L.E. Vanattaa, D.E. Coleman
Journal of Chromatography A
From ion chromatography, combinations of concentrated HF, H₃PO₄ and HNO₃ were found to generate a fourth species, H₂PO₃F. A thorough ion chromatographic study was undertaken to determine the role of each species in the equilibrium reaction, and to quantitate the final concentrations of the acids. Mixture-design experiments were generated and conducted systematically. Statistical data analyses resulted in prediction equations for the relevant components. An additional or different parameter (possibly activity) was found to be necessary to explain the behavior completely. However, these quantities were not available and concentrations provided reasonable empirical explanations; therefore, units of weight percent were used throughout. A Dionex DX 500 ion chromatograph and JMP statistical software were used for the study. Read more