Solid phase extraction of heavy metal ions in environmental samples on chemically bonded single-walled carbon nanotubes with 2-((3-silylpropylimino) methyl) phenol



A new, simple method based on the use of chemically 2-((3-silylpropylimino) methyl) phenol (SPIMP) bonded single-walled carbon nanotubes (SPIMP-SWCNTs) as solid-phase extraction (SPE) stationary phase is proposed for simultaneous preconcentration of trace Cu2+, Zn2+, Ni2+ and Fe3+ ions prior to the measurement by flame atomic absorption spectrometry (FAAS). This new SPE method provides several advantages, such as high extraction efficiency, high breakthrough volumes, convenient extraction procedure, and short analysis times. The different experimental parameters for preconcentration of metal ions have been investigated on a column packed with SPIMP-SWCNTs. The optimum pH value for the separation of metal ions was 7.0. The metal ions retained on chemically modified SWCNTs efficiently were eluted using 6.0 mL of 4.0 mol L-1HNO3 solution. The detection limits of the method was found to be 2.10, 2.97, 1.55 and 3.03 µg L-1 for Cu2+, Zn2+, Ni2+ and Fe3+, respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n=8). The method has been successfully applied for analysis of the metal contents in different real samples including mineral water, sour cherry juice, pine apple juice and cabbage.