Search results for "spme"
showing 10 items of 53 documents
Sesquiterpene volatile organic compounds (VOCs) are markers of elicitation by sulfated laminarine in grapevine
2015
SPE IPM UB CT1; International audience; Inducing resistance in plants by the application of elicitors of defense reactions is an attractive plant protection strategy, particularly for grapevine (Vitis vinifera), which is susceptible to severe fungal diseases. Although induced resistance (IR) can be successful under controlled conditions, in most cases, IR is not sufficiently effective for practical disease control under outdoor conditions. Progress in the application of IR requires a better understanding of grapevine defense mechanisms and the ability to monitor defense markers to identify factors, such as physiological and environmental factors, that can impact IR in the vineyard. Volatile…
Sensory evaluation of headspace extracts by direct GC-olfactometry : application to fresh orange juice
2002
National audience
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 <
Desarrollo de estrategías analíticas para la identificación de contaminantes emergentes
2015
En la presente Tesis, se han desarrollado diferentes métodos para identificar la presencia de contaminantes procedentes de diferentes fuentes naturales. Los métodos desarrollados han sido abordados utilizando dos metodologías: (i) IT-SPME acoplado a CapLC y UHPLC con detección DAD y MS, y (ii) dispositivos de análisis in situ. La estrategia basada en el acoplamiento entre IT-SPME y CapLC y UHPLC se ha utilizado para la estimación de la presencia de contaminantes (pesticidas como triazinas, nitroanilina, fenilureas y organofosforados, y plastificantes como productos de degradación del DEHP y principalmente DEHP) en muestras de aguas superficiales, de aguas de depuradoras, biota y sedimentos.…
Partition of volatile compounds in pea globulin–maltodextrin aqueous two-phase system
2014
International audience; This study is based on the assumption that the off-flavour of pea proteins might be decreased using the retention of volatile compounds by a mixture with another biopolymer. The partition of volatile compounds in an aqueous system containing pea protein and maltodextrins was followed under thermodynamic incompatibility conditions. Firstly, the phase diagram of the system was established. Then, the partition of aroma compounds between the phase rich in protein and the phase rich in maltodextrin was measured by SPME–GC–MS. There was a transfer of volatile compounds during phase separation. Variations of pH were also used to vary the retention of volatile compounds by p…
Involvement of an Alkane Hydroxylase System of Gordonia sp. Strain SoCg in Degradation of Solid n-Alkanes▿
2010
ABSTRACT Enzymes involved in oxidation of long-chain n -alkanes are still not well known, especially those in Gram-positive bacteria. This work describes the alkane degradation system of the n -alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n -alkanes from dodecane (C 12 ) to hexatriacontane (C 36 ) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4…
Volatile compounds of fresh fruits of Phillyrea latifolia L.
2004
The volatiles constituents of fresh fruits of Phillyrea latifolia were submitted to investigation by GC-MS. The plants grows wild in different zones of the mediterranean region and its leaves and fruits are used as astringent, diuretic and anti-inflammatory. The volatiles were sampled by solid-phase microextraction (SPME), with a 100 mm polydimethylsiloxane fibre a 50 °C for 1 h. The headspace main components of fresh fruits of Phillyrea latifolia included limonene, β-cariophillene, eremophilene, α-muurolene, β -eudesmol e spatulenol.
Halogenated Anesthetics Determination in Urine by SPME/GC/MS and Urine Levels Relationship Evaluation with Surgical Theatres Contamination
2014
In this work, a new sensitive analytical method has been developed and evaluated for the determination of the most commonly used gaseous anesthetics, desflurane, sevoflurane, and this latter’s hepatic metabolite hexafluoroisopropanol (HFIP) in the urine. In addition, an evaluation of anesthetics exposition on the urine levels of a small population of surgical operators has been performed and results are briefly discussed.
Impact of Ageing on Pea Protein Volatile Compounds and Correlation with Odor
2022
Vegetal proteins are of high interest for their many positive aspects, but their ‘beany’ off-flavor is still limiting the consumer’s acceptance. The aim of this work was to investigate the conservation of pea protein isolate (PPI) during time and especially the evolution of their organoleptic quality under two storage conditions. The evolution of the volatile compounds, the odor and the color of a PPI has been investigated during one year of storage. PPI was exposed to two treatments mimicking a lack of control of storage conditions: treatment A with light exposition at ambient temperature (A—Light 20 °C) and treatment B in the dark but with a higher temperature …
Caratterizzazione della componente volatile rilasciata da sostanza organica naturale di suoli vulcanici
2008
Il suolo è una matrice caratterizzata da notevole complessità chimico-fisica. Tra le varie componenti, la sostanza organica naturale (NOM) gioca un ruolo fondamentale nelle interazioni con contaminanti di natura organica ed inorganica. La NOM è attualmente considerata una associazione supramolecolare di sistemi organici con un peso molecolare non superiore a 1000-2000 Da. La sua caratterizzazione è tradizionalmente effettuata mediante l’ausilio di tecniche cromatografiche e spettroscopiche. La verifica dell’allontanamento di molecole a basso peso molecolare all’aumento della temperatura, nell’intervallo 40-100 °C, è stata condotta con tecniche di microestrazione in fase solida in spazio di …