were increased in the shortest possible time period. The effective parameters were optimised via the central composite experimental design (CCD). Under the optimised experimental conditions, the limits of detection (LOD) were obtained to be 0.16 and 0.06 μg/L for the Pb(II) and Cu(II) ions, respectively, and the linear dynamic range extended from 0.2 to 30 μg/L. Also, the relative standard deviations (RSD, n = 3) were obtained to be 1.1% and 1.2% for Pb(II) and Cu(II), respectively. In addition, according to the result obtained, the adsorbent could be reused for 8 times with negligible changes in the extraction recoveries.