Abstract: A combination DSC testing and Raman spectroscopy system is provided for running investigations on a single sample in the same experiment. A DSC instrument includes a set of optics, which allows an associated Raman unit to emit a pulsed laser that intermittently directs a laser signal to the sample and to collect the Raman signal while simultaneously running a DSC experiment on the same sample. The DSC has a vessel adapted to contain the sample, a thermal analysis environment is adapted to hold the vessel. An associated temperature control apparatus changes the temperature of the analysis environment between temperature endpoints to observe the sample at various transitions. The Raman spectroscopy unit is configured to generate laser pulses which stimulate emission of Raman spectra to provide further information about the sample without introducing excessive noise in the DSC aspect of the investigation.

Abstract: A method for determining concentration of an analyte in a sample includes generating a spectrum of a selected analyte and interferents, generating a spectrum of an unknown sample, computing first and second derivatives of the sample spectrum, deriving a matrix model that includes the analyte spectrum and the derivatives, and applying the matrix model to the sample spectrum so as to yield a parameter representing concentration of the selected analyte in the unknown sample. Multiple linear least squares regression is utilized to fit the model and calculate the parameter.