Electrothermal atomization laser-excited atomic fluorescence spectrometry for direct analysis of germanium in water and blood samples

Laser-excited atomic fluorescence spectrometry using a copper vapor laser as the excitation source has been used to develop a very sensitive method for direct determination of ultratrace amounts of germanium. For more efficient sample atomization, a graphite furnace was employed. Two excitation-detection schemes were evaluated. The best conditions for the analysis of germanium in water and blood are described. The effect of matrix modifiers and some possible interferences are reported. Absolute limits of detection of 0.7 pg (3σ) with a precision of 3.5% at the 2 ppb level for water samples and 1.0 pg (3σ) with 8.0% precision at the 2 ppb level for blood samples were achieved with no need for preconcentration.