Abstract: Spectrophotometers and spectroscopy processes are described that can provide for in-line calibration at every spectral acquisition as well as for continuous response correction during sample processing. The spectrophotometers include multiple polychromatic light sources that include characteristic emission spectra for use as an internal wavelength drift calibration system that is independent of environmental factors. Correction functions provided by the internal calibration process can be applied continuously and across an entire sample spectrum. The intensity response of each spectrometer in a spectrophotometer can also be monitored and continuously corrected for stray light, dark current, readout noise, etc.

Abstract: Analysis techniques by generation and interpretation of multivariate data that can provide for highly accurate analyte detection are described. Protocols can include a tiered principal component analysis (PCA) utilizing a partial least squares (PLS) approach for classification of a sample. Methods include selection of a particular local model for each classification category. The classification categories are determined based on assessment of sample characteristics such as solution absorbance, acidity, analyte oxidation state distribution, temperature, presence of one or more interferents, etc.

Abstract: Spectrophotometers and spectroscopy processes are described that can provide for in-line calibration at every spectral acquisition as well as for continuous response correction during sample processing. The spectrophotometers include multiple polychromatic light sources that include characteristic emission spectra for use as an internal wavelength drift calibration system that is independent of environmental factors. Correction functions provided by the internal calibration process can be applied continuously and across an entire sample spectrum. The intensity response of each spectrometer in a spectrophotometer can also be monitored and continuously corrected for stray light, dark current, readout noise, etc.