Patent ID: 6871169

Claim:
A method of developing a calibration for predicting concentration of a target analyte in sample spectra, said method employing factor-based multivariate techniques, said method comprising the steps of: A. providing a matrix of calibration spectra; B. modeling at least one spectral region using a first selected number of factors; C. removing said modeled regions from said spectral matrix, so that, a residual matrix is generated; D. modeling at least one region of said residual matrix using a further selected number of factors, wherein said further selected number of factors may be equal to or different from said first selected number; E. repeating steps B through D, using said residual matrix as an input matrix for step B, until the number of factors employed for all iterations is equal to an optimal number of factors required to model at least a portion of said sample spectrum; and F. generating a vector of calibration coefficients wherein said vector constitutes said calibration; wherein a specific number of factors models at least one region of a spectrum independently of the number of factors used to model other spectral regions, thus minimizing prediction error.