Four-way calibration applied to the simultaneous determination of folic acid and methotrexate in urine samples |
| |
Authors: | A Muñoz de la Peña I Durán Merás A Jiménez Girón |
| |
Institution: | (1) Department of Analytical Chemistry, University of Extremadura, 06071 Badajoz, Spain |
| |
Abstract: | First-, second- and third-order calibration methods were investigated for the simultaneous determination of folic acid and
methotrexate. The interest in the determination of these compounds is related to the fact that methotrexate inhibits the body’s
absorption of folic acid and prolonged treatment with methotrexate may lead to folic acid deficiency, and to the use of folic
acid to cope with toxic side effects of methotrexate. Both analytes were converted into highly fluorescent compounds by oxidation
with potassium permanganate, and the kinetics of the reaction was continuously monitored by recording the kinetics curves
of fluorescence emission, the evolution with time of the emission spectra and the excitation–emission matrices (EEMs) of the
samples at different reaction times. Direct determination of mixtures of both drugs in urine was accomplished on the basis
of the evolution of the kinetics of EEMs by fluorescence measurements and four-way parallel-factor analysis (PARAFAC) or multiway
partial least squares (N-PLS) chemometric calibration. The core consistency diagnostic (CORCONDIA) was employed to determine
the correct number of factors in PARAFAC and the procedure converged to a choice of three factors, attributed to folic acid,
methotrexate and to the sum of fluorescent species present in the urine.
![MediaObjects/216_2006_408_Figa_HTML.jpg](/content/a6p7241430047816/MediaObjects/216_2006_408_Figa_HTML.jpg) |
| |
Keywords: | Four-way parallel-factor analysis Multiway partial least squares Excitation– emission matrices Methotrexate Folic acid |
本文献已被 PubMed SpringerLink 等数据库收录! |
|