Pre-concentration and determination of Pb(II) from water samples using modified multiwalled carbon nanotubes

Pb(II) is a topically poisonous metal ion that can affect almost every organ and system in the body; it can accumulate in the body and cause kidney malfunctioning, hematological and brain damages. Recently, carbon nanotubes (CNTs), the nano-structured material, are applied for pre-concentration of heavy metal ions. This study investigates the pre-concentration of lead ion using oxidized multiwalled carbon nanotubes (MWCNT-COOH) via solid phase extraction method. MWCNT-COOH was prepared using as-synthesized MWCNT and the products were characterized by FTIR, FESEM, TEM and TGA. Various factors influencing the separation and pre-concentration were investigated namely the effects of pH (2-7) and the elution conditions (type, concentration and volume of eluent). The best extraction conditions were sample of pH 5 and 5 mL of 1M HNO3 as eluent. The developed method was successfully applied to the determination of trace quantities of Pb(II) in water samples with good analyte recoveries (90-102.5%)