Cultivar characterization of stone fruits for their minimal processing.

Due to their physicochemical properties, minimal processing of fruits is challenging because of their quick quality loss. Therefore, several preservative steps are needed, such as washing treatments, modified atmosphere packaging, cultivar selection, etc. The latter is an important pre-harvest condition due to the fact that many functional compounds and enzymes are dependent on the cultivar.

Spectrofluorimetric determination of SN-38, a promising new anti-tumor agent, in the presence and absence of organized media.

This study focuses on the spectrofluorimetric behavior of the camptothecin derivative 7-ethyl-10-hydroxycamptothecin (SN-38) alone and in the presence of organized media and also on its potential analytical applications. SN-38 displays native fluorescence in both lactone and carboxylate form, which has been the base for development of two spectrofluorimetric methods, one for the lactone form (acidic media) and another for the carboxylate form (basic media). In an attempt to improve the understanding of SN-38, its interaction with several cyclodextrins and surfactants has been studied using spectrofluorimetry.

Fluorescent determination of Hg2+ in water and fish samples using a chemodosimeter based in a Rhodamine 6G derivative and a portable fiber-optic spectrofluorimeter.

A fluorimetric chemodosimeter (FC1), based on a Rhodamine 6G derivative, is proposed for the recognition of Hg(2+) ions in water and fish samples. The reagent shows a highly selective and sensitive reaction with Hg(2+), giving rise to strong fluorescence emission at 555 nm. The obvious color change of the solution from colorless to pink upon the addition of Hg(2+) demonstrates that FC1 can be used for "naked-eye" detection of Hg(2+) in water effluents.

Second-order advantage achieved by unfolded-partial least-squares/residual bilinearization modeling of excitation-emission fluorescence data presenting inner filter effects.

A second-order multivariate calibration approach, based on a combination of unfolded-partial least-squares with residual bilinearization (U-PLS/RBL), has been applied to fluorescence excitation-emission matrix data for multicomponent mixtures showing inner filter effects. The employed chemometric algorithm is the most successful one regarding the prediction of analyte concentrations when significant inner filter effects occur, even in the presence of unexpected sample components, which require strict adherence to the second-order advantage. Results for simulated fluorescence excitation-emission data are described, in comparison with the classical approach based on parallel factor analysis and other second-order algorithms, including generalized rank annihilation, bilinear least squares combined with residual bilinearization and multivariate curve resolution-alternating leastsquares.