[Partial least-squares regression analysis for simultaneous spectrophotometric determination of Fe3+ and Al3+].

Adding hexodecyltrimethylammonium bromide(CTMAB) to improve solubility and delic acy, and using chromazurol S as a chromogenic reagent, and acetone as a stabil izing reagent, partial least-squares regression(PLS) was used to determine sim ultaneously trace amounts of Fe(Ⅲ) and Al(Ⅲ) in sythetic samples. Consid ering the stability of the rays, and the absorption properties of the two ingred ients, seven wavelengths between 610 and 670 nm were selected for data collectio n. As a comparison, the methods of CPA and PLS were used respectively for analy sing the data obtained from the experiment, and the results suggested that the latter was much better.