文摘
A new third-order multivariate calibration approach,based on the combination of multiway-partial least-squares with a separate procedure called residual trilinearization (N-PLS/RTL), is presented and applied tomulticomponent analysis using third-order data. Theproposed chemometric algorithm is able to predict analyteconcentrations in the presence of unexpected samplecomponents, which require strict adherence to the second-order advantage. Results for the determination of procaineand its metabolite p-aminobenzoic acid in equine serumare discussed, based on kinetic fluorescence excitation-emission four-way measurements and application of thenewly developed multiway methodology. Since the analytes are also the reagent and product of the hydrolysisreaction followed by fast-scanning fluorescence spectroscopy, the classical approach based on parallel factoranalysis is challenged by strong linear dependencies andmultilinearity losses. In comparison, N-PLS/RTL appearsan appealing genuine multiway alternative that avoids thelatter complications, yielding analytical results that arestatistically comparable to those rendered by relatedunfolded algorithms, which are also able to process four-way data. Prediction was made on validation samples witha qualitative composition similar to the calibration set andalso on test samples containing unexpected equine serumcomponents.