The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform

Andrew C. Singer - One of the best experts on this subject based on the ideXlab platform.

  • Phytoremediation of mixed-contaminated soil using the hyperaccumulator plant Alyssum lesbiacum: evidence of histidine as a measure of phytoextractable nickel.
    Environmental pollution (Barking Essex : 1987), 2006
    Co-Authors: Andrew C. Singer, Thomas Bell, Chloe A. Heywood, Jennifer A. Smith, Ian P. Thompson
    Abstract:

    In this study we examine the effects of polycyclic aromatic hydrocarbons (PAHs) on the ability of the hyperaccumulator plant Alyssum lesbiacum to phytoextract nickel from co-contaminated soil. Planted and unplanted mesocosms containing the contaminated soils were repeatedly amended with Sorbitan Trioleate, salicylic acid and histidine in various combinations to enhance the degradation of two PAHs (phenanthrene and chrysene) and increase nickel phytoextraction. Plant growth was negatively affected by PAHs; however, there was no significant effect on the phytoextraction of Ni per unit biomass of shoot. Exogenous histidine did not increase nickel phytoextraction, but the histidine-extractable fraction of soil nickel showed a high correlation with phytoextractable nickel. These results indicate that Alyssum lesbiacum might be effective in phytoextracting nickel from marginally PAH-contaminated soils. In addition, we provide evidence for the broader applicability of histidine for quantifying and predicting Ni phytoavailability in soils.

  • bioremediation of polychlorinated biphenyl contaminated soil using carvone and surfactant grown bacteria
    Applied Microbiology and Biotechnology, 2000
    Co-Authors: Andrew C. Singer, Eric S Gilbert, Ekawan Luepromchai, David E Crowley
    Abstract:

    Partial bioremediation of polychlorinated biphenyl (PCB)-contaminated soil was achieved by repeated applications of PCB-degrading bacteria and a surfactant applied 34 times over an 18-week period. Two bacterial species, Arthrobacter sp. strain B1B and Ralstonia eutrophus H850, were induced for PCB degradation by carvone and salicylic acid, respectively, and were complementary for the removal of different PCB congeners. A variety of application strategies was examined utilizing a surfactant, Sorbitan Trioleate, which served both as a carbon substrate for the inoculum and as a detergent for the mobilization of PCBs. In soil containing 100 μg Aroclor 1242 g−1 soil, bioaugmentation resulted in 55–59% PCB removal after 34 applications. However, most PCB removal occurred within the first 9 weeks. In contrast, repeated addition of surfactant and carvone to non-inoculated soil resulted in 30–36% PCB removal by the indigenous soil bacteria. The results suggest that bioaugmentation with surfactant-grown, carvone-induced, PCB-degrading bacteria may provide an effective treatment for partial decontamination of PCB-contaminated soils.

Mirka Korhonen - One of the best experts on this subject based on the ideXlab platform.

  • RHEOLOGICAL PROPERTIES OF PHARMACEUTICAL CREAMS CONTAINING Sorbitan FATTY ACID ESTER SURFACTANTS
    2014
    Co-Authors: Mirka Korhonen, Sari Kallioinen Ph. D
    Abstract:

    Korhonen, M., 2003. Rheological properties of pharmaceutical creams containing Sorbitan fatty acid ester surfactants. ISBN 952-91-6585-4 (paperback) ISBN 952-10-1476-8 (PDF) The main purpose of the present study was to gain understanding about the rheological (elastic, viscoelastic and viscous) properties of pharmaceutical creams containing Sorbitan fatty acid ester surfactants (Sorbitan monolaurate, Sorbitan monopalmitate, Sorbitan monostearate, Sorbitan monooleate and Sorbitan Trioleate). The study investigated the effects of an increase in the hydrocarbon chain length, the double bonded hydrocarbon chains and the concentration of the surfactant on the rheological properties of the Sorbitan fatty acid ester surfactant containing creams. In addition, the effects of the volume of inner phase and the short-term storage on the rheological properties of the Sorbitan fatty acid ester surfactant containing creams were investigated. The creams studied were either simple, three-component creams, or complex, multi-component creams. The rheological properties were determined with dynamic oscillation stress sweep and oscillation frequency sweep measurements, with static creep recovery measurements and with time-dependent viscosity measurements

  • rheological properties of pharmaceutical creams containing Sorbitan fatty acid ester surfactants
    2004
    Co-Authors: Mirka Korhonen
    Abstract:

    Korhonen, M., 2003. Rheological properties of pharmaceutical creams containing Sorbitan fatty acid ester surfactants. ISBN 952-91-6585-4 (paperback) ISBN 952-10-1476-8 (PDF) The main purpose of the present study was to gain understanding about the rheological (elastic, viscoelastic and viscous) properties of pharmaceutical creams containing Sorbitan fatty acid ester surfactants (Sorbitan monolaurate, Sorbitan monopalmitate, Sorbitan monostearate, Sorbitan monooleate and Sorbitan Trioleate). The study investigated the effects of an increase in the hydrocarbon chain length, the double bonded hydrocarbon chains and the concentration of the surfactant on the rheological properties of the Sorbitan fatty acid ester surfactant containing creams. In addition, the effects of the volume of inner phase and the short-term storage on the rheological properties of the Sorbitan fatty acid ester surfactant containing creams were investigated. The creams studied were either simple, three-component creams, or complex, multi-component creams. The rheological properties were determined with dynamic oscillation stress sweep and oscillation frequency sweep measurements, with static creep recovery measurements and with time-dependent viscosity measurements. An increase in the length of the saturated hydrocarbon chain of the surfactant increased the elastic nature of the creams. A double bond in the hydrocarbon chain of the surfactant decreased, and an increase in the number of double bonded hydrocarbon chains within the surfactant molecule increased the elastic nature of the creams. An increase in the concentration of the surfactant and an increase in the volume of the inner phase increased the elastic nature of the creams. Storage time decreased and storaging the creams at three different conditions levelled off the differences in the elastic properties of the creams. In the three-component cream formulations the rheological properties of the creams were concluded to be mainly due to the interfacial properties of the surfactants. In the multi-component cream formulations the rheological properties of the creams were concluded to be due, in addition to the surfactants used, to the multiphase structures of the creams. Determination of rheological properties, i.e. unrecoverable viscous, partly recoverable viscoelastic and recoverable elastic properties, gave valuable information about the structural and intermolecular properties of the creams. Rheological measurements can be regarded as sensitive tools for detecting structural changes in pharmaceutical creams and should be regarded as an integral part of the quality evaluation of pharmaceutical creams.

Jianwen Zhang - One of the best experts on this subject based on the ideXlab platform.

  • rapid characterization of commercial polysorbate 80 by ultra high performance supercritical fluid chromatography combined with quadrupole time of flight mass spectrometry
    Journal of Chromatography A, 2016
    Co-Authors: Yu Ji, Zhenxia Du, Jianwen Zhang
    Abstract:

    Abstract Polysorbate 80, as a nonionic surfactant, is widely used in the food, personal care, and pharmaceutical industries due to the advantages of high surface activity, low toxicity, etc. In fact, the products of polysorbate 80 are complex mixtures of oligomers. In this work, a novel and fast method was developed to characterize the commercial polysorbate 80 by ultra-high performance supercritical fluid chromatography (UHPSFC) combined with quadrupole time-of-flight mass spectrometry (QTOF-MS). Some crucial parameters, such as temperature, back pressure and flow rate were optimized. UHPSFC could distinguish n-mer from (n − 1)-mer and (n + 1)-mer in the same series, which provided the high separation resolution needed for quantitative determination of each oligomer in same series. It was not achieved in previous studies. Furthermore, the characteristic ion fragments were found in MS/MS experiment and used to identify different series. The results revealed that main components of this nonionic surfactant comprise polyethylene oxide (PEO), PEO-monooleate, PEO-isosorbide, PEO-isosorbide monooleate, PEO-isosorbide dioleate, PEO-Sorbitan, PEO-Sorbitan monooleate, PEO-Sorbitan dioleate and PEO-Sorbitan Trioleate, etc. The separation was performed using BEH stationary phase, so the relationship between molecular structure of these oligomers and chromatographic retention behavior in supercritical fluid chromatography were also investigated for first time. The whole analytical process only takes 8 min for one sample. Therefore, UHPSFC-QTOF-MS is a simple, novel and efficient tool to analyze polysorbate 80.

Sari Kallioinen Ph. D - One of the best experts on this subject based on the ideXlab platform.

  • RHEOLOGICAL PROPERTIES OF PHARMACEUTICAL CREAMS CONTAINING Sorbitan FATTY ACID ESTER SURFACTANTS
    2014
    Co-Authors: Mirka Korhonen, Sari Kallioinen Ph. D
    Abstract:

    Korhonen, M., 2003. Rheological properties of pharmaceutical creams containing Sorbitan fatty acid ester surfactants. ISBN 952-91-6585-4 (paperback) ISBN 952-10-1476-8 (PDF) The main purpose of the present study was to gain understanding about the rheological (elastic, viscoelastic and viscous) properties of pharmaceutical creams containing Sorbitan fatty acid ester surfactants (Sorbitan monolaurate, Sorbitan monopalmitate, Sorbitan monostearate, Sorbitan monooleate and Sorbitan Trioleate). The study investigated the effects of an increase in the hydrocarbon chain length, the double bonded hydrocarbon chains and the concentration of the surfactant on the rheological properties of the Sorbitan fatty acid ester surfactant containing creams. In addition, the effects of the volume of inner phase and the short-term storage on the rheological properties of the Sorbitan fatty acid ester surfactant containing creams were investigated. The creams studied were either simple, three-component creams, or complex, multi-component creams. The rheological properties were determined with dynamic oscillation stress sweep and oscillation frequency sweep measurements, with static creep recovery measurements and with time-dependent viscosity measurements

Thompson, Ian P. - One of the best experts on this subject based on the ideXlab platform.

  • Phytoremediation of mixed-contaminated soil using the hyperaccumulator plant Alyssum lesbiacum: Evidence of histidine as a measure of phytoextractable nickel
    'Elsevier BV', 2007
    Co-Authors: Singer, Andrew C., Bell Thomas, Heywood, Chloe A., Smith J.a.c., Thompson, Ian P.
    Abstract:

    In this study we examine the effects of polycyclic aromatic hydrocarbons (PAHs) on the ability of the hyperaccumulator plant Alyssum lesbiacum to phytoextract nickel from co-contaminated soil. Planted and unplanted mesocosms containing the contaminated soils were repeatedly amended with Sorbitan Trioleate, salicylic acid and histidine in various combinations to enhance the degradation of two PAHs (phenanthrene and chrysene) and increase nickel phytoextraction. Plant growth was negatively affected by PAHs; however, there was no significant effect on the phytoextraction of Ni per unit biomass of shoot. Exogenous histidine did not increase nickel phytoextraction, but the histidine-extractable fraction of soil nickel showed a high correlation with phytoextractable nickel. These results indicate that Alyssum lesbiacum might be effective in phytoextracting nickel from marginally PAH-contaminated soils. In addition, we provide evidence for the broader applicability of histidine for quantifying and predicting Ni phytoavailability in soils. Alyssum lesbiacum was shown to phytoextract nickel from PAH-contaminated soils from which the pool of nickel accessed for phytoextraction is closely modelled by a histidine-soil extract