DOUBLE-INJECTION FLOW-INJECTION ANALYSIS USING MULTIVARIATE CALIBRATION FOR MULTICOMPONENT ANALYSIS

A flow injection analysis (FIA) system is presented in which the reagent and sample are simultaneously injected for multicomponent analysis. A simple eight-port valve is described to perform the double injection. The method is illustrated by the determination of nickel and iron in a model plating bath solution. First-order calibration methods including classical least squares (CLS), principal components regression (PCR), and partial least squares (PLS) are used to analyze the complex time profiles that this method provides. This study shows that very moderate sampling rates and small calibration data sets can be used with multivariate calibration techniques.