General Chemical State Laboratory

Ioánnina, Greece

General Chemical State Laboratory

Ioánnina, Greece
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Apostolidou C.,Aristotle University of Thessaloniki | Apostolidou C.,General Chemical State Laboratory | Adamopoulos K.,Aristotle University of Thessaloniki | Lymperaki E.,Alexander Technological Educational Institute of Thessaloniki | And 2 more authors.
Clinical Nutrition ESPEN | Year: 2015

Background & aims: The role of red wine in cardiovascular risk prevention has been documented by several epidemiological studies in patients and normocholesterolemic healthy individuals. However, it is unclear whether hypercholesterolemic individuals free of cardiovascular disease would equally benefit from moderate red wine consumption to prevent atherosclerosis and the development of cardiovascular disease. Methods: Forty (40) healthy male and female volunteers were recruited, divided into 2 age-adjusted groups according to their total cholesterol levels; in asymptomatic hypercholesterolemics (AHC), and normocholesterolemics (NC). Total Antioxidant Capacity (TAC), Lipid profile, Vitamin E, and cardiovascular risk indexes (Low Density Lipoproteins (LDL)/High Density Lipoproteins (HDL) and Vitamin E/Total Cholesterol (TC) were evaluated in the blood serum of all subjects prior to and 1 month after once daily red wine consumption as well as prior to and after being given a placebo drink following a 1 month wash out period. Results: TAC significantly increased after the intervention in all subjects in AHC and NC group with a mean difference (post-pre) 1.78 mmol/l and 0.87 mmol/l, respectively. Vitamin E significantly increased especially in AHC group (13.1% increase) compared to NC group (5.41%) after red wine consumption, with higher increase in the AHC group. There was marginal significant treatment effect (decrease) on fasting LDL/HDL ratio (0.05) and a statistically significant increase on Vitamin E/TC ratio relative to drinking placebo for NC (< 0.005) and AHC group (< 0.002). Conclusions: Asymptomatic hypercholesterolemic (AHC) individuals are more likely to develop cardiovascular disease as presented by high cholesterol levels in addition to the presence of low baseline serum α-tocopherol (vitamin E) concentrations, leading to atherosclerosis. AHC individuals following an early dietary intervention, seem likely to reduce the risk factors for cardiovascular disease by increasing circulating concentrations of TAC and α-tocopherol (vitamin E) so as vitamin E/TC ratio increases. © 2015 European Society for Clinical Nutrition and Metabolism.

Vareli K.,University of Ioannina | Zarali E.,University of Ioannina | Zacharioudakis G.S.A.,National and Kapodistrian University of Athens | Vagenas G.,General Chemical State Laboratory | And 4 more authors.
Harmful Algae | Year: 2012

Various cyanobacterial species have the capacity to produce different types of toxins. Microcystins, the most prominent cyanotoxins are considered health hazards because of their potential hepatotoxic effects. They are well known to contaminate freshwater ecosystems but their presence in marine ecosystems has been reported only occasionally. We investigated seasonal changes of microcystin concentrations both in water and in the edible species of mussels Mytilus galloprovincialis collected from Amvrakikos Gulf (salinity ranging from 30‰ to 34‰), the biggest semi-enclosed basin in Greece. The microcystin concentrations in the water ranging from 0.003 to 19.8ngl -1, were below the World Health Organization (WHO) upper limit for recreational activities. In contrast, we found that microcystin concentrations in M. galloprovincialis mussels (ranging from 45±2 to 141.5±13.5ngg -1ww) exceeded the upper limit of the tolerable daily intake (TDI) of microcystin as determined by WHO.Genotype composition of the total cyanobacterial community of the Gulf was analyzed by using denaturing gradient gel electrophoresis (DGGE) profiling of the rRNA internal transcribed spacer region (rRNA-ITS). The cyanobacterial community was found to be dominated almost exclusively by the cosmopolitan species Synechococcus - Synechocystis. In order to determine genes involved in the production of microcystins, a range of both specific and degenerate molecular primers against microcystin synthetase gene cluster (mcyS) was used.To our knowledge this is the first report of the presence of the hepatotoxic microcystins in the Mediterranean Sea, the first study on the accumulation of these toxins in mussels from a Mediterranean marine ecosystem and one of the few published works suggesting a potential association of microcystins with Synechococcus and/or Synechocystis cyanobacteria.The importance of our study is strengthened by the fact that Amvrakikos Gulf is among the most productive Greek " seafood" areas and a Mediterranean wetland of international significance according to Ramsar Convention. © 2011 Elsevier B.V.

Economou A.,National and Kapodistrian University of Athens | Petraki O.,National and Kapodistrian University of Athens | Tsipi D.,General Chemical State Laboratory | Botitsi E.,General Chemical State Laboratory
Talanta | Year: 2012

This work reports a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for identification and quantification of seven sulfonamides, trimethoprim and dapsone in honey. The method is based on a solid-phase extraction (SPE) step of the target analytes with Oasis HLB cartridges after acidic hydrolysis of the honey sample to liberate the sugar-bound sulfonamides. Analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the positive electro-spray ionization (ESI) mode with two different isotopically labeled internal standards with the view to improve the quantitative performance of the method. The method validation has been performed according to the Commission Decision 2002/657/EC; the average recoveries, measured at three concentration levels (1.5, 2.5 and 5.0 μg kg-1), have been estimated in the range 70 to 106% while the respective % relative standard deviations of the within-laboratory reproducibility ranged from 6 to 18%. Mean values of the expanded uncertainties calculated were in the range 22-41% at the 99% confidence level. Decision limit (CCα) and detection capability (CCβ) values were in the ranges 0.4-0.9 and 0.7-1.4 μg kg-1, respectively. Matrix effects have been investigated demonstrating a moderate signal suppression/enhancement for most of the target compounds. The method described has been successfully applied to the analysis of honey samples; sulfamethoxazole, sulfathiazole and trimethoprim were detected in some cases. © 2012 Elsevier B.V. All rights reserved.

Botitsi H.V.,General Chemical State Laboratory | Garbis S.D.,Biomedical Research Foundation Of The Academy Of Athens Brfaa | Economou A.,National and Kapodistrian University of Athens | Tsipi D.F.,General Chemical State Laboratory
Mass Spectrometry Reviews | Year: 2011

Analysis of pesticides and their metabolites in food and water matrices continues to be an active research area closely related to food safety and environmental issues. This review discusses the most widely applied mass spectrometric (MS) approaches to pesticide residues analysis over the last few years. The main techniques for sample preparation remain solvent extraction and solid-phase extraction. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) approach is being increasingly used for the development of multi-class pesticide residues methods in various sample matrices. MS detectors-triple quadrupole (QqQ), ion-trap (IT), quadrupole linear ion trap (QqLIT), time-of-flight (TOF), and quadrupole time-of-flight (QqTOF)-have been established as powerful analytical tools sharing a primary role in the detection/quantification and/or identification/confirmation of pesticides and their metabolites. Recent developments in analytical instrumentation have enabled coupling of ultra-performance liquid chromatography (UPLC) and fast gas chromatography (GC) with MS detectors, and faster analysis for a greater number of pesticides. The newly developed "ambient-ionization" MS techniques (e.g., desorption electrospray ionization, DESI, and direct analysis in real time, DART) hyphenated with high-resolution MS platforms without liquid chromatography separation, and sometimes with minimum pre-treatment, have shown potential for pesticide residue screening. The recently introduced Orbitrap mass spectrometers can provide high resolving power and mass accuracy, to tackle complex analytical problems involved in pesticide residue analysis. © 2010 Wiley Periodicals, Inc.

Togkalidou T.,General Chemical State Laboratory | Karoglou M.,National Technical University of Athens | Bakolas A.,National Technical University of Athens | Giakoumaki A.,University of the Basque Country | Moropoulou A.,National Technical University of Athens
Transport in Porous Media | Year: 2013

This paper studies various microstructure parameters of natural and artificial building materials and aims to their correlation to the water vapor permeability. Three categories of building materials were investigated: stones, bricks, and plasters. Mercury intrusion porosimetry was applied in order to obtain the materials microstructure characteristics, a variety of pore size distributions and pore structure measurements, such as total porosity. The water vapor permeability of materials was determined experimentally according to ASTM standard E96-00. A robust principal component regression approach, coupled with multiple outlier detection, was applied in order to correlate water vapor permeability values to pore size distributions. A good quality correlation model was found by utilizing relative specific pore volume and relative specific pore surface distributions, whereas using pore structure measurements, such as total porosity, the correlation results were very poor. From the results, specific ranges of pore size distribution, corresponding to pores radius sizes greater than 10μm and between 1.778 and 0.421μm, contribute to the water vapor permeability of the materials. © 2013 Springer Science+Business Media Dordrecht.

Tsatsaragkou K.,Agricultural University of Athens | Yiannopoulos S.,General Chemical State Laboratory | Kontogiorgi A.,General Chemical State Laboratory | Poulli E.,General Chemical State Laboratory | And 2 more authors.
Journal of Cereal Science | Year: 2012

In this study, gluten free breads (GFBs) made from rice and carob flour in different proportions were investigated. Water added changed in response to the carob amount. Structural and textural parameters of the samples such as porosity, crumb grain characteristics, firmness and relative elasticity of crumb, were measured. Simple mathematical models were developed to correlate the measured properties with carob flour and water content. The simplest and most convenient mathematical model developed was a power model, indicating that water influence on GFBs characteristics was more pronounced than that of carob flour. Carob flour addition enhanced the protein, fiber and minerals amount of the produced samples, and improved their functional properties as well, when water amount used was adequate. GFBs with a ratio of carob flour/water 10/110, 15/130 and 15/140 presented higher quality, in terms of dough proofing, porosity, crumb firmness and viscoelasticity. © 2012 Elsevier Ltd.

Tsatsaragkou K.,Agricultural University of Athens | Yiannopoulos S.,General Chemical State Laboratory | Kontogiorgi A.,General Chemical State Laboratory | Poulli E.,General Chemical State Laboratory | And 2 more authors.
Food and Bioprocess Technology | Year: 2014

In this study, the rheological properties of gluten-free doughs from rice flour containing different amounts of carob flour were investigated. Water added changed in response to the carob amount. Dynamic oscillatory and creep tests were performed in order to gain knowledge on the rheological behaviour of doughs, which is essential for the control of the bread-making procedure and the production of high-quality bread. Simple power law mathematical models were developed in order to evaluate the effect of carob and water added in dough rheological behaviour. Creep data evaluation demonstrates that an increase in water content decreased the resistance of dough to deformation and, therefore, dough strength, whereas carob flour increased the elastic character and structure strength of the dough. This was also found in dynamic oscillatory tests. Increased amounts of carob flour led to an increase in bread dough elastic character since fibre addition elastifies and strengthens the dough structure. Moreover, doughs exhibited a solid-like viscoelastic character, with the storage modulus (G′) predominant over the loss modulus (G″). Dough rheological properties have an important effect on baking characteristics. Rheological experiments and applied mathematical models can provide us with good knowledge of rheological behaviour and dough viscoelasticity prediction. Therefore, dough samples containing carob-to-water ratios of 10:110 and 15:130 can be considered to possess a balance between the viscous and elastic properties compared to the other samples. © 2013 Springer Science+Business Media New York.

Louppis A.P.,University of Ioannina | Badeka A.V.,University of Ioannina | Katikou P.,Institute of Food Hygiene | Paleologos E.K.,General Chemical State Laboratory | Kontominas M.G.,University of Ioannina
Toxicon | Year: 2010

An approach involving both chemical and biological methods was undertaken for the detection and quantification of the marine toxins okadaic acid (OA), dinophysistoxin-1 (DTX-1) and their respective esters in mussels from different sampling sites in Greece during the period 2006-2007. Samples were analyzed by means of a) high performance liquid chromatography with fluorometric detection (HPLC-FLD), using 9-athryldiazomethane (ADAM), as a pre-column derivatization reagent, b) liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and c) the mouse bioassay. Free OA and DTX-1 were determined by both HPLC-FLD and LC-MS/MS, while their respective esters were determined only by LC-MS/MS after alkaline hydrolysis of the samples. The detection limit (L.O.D.) and quantification limit (L.O.Q.) of the HPLC-FLD method were 0.015 μg/g HP and 0.050 μg/g HP, respectively, for OA. The detection limit (L.O.D.) and quantification limit (L.O.Q.) of the LC-MS/MS method were 0.045 μg/g HP and 0.135 μg/g HP, respectively, for OA. Comparison of results between the two analytical methods showed excellent agreement (100%), while both HPLC-FLD and LC-MS/MS methods showed an agreement of 97.1% compared to the mouse bioassay. © 2009 Elsevier Ltd.

Karanikolopoulos G.,General Chemical State Laboratory | Gerakis A.,General Chemical State Laboratory | Papadopoulou K.,General Chemical State Laboratory | Mastrantoni I.,General Chemical State Laboratory
Food Chemistry | Year: 2015

Reliable methods for quantification of synthetic water-soluble colors in complex food matrices are currently not available. The present work describes the development and validation of an improved protocol for the analysis of synthetic food colorants in complex food matrices presenting high protein and/or fat content. The method developed employs an extraction stage, followed by a subsequent sonification, centrifugation and concentration step. A final clean up via SPE on polyamide cartridges was also employed. The isolated colorants were separated and analyzed by an RP-HPLC/DAD system. High and consistent recoveries (min. 81%) and low RSDs (max. 6%) were achieved for all studied colorants. The issue of high fat content matrices was also addressed showing the need for an additional defatting step in the procedure. Overall, the protocol presented shows high precision and accuracy of detection and can provide the basis for future development of similar methods in other complex food matrices. © 2015 Elsevier Ltd.

Louppis A.P.,University of Ioannina | Georgantelis D.,KONVA SA | Paleologos E.K.,General Chemical State Laboratory | Kontominas M.G.,University of Ioannina
Food Chemistry | Year: 2010

Ultrasonically assisted extraction into the micelles of both non-ionic and anionic surfactants was applied as a methodology for the isolation of tributyltin (TBT) from fish and mussel tissue prior to determination with graphite furnace atomic absorption spectrometry (GFAAS). The proposed methodology includes extraction of organotin species in the micelles of Triton X-114 or Sodium Dodecane Sulphonic Acid (SDSA), accelerated by the application of ultrasounds. Isolation and subsequent determination of TBT is achieved by ultrasonic assisted back extraction into a water immiscible solvent, utilising the selective partition of TBT from an alkaline environment. Quantitation is performed by GFAAS. Seventy-seven seafood samples including sardines, anchovies and mussels were analysed for tributyltin (TBT) from different coastal regions of northern, eastern and western Greece on the Aegean and the Ionian Sea. Results showed that the shellfish contained a higher amount of TBT than fish (mean value of 0.91 μg/kg for fish and 2.21 μg/kg for mussels). The highest TBT concentration recorded was 19.50 μg/kg for sardines in N. Mihaniona and 14.27 μg/kg for mussels in Fthiotida. TBT concentrations found in the present study were much lower than those reported in the literature regarding Greece and other countries. © 2010 Elsevier Ltd. All rights reserved.

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