Papers by Véronique Viette
Diagnostics, Feb 10, 2024
Clinical Chemistry and Laboratory Medicine, Jun 27, 2011
Helvetica Chimica Acta, Mar 14, 1990
The kinetics of the electron transfer between reduced spinach [2Fe‐2S]‐ferredoxin and the optical... more The kinetics of the electron transfer between reduced spinach [2Fe‐2S]‐ferredoxin and the optically active complexes [Co((R,R)‐ or (S,S)‐alamp)py]+ (I), [Co((R,R)‐ or (S,S)‐promp)H2O]+ (IIa), and [Co((R,R)‐ or (S,S)‐promp)py]+ (IIb) have been investigated. The reactions are stereoselective, and for I and IIa, the Stereoselectivity strongly depends on temperature due to large differences in the activation enthalpy between enantiomeric reagents. Isokinetic behaviour is observed between enantiomers, the ΔΔH values being largely compensated by the ΔΔS values. The compensation behaviour is explained by the combination of stereochemical interactions and desolvation processes on formation of the precursor complex or the transition state.
Ce travail décrit l'élaboration d'une méthode LC-MS/MS couplée à un logiciel performant e... more Ce travail décrit l'élaboration d'une méthode LC-MS/MS couplée à un logiciel performant et innovant pour la recherche générale de substances inconnues (screening) en tant qu'alternative aux méthodes utilisées en toxicologie clinique. Ce nouveau logiciel d'identification de petites molécules "SmileMS" a été développé en collaboration avec la société Genebio SA. La première partie du travail explique le développement technique de la méthode ainsi que son évaluation à l'aide de 97 composés et métabolites importants. L'étude des effets matrices et la détermination des concentrations limites d'identification est réalisée avec ces composés. Les résultats obtenus dans des échantillons biologiques à l'aide de la méthode LC-MS/MS sont comparés à ceux obtenus avec le système Remedi® (LC-DAD) dans la deuxième partie. En conclusion, la méthode proposée fournit une alternative au système Remedi® pour le laboratoire de toxicologie clinique d'urgence. De plus SmileMS favorise son implémentation dans le travail de routine
Ce travail décrit l'élaboration d'une méthode LC-MS/MS couplée à un logiciel performant e... more Ce travail décrit l'élaboration d'une méthode LC-MS/MS couplée à un logiciel performant et innovant pour la recherche générale de substances inconnues (screening) en tant qu'alternative aux méthodes utilisées en toxicologie clinique. Ce nouveau logiciel d'identification de petites molécules "SmileMS" a été développé en collaboration avec la société Genebio SA. La première partie du travail explique le développement technique de la méthode ainsi que son évaluation à l'aide de 97 composés et métabolites importants. L'étude des effets matrices et la détermination des concentrations limites d'identification est réalisée avec ces composés. Les résultats obtenus dans des échantillons biologiques à l'aide de la méthode LC-MS/MS sont comparés à ceux obtenus avec le système Remedi® (LC-DAD) dans la deuxième partie. En conclusion, la méthode proposée fournit une alternative au système Remedi® pour le laboratoire de toxicologie clinique d'urgence. De plus SmileMS favorise son implémentation dans le travail de routine
Journal of Chromatography A, 2010
Helvetica Chimica Acta, 1990
The kinetics of the electron transfer between reduced spinach [2Fe‐2S]‐ferredoxin and the optical... more The kinetics of the electron transfer between reduced spinach [2Fe‐2S]‐ferredoxin and the optically active complexes [Co((R,R)‐ or (S,S)‐alamp)py]+ (I), [Co((R,R)‐ or (S,S)‐promp)H2O]+ (IIa), and [Co((R,R)‐ or (S,S)‐promp)py]+ (IIb) have been investigated. The reactions are stereoselective, and for I and IIa, the Stereoselectivity strongly depends on temperature due to large differences in the activation enthalpy between enantiomeric reagents. Isokinetic behaviour is observed between enantiomers, the ΔΔH values being largely compensated by the ΔΔS values. The compensation behaviour is explained by the combination of stereochemical interactions and desolvation processes on formation of the precursor complex or the transition state.
cclm, 2011
Toxicological screening is the analysis of a biological specimen to detect and identify compounds... more Toxicological screening is the analysis of a biological specimen to detect and identify compounds in patients admitted to the hospital with acute intoxication of unknown origin. The screening of a wide range of toxicologically relevant compounds in biological samples is a serious challenge for clinical laboratories. The high selectivity and sensitivity of liquid chromatography coupled to mass spectrometry or tandem mass spectrometry technology provides an attractive alternative to the current methods. For these reasons, an increasing number of applications for multi-target screening or general screening of unknown compounds in biological matrices are being published. This paper is an overview of sample clean-up, chromatographic separation and mass spectrometry detection procedures which can be combined to obtain screening methods adapted to the constraints and needs of various laboratories, and none specifically in clinical toxicology. Currently the techniques are in the hands of sp...
CHIMIA, 2012
Toxicological screening is the analysis of biological samples to detect and identify unknown comp... more Toxicological screening is the analysis of biological samples to detect and identify unknown compounds. The high selectivity and sensitivity of liquid chromatography (LC) coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) technology provide an attractive alternative to the current methods (LC-UV, GC/MS, etc.). For these reasons, an increasing number of applications are being published. This paper is a brief overview of LC-MS(/MS) screening methods developed for clinical toxicology in recent years. Various sample treatments, chromatographic separations and detection by mass spectrometry can be combined to obtain screening methods adapted to the constraints and needs of clinical toxicology laboratories. Currently the techniques are in the hands of specialists, mainly in academic institutions. However, the evolution in technology should allow application of these techniques as a tool in toxicology laboratories, thus allowing a more widespread exploitation of their po...
Clinical Biochemistry, 2011
Perform a comparison of results obtained with a LC-MS/MS method and a Remedi® instrument on clini... more Perform a comparison of results obtained with a LC-MS/MS method and a Remedi® instrument on clinical serum samples. Results obtained on 146 selected plasma samples were compared between the two methods. On the 336 positive identifications, 89% were obtained using the LC-MS/MS technique and 57% by the LC-DAD. Benzodiazepines were well recognized by LC-MS/MS. For some compounds such as antidepressant agents, sensitivity was improved using LC-MS/MS. Moreover, this method extended the panel of drugs detected in clinical toxicology. The new software platform developed for screening and identification of small molecules (SmileMS) allows an easy and reproducible detection of drugs and toxic compounds in blood for general unknown screening. It offers automated generation of reports, which makes the LC-MS/MS easier to use without having specialised skills in mass spectrometry. This LC-MS/MS screening method will be a reliable alternative to the Remedi® instrument in the global process of screening in emergency clinical toxicology laboratories.
Analytical Chemistry, 2009
The diversity of experimental workflows involving LC-MS/MS and the extended range of mass spectro... more The diversity of experimental workflows involving LC-MS/MS and the extended range of mass spectrometers tend to produce extremely variable spectra. Variability reduces the accuracy of compound identification produced by commonly available software for a spectral library search. We introduce here a new algorithm that successfully matches MS/MS spectra generated by a range of instruments, acquired under different conditions. Our algorithm called X-Rank first sorts peak intensities of a spectrum and second establishes a correlation between two sorted spectra. X-Rank then computes the probability that a rank from an experimental spectrum matches a rank from a reference library spectrum. In a training step, characteristic parameter values are generated for a given data set. We compared the efficiency of the X-Rank algorithm with the dot-product algorithm implemented by MS Search from the National Institute of Standards and Technology (NIST) on two test sets produced with different instruments. Overall the X-Rank algorithm accurately discriminates correct from wrong matches and detects more correct substances than the MS Search. Furthermore, X-Rank could correctly identify and top rank eight chemical compounds in a commercially available test mix. This confirms the ability of the algorithm to perform both a straight single-platform identification and a cross-platform library search in comparison to other tools. It also opens the possibility for efficient general unknown screening (GUS) against large compound libraries.
Journal of Chromatography A, 2010
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Papers by Véronique Viette