Functional tests of purity

The most logical way of testing the purity of a reagent or a solvent is by means of the reaction in which it is involved. One of the best examples is that 

The effects of progressive purification of both the solvent and the solute used in spectroscopic studies can be followed similarly in terms of changes in the spectrum. If the spectral characteristics of the solute tend to an asymptote as purification proceeds, one may conclude that interfering impurities are being removed progressively. 

A different method of determining the concentration of co-catalytic impurities in a different polymerisation system was used in studies of the polymerisation of isobutene (Biddulph, Plesch and Rutherford, 1965) and of styrene (Longworth, Pan ton and Plesch, 1965) by TiCl4 in CH2CI2 in which 

Initiator EtCOSbF, EtCOSbF, EtCOSbF, NO SbEj EtCOPF, Ph HCShF  

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