title: Combined optimal-pathlengths method for near-infrared spectroscopy analysis.
abstract: Near-infrared (NIR) spectroscopy is a rapid, reagent-less and nondestructive analytical technique, which is being increasingly employed for quantitative application in chemistry, pharmaceutics and food industry, and for the optical analysis of biological tissue. The performance of NIR technology greatly depends on the abilities to control and acquire data from the instrument and to calibrate and analyse data. Optical pathlength is a key parameter of the NIR instrument, which has been thoroughly discussed in univariate quantitative analysis in the presence of photometric errors. Although multiple wavelengths can provide more chemical information, it is difficult to determine a single pathlength that is suitable for each wavelength region. A theoretical investigation of a selection procedure for multiple pathlengths, called the combined optimal-pathlengths (COP) method, is identified in this paper and an extensive comparison with the single pathlength method is also performed on simulated and experimental NIR spectral data sets. The results obtained show that the COP method can greatly improve the prediction accuracy in NIR spectroscopy quantitative analysis.
authors.affiliation: State Key Laboratory of Precision Measuring Technology and Instruments, College of Precision Instruments & Opto-electronics Engineering, Tianjin University, Tianjin, People's Republic of China.
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.forename: Kexin
authors.initials: K
authors.lastname: Xu
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Lu
authors.forename: Huili
authors.initials: H
authors.lastname: Sun
mesh_terms: D000418:Albumins / Q000032:analysis; D000465:Algorithms; D045424:Complex Mixtures / Q000032:analysis; D005947:Glucose / Q000032:analysis; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D013055:Spectrophotometry, Infrared / Q000379:methods*; D041622:Tomography, Optical / Q000379:methods*; D014867:Water / Q000032:analysis
chemical_list: D000418:Albumins; D045424:Complex Mixtures; D014867:Water; D005947:Glucose