Second-order multivariate models for the processing of standard-addition synchronous fluorescence-pH data.Application to the analysis of salicylic acid and its major metabolite in human urine

PAGANI, A. P.; IBAÑEZ, G. A.

TALANTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 122 p. 1 - 7

0039-9140

In the present work we describe the determination of salicylic acid and its major metabolite salicyluric acid in spiked human urine samples, using synchronous fluorescence spectra measured in a flow-injection system with a double pH gradient. Because the fluorescent urine background constitutes a potentially interfering signal, it makes it necessary to achieve the second-order advantage. Moreover, due to significant changes in the signal of the analytes in the presence of the urine matrix, mainly salicyluric acid, standard addition was required in order to obtain appropriate quantifications. Several second-order multivariate calibration models were evaluated for this purpose: PARAFAC and MCR-ALS in two different modes, and PLS/RBL.