THERMAL-STABILITY OF SULFUR-CONTAINING CHELATES AND IMPROVEMENT OF THE SENSITIVITY OF COPPER, LEAD, AND CADMIUM DETERMINATION BY ELECTROCHEMICAL ATOMIC-ABSORPTION SPECTROMETRY

High-temperature complexation processes in electrothermal atomizers in the presence of organic complexing matrix modifier were studied. It i s demonstrated that the pyrolysis of the modifier complex or the cleme nt under determination affects the analytical signal. It is found that the modifier efficiency is determined by the closeness of the decompo sition temperatures of the complex and the reagent father than by the absolute thermal stability of the complex In the solid phase in pyroly sis. The mechanism of transferring the analyte to the preatomization s tate is proposed.