Abstract: The first step of the calibration oi "grey" analytical systems with known scope of pos-sibiy existing components is So identify the truely existing species in a specific sample.In this pa-per,a specially designed matrix which consists of the spectra of all possibly existing species and the analytical sample was constructed,and a method based on the singular value decomposition (SVD) of this matrix was developed to pick out the really components existing in the mixture according to the elements of the relevant singular vector The qualitative detection was followed by quantitative determination by using ordinary regression procedure The method was testified by simulated spectra and experimentally measured data with satisfactory results.

Key words: Singular value decomposition(SVD), Muitivate calibration, "Grey", analytical system, Chemornetrics