MICROANALYTICAL ESTIMATION OF CERIUM BY A MINIATURIZED THERMOELECTRICAL SENSOR

A thermopile transducer made from 76 bismuth/antimony thin-film thermo couples is used for the measurement of heat output from chemical react ions. The method is independent of optical transmission and, therefore , applicable in strongly absorbing or particle-containing liquids. The rmoelectrical voltages up to 30 mV have been measured in sample volume s up to 20 mu l. The influence of the size and shape of the reaction d rops can be controlled by modification of the surface and internal ele ctrical calibration. Cerium is detected down to amounts of 5 nmol (7 m u g, 0.25 mmol l(-1)). A further improvement of the analytical limit d own to the 10 pmol (0.5 nmol l(-1)) range seems realistic.