Data processing techniques and measuring protocol are very important parts of the multisensor systems
methodology. Complex analytical tasks like resolving the mixtures of two components with very similar
chemical properties require special attention. We report on the application of non-linear (artificial neural
networks, ANNs) and linear (projections on latent structures, PLS) regression techniques to the data
obtained from the flow cell with potentiometric multisensor detection of neighouring lanthanides in the
Periodic System of the elements (samarium, europium and gadolinium). Quantification of individual
components in mixtures is possible with reasonable precision if dynamic components of the response
are incorporated thanks to the use of an automated sequential injection analysis system. The average
absolute error in prediction of lanthanides with PLS was around 1 104 mol/L, while the use of ANNs
allows the lowering of prediction errors down to 2 105 mol/L in certain cases. The suggested protocol
seems to be useful for other analytical applications where simultaneous determination of chemically
similar analytes in mixtures is required.