Determination of nickel in biological samples by inductively coupled plasma spectrometry after extraction with 1,5-bis(di-2-pyridylmethylene)thiocarbonohydrazide

Summary An ICP-AES method for the determination of nickel subtraces after extraction of the metal into methyl isobutyl ketone(MIBK) containing 1,5-bis-(di-2-pyridylmethylene)thiocarbonohydrazide is suggested. The complex formed is quite soluble in MIBK, so that the determination of concentrations down to 15 times lower than those by the direct non-extractive method is possible. In addition, the extraction step enhances the selectivity. The described method was applied to the determination of nickel in various biological materials, such as red cabbage, algae, liver, kidney, brain and urine.