First- and second-order multivariate calibration applied to biological samples: determination of anti-inflammatories in serum and urine

Abstract.

First- and second-order multivariate calibration of fluorescence data have been compared as regards the determination of anti-inflammatories and metabolites in the biological fluids serum and urine. The simultaneous resolution of naproxen–salicylic acid mixtures in serum and naproxen–salicylic acid–salicyluric acid mixtures in urine was accomplished and employed for a discussion of the relative advantages of the applied chemometric tools. The analysis of second-order fluorescence excitation-emission matrices was performed using iteratively reweighted generalized rank annihilation method (IRGRAM), parallel factor analysis (PARAFAC), and self-weighted alternating trilinear decomposition (SWATLD). The results were compared with first-order fluorescence emission data analyzed with partial least-squares regression (PLS). In all cases, the performance of the methods was improved through the formation of inclusion complexes of the analytes with β-cyclodextrin. The concentration ranges in which the analytes could be determined were as follows: naproxen, 0–250 ng mL^–1 in serum and 0–200 ng mL^–1 in urine; salicylic acid, 0–500 ng mL^–1 in serum and 0–300 ng mL^–1 in urine, and salicyluric acid, 0–300 ng mL^–1 in urine.