title: Solvent extraction of cadmium as a previous step for its determination in biological samples by electrothermal atomization atomic absorption spectrometry.
abstract: A method is proposed for the solvent extraction of cadmium using 1,5-bis(di-2-pyridylmethylene)thiocarbohydrazide (DPTH) as extractant. The optimum extraction conditions were evaluated from a critical study of the effect of pH, concentration of extractant, shaking time and ionic strength. The maximum volume ratio of the aqueous to organic phase was 30:1 for a single-stage extraction of99-100% of the metal ion. The detection limit is 0.01 ng/ml cadmium, and the calibration is linear from 0.1 to 5 ng/ml. The relative standard deviation for 10 replicate measurements is 1.8% for 2 ng/ml cadmium. The extraction method was applied to the determination of cadmium in some biological materials using graphite furnace atomic absorption spectrometry.
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Málaga, 29071 Málaga, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Almendro
authors.forename: C B
authors.initials: CB
authors.lastname: Ojeda
authors.forename: A G
authors.initials: AG
authors.lastname: de Torres
authors.forename: J M
authors.initials: JM
authors.lastname: Pavon