Showing papers in "Journal of Chromatography A in 2011"

TL;DR: This review summarizes the research done during the last decade on the MAE of active ingredients from plants, together with the advantages and the drawbacks of each MAE techniques.

TL;DR: This review paper shows that some very clear trends can be established in the partitioning of proteins in ATPS, apart from PEG/dextran systems where proteins with higher molecular weights partitioned more readily to the bottom phase.

TL;DR: In this work, matrix effects of 53 pesticides in three different matrices were evaluated and a dilution factor of 15 demonstrated to be enough to eliminate most of the matrix effects, opening the possibility to perform quantification with solvent based standards in the majority of the cases.

TL;DR: The combination betweenHPTLC and mass spectrometric (MS) detection methods will be discussed and it will be shown that this is a very powerful method to investigate the identities of the HPTLC spots in more detail than by the use of common staining methods.

TL;DR: A sensitive rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) method, combined with solid-phase extraction, ultrasonic extraction and silica gel cartridge cleanup, was developed for 28 steroids and applied in the determination of the residual steroidal hormones in surface water, wastewater and sludge samples.

TL;DR: Graphene, a novel class of carbon nanostructures, possesses an ultrahigh specific surface area, and thus has great potentials for the use as sorbent materials in analytical processes, as demonstrated in this work.

TL;DR: The pressing needs to improve analytical throughputs forced particle manufacturers to find a better compromise between the demands for higher column efficiency that require short diffusion paths of analyte molecules in columns and the need for columns that can be operated with the conventional instruments for liquid chromatography, which operate with moderate column back-pressures.

TL;DR: This review provides a survey of the popular stationary phases commercially available and discusses the retention and selectivity characteristics of the polar stationary phases in HILIC.

TL;DR: The present review covers published methods and research articles in which pesticide residues have been extracted from meat and meat products, milk and dairy products, fish and seafood, and eggs, then cleaned up, and isolated by chromatographic techniques to be identified and quantified by various detection methods.

TL;DR: A critically review of the application of flow field flow fractionation for the characterization of natural colloids and natural and manufactured nanoparticles to help users understand the theoretical principles and experimental consideration of the FlFFF and the range of analytical tools that can be used to further characterize the nanoparticles after fractionation.

TL;DR: The graphene-based magnetic nanocomposite synthesized and used for the first time as an effective adsorbent for the preconcentration of the five carbamate pesticides in environmental water samples prior to high performance liquid chromatography-diode array detection has been successfully applied.

TL;DR: The review discusses three versions of bioautography, i.e. contact, immersion and direct bioautographic, and the most promising among them seems to be TLC-bioluminescence screening.

TL;DR: Of the targeted 65 compounds, 46 analytes were detected at levels above the method quantification limit (MQL) in wastewater treatment plant (WWTP) influent, 43 in WWTP effluent and 36 compounds in river water in the UK environment.

TL;DR: Under the optimal conditions, a rapid and effective determination of SAs in environmental water samples was achieved and good reproducibility was obtained.

TL;DR: In this review, the different approaches to their trace determination are reviewed with special attention being paid to sample preparation procedures, state-of-the-art high-performance separation methods hyphenated with mass spectrometry, and immunochemical methods.

TL;DR: Standard OECD media causes aggregation of nanoparticles, which result in changes in organism exposure levels and the nature of the exposed particles compared to exposure to fully dispersed particles, and nanoparticles are likely to have far greater biological effects than suggested thus far by poorly controlled exposures.

TL;DR: A multi residue analysis was developed to quantify 80 environmental contaminants, pesticides and veterinary drugs, belonging to different chemical classes, in honeys, honeybees and pollens and application to more than 100 samples of each matrix was achieved for a global view of pesticide presence in the honeybee environment.

TL;DR: The most unstable compound in tested condition was myricetin, and the higher number of hydroxyl groups promote degradation of flavonoids, whereas sugar moiety and methoxyl groups protect flavonoid of degradation during microwave and ultrasonic assisted extraction.

TL;DR: The main aim of this manuscript is to provide a comprehensive and critical verification of methodology commonly used for sample collection, storage and preparation in studies concerning the analysis of pharmaceuticals and illicit drugs in aqueous environmental samples with the usage of SPE-LC/MS techniques.

TL;DR: UHPLC-MS/MS coupled to tandem mass spectrometry has been used for the analysis of these compounds in less than 7 min and aflatoxins B1, B2, G1, G2, and beauvericin were detected at trace levels.

TL;DR: The application of AF⁴ coupled with highly sensitive detectors turned out to be a powerful method to follow the aggregation of n-Ag particle suspensions at different physical-chemical conditions and to get meaningful information on their chemical composition and particle size distributions.

TL;DR: Principal component analysis (PCA) is used to show how a significant reduction on data complexity was achieved, improving the ability to highlight chemical differences amongst the samples.

TL;DR: Almost all the pharmaceuticals selected in this work were detected, mainly in effluent wastewater.

TL;DR: A clearer understanding of the physico-chemical behavior of supercritical fluids in preparative chromatographic columns under nonlinear conditions is still needed, which seems to be the main obstacle to the establishment of SFC as a sustainable separation tool.

TL;DR: The main uses of nanoparticles to carry out solid phase extraction, solid phase microextraction, liquid-liquid extraction and filtration techniques are described for a wide range of nanoparticle including carbon nanoparticles, metallic, silica and molecular imprinted polymer nanoparticles.

TL;DR: The LC-MS/MS method was satisfactorily validated for the analysis of 150 agricultural samples and showed excellent linearity, precision and precision for all compounds.

TL;DR: The developed magnetic extraction is a robust pre-concentration technique that can be coupled to other analytical methods for the quantitative determination of tetracyclines.

TL;DR: Principal component analysis of the data showed that partitioning was a dominating mechanism for uncharged solutes in HILIC, and correlations between functional groups and interactions were observed, which confirms that the HilIC retention mechanism is partly contributed by adsorption mechanisms involving electrostatic interaction and multipoint hydrogen bonding.

TL;DR: Among the strongly retentive stationary phases, zwitterionic and amide functionalities were found to be the most selective on the basis of partial structural differences, while the hydroxyethyl-type stationary phase showed the highest retention factor, but with low separation efficiency.

TL;DR: Zeolite imidazolate framework 8 (ZIF-8) was synthesized and used as a sorbent for micro-solid-phase extraction of 6 polycyclic aromatic hydrocarbons (PAHs) from environmental water samples for the first time using this novel μ-SPE procedure.