Application of Cloud Point Extraction for Cadmium in Biological Samples of Occupationally Exposed Workers: Relation Between Cadmium Exposure and Renal Lesion

Biol Trace Elem Res. 2015 Dec;168(2):303-10. doi: 10.1007/s12011-015-0365-9. Epub 2015 May 22.


Cadmium (Cd) level in blood and urine of soldering iron workers (n=49) and 41 matched healthy controls has been assessed. Cloud point extraction was employed for preconcentration of Cd. The Cd ions formed hydrophobic complex with 9,10-phenanthraquinone monoethyl thiosemicarbazone that was extracted by surfactant-rich phases in the nonionic surfactant Triton X-114. The surfactant-rich phase was diluted with 1 M HNO3 in methanol prior to its analysis by graphite furnace atomic absorption spectrometry. The parameters affecting the extraction efficiency of the proposed method, such as solution pH, amount of complexing agent, surfactant concentration, temperature, and incubation time, were optimized. Under the optimum experimental conditions, the detection limit and the enrichment factor were 0.04 μg L(-1) and 61, respectively. Relative standard deviation of 10 μg L(-1) Cd was less than 3.0%. The accuracy of the method was examined by analysis of certified reference materials. It was observed that soldering iron workers are liable to Cd overload as indicated by higher levels of Cd in blood and urine when compared with the controls. This exposure may lead to kidney damage indicated by elevation of urinary excretion of both N-acetyl-β-D-glucosaminidase and β2-microglobulin.

Keywords: Biological samples; Cadmium; Cloud point extraction; Exposed workers; Nephrotoxicity.

MeSH terms

  • Adult
  • Cadmium / analysis*
  • Cadmium / blood*
  • Cadmium / chemistry
  • Hexosaminidases / metabolism
  • Humans
  • Hydrogen-Ion Concentration
  • Ions
  • Kidney / drug effects
  • Kidney / pathology*
  • Kidney Diseases / chemically induced*
  • Kidney Diseases / diagnosis
  • Ligands
  • Male
  • Microwaves
  • Occupational Diseases / blood*
  • Occupational Exposure / analysis*
  • Octoxynol
  • Polyethylene Glycols / chemistry
  • Spectrophotometry, Atomic
  • Surface-Active Agents / chemistry
  • Temperature
  • Viscosity
  • Young Adult
  • beta 2-Microglobulin / metabolism


  • Ions
  • Ligands
  • Surface-Active Agents
  • beta 2-Microglobulin
  • Cadmium
  • Polyethylene Glycols
  • Octoxynol
  • Nonidet P-40
  • Hexosaminidases