Abstract: A process for quantitative and qualitative analysis for identifying compounds in a sample mixture involves the identification of a set of reference spectra selected according to a measured condition of the sample, which collectively define a composite spectrum which best matches a spectrum produced from the sample. The compounds associated with respective reference spectra of the identified set are the compounds that are determined to be likely to be present in the sample. Quantities of the compounds may be determined from the intensities of certain representative peaks associated with the compounds, relative to the intensity of a peak associated with a reference compound which is unaffected by the measured condition of the sample. A measured condition may be pH of the sample, for example, and an accurate measurement of pH can be obtained from the test spectrum. Thus, given a test spectrum of a sample and given a set of reference spectra, the process can identify and quantify compounds present in the sample.

Abstract: A computer implemented process for producing a representation of a reference spectrum for a reference solution having a first pH condition, for use in determining the composition of a test sample, is disclosed. The process involves producing a position value for at least one peak of the reference spectrum in response to a measured pH condition of the test sample, and a property of at least one peak in a base reference spectrum for the reference solution, the base reference spectrum being associated with a pH condition of the reference solution that is different from said measured pH condition.