Abstract: Anew wavelength selection method, orthogonal projection-based regression(OPR), was presented, which can indicate whether the unknown interferences exist in the determined systeMAnd show the wavelength region where the unknown interferences do not have absorbance.Amulti-vitamine system was analyzed by using the newly developed multivariate calibration method-extension of hybrid linear analysis(HLAE) after the wavelength selection of OPR, and the results were compared to those of HLA and PLS.The results showed that only after the wavelength selection of OPR, can satisfactory results be got by using HLAE; and without pure spectra of analyzed components, HLAE can produce the results better than PLS and at least equivalent to HLA, and can be used as a replacement of HLA when it is difficult to get the precise pure spectra of the determined components.

Key words: Hybrid linear analysis, Orthogonal projection, Vitamine