title: Scatter correction of transmission near-infrared spectra by photon migration data: quantitative analysis of solids.
abstract: The scope of this work is a new methodology to correct conventional near-infrared (NIR) data for scattering effects. The technique aims at measuring the absorption coefficient of the samples rather than the total attenuation measured in conventional NIR spectroscopy. The main advantage of this is that the absorption coefficient is independent of the path length of the light inside the sample and therefore independent of the scattering effects. The method is based on time-resolved spectroscopy and modeling of light transport by diffusion theory. This provides an independent measure of the scattering properties of the samples and therefore of the path length of light. This yields a clear advantage over other preprocessing techniques, where scattering effects are estimated and corrected for by using the shape of the measured spectrum only. Partial least squares (PLS) calibration models show that, by using the proposed evaluation scheme, the predictive ability is improved by 50% as compared to a model based on conventional NIR data alone. The method also makes it possible to predict the concentration of active substance in samples with other physical properties than the samples included in the calibration model.
authors.affiliation: Department of Physics, Lund Institute of Technology, P.O. Box 118, SE-221 00 Lund, Sweden. abrahamsson@fysik.lth.se
authors.forename: Christoffer
authors.initials: C
authors.lastname: Abrahamsson
authors.forename: Alexandra
authors.initials: A
authors.lastname: Löwgren
authors.forename: Birgitta
authors.initials: B
authors.lastname: Strömdahl
authors.forename: Tomas
authors.initials: T
authors.lastname: Svensson
authors.forename: Stefan
authors.initials: S
authors.lastname: Andersson-Engels
authors.forename: Jonas
authors.initials: J
authors.lastname: Johansson
authors.forename: Staffan
authors.initials: S
authors.lastname: Folestad
mesh_terms: D000465:Algorithms; D045424:Complex Mixtures / Q000032:analysis* / Q000737:chemistry*; D004058:Diffusion; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D017785:Photons; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation; D013055:Spectrophotometry, Infrared / Q000379:methods*
chemical_list: D045424:Complex Mixtures