Enhanced ionic mobility in organic ionic plastic crystal - dendrimer solid electrolytes

We report the first study of the characterisation of the organic ionic plastic crystal (OIPC) N-ethyl-N-methylpyrrolidinium tetrafluoroborate (C2mpyrBF4) upon mixing with a dendrimer additive. Whereas previous reports of OIPC composite formation (i.e. with ceramics and polymers) have typically reported a decrease in the conductivity when lithium salt had been added, the addition of dendrimer is shown to lead to a substantial enhancement in the lithium containing system, approaching 3 orders of magnitude at 30°C. Mechanical analysis indicates that dendrimer addition leads to a softer more ductile material while microscopy shows that the dendrimer is uniformly distributed and that the crystal microstructure is substantially disrupted, ultimately adopting a dendritic microstructure at 1mol% dendrimer content. Thermal analysis indicates a new phase in the lithium OIPC system, the crystallisation of which is suppressed in the presence of dendrimer. Instead, a decrease in the phase transition enthalpies indicates a large increase in the amorphous component of the Lithium OIPC, particularly for the most conductive system -C2mpyrBF4 +10mol% LiBF4 +0.1mol% dendrimer. Variable temperature powder X-ray diffraction confirms the presence of a new distinct phase and its absence in the presence of dendrimer. A change in the progression of the thermal phase behaviour of the OIPC in the presence of dendrimer is also shown, exhibiting the phase I (high temperature) structure at temperatures below the phase II-I transition.

Electrochemistry of tris(2,2′-bipyridyl) cobalt(II) in ionic liquids and aprotic molecular solvents on glassy carbon and platinum electrodes

The tris(2,2′-bipyridyl) complexes of cobalt(II) and (III) ([Co(bpy)3]^2+/3+) produce a redox couple of great interest in thermoelectrochemical cells and dye sensitized solar cells including both types of devices based on ionic liquid electrolytes. We present a systematic study of the electrochemistry of [Co(bpy)3]²⁺ [NTf2]^-2 in two ionic liquids (ILs) based on the 1-ethyl-3-methylimidazolium (C2mim) cation and two ILs based on the 1-butyl-1-methylpyrrolidinium cation (C4mpyr), as well as three aprotic molecular solvents. Platinum (Pt) and glassy carbon (GC) working electrodes were compared. In all solvents better electrochemical responses were observed on GC, which yielded higher currents in the cyclic voltammograms and lower rate constants for the redox reaction. The [Co(bpy)3]^1+/2+ couple is also readily observed, but this redox reaction is chemically irreversible, possibly because the [Co(bpy)3]¹⁺ complex dissociates. However, the [Co(bpy)3]^1+/2+ reaction is chemically reversible in all of the solvents studied, except 3-methoxypropionitrile, if excess of 2,2′-bipyridyl is added to the solution.

Blue electrogenerated chemiluminescence from water-soluble iridium complexes containing sulfonated phenylpyridine or tetraethylene glycol derivatized triazolylpyridine ligands

Incorporating phenylpyridine- and triazolylpyridine-based ligands decorated with methylsulfonate or tetraethylene glycol (TEG) groups, a series of iridium(III) complexes has been created for green and blue electrogenerated chemiluminescence under analytically useful aqueous conditions, with tri-n-propylamine as a coreactant. The relative electrochemiluminescence (ECL) intensities of the complexes were dependent on the sensitivity of the photodetector over the wavelength range and the pulse time of the applied electrochemical potential. In terms of the integrated area of corrected ECL spectra, with a pulse time of 0.5 s, the intensities of the Ir(III) complexes were between 18 and 102 % that of [Ru(bpy)3 ](2+) (bpy=2,2'-bipyridine). However, when the intensities were measured with a typical bialkali photomultiplier tube, the signal of the most effective blue emitter, [Ir(df-ppy)2 (pt-TEG)](+) (df-ppy=2-(2,4-difluorophenyl)pyridine anion, pt-TEG=1-(2-(2-(2-(2-hydroxyethoxy)ethoxy)ethoxy)ethyl)-4-(2-pyridyl)-1,2,3-triazole), was over 1200 % that of the orange-red emitter [Ru(bpy)3 ](2+) . A combined experimental and theoretical investigation of the electrochemical and spectroscopic properties of the Ir(III) complexes indicated that the greater intensity from [Ir(df-ppy)2 (pt-TEG)](+) relative to those of the other Ir(III) complexes resulted from a combination of many factors, rather than being significantly favored in one area.

Rechargeable Zn/PEDOT battery with an imidazolium-based ionic liquid as the electrolyte

 A non-aqueous secondary battery has been constructed by using Zn metal as the anode and chemically synthesised PEDOT as the cathode, with a 1-ethyl-3-methylimidazolium dicyanamide ionic liquid as the electrolyte, which avoids dendritic growth processes on the Zn surface upon charge/discharge cycling. The novel Zn/PEDOT rechargeable cell shows high efficiency and cycling ability, performing over 320 cycles with no indication of short circuit. Both the Zn and PEDOT surfaces showed minimal signs of degradation, suggesting that a Zn/PEDOT electrochemical device would be capable of extended cycle life under numerous charge/discharge cycles.

Thermally stable imidazoline-based sulfonate copolymers for enhanced oil recover

Novel imidazoline-based sulfonate copolymers (noted PAMDSCM and PAMPSCM) were successfully prepared by copolymerization of acrylamide (AM), acrylic acid (AA), 1-acrylamido ethyl-2-oleic imidazoline (ACEIM) with the sodium salts of 3-(diallyl-amino)-2-hydroxypropyl (NDS) or 2-acrylamido-2-methylpropane sulfonic acid (AMPS), respectively. The copolymers were characterized by infrared (IR) spectroscopy, 1H nuclear magnetic resonance (1H NMR) spectroscopy, pyrene fluorescence probe spectroscopy, viscosimetry and thermogravimetry (TG). Both PAMDSCM and PAMPSCM copolymers had excellent high-temperature tolerance in comparison with the same concentration of HPAM, and the residual viscosities were 32.0 mPa s and 31.3 mPa s (viscosity retention rates were 38.8% and 37.1%) at 140 °C, respectively. The copolymers possessed superior long-term thermal stability and their residual viscosity rates were up to 81.8% and 63.8% (52.9 mPa s and 47.1 mPa s) lasting 1.5 hours at 100 °C and 170 s-1, respectively.

Reduction of oxygen in a trialkoxy ammonium-based ionic liquid and the role of water

The oxygen reduction reaction in a novel trialkoxy ammonium-based ionic liquid, N-ethyl-2-(2-methoxyethoxy)-N,N-bis(2-(2-methoxyethoxy)ethyl)ethan-1-aminium bis(trifluoromethylsulfonyl)imide, [N2(20201)(20201)(20201)] [NTf2] has been studied on glassy carbon and gold electrodes, showing faster electrokinetics on glass carbon because of weaker adsorption of the IL. This has been demonstrated by theoretical calculations and electrochemical studies. In the neat IL, the oxygen is reduced to superoxide (O2 -) through a one electron process; however, better performance is attained in the presence of water (42 mol%), in terms of current density, and onset potential of the reduction process via a reversible 2-electron process. Furthermore, a remarkable increase in cyclic coulombic efficiency is observed for the wet IL (66% in comparison with the neat IL (24%), showing the practicality of a reversible O2/H2O2 system for energy storage.

Rapid surface functionalization of carbon fibres using microwave irradiation in an ionic liquid

The modification of carbon fibre surfaces has been achieved using a novel combination of low power microwave irradiation (20 W) in both an ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) and an organic solvent (1,2-dichlorobenzene). The use of the ionic liquid was superior to the organic solvent in this application, resulting in a higher density of surface grafted material. As a consequence, carbon fibres treated in the ionic liquid displayed improved interfacial adhesion in the composite material (+28% relative to untreated fibres) compared to those treated in organic solvent (+18%). The methodology presented herein can be easily scaled up to industrially relevant quantities and represent a drastic reduction in both reaction time (30 min from 24 h) and energy consumption, compared to previously reported procedures. This work opens the door to potential energy and time saving strategies which can be applied to carbon fibre manufacture for high performance carbon fibre reinforced composites.

Estudo da corrosao do aco ABNT 1010 em alcool etilico adicionado de inibidores

Estudou-se o comportamento do aço AISI 1010 em AISI 1010 em àlcool etílico puro com 3,5% H20 e diferentes aditivos (acetato de sódio, um aditivo comercial e trietanolamina) em meio arejado e desarejado, com e sem agitação. Os resultados experimentais mostram que os aditivos usados exercem efeito inibidor da corrosão no aço. A água (3,5%) origina um período de incubação até o aparecimento de pite. A reação de redução catódica do oxigênio apresenta duas ondas, o que permite dizer que a presença de algum filme modifica a mesma. Os ensaios em etanol carburante, a longo prazo, apresentaram corrosão localizada em meio arejado (a qual é evitada com adição de 10-² M de acetato de sódio), e corrosão generalizada em meio desarejado.

Corrosão de vários materiais metálicos em álcool etílico hidratado combustível e sua inibição a 25 graus C

Estudou-se o comportamento à corrosão de diversos materiais metálicos como aço, cobre, latão e pares galvânicos (aço-latão) em álcool etilico combustível (91.1 - 93.9 -INPM) adicionado de várias substâncias a fim de avaliar possíveis efeitos inibidores ou aceleradores da corrosão. Foi verificado a influência na corrosão, de ion cloreto, acetato de sódio, ácido benzóico, trietanolamina, butinodiol e um inibidor comercial. O acetato de sódio seguido do produto comercial se revelaram os melhores aditivos sob o ponto de vista da inibição da corrosão. A adição de cloreto, como um possível contaminante foi estudada e obteve-se um aumento bastante grande na taxa de corrosão. A adição de perclorato de potássio ao álcool combustível normalmente utilizado para aumentar a condutividade da solução nos ensaios eletroquímicos, mostrou ser prejudicial por modificar apreciavelmente as características do comportamento à corrosão dos materiais ensaiados, aumentando-a ou diminuindo-a conforme o caso.

A vanilina como um agente modulador da genotoxicidade : risco ou benefício?

Há cerca de 20 anos a vanilina vem sendo descrita como uma substância moduladora capaz de inibir eventos relacionados à indução e promoção do processo carcinogênico. Este comportamento associado ao seu consumo elevado despertou o nosso interesse científico - resultando na publicação do primeiro trabalho associando a VA a acréscimos expressivos em eventos recombinacionais mitóticos, acompanhados de decréscimos na freqüência de mutações pontuais e cromossômicas. Entretanto, quando a antimutagênese e a co-recombinogênese foram avaliadas simultaneamente, a ação final da VA refletiu-se não como proteção, mas sim como um efeito potencializador expresso como um aumento de cerca de 200 vezes na genotoxicidade total da MMC. Na procura de respostas adicionais concernentes à ação da VA como moduladora de diferentes espectros de lesões no DNA utilizamos o Teste para Detecção de Mutação e Recombinação Somática em Drosophila melanogaster (SMART) com o intuito de avaliar o comportamento deste flavorizante em relação à genotoxicidade dos agentes químicos: N-methyl-N-nitrosourea (MNU), N-ethyl-N-nitrosourea (ENU), ethylmethanesulphonate (EMS) e bleomicina (BLEO), em dois protocolos de administração do modulador – pós e co-tratamento. Pós-tratamento Os dados obtidos através do sistema de pós-tratamento evidenciaram que a VA não altera a mutagenicidade e a recombinogenicidade do ENU e MNU - o que sugere a não interferência deste flavorizante sobre os mecanismos envolvidos na correção das lesões induzidas por estes alquilantes. Ao contrário, a toxicidade genética do EMS foi significativamente aumentada em valores compreendidos entre 7,79 a 29,79%, representando a expressão final de dois efeitos antagônicos: (i) sinergismo em recombinação mitótica e (ii) proteção em relação à mutagênese. Tais achados sugerem que diferenças entre o espectro dos danos induzidos por estes agentes alquilantes, podem afetar os caminhos de reparação a serem priorizados. Como conseqüência, o efeito potencializador da VA sobre recombinação homóloga (HR) está restrito ao EMS – o único dos agentes alquilantes monofuncionais estudados cujas lesões são processadas, em Drosophila melanogaster, por ambos mecanismos de reparo: excisão de nucleotídeos e pós-replicativo. A VA também causou drásticos incrementos na genotoxicidade da BLEO - 120 a 178% - que estão limitados a aumentos em recombinação, uma vez que não foram observadas alterações na sua potência mutacional. Como a genotoxicidade da BLEO resulta basicamente da indução de quebras duplas corrigidas por mecanismos de reparação dependentes de recombinação - que podem ocorrer tanto entre cromossomos homólogos (HR) como não-homólogos (end joining -NHEJ) – e como o teste SMART privilegia a detecção de recombinação homóloga, os nossos dados indicam que a ação potencializadora de VA em relação a BLEO deve-se especificamente a incrementos em reparo dependente de HR. Ainda relevante é o fato de que estes acréscimos não estão associados a decréscimos em mutação, como anteriormente observado para a MMC.Todos estes dados indicam que a modulação da VA está restrita ao seu efeito sinérgico sobre recombinação somática – promovendo especificamente a recombinação homóloga em células proliferativas de Drosophila. Co-tratamento Através deste procedimento ficou claro que a VA diminui significativamente a toxicidade genética total dos alquilantes MNU e ENU e do agente intercalante bleomicina. Os decréscimos observados tanto para o MNU quanto para o ENU são basicamente atribuídos ao seu papel promotor sobre o processo de detoxificação - que leva a diminuição no número de metilações e etilações induzidas respectivamente pelo MNU e pelo ENU. Adicionalmente, a caracterização da VA como um potente captador de radicais livres, especialmente em função do seu efeito sobre os danos oxidativos induzidos pela BLEO – explica a sua ação desmutagênica em relação a este agente intercalante. Todos estes dados referentes ao efeito modulador da VA não permitem a quantificação da relação risco-benefício do seu consumo, especialmente pela dificuldade prática de se medir o quanto a sua presença concomitante com as genotoxinas – representado por efeito benéfico, via interferência no potencial genotóxico – ou a sua ação após a indução dos danos genéticos, através da promoção de reparo recombinacional e conseqüente aumento em HR, contribuem para a expressão final do seu efeito modulador. Entretanto, o papel fundamental da recombinação homóloga na gênese de inúmeras doenças genéticas, incluindo o câncer, e a preponderante ação recombinogênica da VA são um sinal de alerta.

Produção de acetato de etila em biorrefinaria: uma análise de viabilidade

O estudo aqui apresentado tem como objetivo mostrar que a competitividade da indústria química brasileira pode ser revista por meio do desenvolvimento da área química a partir dos recursos naturais renováveis e de alto desempenho de produtividade, aqui representado pela cana-de-açúcar. A base deste estudo analisa a competitividade econômica da produção do acetato de etila, utilizando o etanol como única matéria-prima, sendo o Brasil um grande exportador e, ao mesmo tempo, detentor de um mercado interno forte quando comparado a outros países desenvolvidos. O acetato de etila exportado representou 52% da capacidade nominal instalada no Brasil no ano de 2008. No Brasil existem três ofertantes, mas apenas um produtor é exportador. Todos usam a esterificação como tecnologia de produção, via reação do ácido acético e etanol, sendo o ácido acético largamente importado. O estudo tem como premissa que a competitividade do acetato de etila no Brasil seja dada pelo etanol, que aqui é produzido pela fermentação do caldo de cana-de-açúcar. Já a tecnologia de esterificação é conhecida e de domínio público mundial, e o ácido acético é uma commodity petroquímica com preço referenciado globalmente. Argumenta-se neste trabalho que a competitividade do acetato de etila decorre da linkage com a produção de etanol de cana-de-açúcar, o que coloca o Brasil como grande potencial exportador desse produto. Utilizando a tecnologia de desidrogenação do etanol, pode-se obter acetato de etila utilizando-se apenas o etanol como matéria-prima, reduzindo-se assim a necessidade de importação de ácido acético, que representaria redução anual do déficit da balança comercial petroquímica brasileira em aproximadamente meio bilhão de dólares e, ademais, permitindo que o acetato de etila produzido no Brasil seja ainda mais competitivo. A partir deste estudo é possível avaliar, por analogia, a competitividade de outros produtos químicos produzidos a partir da matriz cana-de-açúcar, tais como eteno, lubrificantes, plásticos etc. Tal caminho permite criar um novo marco para a indústria química brasileira, com consequente redução da dependência de petróleo e gás natural.

Novel catalyst systems based on Ni(II), Ti(IV), and Cr(III) complexes for oligo-and polymerization of ethylene

The complex of Brookhart Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6- diisopropylphenyl)-acenaphthenediimine) has been characterized after impregnation on silica (S1) and MAO-modified silicas (4.0, 8.0 and 23.0 wts.% Al/SiO2 called S2, S3 and S4, respectively). The treatment of these heterogeneous systems with MAO produces some active catalysts for the polymerization of the ethylene. A high catalytic activity has been gotten while using the system supported 1/S3 (196 kg of PE/mol[Ni].h.atm; toluene, Al/Ni = 1000, 30ºC, 60 min and atmospheric pressure of ethylene). The effects of polymerization conditions have been tested with the catalyst supported in S2 and the best catalytic activity has been gotten with solvent hexane, MAO as cocatalyst, molar ratio Al/Ni of 1000 and to the temperature of 30°C (285 kg of PE/mol[Ni].h.atm). When the reaction has been driven according to the in situ methodology, the activity practically doubled and polymers showed some similar properties. Polymers products by the supported catalysts showed the absence of melting fusion, results similar to those gotten with the homogeneous systems by DSC analysis. But then, polymers gotten with the transplanted system present according to the GPC’s curves the polydispersity (MwD) varies between 1.7 and 7.0. A polyethylene blend (BPE/LPE) was prepared using the complex Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6-diisopropylphenyl)-acenaphthenediimine) and {TpMs*}TiCl3 (2) (TpMs* = hydridobis(3-mesitylpyrazol-1-yl)(5-mesitylpyrazol-1-yl)) supported in situ on MAO-modified silica (4.0 wts. -% Al/SiO2, S2). Reactions of polymerization of ethylene have been executed in the toluene in two different temperatures (0 and 30°C), varying the molars fraction of nickel (xNi), and using MAO as external cocatalyst. To all temperatures, the activities show a linear variation tendency with xNi and indicate the absence of the effect synergic between the species of nickel and the titanium. The maximum of activity have been found at 0°C. The melting temperature for the blends of polyethylene produced at 0 °C decrease whereas xNi increases indicating a good compatibility between phases of the polyethylene gotten with the two catalysts. The melting temperature for the blends of polyethylene showed be depend on the order according to which catalysts have been supported on the MAO-modified silica. The initial immobilization of 1 on the support (2/1/S2) product of polymers with a melting temperature (Tm) lower to the one of the polymer gotten when the titanium has been supported inicially (1/2/S2). The observation of polyethylenes gotten with the two systems (2/1/S2 and 1/2/S2) by scanning electron microscopy (SEM) showed the spherical polymer formation showing that the spherical morphology of the support to been reproduced. Are described the synthesis, the characterization and the catalytic properties for the oligomerization of the ethylene of four organometallics compounds of CrIII with ligands ([bis[2-(3,5-dimethyl-1-pyrazolyl)ethyl]amine] chromium (III) chloride (3a), [bis[2-(3,5- dimethyl-l-pyrazolyl)ethyl]benzylamine] chromium (III) chloride (3b), [bis[2-(3,5-dimethyl-lpyrazolyl) ethyl]ether] chromiun(III)chloride (3c), [bis[2-(3-phenyl-lpyrazolyl) ethyl]ether]chromiun(III)chloride (3d)). In relation of the oligomerization, at exception made of the compounds 3a, all complex of the chromium showed be active after activation with MAO and the TOF gotten have one effect differentiated to those formed with CrCl3(thf)3. The coordination of a tridentate ligand on the metallic center doesn't provoke any considerable changes on the formation of the C4 and C6, but the amount of C8 are decrease and the C10 and C12+ have increased. The Polymers produced by the catalyst 3a to 3 and 20 bar of ethylene have, according to analyses by DSC, the temperatures of fusion of 133,8 and 136ºC respectively. It indicates that in the two cases the production of high density polyethylene. The molar mass, gotten by GPC, is 46647 g/mols with MwD = 2,4 (3 bar). The system 3c/MAO showed values of TOF, activity and selectivity to different α-olefins according to the pressure of ethylene uses. Himself that shown a big sensibility to the concentration of ethylene solubilized.

Olfactory perception threshold assessment of volatile acidity in Madeira wines

Madeira wine is a fortified wine with impact in the Madeira Island’s economy. Similarly to other wines, its acidity should be well controlled in order to ensure Madeira wine quality, mostly the volatile acidity. Due to Madeira wine complex flavour, it is crucial to get a better knowledge about the volatile acidity impact in its features, namely determine the perception limit of acetic acid and ethyl acetate, as both are the main contributors for volatile acidity. Firstly, the olfactory perception threshold of volatile acidity was assessed by a trained and an untrained panel, using 5 and 10 years-old Sercial and Malvasia wines. Moreover, the current work also presents the evolution of organic acids, acetic acid and ethyl acetate during 540 days of ageing of Madeira wines (Malvasia, Bual, Verdelho and Sercial), comparing the same wines aged by both traditional ageing processes: canteiro and estufagem. Other wine samples, aged in wood casks (canteiro) for at least 5 years, were also evaluated. HS-SPME followed by GC-MS analysis was used to determine ethyl acetate concentration and IEC-HPLC-DAD was used for the organic acids determination, including acetic acid. The results indicated that acetic acid and ethyl acetate olfactory perception threshold depends essentially on wine’s age. Concerning acetic acid, the untrained panel was in average 5.45 g/L (5 years-old) and 6.22 g/L (10 years-old). Training the expert panel to recognize acetic acid odour, the values decreased for 1.44 g/L (5 years-old) and 1.87 g/L (10 years-old), but still remained higher than the established volatile acidity legal limits. Ethyl acetate threshold was similar for both panels (in average 327.97 mg/L). Both compounds tend to increase exponentially with age, being more evident in sweet wines. Organic acids in young Madeira wines depend mostly on the nature of grape varieties, but this difference is minimized with wine ageing.

Comparative study of the whisky aroma profile based on headspace solid phase microextraction using different fibre coatings

A dynamic headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to ion trap mass spectrometry (GC–ITMS) method was developed and applied for the qualitative determination of the volatile compounds present in commercial whisky samples which alcoholic content was previously adjusted to 13% (v/v). Headspace SPME experimental conditions, such as fibre coating, extraction temperature and extraction time, were optimized in order to improve the extraction process. Five different SPME fibres were used in this study, namely, poly(dimethylsiloxane)(PDMS),poly(acrylate)(PA),Carboxen-poly(dimethylsiloxane)(CAR/PDMS),Carbowax-divinylbenzene(CW/DVB)and Carboxen-poly(dimethylsiloxane)-divinylbenzene (CAR/PDMS/DVB). The best results were obtained using a 75 m CAR/PDMS fibre during headspace extraction at 40◦C with stirring at 750rpm for 60min, after saturating the samples with salt. The optimised methodology was then appliedtoinvestigatethevolatilecompositionprofileofthreeScotchwhiskysamples—BlackLabel,BallantinesandHighlandClan.Approximately seventy volatile compounds were identified in the these samples, pertaining at several chemical groups, mainly fatty acids ethyl esters, higher alcohols, fatty acids, carbonyl compounds, monoterpenols, C13 norisoprenoids and some volatile phenols. The ethyl esters form an essential group of aroma components in whisky, to which they confer a pleasant aroma, with “fruity” odours. Qualitatively, the isoamyl acetate, with “banana” aroma,wasthemostinteresting.Quantitatively,significantcomponentsareethylestersofcaprilic,capricandlauricacids.Thehighestconcentration of fatty acids, were observed for caprilic and capric acids. From the higher alcohols the fusel oils (3-methylbutan-1-ol and 2.phenyletanol) are the most important ones.

Screening of volatile composition from portuguese multifloral honeys using headspace solid-phase microextraction-gas chromatography–quadrupole mass spectrometry

The volatile composition from four types of multifloral Portuguese (produced in Madeira Island) honeys was investigated by a suitable analytical procedure based on dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography–quadrupole mass spectrometry detection (GC–qMS). The performance of five commercially available SPME fibres: 100 μm polydimethylsiloxane, PDMS; 85 μm polyacrylate, PA; 50/30 μm divinylbenzene/carboxen on polydimethylsiloxane, DVB/CAR/PDMS (StableFlex); 75 μm carboxen/polydimethylsiloxane, CAR/PDMS, and 65 μm carbowax/divinylbenzene, CW/DVB; were evaluated and compared. The highest amounts of extract, in terms of the maximum signal obtained for the total volatile composition, were obtained with a DVB/CAR/PDMS coating fibre at 60 °C during an extraction time of 40 min with a constant stirring at 750 rpm, after saturating the sample with NaCl (30%). Using this methodology more than one hundred volatile compounds, belonging to different biosynthetic pathways were identified, including monoterpenols, C13-norisoprenoids, sesquiterpenes, higher alcohols, ethyl esters and fatty acids. The main components of the HS-SPME samples of honey were in average ethanol, hotrienol, benzeneacetaldehyde, furfural, trans-linalool oxide and 1,3-dihydroxy-2-propanone.