Evaluation of multicomponent fluorimetric analytical data by use of partial least-squares calibration. Application to the determination of codeine and ephedrine in urine

A partial least-squares calibration (PLS) method for the simultaneous spectrofluorimetric determination of acetylsalicylic acid, codeine and ephedrine is proposed. The use of PLS for the multicomponent spectrofluorimetric determination is demonstrated by analysing synthetic mixtures. Analyte mixtures can be resolved even in the presence of strongly overlapped fluorescence signals. The method was validated by subjecting experimental data to exhaustive statistical analysis, The proposed method was applied to the simultaneous determination of the three drugs in synthetic mixtures with a urine matrix, The concentration ranges considered are 1.56-10.92 and 25-100 mu g/ml for the codeine-ephedrine mixture, and 0.8-3.2, 0.1-0.5 and 1.6-4.8 mu g/ml for the acetylsalicylic acid-codeine-ephedrine mixture. The analytical results were quite good in all cases.