DETERMINATION OF COBALT IN BIOLOGICAL SAMPLES BY INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY AFTER PRECONCENTRATION BY EXTRACTION WITH 1,5-BIS (DI-2-PYRIDYLMETHYLENE)THOIOCARBONHYDRAZIDE
Gc. Gomez et al., DETERMINATION OF COBALT IN BIOLOGICAL SAMPLES BY INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY AFTER PRECONCENTRATION BY EXTRACTION WITH 1,5-BIS (DI-2-PYRIDYLMETHYLENE)THOIOCARBONHYDRAZIDE, Analytical letters, 28(7), 1995, pp. 1181-1196
A method is proposed for the solvent extraction of cobalt using 1,5-bi
s(di-2-pyridylmethylene) thiocarbonohydrazide (DPTH) as extractant. Th
e optimum extraction conditions were evaluated from a critical study o
f the effect of pH, concentration of extractant, shaking time and ioni
c strength. The maximum volume ratio of the aqueous to organic phase w
as 30:1 for a single-stage extraction of 99-100 % of the metal ion. Th
e detection limit is 0.9 ng/ml cobalt, and the calibration is linear f
rom 0.9 to 1000 ng/ml. The effect of interferences was studied and no
interferences from the elements commonly found in biological materials
were observed. The extraction method was applied to the determination
of cobalt in some biological materials using inductively coupled plas
ma atomic emission spectrometry (ICP-AES).