Das kapazitiv gekoppelte mikrowellenplasma (CMP) als atomisierungsquelle in der atomabsorptions-spektralanalyse

Abstract

The capacitively coupled microwave plasma (CMP) with N 2 as working gas is shown to be suitable as an atomizer for atomic absorption spectroscopy. The sensitivities for Ba, Ca, Co, Cr, Fe, Mg, Mo, Ni, Sr, W and Zn are given. Their relative position in this sequence reflects the differences in the dissociation energies of the monoxides. The type of CMP used has an excitation temperature of 5600 to 4750 K and a kinetic temperature of 4450 K. Referring to equal optical path lengths the sensitivity in the CMP (and also in the ICP) is not better than in the 1500 K “cooler” reducing acetylene flames. A high kinetic temperature alone is not sufficient; better degrees of atomization will only be achieved if plasmas with much higher analyte residence time or with reducing chemical properties can be developed.