Automated on-line solid-phase extraction-liquid chromatography-electrospray tandem mass spectrometry method for the determination of ochratoxin A in wine and beer     

Bacaloni A  Cavaliere C  Faberi A  Pastorini E  Samperi R  Laganà A 《Journal of agricultural and food chemistry》2005,53(14):5518-5525

An automated on-line solid-phase extraction-liquid chromatography-electrospray tandem mass spectrometry (SPE-LC-ESI-MS/MS) method was developed for the determination of ochratoxin A (OTA) in alcoholic beverages. Mean recoveries for wine and beer were, respectively, 75 and 82%. Detection was achieved in negative ionization with a Q TRAP mass spectrometer operating in multiple-reaction monitoring (MRM) mode or enhanced product ion (EPI) mode, using the third quadrupole as linear ion trap. The MRM mode turned out to be more sensitive; the method allowed accurate determination of OTA in the range of 0.01-25 ng mL(-1) using external calibration. Within-day and between-day relative standard deviation percentages were <6.2 and <9.1%, respectively. In EPI mode, fragmentation spectra at the limit of quantification (0.03 ng mL(-1)) and good linearity could be obtained. Application of the method (MRM mode) to the analysis of several wine and beer samples purchased in local stores revealed OTA levels in the ranges of 0.03-1.44 ng mL(-1) for wines and 0.02-0.14 ng mL(-1) for beers.  相似文献   

Chemical characterization of Sacha Inchi (Plukenetia volubilis L.) oil     

Fanali C  Dugo L  Cacciola F  Beccaria M  Grasso S  Dachà M  Dugo P  Mondello L 《Journal of agricultural and food chemistry》2011,59(24):13043-13049

A chemical characterization of the major components, namely, triacylglycerols (TAGs), polyphenols, and tocopherols in a Sacha inchi oil derived from cold pressing of the seed, is hereby reported. To tackle such a task, high-performance liquid chromatography in combination with photodiode array (PDA), fluorescence (RF), and mass spectrometry (MS) detection was employed. The latter was interfaced with atmospheric pressure chemical ionization and with electrospray ionization for the analysis of TAGs and polyphenols, respectively, whereas RF detection was tested for the determination of tocopherol content. Furthermore, fatty acid methyl esters (FAMEs) were evaluated by gas chromatography-flame ionization detector. A 93% amount of total fatty acids was represented by unsaturated FAMEs with the greatest percentage represented by linoleic (L) and linolenic (Ln) accounting for approximately 50 and 36%, respectively. The main TAGs (>10%) were represented by LLnL, LnLnLn, and LnLLn; the latter was present in the oil sample at the highest percentage (22.2%). Among tocopherols, γ-tocopherol was detected to be the most abundant component (over 50%). The polyphenolic composition was also investigated, and a total of 15 compounds were positively identified, through the complementary analytical information coming from PDA and MS data. To the best of our knowledge, this is the first report providing a thorough chemical characterization of a Plukenetia volubilis L. oil.  相似文献   

Biological role of the HGF/MET ligand/receptor couple in bovine mammary epithelial cells     

Accornero P  Luvarà S  Favole A  Macchi E  Motta M  Baratta M 《Veterinary research communications》2007,31(Z1):161-164

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Biomonitoring and Sourcing Toxic Elements Using Vascular Epiphytes of the Tillandsia Genus in the Mining Region of Taxco de Alarcón,Guerrero, Southern Mexico     

Mendoza-Ramos  Juan Ernesto  Talavera-Mendoza  Oscar  Lopezaraiza-Mikel  Martha Elena  Salgado-Souto  Sergio Adrián  Sayago-Lorenzana  Roberto Carlos  Ruiz  Joaquin  Sampedro-Rosas  Laura  Rosas-Acevedo  José Luis  Aguirre-Noyola  José Luis 《Water, air, and soil pollution》2021,232(1):1-14

Water, Air, &; Soil Pollution - The concentration of As, Pb, Cd, Zn, Fe, Mn, and Cu and the Sr and Pb isotopic compositions were determined in four species of the vascular epiphyte Tillandsia...  相似文献   

Process-based modelling of erosion,sediment transport and reservoir siltation in mesoscale semi-arid catchments     

Axel Bronstert  José-Carlos de Araújo  Ramon J. Batalla  Alexandre Cunha Costa  José Miguel Delgado  Till Francke  Saskia Foerster  Andreas Guentner  José Andrés López-Tarazón  George Leite Mamede  Pedro Henrique Medeiros  Eva Mueller  Damià Vericat 《Journal of Soils and Sediments》2014,14(12):2001-2018

Purpose

To support scientifically sound water management in dryland environments a modelling system has been developed for the quantitative assessment of water and sediment fluxes in catchments, transport in the river system, and retention in reservoirs. The spatial scale of interest is the mesoscale because this is the scale most relevant for management of water and land resources.

Materials and methods

This modelling system comprises process-oriented hydrological components tailored for dryland characteristics coupled with components comprising hillslope erosion, sediment transport and reservoir deposition processes. The spatial discretization is hierarchically designed according to a multi-scale concept to account for particular relevant process scales. The non-linear and partly intermittent run-off generation and sediment dynamics are dealt with by accounting for connectivity phenomena at the intersections of landscape compartments. The modelling system has been developed by means of data from nested research catchments in NE-Spain and in NE-Brazil.

Results and discussion

In the semi-arid NE of Brazil sediment retention along the topography is the main process for sediment retention at all scales, i.e. the sediment delivery is transport limited. This kind of deposition retains roughly 50 to 60 % of eroded sediment, maintaining a similar deposition proportion in all spatial scales investigated. On the other hand, the sediment retained in reservoirs is clearly related to the scale, increasing with catchment area. With increasing area, there are more reservoirs, increasing the possibility of deposition. Furthermore, the area increase also promotes an increase in flow volume, favouring the construction of larger reservoirs, which generally overflow less frequently and retain higher sediment fractions. The second example comprises a highly dynamic Mediterranean catchment in NE-Spain with nested sub-catchments and reveals the full dynamics of hydrological, erosion and deposition features. The run-off modelling performed well with only some overestimation during low-flow periods due to the neglect of water losses along the river. The simulated peaks in sediment flux are reproduced well, while low-flow sediment transport is less well captured, due to the disregard of sediment remobilization in the riverbed during low flow.

Conclusions

This combined observation and modelling study deepened the understanding of hydro-sedimentological systems characterized by flashy run-off generation and by erosion and sediment transport pulses through the different landscape compartments. The connectivity between the different landscape compartments plays a very relevant role, regarding both the total mass of water and sediment transport and the transport time through the catchment.  相似文献   

Muller & Kirk's Small Animal Dermatology. William Miller Jr,Craig Griffin,Karen Campbell. Saunders‐Elsevier,St Louis; 7th Edition, 2013, 938 p; IBSN: 978‐1‐4160‐0028‐0, £113.     

Adri van den Broek 《Veterinary dermatology》2013,24(5):559-559

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Turnip yellow mosaic virus in Chinese cabbage in Spain: commercial seed transmission and molecular characterisation     

Ana Alfaro-Fernández  Adrián Serrano  Teodora Tornos  María del Carmen Cebrián  María del Carmen Córdoba-Sellés  Concepción Jordá  María Isabel Font 《European journal of plant pathology / European Foundation for Plant Pathology》2016,145(2):433-446

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Ebola outbreak killed 5000 gorillas     

Bermejo M  Rodríguez-Teijeiro JD  Illera G  Barroso A  Vilà C  Walsh PD 《Science (New York, N.Y.)》2006,314(5805):1564

Over the past decade, the Zaire strain of Ebola virus (ZEBOV) has repeatedly emerged in Gabon and Congo. Each human outbreak has been accompanied by reports of gorilla and chimpanzee carcasses in neighboring forests, but both the extent of ape mortality and the causal role of ZEBOV have been hotly debated. Here, we present data suggesting that in 2002 and 2003 ZEBOV killed about 5000 gorillas in our study area. The lag between neighboring gorilla groups in mortality onset was close to the ZEBOV disease cycle length, evidence that group-to-group transmission has amplified gorilla die-offs.  相似文献   

Towards the identification of ecological management units: A multidisciplinary approach for the effective management of bottlenose dolphins in the southern Iberian Peninsula          下载免费PDF全文

Joan Giménez  Marie Louis  Enrique Barón  Francisco Ramírez  Philippe Verborgh  Pauline Gauffier  Ruth Esteban  Ethel Eljarrat  Damià Barceló  Manuela G. Forero  Renaud de Stephanis 《水产资源保护:海洋与淡水生态系统》2018,28(1):205-215

Obtention and characterization of phenolic extracts from different cocoa sources     

Ortega N  Romero MP  Macià A  Reguant J  Anglès N  Morelló JR  Motilva MJ 《Journal of agricultural and food chemistry》2008,56(20):9621-9627

The aim of this study was to evaluate several cocoa sources to obtain a rich phenol extract for use as an ingredient in the food industry. Two types of phenolic extracts, complete and purified, from different cocoa sources (beans, nibs, liquor, and cocoa powder) were investigated. UPLC-MS/MS was used to identify and quantify the phenolic composition of the extracts, and the Folin-Ciocalteu and vanillin assays were used to determine the total phenolic and flavan-3-ol contents, respectively. The DPPH and ORAC assays were used to measure their antioxidant activity. The results of the analysis of the composition of the extracts revealed that the major fraction was procyanidins, followed by flavones and phenolic acids. From the obtained results, the nib could be considered the most interesting source for obtaining a rich phenolic cocoa extract because of its rich phenolic profile content and high antioxidant activity in comparison with the other cocoa sources.  相似文献