Search results for "010401 analytical chemistry"

Natural oxygenation of Champagne wine during ageing on lees: A metabolomics picture of hormesis

2016

International audience; The oxygenation of Champagne wine after 4 and 6 years of aging on lees in bottle was investigated by FTICR-MS and UPLC-Q-TOF-MS. Three levels of permeability were considered for the stoppers, ranging from 0.2 to 1.8 mg/L/year of oxygen transfer rate. Our results confirmed a good repeatability of ultrahigh resolution FTICR-MS, both in terms of m/z and coefficient of variation of peak intensities among biological replicates. Vintages appeared to be the most discriminated features, and metabolite annotations suggested that the oldest wines (2006) were characterized by a higher sensitivity towards oxygenation. Within each vintage, the oxygenation mechanisms appeared to b…

Sulfites and the Wine Metabolome

2017

International audience; In a context of societal concern about food preservation, the reduction of sulfite input plays a major role in the wine industry. To improve the understanding of the chemistry involved in the SO2 protection, a series of bottle aged Chardonnay wines made from the same must, but with different concentrations of SO2 added at pressing were analyzed by ultrahigh resolution mass spectrometry (FT-ICR-MS) and excitation emission matrix fluorescence (EEMF).Metabolic fingerprints from FT-ICR-MS data could discriminate wines according to the added concentration to the must but they also revealed chemistry-related differences according to the type of stopper, providing a wine me…

Modular Breath Analyzer (MBA): Introduction of a Breath Analyzer Platform Based on an Innovative and Unique, Modular eNose Concept for Breath Diagnos…

2021

Exhaled breath analysis for early disease detection may provide a convenient method for painless and non-invasive diagnosis. In this work, a novel, compact and easy-to-use breath analyzer platform with a modular sensing chamber and direct breath sampling unit is presented. The developed analyzer system comprises a compact, low volume, temperature-controlled sensing chamber in three modules that can host any type of resistive gas sensor arrays. Furthermore, in this study three modular breath analyzers are explicitly tested for reproducibility in a real-life breath analysis experiment with several calibration transfer (CT) techniques using transfer samples from the experiment. The experiment …

Analysis of Contact Traces of Cannabis by In-Tube Solid-Phase Microextraction Coupled to Nanoliquid Chromatography

2018

Because of its inherent qualities, in-tube solid-phase microextraction (IT-SPME) coupled on-line to nanoliquid chromatography (nanoLC) can be a very powerful tool to address the new challenges of analytical laboratories such as the analysis of traces of complex samples. This is the case of the detection of contact traces of drugs, especially cannabis. The main difficulties encountered in the analysis of traces of cannabis plants on surfaces are the low amount of sample available (typically &lt

A hardware skin-segmentation IP for vision based smart ADAS through an FPGA prototyping

2017

International audience; In this paper we presents a platform based design approach for fast HW/SW embedded smart Advanced Driver Assistant System (ADAS) design and prototyping. Then, we share our experience in designing and prototyping a HW/SW vision based smart embedded system as an ADAS that helps to increase the safety of car's drivers. We present a physical prototype of the vision ADAS based on a Zynq FPGA. The system detects the fatigue state of the driver by monitoring the eyes closure and generates a real-time alert. A new HW/SW codesign skin segmentation step to locate the eyes/face is proposed. Our presented new approach migrates the skin segmentation step from processing system (S…

2018

Whisky can be described as a complex matrix integrating the chemical history from the fermented cereals, the wooden barrels, the specific distillery processes, aging, and environmental factors. In this study, using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), we analyzed 150 whisky samples from 49 different distilleries, 7 countries, and ranging from 1 day new make spirit to 43 years of maturation with different types of barrel. Chemometrics revealed the unexpected impact of the wood history on the distillate's composition during barrel aging, regardless of the whisky origin. Flavonols, ol…

Food carotenoids and cancer prevention: an overview of current research

1997

Carotenoids are plant pigments that are present in the human diet as microcomponents of fruit and vegetables. Since 1980, a consistent bulk of the results from both epidemiologic and experimental studies has strongly suggested that β-carotene, a widespread food carotenoid with provitamin A activity, could prevent the onset of cancers, especially lung cancer. Unfortunately, subsequent large-scale intervention studies failed, with one exception, to demonstrate any chemopreventive potency for β-carotene supplementation in humans, revealing a lack of knowledge of the mechanisms involved. In addition to their antioxidant properties, which have long been thought to be the clue to their biological…

Formation of Aroma by Hydrolysis of Glycosidically Bound Components

1992

SUMMARY Acid hydrolysis has been used in order to establish the presence of glycosidically bound components in fruits. During this treatment, rearrangement reactions of free monoterpene alcohols generally occur. This inconvenient may be avoided using enzymatic hydrolysis, however the specificity of enzymes requires the previous knowledge of the structures of compounds used as substrates in order to control the reaction. Several glycosidically bound components, glucosides, rutinosides and arabinoglucosides present in grapes and apricot were isolated, separated and identified using non destructive methods, MS-MS low energy CAD spectra and HPLC. s-D-glucosidase, α-L-rhamnosidase, α-L-arabinase…

Electrospray ion mobility mass spectrometry of positively and negatively charged (1R,2S)-dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium br…

2015

Rationale Self-assembling processes of surfactants in the gas phase constitute a developing research field of interest since they allow information to be gained on the peculiar structural organization of these aggregates, on their ability to incorporate from small molecules up to proteins and on their possible use as carriers of drugs in the gas phase or as cleaning agents and exotic reaction media. Methods The mass spectra of charged aggregates of the chiral surfactant (1R,2S)-dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB) in the gas phase have been recorded using a Synapt G2-Si mass spectrometer in the positive and negative ion mode. For comparison purposes, the …

Molecular beacon strategies for sensing purpose

2021

Abstract The improvement of nucleic acid probes as vital molecular engineering devices will cause a noteworthy contribution to developments in bioimaging, biosensing, and disorders diagnosis. The molecular beacon (MB) which was designed by Tyagi and Kramer in 1996, are loop-stem hairpin-designed oligonucleotides armed with a quencher and a dye (also named reporter groups) at the 3′ or 5′ ends. This construction allows that MBs in the absence of their target complementary molecules do not fluoresce. Through hybridization with their specific targets a spontaneous configuration change on MBs occur and the dye and quencher separate from each other, resulting in emitting the fluorescence. MBs ar…