Application of Carboxylic Carbon Nanotubes for the Rapid Determination of Lead by Spectrophotometry

A novel spectrometric method for determination of lead was developed with the application of carboxylic carbon nanotubes (CNTs). The optimum operating conditions including pH, volume and addition order of reagents solution were established. The nature of the novel complex was also investigated. Comparative experiments proved that the application of carboxyl CNTs exhibit the obvious hyperchromic effect: the absorbance of the complex was increased by nearly 52.2% through optimizing the technological parameters; the coloration system showed the maximum absorbance at 580.4 nm with a molar absorptivity value of 1.35×105 L mol−1 cm−1; the calibration graph was linear in the range 1–24.0 μg/25.0mL and the limit of detection was 10.4 ng/mL. The proposed method is simple, sensitive and direct for the determination of lead.