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    • Tips and tricks for vortex evaporators Tips and tricks for vortex evaporators Jeff Reid Recorded: Sep 2 2014 6:00 pm UTC 30 mins
    • Discover ways to produce fast, reproducible results when using the BUCHI Syncore® or Multivapor™ products. If you currently use a vortex evaporator or will be in the near future this webinar provides good insight on how to maximize the efficiency of your evaporation process.

      During this webinar you will:
      - Discover different ways to enhance analyte recovery
      - Learn methods for developing application parameters
      - Gain insights into technologies that will allow you to collect >95% of evaporated solvents(s)

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    • Retention Mechanisms in HILIC Chromatography:  Robust Method Development Retention Mechanisms in HILIC Chromatography: Robust Method Development David S. Bell, Ph.D. Recorded: Jun 28 2012 6:00 pm UTC 55 mins
    • Hydrophilic interaction liquid chromatography (HILIC), especially in conjunction with mass spectrometry (MS), has become a powerful tool for the analysis of a wide variety of challenging analytes. Applications of the technique have increased dramatically over the past decade, especially for the analysis of polar analytes where reversed-phase chromatography suffers. HILIC conditions employ a high percentage of acetonitrile which enables facilitated solvent evaporation in LC/MS sources and thus often an increase in analyte response when compared to more aqueous based systems. The increased retention of polar analytes afforded by HILIC provides improved selectivity and decreases the impact of endogenous species, often leading to improved qualitative and quantitative analyses.

      Although HILIC has proven useful, it has also been thwarted with complications including difficulties in method development and method robustness.

      In this presentation, studies investigating the underlying retention mechanisms dominant in HILIC chromatography are presented and discussed. Along with reversed-partitioning HILIC is well known to exhibit, ion-exchange and the interplay of the dominant mechanisms are unveiled and used to develop a model of overall retention and selectivity. Interactions that operate using different stationary phase chemistries and conditions are presented. The impact of analyte polarity and charge as well as the variations caused by high percentages of organic on these physiochemical parameters are highlighted. Throughout the discussion, examples of use and misuse of HILIC are employed to illustrate these important concepts to build a solid fundamental foundation for efficient and effective use of this powerful technique.

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    • Miniaturization of Sample Handling in Bioanalysis with SPME Miniaturization of Sample Handling in Bioanalysis with SPME Professor Janusz Pawliszyn - University of Waterloo Recorded: May 9 2012 3:00 pm UTC 50 mins
    • Bio-Solid-phase microextraction (BioSPME) is a simple, fast and sensitive non-exhaustive sample preparation technique that allows the integration of sampling and sample preparation steps. The objective of current research was to automate SPME in 96-well plate format for the first time. The proposed system allows sample preparation of >1000 samples/day, simultaneous determination of both free and total concentration and suitability for performing ligand-receptor binding studies. Open-bed configuration of SPME enables direct handling of heterogeneous matrices such as whole blood, thus further simplifying the entire sample preparation process. The automation of SPME in 96-well plate format enables the highest throughput of any SPME technique to date.
      In metabolomics studies of biofluids, the efficiency of metabolism quenching and stability of analytes in selected biofluid dictate how accurately the analytical results represent true metabolome composition at the time of sampling. However, complete quenching of metabolism is not easily accomplished and/or changes due to poorly stable compounds can occur, so the processes of sampling and sample preparation can significantly affect metabolome’s composition. The use of SPME for direct in vivo sampling of drugs and metabolites in the bloodstream of freely moving animals eliminates the need for blood withdrawal in order to generate pharmacokinetic (PK) or metabolomic profiles in support of pharmaceutical drug discovery studies. This is particularly important for situations with a limited blood volume such as mice because it enables the use of a single animal to construct an entire profile or conduct longitudinal studies. The aim of the current research was to apply SPME for in vivo sampling in mice for the first time. Furthermore, we investigate the use of in vivo SPME as an effective sample preparation method for both targeted pharmacokinetic and untargeted LC-MS metabolomics studies.

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    • Sports Drug Testing: Chromatography & Mass Spec-Based Approaches Sports Drug Testing: Chromatography & Mass Spec-Based Approaches Professor Mario Thevis Recorded: Sep 9 2010 3:00 pm UTC 51 mins
    • Doping control analysis predominantly utilises chromatography and mass spectrometry-based approaches to detect prohibited substances and methods of doping. These compounds and methods present both low and high molecular weight analytes of xenobiotic or natural / endogenous origin, which are to be detected, and occasionally quantified, using state-of-the-art instruments.

      The majority of the employed tools provides low resolving power. However, high resolution / high accuracy mass spectrometry has gained much attention recently due to: constantly increasing analytical requirements concerning the number of target compounds; the complexity of analytes (e.g. peptides and proteins); and the desire to accelerate analyses and obtain information (allowing for retrospective data mining).

      A selection of compounds, new challenges, and methods currently employed in doping control laboratories will be presented to the audience including, for example: new anabolic agents referred to as selective androgen receptor modulators (SARMs); insulins; so-called "releasing peptides" that stimulate the endogenous production of natural hormones; and ways of manipulating drug tests.

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