Preconcentration methods for the determination of trace elements in water by x-ray fluorescence spectrometry: Part 2. Interference studies

Seven methods for the preconcentration of fifteen elements for their subsequent measurement by x-ray fluorescence spectrometry have been evaluated for their susceptibility to interferences. A two-level factorial experimental design has been used, enabling an economical and meaningful comparison of the seven methods to be made. A scheme for rating the methods on the basis of the effect of several interfering species is proposed. Use of such a scheme has enabled an objective comparison of the methods considered to yield their relative ranks. It is also shown that spectral and chemical interferences can be discerned to some extent. Combination of the response rating proposed earlier and the interference rating schemes reported here gives rise to an overall comparison and rank for the methods, allowing an objective choice of the optimal method(s) to be made.