Abstract
In view of optimising the multiβelement sparkβsource mass spectrometric analysis of biological material by photoplate detection, the effect of changing some important parameters in the densitometry, linearisation procedure and further data evaluation has been investigated. In the used procedure, the relative exposure values for the different stages on the photoplate are derived from the overall experimental relative blackening data rather than from coulometer readings. This approach is especially attractive when the simple Seidel linearization method is applied.
The influence of changing the maximum transmittance setting for continuous background correction appeared not to be critically important in practice. The setting of boundaries of a linear working range of the photoplate characteristic curve and its influence on the final concentration value was studied in detail. A significant difference was found, especially in trace element analysis, between the results obtained by presuming intuitively a routine dynamic range and by using a carefully established range. A comparison was also made with the more laborious Hull linearization procedure. The importance of the assumed linear range on the analytical data quality has to be emphasized.