In torchlaser ablation sampling for inductively coupled plasma time of flight mass spectrometry

Abstract

In torch laser ablation (LA) sampling was implemented to an inductively coupled plasma time of flight mass spectrometer (ICP-TOFMS). The achieved signal to noise ratios (S/N) for minor elements were found to be two times higher than the S/N ratios calculated from continuous signals of conventional 10 Hz LA in an ablation cell. The elemental signal intensity ratios during single spot analysis were the same for in torch and in cell LA. This indicates that the same particle size distributions are formed by the laser impact and consequently sampled into the ICP. Fast Fourier Transformation (FFT) was used as an alternative data evaluation tool for the repetitive in torch LA signals. The ratios of the 10 Hz amplitudes in the FFT spectra of different elements and isotopes were identical to the ratios between peak maxima in the background corrected transient signals. Single shot in torch LA-ICP-MS exceeds the figures of merit of continuous LA in an ablation cell and provides 10 Hz LA analyses with single shot resolution.