DETERMINATION OF TRACE HEAVY-METALS IN BIOLOGICAL SAMPLES BY INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY AFTER EXTRACTION WITH ,5-BIS-(DI-2-PYRIDYLMETHYLENE)THIOCARBONOHYDRAZIDE

A sensitive inductively-coupled plasma atomic emission spectrometric s equential method for the determination of trace heavy metals (cadmium, cobalt, copper and nickel) in biological samples after extraction of the metals into isobutyl methyl ketone (IBMK) containing ,5-bis-(di-2- pyridylmethylene)thiocarbonohydrazide (DPTH) is described. A systemati c study was made to determine the optimum conditions for extraction of the metals into IBMK. The complexes formed are quite soluble in IBMK, so much so that this allows the use of aqueous-to-organic phase volum e ratios of up to 40 and hence the determination of concentrations dow n to 30 times lower than those afforded by the direct non-extractive m ethod. The method has been used for the determination of these element s in various biological materials with good results.