Laser ablation for aerosol deposition graphite furnace atomic absorption spectrometry

Abstract A commercially available pulse laser was used with a graphite furnace (GF) atomic absorption (AA) spectrometer for the trace analysis of metals in solid samples. Laser ablated solid material was deposited onto the inner surface of the GF. The optimum deposition temperature was 300 K. The deposited aerosol was atomized in a conventional GF heating regime. The analytical results in the deposition technique for Cd, Zn, Pb, Ag, Mn, Fe and Ni contained in different target materials were compared with results obtained with another laser ablation GF technique, which is characterized by the transport of the ablated material into a constant temperature GF with immediate atomization of the aerosol particles. The deposition technique improved the sensitivity and precision for the low volatile elements Cd, Zn and Pb. In contrast, the aerosol injection technique is preferable for the determination of elements that require more energy for atomization. Working with tube temperatures of up to 2800 K the authors obtained higher absorbance values (peak height) for Mn, Fe and Ni using the injection technique. The use of multiple deposition of laser ablated material inside the GF to achieve improved detection limits and higher precision for one atomization seems promising only for selected matrices.