Nour Kayali

• PhD
• Director Científico at CSI Analitica S.L.

Bisphenol A (BPA) is a compound used in theproduction of polycarbonates and epoxy resins and is widely used in the industry. BPA can be passed into the body through the diet, since its molecules can easily migrate from the containers made with BPA to the food in those containers.The presence of BPA in dental materials is very common. A large number...

CSI ANALITCA has participated in the interlaboratory test for the determination of BPA in polymers, validating the developed method.

Miltefosine is the only currently available oral drug for treatment of leishmaniasis. However, information on the pharmacokinetics (PK) of miltefosine is relatively scarce in animals. PK parameters and disposition of the molecule was determined in healthy NMRI mice and Syrian hamsters infected and treated with different miltefosine doses and regime...

Miltefosine is the only currently available oral drug for treatment of leishmaniasis. However, information on the pharmacokinetics (PK) of miltefosine is relatively scarce in animals. PK parameters and disposition of the molecule was determined in healthy NMRI mice and Syrian hamsters infected and treated with different miltefosine doses and regime...

Saccharomyces cerevisiae is the most important yeast species for the production of wine and other beverages. In addition, nowadays, researchers and winemakers are aware of the influence of non-Saccharomyces in wine aroma complexity. Due to the high microbial diversity associated to several agro-food processes, such as winemaking, developing fast an...

In the present study chemical composition of four brands of gutta-percha (Autofit, Endose- quence, Wave One Gold and Dia-ProT) was analyzed for use in warm vertical condensation techniques from a qualitative point of view, using microextraction in solid-phase with sub- sequent analysis by gas chromatography cou- pled to mass spectrometry to perform...

Introduction: The aim of this research was to obtain analytical information about the chemical purity and the homogeneity of the endodontic materials MTA AngelusTM and BiodentineTM. Methods: On the one hand, solid phased microextraction-gas chromatography-mass spectrometry (SPME-GCMS) was carried out with MTA Angelus and Biodentine mate- rials, iso...

Introduction: The aim of this research was to obtain analytical information about the chemical purity and the homogeneity of the endodontic materials MTA Angelus™ and Biodentine™. Methods: On the one hand, solid phased microextraction-gas chromatography-mass spectrometry (SPME-GCMS) was carried out with MTA Angelus and Biodentine materials, isolati...

HPMC capsules are made by a dipping process and a surface lubricant for the mould pins is an essential processing aid for removing dried capsules shells. For the purpose of this study, the level was determined by quantifying methyloleate (MO) a component found in the lubricant but not in the hypromellose capsules. Here we investigated the influence...

The plant cuticle has traditionally been conceived as an independent hydrophobic layer that covers the external epidermal cell wall. Due to its complexity, the existing relationship between cuticle chemical composition and ultra-structure remains unclear to date. This study aimed to examine the link between chemical composition and structure of iso...

A new SPME/HPLC interface is developed. It is based on thermal desorption from the SPME fiber and organic solvent collection of the desorbed analytes by sweeping them with an argon flow into a small organic solvent volume which is further injected into the HPLC chromatograph. Extraction and desorption parameters were investigated using five PAHs of...

An easy and rapid method is proposed for the determination of PCBs in automotive shredder residues, using gas chro-matography combined with low resolution mass spectrometry (GC-MS). It is based on direct n-hexane solid-liquid ex-traction, subtracting background of the lineal aliphatic hydrocarbon interferences and integration of chromatographic pea...

Difficulties detected in the determination of the diethylhexylphthalate (DEHP) at trace levels by gas chromatography-mass spectrometry (GC-MS) using SPME, due to its ubiquitous distribution in the environment has been overcome and a new method for the determination of DEHP in drinking water has been proposed. The method is based on solid phase micr...

This work validates a method for detecting potential semiochemicals in mouse urine samples with a volume as small as 10μL. Using solid-phase microextraction, gas chromatography and mass spectrometry, we screened 2,3,5-trithiahexane, 2-sec-butyl-4,5-dihydrothiazole, geraniol, indole, trans-β-farnesene and farnesol in individual urine samples taken d...

New fulleropyrrolidines endowed with chlorine-containing biological active 1,4-dihydropyridines (1,4-DHPs) have been synthesised from the respective formyl substituted 1,4-DHPs by following Prato's procedure. The presence of the chlorine atom on C2 of the 1,4-DHP ring brings about important spectroscopical and structural differences in compounds 10...

Object: To determine the presence and persistence of formaldehyde residues in different plastic materials sterilised by low temperature steam and formaldehyde (LTSF) and the cumulative effect of several sterilisations, using an optimised extraction and quantification method. Material and methods: Different plastic materials (4 samples/type of plast...

Given the key role of pheromones in animal communication and behaviour, there is need to identify the different classes of these molecules under varying physiological conditions. However, the highly volatile nature of pheromones and the fact that they occur at very low concentrations in urine makes this task all the more difficult. Herein, we prese...

Fischer carbene complexes 1-7 are not ionized under standard electrospray ionization (ESI) conditions. We report here that unsaturated chromium and tungsten (Fischer) carbene complexes can be ionized in an electrospray ion source in the presence of electron-donor compounds such as hydroquinone (HQ) or tetrathiafulvalene (TTF). The addition of these...

A variety of acylthiocarbamates and acylthioureas have been investigated under electron impact ionization (0), chemical ionization (CI) and electrospray ionization (ESP conditions. Sequential product-ion fragmentation (MS') was performed to elucidate the degradation pathways for these compounds. Comparisons are made between positive and negative ev...

A variety of 5-alkoxycarbonyl-4-aryl-6-methyl-3,4-dihydro-2(1H)-pyridones and hexahydrofuro[3,4-b]-2(1H)-pyridones have been investigated by electron impact (EI) and electrospray ionisation (ESI) techniques. Sequential product ion fragmentation (MS(n)) was performed to elucidate the degradation pathways for these compounds. Comparisons are made bet...

The electrospray ionisation (ESI) in negative mode of the pharmacologically significant 3,5-disubstituted tetrahydro-2H-1,3,5-thiadiazin-2-thiones, and their subsequent fragmentations using an ion-trap mass spectrometer, have been investigated. Experiments on sequential product ion fragmentations (MS(n)) were performed in order to elucidate the deg...

Electron impact ionization (EI), chemical ionization (CI), electrospray ionization (ESI) and tandem mass spectrometry (MS/MS) were used to investigate a number of relatively large and structurally related new heterocycles such as substituted 1,4,5,6,7,8-hexahydroquinolines and their oxa-analogues 5,6,7,8-tetrahydro-4H-chromenes. In the EI spectra t...

A rapid method for the determination of PAHs in soil samples based on their extraction with methylene chloride by sonication and subsequent separation by HPLC with fluorimetric detection is proposed. A Hypersil Green PAH column was used with a gradient of acetonitrile/water as the mobile phase, together with a program of nine excitation and emissio...

A new method for PAHs determination in toasted bread samples is proposed. The method is based on supercritical-fluid extraction, using CO2 and acetonitrile as modifier. The extracted PAHs were collected in 1 mt acetonitrile. Quantitation was carried out by HPLC with fluorimetric detection. A Hypersil Green PAH column, acetonitrile-water gradient mo...

A rapid analytical method is proposed for the determination of PAHs (fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[e]pyrene, benzo[a]pyrene, dibenzo[a,h]anthracene and benzo[g,h,i]perylene) in coffee brew samples. The method is based on solid phase extraction with Sep-Pak Vac tC-18 cartridges and elution with ethyl ether. The extracts w...

This paper describes a method for the determination of PAHs in black, green and decaffeinated tea infusion samples. The method is based on the solid phase extraction of the PAHs using Sep-Pak vac tC-18 cartridges. The PAHs are then eluted from the cartridges with dichloromethane. Quantification and detection are carried out by HPLC with a fluorimet...

A rapid, sensitive and selective method for determining 13 PAHs in drinking water samples using solid-phase extraction and HPLC with programmed fluorescence detection is developed. A solid-phase extraction method is described for preconcentrating the PAHs on Sep-Pak vac tC-18 cartridges. The volume of water analyzed was 1500 mL. The PAHs were elute...

The possibility of using micellar sodium dodecyl sulfate mobile phase modified with n-propanol to separate six PAHs on apolar columns was examined. The large capacity factors found in large-chain stationary phases made the analysis impractical. The use of short-chain stationary phases and the presence of n-propanol in the mobile phase, as a modifie...

A method for the determination of the benzo(a)pyrene by RP-HPLC with fluorimetric detection in total particulate matter of Virginia and blak tobacco smoke is developed. The total particulate matter was collected on glass fibre filters, which were ultrasonically extracted with cyclohexane. A fraction of the resulting extract was cleaned up on Sep-Pa...

A method for the determination of polycyclic aromatic hydrocarbons by high-performance liquid chromatography using a fluorometric detector is proposed. A Hypersil Green PAH column and a program of nine excitation and emission wavelength pairs are used as a detection system. The mobile phase is a linear gradient of acetonitrile-water. The relative s...

An acetonitrile/0.2OM SDS mobile phase was used to determine PAHs by HPLC with fluorimetric detection.Because the peak area is greater the method is more sensitive than using an acetonitrile/water mobile phase. The method was applied to determine PAHs in particulate air samples and the results are in good agreement with those found by GC.

The fluorescence intensity of polycyclic aromatic hydrocarbons (PAHs) is higher in Brij-35 micellar solution than in methanol. Pyrene, benzo[ghi]perylene and benzo[a]pyrene could be determined in the presence of up to a 100-fold excess of other PAHs, the errors being lower than 5%. The relative standard deviation was 5% at the pg ml−1 level. The de...