Linear stability analysis and nonlinear simulations of convective dissolution in an inclined porous layer between impermeable surfaces.

Convective dissolution can occur in porous media when a given solute dissolves in a host layer from above and increases the density of the host solution. Buoyancy-driven fingering can then develop, which increases the transfer flux of the solute. We investigate here numerically the properties of this convective dissolution when the porous host layer is inclined by an angle θ relative to the horizontal direction. We consider an incompressible flow in porous media governed by Darcy's law, driven by density gradients associated with the concentration of the dissolving solute. The model problem focuses on the case of a very long (infinite) tilted porous layer limited by two parallel impermeable surfaces. A linear stability analysis and nonlinear simulations are performed using the Boussinesq approximation. A vorticity-stream function formulation is adopted to solve the two-dimensional hydrodynamic field through the finite element method. We find that the inclination of the interface decreases the growth rate of the instability and the range of unstable wavenumbers, delaying or even suppressing the onset of the fingering instability. Moreover, it introduces a drift velocity on the perturbations, which is characterized here in both the linear stability analysis and the nonlinear simulations.

Unmodified cellulose filter paper, a sustainable and affordable sorbent for the isolation of biogenic amines from beer samples.

While current trends in Green Analytical Chemistry aim at reducing or simplifying sample treatment, food usually comprises complex matrices where direct analysis is not possible in most cases. In this context, sample treatment plays a pivotal role. Biogenic amines are naturally formed in many foodstuffs due to the action of microorganisms, while their presence has been associated with adverse health effects. In this work, the extraction of seven biogenic amines (cadaverine, histamine, phenylethylamine, putrescine, spermidine, spermine, and tyramine) from beer samples has been simplified using laboratory filter paper as sorbent without any further modification. The analysis of the eluates by direct infusion mass spectrometry reduces the time of analysis, increasing the sample throughput. This simple but effective method enabled the determination of the analytes with limits of detection as low as 0.06 mg L-1 and relative standard deviations better than 11.9%. The suitability of the method has been assessed by analyzing eight different types of beers by the standard addition method.

Erratic migration of Ascaridia hermaphrodita (Nematoda: Ascaridida) in a blue-fronted Amazon parrot (Amazona aestiva) from illegal wildlife trade: case report / [Migração errática de Ascaridia hermaphrodita (Nematoda: Ascaridida) em papagaio-verdadeiro (Amazona aestiva) oriundo do comércio ilegal: relato de caso]

Ascaridiasis by Ascaridia hermaphrodita is a common parasitic disease in blue-fronted Amazon parrots (Amazona aestiva) and the contamination occurs by ingestion of eggs. Illegal trade of wild birds can increase the frequency of visceral erratic migration by this parasite. Hence, this report describes the erratic migration of A. hermaphrodita and associated lesions in a blue-fronted Amazon parrot. This is a retrospective study, which originated from several apprehension of illegal birds in the state of Paraíba, Brazil. Necropsy revealed intense intestinal ascarid infestation. Hepatic lesions were also observed associated with the parasite migration. Stereoscopy allowed the identification of the morphology of the parasites. Summarizing, this condition in wild birds is not fully understood and may be associated with illegal trade.(AU)

Ascaridíase por Ascaridia hermaphrodita é uma doença parasitária comum em papagaios-verdadeiros. Sua contaminação ocorre pela ingestão de ovos. O tráfico de aves silvestres pode facilitar a migração errática visceral desse parasita. Este relato descreve a migração errática de A. hermaphrodita e lesões associadas em papagaio-verdadeiro. Trata-se de um relato retrospectivo, analisado a partir de uma série de apreensões de aves no estado da Paraíba, Brasil. A necropsia revelou intensa infestação ascarídea intestinal. Também foram observadas lesões hepáticas em uma ave, associadas à migração do parasita. A estereoscopia permitiu distinguir a morfologia dos parasitas. Resumidamente, essa condição em aves silvestres é pouco conhecida e pode ser considerada, inclusive, associada à comercialização ilegal.(AU)

Paper-based sorptive phases for microextraction and sensing.

The simplification of the analytical procedures, including cost-effective materials and detectors, is a current research trend. In this context, paper has been identified as a useful material thanks to its low price and high availability in different compositions (office, filter, chromatographic). Its porosity, flexibility, and planar geometry permit the design of flow-through devices compatible with most instrumental techniques. This article provides a general overview of the potential of paper, as substrate, on the simplification of analytical chemistry methodologies. The design of paper-based sorptive phases is considered in-depth, and the different functionalization strategies are described. Considering our experience in sample preparation, special attention has been paid to the use of these phases under the classical microextraction-analysis workflow, which usually includes a chromatographic separation of the analytes before their determination. However, the interest of these materials extends beyond this field as they can be easily implemented into spectroscopic and electrochemical sensors. Finally, the direct analysis of paper substrates in mass spectrometry, in the so-called paper-spray technique is also discussed. This review is more focused on presenting ideas rather than the description of specific applications to draw a general picture of the potential of these materials.

Cotton fibers functionalized with ß-cyclodextrins as selectivity enhancer for the direct infusion mass spectrometric determination of cocaine and methamphetamine in saliva samples.

Cotton is a natural material with good mechanical and chemical properties. It presents a hydrophilic surface that must be modified by the introduction of appropriate groups, if semi-polar or non-polar analytes are intended to be isolated from an aqueous matrix. In this article, cotton is modified with ß-cyclodextrins, which presents a hydrophobic cavity where target molecules can be hosted. The cavity size restricts the access of larger or less accessible molecules due to their conformation, thus improving the extraction selectivity. The modified cotton fibers are packed in a disposable syringe device where all the steps of the extraction take place. The ensuing fibers were evaluated for the extraction of several drugs providing the best results for cocaine (CO) and methamphetamine (MTA). These targets were extracted from saliva samples and finally determined by direct infusion mass spectrometry. The method provides limits of detection and quantification of 0.6 and 2 µg L-1 for CO and 0.8 and 2.7 µg L-1 for MTA, with precision values at the quantification level better than the 9% (expressed as relative standard deviation). Also, relative recoveries ranged from 115% to 111% for CO and MTA, respectively, demonstrating the applicability of the proposed method. Matrix effect, which has been statistically evaluated, is not significant, showing that the extraction selectivity can compensate the circumvent of the chromatographic separation.

Frequência das doenças de pele não tumorais em cães no município de João Pessoa, Paraíba, Brasil (2014-2016) / [Frequency of non tumor skin diseases in dogs in the city of João Pessoa, Paraíba, Brazil (2014-2016)]

Diante da carência de estudos sobre a frequência de dermatopatias que acometem cães por região geográfica no Brasil, o presente estudo objetivou conhecer a frequência das principais doenças cutâneas que afetam cães na região metropolitana de João Pessoa, Paraíba, Brasil. Os dados foram coletados de cães que passaram por atendimento dermatológico no período de setembro de 2014 a dezembro de 2016. Além dos exames clínicos e dermatológicos os cães foram submetidos a exames complementares (citológico, raspado de pele, parasitológico, tricograma, bacteriológico, micológico, histopatológico e molecular). No período do estudo, foram atendidos 1.083 cães, em que 18,65% (202/1.083) apresentavam algum tipo de dermatopatia não tumoral. Dos 202 cães acometidos, 51,49% (104/202) eram machos e 48,51% (98/202), fêmeas. Desses 202 cães, 13 tinham dois diagnósticos, totalizando 215 dermatopatias. Dos cães afetados, 62,87% (127/202) eram de raça definida e 37,13% (75/202), sem raça definida (SRD). As lesões observadas com mais frequência caracterizaram-se por áreas alopécicas, hipotricoicas, maculosas, erosivas e ulcerativas, placoides, eritematosas, assim como comedões, colaretes, seborreia. As dermatopatias parasitárias foram as mais frequentes (35,35%; 76/215), seguidas pelas dermatopatias bacterianas (24,19%; 52/215), dermatopatias alérgicas (20,00%; 43/215), dermatopatias fúngicas (17,21%; 37/215), dermatopatias por outras causas (2,32%; 5/215) e pelas dermatopatias autoimunes (0,93%; 2/215). Os exames físicos e dermatológicos, incluindo anamnese detalhada, histórico clínico apurado, associado a exames complementares, são ferramentas importantes para o diagnóstico das dermatopatias em cães. Presume-se que a frequência de dermatopatias em cães na região de estudo possa ser maior do que a observada.(AU)

Faced with the lack of studies on the frequency of dermatopathies that affect dogs by geographical region in Brazil, the present study aimed to evaluate the frequency of dermatopathies that affect the canine species in the metropolitan region of João Pessoa, Paraíba, Brazil. Data was collected from dogs that underwent dermatological care from September 2014 to December 2016. In addition to the clinical and dermatological examinations, dogs underwent complementary exams, such as cytological, skin scraping, parasitological skin examination, trichogram, bacteriological, mycological, histopathological and/or polymerase chain reaction. During the study period, 1,083 dogs were examined, in which 18.65% (202 /1,083) had some form of non-tumoral dermatopathy. Of the 202 dogs affected, 51.49% (104/202) were males and 48.51% (98/202) females. Of these 202 dogs, thirteen had two diagnoses, totaling 215 dermatopathies. 62.87% (127/202) of the affected dogs were purebred and 37.13% (75/202) were without a defined breed (WDB). The most frequently observed lesions were alopecia, hypotric, macular, erosive and ulcerative, placoid, erythematous areas, as well as comedones, collaretes and seborrhoea. The parasitic dermatopathies were the most frequent (35.35%; 76/215), followed by bacterial dermatopathies (24,19%; 52/215), allergic dermatopathies (20,00%; 43/215), dermatomycosis (17,21%; 37/215), dermatopathies for other causes (2,32%; 5/215) and autoimmune dermatopathies (0.93%; 2/215). Clinical and dermatological examination, including a detailed anamnesis, accurate clinical history and associated complementary exams are important tools for the diagnosis of dermatopathies in dogs. Available literature present some studies with canine dermatopathies frequencies superior to that obtained in the present study; however, the number of animals examined was smaller. In this survey, it was possible to establish the primary and secondary diagnoses in 100.0% of the non-tumoral dermatopathies in dogs, results higher than in previous studies. Probably, the frequency of canine dermatopathies in this region is higher than that observed, thus requiring additional studies with greater sampling.(AU)

Silver nanoflower-coated paper as dual substrate for surface-enhanced Raman spectroscopy and ambient pressure mass spectrometry analysis.

Paper-based analytical devices (PADs) have encountered a wealth of applications in recent years thanks to the numerous advantages of paper as a support. A silver nanoflower (AgNF) modified paper-based dual substrate for both surface-enhanced Raman spectroscopy (SERS) and ambient pressure paper spray mass spectrometry (PS-MS) was developed. AgNFs were immobilized on nylon-coated paper modified with silver and ethylenediamine. The developed substrate was characterized via scanning electron microscopy and infrared spectroscopy. The densely packed nanoscale petals of the AgNFs lead to a large number of so-called hot spots at their overlapping points, which result in an enhancement of the Raman signal. In addition, the presence of the AgNFs produces an increase in the sensitivity of the mass spectrometric analysis as compared with bare paper and nylon/Ag-coated paper. The dual substrate was evaluated for the identification and quantification of ketoprofen in aqueous standards as well as human saliva from healthy volunteers. The method enables the determination of ketoprofen with a limit of detection and limit of quantification via PS-MS of 0.023 and 0.076 mg L-1, respectively, with a relative standard deviation (RSD) of 3.4% at a concentration of 0.1 mg L-1. This dual substrate enables the simple and fast detection of ketoprofen with minimal sample preparation, providing complementary Raman and mass spectrometric information. Graphical abstract.

Caracterização anatomopatológica e imuno-histoquímica dos tumores das glândulas cutâneas em cães / Anatomopathological and immunohistochemical characterization of skin gland tumors in dogs

O presente estudo objetivou caracterizar os aspectos anatomopatológicos e imuno-histoquímicos dos tumores das glândulas cutâneas em cães. A caracterização morfológica seguiu a classificação atualizada da Organização Mundial de Saúde. Para a caracterização imuno-histoquímica, utilizaram-se anticorpos monoclonais primários anti-citoqueratina 14 (CK14), vimentina, p63, calponina, EGFR e Ki-67. Dos animais examinados, 66,67% (18/27) eram machos e 33,33% (9/27) fêmeas, 21 tinham raça definida e seis eram sem raça definida (SRD), com idade variando entre sete e 15 anos. Dos tumores caracterizados, 40,74% eram hepatoides (11/27), 29,63% sebáceos (8/27), 25,92% apócrinos (7/27) e 3,70% meibômio (1/27). Os tumores malignos representaram 55,56%, e os benignos 44,44%. Com esses resultados, foi possível demonstrar que os tumores das glândulas cutâneas em cães são frequentes, sem predileção por raça, sexo e com idade superior ou igual a sete anos. Os anticorpos CK 14, p63, vimentina e EGFR foram imunoexpressos nas células basais, células de diferenciação sebácea dos tumores hepatoides e de meibômio e células mioepiteliais. Entretanto, a vimentina e o EGFR não demonstraram imunomarcação para os tumores sebáceos. A calponina foi um bom marcador para as células mioepiteliais. O índice de Ki-67 foi mais acentuado nos tumores malignos em relação aos benignos. No entanto, estudos futuros utilizando maior número de casos se fazem necessários.(AU)

The present study aimed to characterize the anatomopathological and immunohistochemical aspects of cutaneous glandular tumors in dogs. Tumours were diagnosed according to the WHO criteria for canine skin neoplasms. For the immunohistochemical characterization, the primary monoclonal antibodies anti-cytokeratin 14 (CK14), vimentin, p63, calponin, EGFR and Ki-67 were used. Males were 66.67% (18/27) and females 33.33% (9/27), 21 had a defined race and 6 were mixed breed, with ages varying from 7 to 15 years. The tumors characterized were 40.74% hepatoid (11/27), 29.63% sebaceous (8/27), 25.92% apocrine (7/27) and 3.70% Meibômio (1/27). Malignant tumors accounted for 55.56% and benign tumors 44.44%. With these results it was possible to demonstrate that tumors of cutaneous glands in dogs are frequent, with no predilection for race, sex and with an age ≥ seven years. The CK 14 antibodies, p63, vimentin, and EGFR were imunoexpressed in the basal cells of the sebaceous cell differentiation and Meibomian hepatoides tumors and myoepithelial to cells. However, vimentin and EGFR did not demonstrate immunostaining for sebaceous tumors. Calponin was a good marker for myoepithelial cells. The Ki-67 index was more pronounced in malignant tumors compared to benign tumors. However, more studies are needed mainly using a higher number of tumors.(AU)

Effect of Enterococcus faecium SF68 on serum cobalamin and folate concentrations in healthy dogs.

OBJECTIVE: To study the effect of a 14-day administration of the probiotic Enterococcus faecium SF68 on serum concentrations of cobalamin and folate in healthy dogs. MATERIALS AND METHODS: Thirty-six healthy dogs were randomly allocated between probiotic and control groups. Enterococcus faecium SF68 was administered to the probiotic group for 14 days whereas the control group did not receive any product. A blood sample was taken from all dogs when starting the administration (day 1), when the administration ended (day 14) and 14 days later (day 28). Serum cobalamin and folate concentrations and the canine inflammatory bowel disease activity index scores were determined at each time point. RESULTS: There was a progressive reduction of mean serum cobalamin in the probiotic group during the 28-day study, with significantly lower concentration at day 28 compared to baseline and day 14 concentrations. Moderate hypocobalaminaemia was observed in eight dogs at day 28. Probiotic administration was associated with a non-significant increase in mean serum folate concentration at day 14, and a significant decrease at day 28 compared with day 1. The canine inflammatory bowel disease activity index score remained unaltered during the study. CLINICAL SIGNIFICANCE: Short-term Enterococcus faecium SF68 administration caused a significant reduction of mean cobalamin concentration and moderate hypocobolaminaemia in eight of 18 dogs. Monitoring serum folate appears unnecessary because the probiotic caused a non-significant increase that returned to baseline values after administration was discontinued.

Escherichia coli and Salmonella ser. Saintpaul natural co-infection in a free-living ruddy ground dove (Columbina talpacoti): a case report / Coinfecção por Escherichia coli e Salmonella ser. Saintpaul em Columbina talpacoti: relato de caso

This study reports a co-infection of Escherichia coli and Salmonella in a free-living ruddy ground dove (Columbina talpacoti) received at the Laboratory of Ornithological Studies of the State University of Ceará, Brazil. The bird presented diarrhea, leg paralysis and anorexia, and died shortly after. Necropsy was then performed and samples from lung, kidney, liver and intestine were collected for microbiological and histopathological analyses. Escherichia coli was isolated from cloacal swab, lung and kidney samples. Salmonella ser. Saintpaul was identified in liver and spleen samples. Escherichia coli isolates were tested for the presence of eight diagnostic genes for diarrheagenic pathotypes (STEC, ETEC, EPEC, EIEC, EAEC) with conventional polymerase chain reaction (PCR). EAEC was detected in the lung and kidney, and STEC in the intestine. In conclusion, Columbina talpacoti is susceptible to enteroaggregative Escherichia coli and Salmonella ser. Saintpaul infection, which may have public health implications.(AU)

Este estudo relata um caso de coinfecção por Escherichia coli e Salmonella ser. Saintpaul em uma rolinha-roxa (Columbina talpacoti) recebida pelo Laboratório de Estudos Ornitológicos da Universidade Estadual do Ceará, Brasil. A ave apresentava diarreia, paralisia nas pernas e anorexia, indo a óbito rapidamente. A necropsia foi realizada e amostras de pulmão, rim, fígado e intestino foram coletados para isolamento microbiológico e análise histopatológica. Escherichia coli foi identificada em amostras de suabe cloacal, pulmão e rim. Salmonella ser. Saintpaul foi identificada no fígado e baço. Isolados de E. coli foram testados para a presença de oito genes de diagnóstico para patotipos diarreiogênicos (STEC, ETEC, EPEC, EIEC, EAEC) através de reação em cadeia de polimerase (PCR) convencional. EAEC foi detectada no pulmão e rim, e STEC foi identificada no intestino. Em conclusão, Columbina talpacoti é suscetível a infecção por Escherichia coli enteroagregativa e Salmonella ser. Saintpaul, o que pode implicar em risco para a saúde pública.(AU)

In-syringe dispersive micro-solid phase extraction using carbon fibres for the determination of chlorophenols in human urine by gas chromatography/mass spectrometry.

In this article, carbon fibres (CFs) are presented as sorbent material for the dispersive micro-solid phase extraction of twelve chlorophenols from urine samples. CFs are synthesized by a reagentless and green procedure consisting of heating raw cotton, a natural precursor, at high temperature (400°C) in an inert atmosphere (Ar) during 2h. The resulting fibres, which present good water dispersibility, are finally loaded on an in-syringe device. This device, which integrates the extraction and final elution of the analytes, is disposable and it is adapted to process low sample volumes. Working at the optimum conditions, the extraction procedure in combination with gas chromatography/mass spectrometry allows the determination of the analytes in urine at the low µg/L range. In fact, the limits of quantification (LOQs) of the analytes were in the interval from 1µg/L to 2.5µg/L with precision values, expressed as relative standard deviations (RSD), better than 13%. Relative recovery values, ranging from 74.5% to 113%, demonstrate the applicability of the proposed method.

Cuantificación fisicoquímica en gorro turco [Melocactus zehntneri (Britton & Rose) Luetzelburg - Cactaceae] / Quantificação Fitoquímica da coroa-de-frade [Melocactus zehntneri (Britton & Rose) Luetzelburg - Cactaceae] / Quantification Physicochemical in Melon Cactus [Melocactus zehntneri (Britton & Rose) Luetzelburg - Cactaceae]

RESUMO No Nordeste do Brasil é bastante comum e variado o uso da coroa-de-frade (Melocactus spp.). Assim, o objetivo deste estudo foi realizar diversas análises em cladódios de coroa-de-frade [Melocactus zehntneri (Britton & Rose) Luetzelburg], para que possamos compreender as razões estes usos. Os cladódios foram coletados na cidade de Campina Grande e levados ao Laboratório de Engenharia de Alimentos da Universidade Federal de Campina Grande, onde foram feitas as seguintes análises: peso, altura, diâmetro, cor, umidade, acidez, pH, ácido ascórbico, carotenoides, flavonoides e compostos fenólicos, tanto na epiderme quanto no parênquima aquífero. Os resultados mostraram que a epiderme tem uma acidez elevada e mais ácido ascórbico, e um pH mais baixo em comparação com o parênquima aquífero. O conteúdo de carotenoides, flavonoides e compostos fenólicos, foram diferentes nas partes estudadas. A epiderme apresentou sempre maiores quantidades de carotenoides, flavonoides e compostos fenólicos em relação ao parênquima aquífero, nas três plantas estudadas, indicando que a maior parte da defesa da planta acontece neste tecido. Mais estudos são necessários com técnicas mais precisas, para identificar os componentes bioativos desta espécie.

ABSTRACT In Northeast Brazil, the use of melon cactus (Melocactus spp.) is quite common and varied. Thus, the present study aimed to perform various analyzes in cladodes of melon cactus [Melocactus zehntneri (Britton & Rose) Luetzelburg], to understand the reasons for the use of this species. The cladodes were collected in the city of Campina Grande and taken to the Food Engineering Laboratory of the Federal University of Campina Grande, where we performed the following analyses: mass, height, diameter, color, moisture, acidity, pH, ascorbic acid, carotenoids, flavonoids and phenolic compounds, both in the epidermis and in the aquifer parenchyma. The results showed that the epidermis has a higher acidity, ascorbic acid content and lower pH compared to the aquifer parenchyma. The contents of carotenoids, flavonoids and phenolic compounds, were different from the both parts analyzed. The epidermis always had greater quantities of carotenoids, flavonoids and phenolic compounds than the aquifer parenchyma for the three plants, showing that most of the plant defense takes place in this tissue. Further studies, with more accurate techniques, are needed to identify the bioactive components of this species.

Octadecyl functionalized core-shell magnetic silica nanoparticle as a powerful nanocomposite sorbent to extract urinary volatile organic metabolites.

In this present study, magnetic Fe3O4@SiO2 nanoparticles (MNPs) functionalized with octadecyl groups (Fe3O4@SiO2-C18 NPs) were synthesized, characterized and employed, for the first time, as powerful nanosorbent to extract endogenous volatile organic metabolites (EVOMs) namely, hexanal, heptanal, decanal, benzaldehyde, 4-heptanone, 5-methyl-2-furfural and phenol, described as potential biomarkers of cancer, from human urine. By using co-precipitation, surface modification methods, the carbon-ferromagnetic nanocomposite was synthesized and characterized by infrared spectrum (IR) and transmission electron microscopy (TEM). By coupling with gas chromatography-mass spectrometry (GC-qMS), a reliable, sensitive and cost-effective method was validated. To test the extraction efficiency of the carbon-ferromagnetic nanocomposite toward urinary EVOMs experimental variables affecting the extraction performance, including nanosorbent amount, adsorption time, elution time, and nature of elution solvent, were investigated in detail. The extraction process was performed by dispersing Fe3O4@SiO2-C18 NPs into working solution containing targeted VOMs, and into urine samples, and then eluted with an adequate organic solvent. The eluate was collected, concentrated and analyzed by GC-qMS. Under the optimized conditions, the LODs and LOQs achieved were in the range of 9.7-57.3 and 32.4-190.9ng/mL, respectively. Calibration curves were linear (r(2)≥0. 988) over the concentration ranges from 0.25 to 250ng/mL. In addition, a satisfying reproducibility was achieved by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) less than 3 and 11%, respectively. The method also afforded satisfactory results in terms of the matrix effect (72.8-96.1%) and recoveries (accuracy) higher than 75.1% for most of the studied EVOMs. The Fe3O4@SiO2-C18 NPs-based sorbent extraction combined with GC-qMS revealed that the new nanosorbent had a strong ability to retain the target metabolites providing a new, reliable and high throughput strategy for isolation of targeted EVOMs in human urine, suggesting their potential to be applied in other EVOMs.

Magnetic nanoparticles-nylon 6 composite for the dispersive micro solid phase extraction of selected polycyclic aromatic hydrocarbons from water samples.

In this article, the easy synthesis of magnetic nanoparticles-nylon 6 composite is presented, characterized and applied in the microextraction field. The one-step synthesis of the composite is performed by a solvent changeover playing with the different solubility of the polymeric network in formic acid and water. The new material has been characterized by different techniques including infrared spectroscopy, transmission and scanning microscopy. The extraction performance of the composite under a dispersive micro solid phase extraction format has been evaluated by determining four polycyclic aromatic hydrocarbons (benzo[b]fluoranthene, fluoranthene, indeno[1,2,3-cd]pyrene and phenanthrene) in water using ultra performance liquid chromatography (UPLC) combined with photo diode array detection. The developed methodology allows the determination of the analytes with limits of detection in the range from 0.05 µg/L (benzo[b]fluoranthene) to 0.58 µg/L (phenanthrene). The repeatability of the method was better than 6.9% at the limit of quantification level. The relative recoveries varied in the interval 80-111%.

Carbon coated titanium dioxide nanotubes: synthesis, characterization and potential application as sorbents in dispersive micro solid phase extraction.

In this article, carbon coated titanium dioxide nanotubes (c-TNTs) have been synthesized. The synthesis of the bare TNTs (b-TNTs) using anatase as precursor and their coating with a caramel layer have been performed by simple and cheap hydrothermal processes. The final conversion of the caramel layer in a carbon coating has been accomplished by a thermal treatment (600°C) in an inert (Ar) atmosphere. The c-TNTs have been characterized by different techniques including transmission microscopy, infrared spectroscopy, X-ray powder diffraction, thermogravimetry and Brunauer, Emmett and Teller (BET) adsorption isotherms. The extraction performance of the c-TNTs under a microextraction format has been evaluated and compared with that provided by b-TNTs and multiwalled carbon nanotubes (MWCNTs) using naproxen and ketoprofen as model analytes. c-TNTs provided better results than the other nanoparticles, especially at low acidic pH values. In addition, c-TNTs presented a better dispersibility than MWCNTs, which is very interesting for their use in dispersive micro-solid phase extraction. Finally, a microextraction format, adapted to low sample volumes, has been proposed and applied for the determination of naproxen and ketoprofen in saliva and urine samples by liquid chromatography with UV detection. The results indicate that this approach is promising for the analysis of biological samples. In fact, the recoveries were in the range between 96% and 119% while the precision, expressed as relative standard deviation, was better than 8.5% and 26.3% for urine and saliva, respectively. The detection limits were in the range 34.1-40.8µg/L for saliva samples and 81.1-110µg/L for urine samples.

A quantitative model to assess Social Responsibility in Environmental Science and Technology.

The awareness of the impact of human activities in society and environment is known as "Social Responsibility" (SR). It has been a topic of growing interest in many enterprises since the fifties of the past Century, and its implementation/assessment is nowadays supported by international standards. There is a tendency to amplify its scope of application to other areas of the human activities, such as Research, Development and Innovation (R + D + I). In this paper, a model of quantitative assessment of Social Responsibility in Environmental Science and Technology (SR EST) is described in detail. This model is based on well established written standards as the EFQM Excellence model and the ISO 26000:2010 Guidance on SR. The definition of five hierarchies of indicators, the transformation of qualitative information into quantitative data and the dual procedure of self-evaluation and external evaluation are the milestones of the proposed model, which can be applied to Environmental Research Centres and institutions. In addition, a simplified model that facilitates its implementation is presented in the article.

Stir octadecyl-modified borosilicate disk for the liquid phase microextraction of triazine herbicides from environmental waters.

In the present article, a novel extraction/stirring approach in the liquid phase microextraction context is presented. The new technique is based on octadecyl coated borosilicate disks which act as support of the organic extracting solvent thanks to hydrophobic interactions. The disk is integrated in a stirring element which favors the transference of the analytes to the extraction phase. The proposed extraction procedure has been characterized using the determination of nine herbicides in water samples by ultra performance liquid chromatography (UPLC) combined with ultraviolet (UV) detection as model analytical problem. All the variables involved in the extraction have been studied and optimized in depth and the optimized technique provides enrichment factors in the range from 79 to 839. The method has been analytically characterized on the basis of its linearity, sensitivity and precision. Limits of detection were in the range from 0.14µg/L (atrazine) to 0.56µg/L (terbumeton) with precision better than 7.3% (expressed as relative standard deviation). Relative recoveries were close to 100%, which demonstrated the applicability of the stir octadecyl-modified borosilicate disk for the proposed analytical problem.