Second-Order Calibration of Excitation—Emission Matrix Fluorescence Spectra for the Determination of N-Phenylanthranilic Acid Derivatives

Abstract

A spectrofluorimetric method has been developed for the quantitative determination of mefenamic, flufenamic, and meclofenamic acids in urine samples. The method is based on second-order data multivariate calibration (unfolded partial least squares (unfolded-PLS), multi-way PLS (N-PLS), parallel factor analysis (PARAFAC), self-weighted alternating trilinear decomposition (SWATLD), and bilinear least squares (BLLS)). The analytes were extracted from the urine samples in chloroform prior to the determination. The chloroform extraction was optimized for each analyte, studying the agitation time and the extraction pH, and the optimum values were 10 minutes and pH 3.5, respectively. The concentration ranges in chloroform solution of each of the analytes, used to construct the calibration matrix, were selected in the ranges from 0.15 to 0.8 microg mL-1 for flufenamic and meclofenamic acids and from 0.25 to 3.0 microg mL-1 for mefenamic acid. The combination of chloroform extraction and second-order calibration methods, using the excitation-emission matrices (EEMs) of the three analytes as analytical signals, allowed their simultaneous determination in human urine samples, in the range of approximately 80 mg L-1 to 250 mg L-1, with satisfactory results for all the assayed methods. Improved results over unfolded-PLS and N-PLS were found with PARAFAC, SWATLD, and BLLS, methods that exploit the second-order advantage.

Calibration, standardization, and quantitative analysis of multidimensional fluorescence (MDF) measurements on complex mixtures (IUPAC Technical Report)

“…These include, amongst others, the characterization of natural organic matter in soil and aquatic ecosystems [72,108,109], oil-spill forensics [110] and oil characterization [6,111], monitoring of food quality and production [67,71,112], and diagnostics on body fluids e.g. [113,114]. In the near future, we anticipate that there will be a significant increase in the use of EEM/SFS and chemometrics for routine and high-value analytical applications.…”

Development of a potentiometric flufenamate ISE and its application to pharmaceutical and clinical analyses

“…16 . The limit of detection, as determined from the intersection of the two extrapolated segments of the calibration graph (Figure 1), was 7.1 10 -7 mol L -1…”

“…These methods include spectrophotometry, [3][4][5] chromatography, [6][7][8][9][10][11] capillary electrophoresis, 12,13 atomic absorption spectrometry, 14 spectrofluorimetry, [15][16][17] derivative synchronous fluorescence spectrometry, 18 high-performance liquid chromatography-mass spectrometry, 19 flow injection analysis, 20 and voltammetry. 21,22 However, many of these methods are often time-consuming, technically demanding and require the use of costly, highly specialized instruments.…”

Determination of Indole-3-Acetic Acid in Soil Using Excitation–Emission Matrix Fluorescence with Trilinear Decomposition-based Calibration Methods

“…Even in the presence of unknown interferents, the trilinearity of the three-way data can also be utilized in a unique decomposition that allows spectral profiles as well as relative concentrations of each sample component to be extracted directly. 25 Although this is the first time for it to be utilized in quantification of IAA in soil, the property has been a hot topic in the current chemometric domain, and has been successfully employed for many practical applications, such as drugs analysis, [26][27][28] environment monitoring, 29 quality control and food analysis, 30 and bioprocesses monitoring. 31,32 In this study, a strategy for sensitive and selective determination of IAA in soil is proposed, which combines the fluorescence excitation-emission matrices (EEMs) with secondorder calibration methods based on ATLD and SWATLD algorithms.…”