Cloud point extraction and flame atomic absorption spectrometry determination of lead (II) in environmental and food samples

J AOAC Int. 2012 Nov-Dec;95(6):1797-802. doi: 10.5740/jaoacint.10-370.

Abstract

A cloud point extraction procedure for the preconcentration of Pb2+ in various samples following complexation with 2,2'-(1E,1'E)-1,1'-(2,2'-azanediylbis(ethane-2,1-diyl)bis(azan-1-yl-1-ylidene)) bis(ethan-1-yl-1-ylidene)diphenol in Triton X-114 after centrifugation is reported. A 0.5 mL portion of methanol acidified with 1.0 M HNO3 was added to the surfactant-rich phase prior to analysis by flame atomic absorption spectrometry. The influence of analytical parameters--including pH, concentrations of ligand, Triton X-114, and HNO3, bath temperature, heating time, and centrifugation rate and time--were optimized, and the effect of the matrix ions on the recovery of Pb2+ was investigated. An LOD of 1.9 ng/mL along with a preconcentration factor of 50 with RSD of 1.0% for Pb2+ were achieved. The proposed procedure was applied to the analysis of various real samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Buffers
  • Calibration
  • Environmental Pollutants / analysis*
  • Environmental Pollutants / chemistry
  • Food Analysis / methods*
  • Hydrogen-Ion Concentration
  • Indicators and Reagents
  • Lead / analysis*
  • Lead / chemistry
  • Limit of Detection
  • Nicotiana / chemistry
  • Nitric Acid / chemistry
  • Octoxynol
  • Polyethylene Glycols
  • Reproducibility of Results
  • Spectrophotometry, Atomic
  • Surface-Active Agents
  • Temperature

Substances

  • Buffers
  • Environmental Pollutants
  • Indicators and Reagents
  • Surface-Active Agents
  • Lead
  • Polyethylene Glycols
  • Nitric Acid
  • Octoxynol
  • Nonidet P-40