AUTOMATED LASER-EXCITED ATOMIC FLUORESCENCE SPECTROMETER FOR DETERMINATION OF TRACE CONCENTRATIONS OF ELEMENTS

A new version of a computer-controlled laser excited atomic fluorescence spectrometer LAFAS-1 is described. The laser part of the spectrometer consists of a dye laser pumped by an excimer laser. Electrothermal atomization in an argon atmosphere and under vacuum conditions may be employed. The spectrometer was tested by acidified standard solutions prepared in the Grenoble clean laboratory. These standards were based on ultrapure water. A limit of detection for Pb of 0.18 pg/ml was achieved. For a 20 μl aliquot volume this value gives an absolute limit of detection of 4 fg. A Pb content of 0.28 pg/ml in the Grenoble ultrapure water was measured by LAFAS-1 with a confidence interval of 0.05 pg/ml. This value is in excellent agreement with that obtained previously by isotope dilution mass spectrometry: 0.27 pg/ml.