Pulse nebulisation

The measurement of Zn in body tissues or fluids for clinical purposes does not require the sensitivity of ETA—AAS. The very early methods using carbon-rod atomisers required only 0.5 pi serum for direct analysis of Zn [48], and current techniques require <0.1 pi. The measurement of Zn in cerebrospinal fluid (CSF) by ETA—AAS [49] could have just as easily been determined using pulsed —nebulisation FAAS with <100 pi sample volumes. 

C, is one of the most critical parameters in TSP operation, and should be optimised for different samples, wherever possible. This is considered to be a considerable drawback in routine operation of unknown polymer/additive extracts. Too low a vaporiser temperature results in the solute and solvent spraying into the ionisation source in their liquid form, without formation of gas-phase ions. Too high a vaporiser temperature causes premature evaporation of the solute and solvent before the outlet of the capillary is reached. This causes an unstable, pulsing ion beam. As ion formation in TSP operation depends very critically on the extent of desolvation and the energy of the nebulised droplets, it is clear that an inappropriate vaporiser temperature will cause loss of sensitivity. 

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