A new method with high sensitivity and good selectivity for trace multicomponent anal. was investigated based on highly-sensitive color reaction or fluorescent chelating reaction combined with Kalman filtering treatment. Fifteen chelating reactions were employed for assay of metallic ions but give overlapped spectra and show mutual interference in their determination through obtaining the optimal estimation of their concns. by a new series of correction of the measurement of absorbance or fluorescent intensity using the recursive algorithm written in BASICA, FORTRAN and/or PASCAL languages. Also, the effect on the results from the initial values, the tendency of the state-ests., the reduction of the error covariance, the correlation of innovation sequence, and the information gain obtained from the stepwise filtering were studied and used for judging the reliability (accuracy) of the anal., for indicating the stop-point of filtering and for selecting the measurement wavelength. The results can be improved through filtering the data modified with the moving windows smoothing technique. The proposed method has been applied to the determination of Co/Ni/Cu(/Zn/Cd), Zn/Mn, and Al/Ga/Fe, rare earths, Zr/Hf, Nb/Ta, Mo/W(/Sn/Ge/Ti) in mixtures and samples with relative standard deviation f10% and/or recoveries 90-110%.1

Key words: SPECTROPHOTOMETRY, MULTICOMPONENT SYSTEM, COLOR REACTION, TRACE ANALYSIS, SIMULTANEOUS DETERMINATIONS, METAL ION, KALMAN FILTERING