Pascal Cardinael

• Professor
• Managing Director at Université de Rouen Normandie

Glycerophospholipids (GPLs) play important roles in cellular compartmentalization and signaling. Among them, phosphatidic acids (PA) exist as many distinct species depending on acyl chain composition, each one potentially displaying unique signaling function. Although the signaling functions of PA have already been demonstrated in multiple cellular...

Temperature-Cycle-Induced Deracemization (TCID) offers a promising approach to obtain enantiopure solids from racemic mixtures. By combining rapid racemization in solution and temperature swings, homochirality is theoretically achieved. Despite theoretical expectations of doubled yields compared to traditional chiral separation methods, such as in...

Temperature Cycle Induced Deracemization (TCID) offers a promising approach to obtain enantiopure solids from racemic mixtures. By combining rapid racemization in solution and temperature swings, homochirality is theoretically achieved. Despite theoretical expectations of doubled yields compared to traditional chiral separation methods, such as in...

Asphalt is subjected to aging, leading to physical and chemical modifications reducing its performance. Recently, the Western Research Institute developed the SAR-AD method that allowed the separation of asphalt into eight fractions (saturates, aromatics 1, aromatics 2, aromatics 3, resins, asphaltenes 1, asphaltene 2, and asphaltenes 3). In this w...

For decades, it has been known that the creation of oxygenated functional groups, especially carbonyl and sulfoxide, is among the main causes of chemical aging and degradation of asphalt. However, is the oxidation of a bitumen homogeneous? The focus of this paper was to follow the oxidation phenomena through an asphalt puck during a pressure aging...

Preferential enrichment (PE) is a crystallization process, starting from either a racemic of slightly enantio-enriched solution (ca. +5%) that results in a high enantiomeric excess in the liquid phase (>+90%ee) and a slight opposite excess in the deposited crystals (−2 to −5%ee). The mechanism(s) of this symmetry-breaking phenomenon is (are) still...

The present study investigated the use of a dedicated gas chromatography (GC) column (L = 70 cm, 75 μm deep, and 6.195 mm wide) with radially elongated pillars (REPs) as the second column in a comprehensive two-dimensional gas chromatography (GC × μGC) system. Three stationary phases [apolar polydimethylsiloxane (PDMS), medium polar room-temperatur...

For over 50 years, ion chromatography has been demonstrated to be a successful technique used to quantify a wide range of ions and ionizable compounds, either organic or inorganic, in various matrices using conductimetric or electrochemical detection. It was only since 1996 that ion chromatography was coupled to electrospray-mass spectrometry, open...

Pesticide extraction in rapeseed samples remains a great analytical challenge due to the complexity of the matrix, which contains proteins, fatty acids, high amounts of triglycerides and cellulosic fibers. An HPLC-MS/MS method was developed for the quantification of 179 pesticides in rapeseeds. The performances of the quick, easy, cheap, effective,...

Performances of multiresidue analysis of one hundred of pesticides and contaminants, using GC-Q-Orbitrap method in full scan mode were compared to those obtained with GC-triple-quadrupole method in multiple reaction monitoring mode. In terms of sensitivity, 86% of molecules exhibited lower limit of detection values using GC-Q-Orbitrap than using GC...

In this work, the synthesis, characterization and chromatographic performance of a silica material chemically bonded with a liquid crystal based on terminal citronellol for HPLC separation were investigated. This bonded liquid crystal stationary phase denoted as LC-LCC8 resulted from the grafting of a mesogenic carboxylic acid, 3′-((3,7-dimethyloct...

A method utilizing turbulent flow to perform ultra-fast separations and screen chiral compounds in supercritical fluid chromatography (SFC) is described. Carbon dioxide at high flow rates (up to 4.0 mL/min) is delivered into gas chromatography (GC) open-tubular columns (0.18 mm ID, 20 m long, ~ 0.2 μm stationary film thickness) to establish turbule...

Room-temperature ionic liquids (RTILs) have proven to be efficient polar or highly polar stationary phases for GC. Nevertheless, the thermal stability of monocationic RTILs limits their use in high-temperature GC. To improve the thermal stability, an RTIL based on a 1-methylimidazolium derivative was anchored in a three-dimensional network using th...

Comprehensive Gas Chromatography (GC) has emerged in recent years as the technique of choice for the analysis of volatile and semi‐volatile compounds in complex matrices. Coupling it with high‐resolution mass spectrometry makes a powerful tool for identification and quantification of organic compounds. The results obtained in this study showed a si...

“In our daily life, map apps are essential for many people to access their destinations. Phase diagrams play a similar role to map apps in the crystallization.” Read more about the story behind the cover in the Cover Profile and about the research itself on page 13890 ff. (DOI: 10.1002/chem.201903338). image

A productive deracemization process based on a quaternary phase diagram study of a naphthamide derivative is reported. New racemic compounds of an atropisomeric naphthamide derivative have been discovered, and a quaternary phase diagram has been constructed that indicated that four solids are stable in a methanol/H2O solution. Based on the results...

Phase diagrams play a critical role for tuning crystallization. This study explains the basics of phase diagrams starting from the ternary system to a quaternary system with and without fast racemization in the liquid phase. Experimentally, an atropisomeric naphthamide derivative in MeOH/H2O serves as an example. Deracemization is ensured by a seco...

Stable NH-form of the threonine-based Schiff base 4, (2S,3R)-3-((tert-butyldimethylsilyl)oxy)-2-(((E)-(2-hydroxynaphthalen-1-yl)methylene)amino)butanamide, was synthesized and characterized in the crystalline state by means of IR spectroscopy and X-ray crystallographic analysis. This is the first X-ray determination of an amino acid-based Schiff ba...

Temperature-cycle-induced deracemization (TCID) has been widely studied in the field of chiral separation, ranging from fundamental research to applications. In this study, the second-order asymmetric transformation (SOAT) of 2-methoxy-1-naphthamide in an azeotropic mixture of ethyl acetate and cyclohexane is compared with TCID, in terms of process...

Preferential Enrichment is a relatively new process of chiral resolution developed in the 90’s. Extension of the scope of Preferential Enrichment was attempted with tryptophan ethyl ester hydrochloride. This salt presents one of the most important requirements for Preferential Enrichment: i.e. a larger solubility for the pure enantiomers with refer...

Herein, we report the chiral symmetry breaking of 2-methoxy-1-naphthamide atropisomers through temperature cycling with-out the use of any racemization reagent. The racemization rate (k1) controls the deracemization process when the cooling of the slurry is slow enough to keep the system close to equilibri-um. The productivity appears proportional...

The development of the reversed fill/flush modulator represents a significant advancement in flow-modulated, comprehensive two-dimensional gas chromatography (GC × GC). Compared to the forward flush/fill modulator, the reversed-flow modulator is less susceptible to baseline anomalies and peak tailing as a result of modulator channel overfilling or...

Objective: The objective of this work is to show the feasibility of manufacturing from a spray drying process particles containing immunoglobulin G capable of being administered by inhalation via a pressurized metered dose inhaler. Methods: Spray drying were made from aqueous solutions containing IgG and two types of excipients, mannitol and tre...

New polar embedded aromatic stationary phases (mono- and trifunctional versions) that contain an amide-embedded group coupled with a tricyclic aromatic moiety were developed for chromatographic applications and described in the first paper of this series. These phases offered better separation performance for PAHs than for alkylbenzene homologues,...

Supercritical Fluid Chromatography is frequently used to efficiently handle separations of enantiomers. The separation of basic analytes usually requires the addition of a basic additive in the mobile phase to improve the peak shape or even to elute the compounds. The effect of increasing the concentration of 2-propylamine as additive on the elutio...

New polar embedded aromatic stationary phases of different functionalities (mono- and trifunctional) and on different silica supports (Fully Porous Particle (FPP) and Superficially Porous Particle (SPP)) were synthesized to determine the impact of the functionality on the retention process and the selectivity towards aromatic compounds. A full expe...

The present study deals with the experimental determination of binary phase diagrams between Phenanthrene and two of its impurities in most commercial samples: 9,10-dihydroanthracene and carbazole. Phase equilibria were investigated by combining Differential Scanning Calorimetry and X-Ray Powder Diffraction analyses. The results highlighted the exi...

This study aims at modelling and predicting solute retention in capillary Gas Chromatography (GC) and Flow Modulation comprehensive GC (FM-GCxGC). A new thermodynamic model, taking into account the effects of temperature and pressure, is proposed to describe the variation of the equilibrium partition constant of a solute during its elution. This re...

Epoxyeicosatrienoic acids (EETs) are vasodilating lipid mediators metabolized into dihydroxyeicosatrienoic acids (DHETs) by soluble epoxide hydrolase. We aimed to develop a LC-MS/MS method to quantify EETs and DHETs in human plasma and monitored their levels during vascular endothelial stimulation. Plasma samples, collected from 14 healthy and five...

Over 30 years, portable systems for fast and reliable gas analysis are at the core of both academic and industrial research. Miniaturized systems can be helpful in several domains. The way to make it possible is to miniaturize the whole gas chromatograph. Micro-system conception by etching silicon channel is well-known. The main objective is to obt...

The purification of Phenanthrene is a prerequisite before studying its solid-solid phase transition at the molecular scale. In this work, two purification methods – Zone Melting and Co-Crystallization with 3,5-dinitrobenzoic acid – were separately studied and compared, in view of reaching ultrapurity (purity > 99.9 mol. %). An explanation of the re...

Three novel hydrophilic interaction chromatography columns packed with bare silica 2.6 μm superficially porous particles were evaluated. These stationary phases undergo a different pretreatment temperature (400, 525 and 900°C) that might influence their kinetic performance and thermodynamic properties. In the first instance, we demonstrated that th...

Extended abstract for CRISTAL8 conference (Rouen, 2016) L' étude du mécanisme de la transition solide-solide – à l'échelle moléculaire – du phénanthrène requiert son ultrapurification (pureté molaire > 99,9 %). La présente étude aborde la purification du composé par co-cristallisation avec l'acide 3,5-dinitrobenzoïque. L'effet purifiant de la techn...

Enantiomerization of allylic trifluoromethyl sulfoxides occurs spontaneously at room temperature through the corresponding allylic trifluoromethanesulfenates via a [2,3]-sigmatropic rearrangement. Dynamic enantioselective high-performance liquid chromatography (HPLC) analysis revealed the stereodynamics of these sulfoxides ranging from chromatograp...

Chromatographic methods have made so much progress that they are today the method of choice in analytical laboratories. Not all molecules can be separated by the desired method. Derivatization reactions are simple chemical modification of the sample that will render it compatible with the selected separation method. Gas chromatography (GC) can sepa...

Due to their easy functionalization and their unique conformational and recognition properties, calixarenes are attracting molecular platforms for the elaboration of separation systems. Thus, in the last decades, these macrocyclic compounds have been subject to extensive research in analytical chemistry. This review is focused on the use of calixar...

This study reports the impact of thermal pretreatment between 400 and 1100°C on superficially porous silica particles (e.g. core-shell, fused-core; here abbreviated as SPP silica). The different thermally pretreated SPP silica (400°C, 900°C and 1100°C) were chemically bonded with an octadecyl chain under microwave irradiation. The bare SPP silica,...

The development of new efficient conversion processes to transform heavy petroleum fractions into valuable products, such as diesel, requires improved chemical knowledge of the latter. High-temperature comprehensive gas chromatography (HT-GC×GC) has proven to be a powerful technique for characterizing such complex samples. This paper reports on an...

In this study, different grafting methods were examined to develop high-density chemically modified octadecyl core–shell silica particles for HPLC applications. The influence of the reagents and the experimental conditions were evaluated, either through conventional heating or by microwave irradiation. For both experimental synthetic processes, che...

Two novel room-temperature ionic liquids (RTILs), a mono-cationic (tetra-n-octylammonium) and a dicationic (bis-methylpiperidinium-butylidene) room-temperature ionic liquid with the bis[(trifluoromethyl)sulfonyl]imide anion, were individually mixed with OV-1701 polysiloxane to tune the selectivity and the polarity of stationary phases for GC. The i...

A new process for the enantiomeric separation of racemic 3,6-dihydro-1,3,5-triazine derivatives for the treatment of disorders associated with insulin-resistance syndrome, by preferential crystallization.

New polyethylene-glycol-based sol-gels containing cyclodextrin or calix[6]arene derivatives have been synthesized. An original method for sol-gel preparation and capillary column coating, which consumes smaller quantities of selectors and allows for control of their amounts in the stationary phase, is reported herein. The new stationary phases exhi...

The knowledge of the thermodynamic parameters related to the hydration of organic solid phases is paramount to exert a very good control over this transition during industrial production or storage. To study this phenomenon, the citric acid was chosen as a model compound. By an original combination of gravimetric and thermal analyses (dynamic vapor...

Original mixed selectors were synthesized by coupling a single l-valine diamide moiety on permethylated β-cyclodextrin. The structures of the new selectors were designed to limit the interactions between the l-valine derivative and cyclodextrin by removing the amino acid moiety from the cyclodextrin cavity by means of an amide linkage on mono-6-ami...

We describe the conception, synthesis, and characterization of a novel cyclopeptide designed for chiral recognition. The asymmetric units are built from an unnatural amino acid in the series of alpha-aryl-alpha-methyl glycine. Modifications of standard methods of peptide synthesis are described in order to improve yields and purities when applied to...

Both pure enantiomers of α-phenyl- (or α-(p-methoxyphenyl))-α-trifluoromethyl-glycine and their corresponding methyl esters were obtained on a preparative scale using the following four-step sequence: the preparation of 5-aryl-5-trifluoromethylhydantoins by a Bücherer–Bergs reaction starting from trifluoromethyl aryl ketones, optical resolution by...

It is important to develop methods of optimizing the selection of column sets and operating conditions for comprehensive two-dimensional gas chromatography. A new method for the calculation of the percentage of separation space used was developed using Delaunay's triangulation algorithms (convex hull). This approach was compared with an existing me...

A series of novel 3-alkoxy-1,2-dihydro-3H-1,4-benzodiazepin-2-ones (7-15) was synthesized and their in vitro affinity for both the central benzodiazepine receptor (CBR) and the peripheral benzodiazepine receptor (PBR) of rat brain was studied. Racemic mixture of 7-bromo-3-(2-methoxy)ethoxy-5-phenyl-1,2-dihydro-3H-1,4-benzodiazepin-2-one (13) was se...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

This work deals with the synthesis of two mixed binary chiral selectors prepared by grafting (L)- or (D)-valine tert-butylamide on permethylated cyclodextrin macrocycle. The enantioselective properties of the new chiral selectors diluted in OV11 polysiloxane (35% phenyl- and 65% methylsiloxane) were investigated by means of injections of 117 racemi...

This work deals with the evaluation of three monohydroxy methylated β-cyclodextrin isomers as chiral selectors for capillary gas chromatography. Chromatographic properties of these stationary phases have been investigated in terms of efficiency, inertness and polarity. Injections of homologous series of hydantoin derivatives and 1-phenylethan-1-ol...

Separation of alkyl sulfate ethoxymers is investigated on various high-performance liquid chromatography (HPLC) stationary phases: Acclaim C18 Surfactant, Surfactant C8, and Hypercarb. For a fixed alkyl chain length, ethoxymers are eluted in the order of increasing number of ethoxylated units on Acclaim C18 Surfactant, whereas a reversed elution or...

This syudy aims to demonstrate the interest of GCxGC for research of target compounds in a complex environmental matrix. A sample of raw waste water extracted at basic pH has been analysed by GC/MS (ion trap spectrometer) and GCxGC-TOF-MS (time of flight spectrometer). The search for 58 target compounds, as well as a screening of other pollutants w...

An unprecedented enantioselective deprotonation/conjugate elimination sequence, which transforms an allylic meso-dioxepane into a chiral diene, is described. The best desymmetrization conditions (ee up to 70%) involve s-BuLi and sparteine at -78 degrees C in THF.

6I-O-Benzyl-2I–VIII, 3I–VIII, 6II–VIII-tricosa-O-methyl-γ-cyclodextrin was synthesized using indirect and direct approaches. The first indirect strategy consists of a multi-step sequence including the ring opening of the permethylated α-cyclodextrin, elongation of the chain with a 6-O-benzyl methylated disaccharide derivative, and macrocyclization....

The list of priority chemicals included in various regulations such as the European Water Framework Directive, as well as the list of hazardous contaminants identified in the aquatic environment, are increasing at an accelerated pace. Therefore, there is a need for broad spectrum methods capable of simultaneously determining hundreds, if not thousa...

Crosslinked carboxymethylpullulan have been synthesized by using the dibromohexan as a crosslinking agent. Two phases are obtained after synthesis: a gel and a sol fraction. The sol/gel ratio is dependent on the variation of the polymer concentration (Cp), the incorporation ratio of the dibromohexan (Rc) and the average molar mass (Mn). The study o...

The synthesis and the structure of new macrocycles containing semiflexible dispiro-1,3-dioxane units is reported. The structural analysis of the compounds is performed by high field NMR spectra, mass spectrometry investigations (MALDI, ESI-MS) and the solid state molecular structure obtained for two compounds by single crystal X-ray diffractometry....

Bachus et al. [1] recently described a new derivatisation method using 2-furoyl chloride for the characterisation of mixtures of polyethoxylated alcohols and their corresponding sulfates. This paper deals with the control of the derivatisation steps; hydrolysis and extraction conditions were optimised. The method is extended to the characterisation...

2I-O-Methoxycarbonylmethyl-2II–VII,3I–VII,6I–VII-eicosa-O-methyl-cyclodextrin (20Me/P2OCH2COOMe), 6I-O-methoxycarbonylmethyl-2I–VII,3I–VII,6II–VII-eicosa-O-methyl-cyclodextrin (20Me/P6OCH2COOMe), 6I-O-methoxycarbonyl-6I-deoxy-2I–VII,3I–VII,6II–VII-eicosa-O-methyl-cyclodextrin (20Me/P6COOMe) have been evaluated as chiral stationary phases (CSPs) for...

The static headspace technique is the most common approach to residual solvent analysis in pharmaceutical and environmental matrices. This paper presents an alternative tool where the volatile impurities are released from the matrix by working directly on a small amount of sample at a high equilibration temperature: the so-called Full Evaporation T...

A direct way to reach mono 3-hydroxy per-O-methylated α-cyclodextrin by de-O-methylation with phenylthiotrimethylsilane is reported. This compound is fully characterized by NMR spectroscopy and liquid chromatography with mass spectroscopy coupling.

Although the title compound crystallizes as a stable conglomerate without any detectable solid solution, particles in the shape of single crystals grown from the racemic aqueous solution without stirring contain almost no enantiomeric excess. From stereoselective dissolution experiments carried out in a solution saturated with a single enantiomer,...

Dexamethasone acetate can crystallize as a DSMO (dimethylsulfoxide) solvate with a stoechiometry (1 : 1), and its crystal structure shows the presence of channels containing the DMSO molecules. When single crystals of this solvate are immersed in water according to the methodology proposed by Nordhoff & Ulrich [9], the exchange between DMSO and wat...

It is shown that (±) 5-ethyl-5-methylhydantoin (12Hyd) can be separated at a preparative scale by means of the auto-seeded and polythermic preferential crystallisation in water, provided that a small proportion of wetting agent is used. The influences of enantiomeric purity, supersaturation and wetting agent during the crystal growth of 12Hyd in wa...

Crystallization, at room temperature under normal pressure, of heptakis (2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB) in the presence of various hydrocarbons (n-pentane, n-hexane, cyclohexane, methylcyclohexane, (RS)-α-pinene, (S)-α-pinene and (R)-α-pinene) gave two series of isomorphous crystalline phases: Ua (metastable) and Ub (stable). In this s...

Static headspace-gas chromatography (HS-GC) method is used for determination of the stoichiometry of crystalline inclusion complexes of heptakis (2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB) with methylcyclohexane, pentane, cyclohexane, hexane, (–)-α-pinene, and (±)-α-pinene. The ‘Full Evaporation Technique’ (FET) with Multiple Headspace Extraction...

The three isomeric mono-2-, 3- or 6-hydroxy permethylated β-cyclodextrins are good precursors for a wide variety of mono functionalised ‘permethyl’ β-cyclodextrins. In this work, we describe the selective access to mono-6-hydroxy (via the mono-6-tertbutyldimethylsilyl derivative), mono-2-hydroxy (via the mono-2-benzyl derivative) and mono-3-hydroxy...

Enantiomeric resolution of the title compound is performed by means of preferential nucleation. The antagonism between the absolute configuration of the dissolved additive and the absolute configuration of the major part of the solute resulting from the process is confirmed (rule of reversal). Experimental data suggest that the stereospecific induc...

Permethylated β-cyclodextrin (hereafter designated perMe-β-CD), dililuted or not in polysiloxane, is an efficient chiral discriminant for native, 3-methylated, and 1,3-dimethylated series of 5-methyl-5-(CnH2n + 1)hydantoins. From thermodynamic data obtained with pure perMe-β-CD and with the aid of molecular modeling, it is concluded that: (i) For n...

The enantiomers are obtained in preparative amounts without a resolving agent via the following sequence: hydantoin synthesis, resolution by entrainment, and ring cleavage by means of hydrolysis in basic conditions. The new variant of preferential crystallization (AS3PC), implemented without using seeds, shows good reproducibility and yield.

The list of priority chemicals included in various regulations such as the European Water Framework Directive as well as the list of hazardous contaminants identified in the aquatic environment are increasing at an accelerated pace. Therefore there is a need for broad spectrum methods capable of simultaneously determining hundreds if not thousands...