Applications of chemically modified ordered mesoporous carbon as solid phase extraction sorbent for preconcentration of trace lead ion in water samples

Abstract

Chemically modified ordered mesoporous carbon (COMC) was synthesized for solid phase extraction (SPE) for the determination of Pb(II) in environmental samples by flame atomic absorption spectrophotometry (FAAS). The method comprises the preconcentration of Pb(II) ions in buffered solutions onto 25 mg of ordered mesoporous carbon oxidized with concentrated HNO3. The elution step is carried out with 2.2 mmol L-1 HNO3. At pH 5-6, the maximum adsorption capacity of Pb(II) onto the COMC was 1.44 mmol g-1. The optimum experimental parameters for preconcentration of lead, such as pH of the sample, sample flow rate and volume, elution solution and interfering ions, have been investigated. The limit of detection of the method was found to be 3.31 ng mL-1. The relative standard deviation for four preconcentration experiments was found to be ≤3% in this case. It was concluded that mesoporous carbon packed cartridge coupled with FAAS was an excellent alternative for the routine analysis of lead ion at trace level.