How to build a robust model with only a few reference values: a chemometric challenge at 'Chimiométrie 2007'

Following up on the success of previous chemometric challenges arranged during the annual congress organised by the French Chemometrics Society, the organisation committee decided to repeat the idea for the Chimiometrie 2007 event (http://www.chimiometrie.org/) held in Lyon, France (2930 November) by featuring another dataset on its website. As for the first contest in 2004, this dataset was selected to test the ability of participants to apply regression methods to NIR data. The aim of Challenge 2007 was to perform a calibration model as robust and precise as possible using a data set with only a few reference values available and submitted to different perturbation factors. The committee received nine answers; this paper summarizes the best three approaches, as well as the approach proposed by the organisers

Combination of several mass spectrometry ionization modes: A multiblock analysis for a rapid characterization of the red wine polyphenolic composition

cited By 11International audienceIn the present study, direct flow injection mass spectrometry was investigated for rapid characterization of the polyphenolic composition of red wines. Atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) (in both positive and negative ion modes) have been simultaneously used for a more comprehensive analysis of the samples studied. In this way, four mass spectra have been recorded for each wine. Each spectrum was considered as a fingerprint related to the chemical composition. This methodology was applied to a large number of Beaujolais wines from different grades and different vintages.This data set was processed using a chemometrical multiblock analysis, which allowed to synthesize the whole information collected. The results obtained showed that the wine fingerprints address the composition of the main polyphenolic compounds present in the red wines and can discriminate groups of wines showing different polyphenolic compositions. Multiblock analysis appears as a very promising tool to deal with several data tables of multivariate signals in order to define, by combining the whole information, the best operating protocol according to the desired analytical objectives. © 2010 Elsevier B.V

Chocolates classification according to their volatile compounds fingerprints measured by PTR-ToF-MS

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Dynamics of vasoconstructor-vasodilation potential on the background of the development of experimental diabetic retinopathy

Proved development of endothelial dysfunction in rats that was modeled experimental diabetic retinopathy, as evidenced by increased endothelin-1 levels. It was found that at each stage of the study, pathological vasoconstriction increases (p <0.001 compared with the intact group). It was revealed that simulated diabetic retinopathy negatively affects vasodilation potential, as evidenced by the analysis of the content of S-nitrosothiols in the blood of experimental animals (p <0.001 compared with the data of intact animals). In the analysis of vasoconstrictor-vasodilyatatsiynogo potential at each stage of the experiment proved the prevalence of pathological vasoconstriction (p <0.001). The weakening of the vasodilatory potential was step by step more gradual in comparison w ith the dynamics of the increase in the vasodilation potential. In a comparative experiment characteristic pathological stages most pronounced shifts mounted on stage III of diabetic retinopathy study simulated (180-day)

Chocolates classification according to their volatile compounds fingerprints measured by PTR-ToF-MS

International audienc

Chocolates classification according to their volatile compounds fingerprints measured by PTR-ToF-MS

International audienc

Organoleptic properties of dark chocolates investigated by direct-injection mass spectrometry (PTR-ToF-MS) and GC-MS-Olfactometry

National audienc

Does aroma composition allow to discriminate groups of dark chocolates categorized on the basis of their organoleptic properties? Inputs of direct-injection mass spectrometry (PTR-ToF-MS) and GC-Olfactometry

International audienc

Does aroma composition allow to discriminate groups of dark chocolates categorized on the basis of their organoleptic properties? Inputs of direct-injection mass spectrometry (PTR-ToF-MS) and GC-Olfactometry

International audienc