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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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    • Webinar: The ‘content pinch point’ Webinar: The ‘content pinch point’ Billy Hamilton-Stent, Client strategy director, Octopus Group, marketing strategy Recorded: Feb 29 2016 3:00 pm UTC 49 mins
    • In its annual Tech Heads study, Octopus Group spoke to over 400 UK directors to explore trends in content consumption and buyer behaviours for B2B businesses. (To view the full Tech Heads report, visit: http://bit.ly/TechHeads15)

      The findings reveal a paradox: attention spans are shortening, but decision making time is extending (an average of 16.5 weeks currently according to respondents).

      Octopus Group calls this challenge the ‘Content Pinch Point’, and it’s a big problem for marketers. It means that it’s never been harder to connect with and subsequently convert prospects.

      Marketers now face a difficult task: catching prospects’ attention quickly through bold, creative, differentiating campaigns that are short on words and big on impact; yet once sales teams are engaged with prospects, marketing needs to suddenly become considered, consultative and big on substance to help their sales colleagues get over the finishing line.

      Two very different styles of content marketing, which are incredibly difficult to integrate without appearing to have a bi-polar brand.

      But there’s a huge opportunity for marketers who do manage to get it right, as their brand will give prospects a truly elevated and differentiated experience, which will tell in the pipeline they generate.

      This webinar aims to help marketers capitalise on the opportunity and Billy Hamilton-Stent, Octopus Group’s client strategy director, will cover:

      How the content ‘pinch point’ is adversely affecting marketing departments.
      The tell-tale signs that reveal the pinch in your campaigns.
      Strategies to rectify the problem and turn results around.
      Practical ways marketers can support sales in the journey from interested lead to high value customer.

      Click here to view Tech Heads: http://bit.ly/TechHeads15

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    • What's New in the Investment Trust World? What's New in the Investment Trust World? Best Advice: Closed-end Fund Forum Recorded: Sep 11 2013 12:00 pm UTC 30 mins
    • We review the latest developments in investment trusts - new launches, new issuance, funds closing and restructuring. We look at the bull and bear cases for the different trusts - and how they can serve a range of investor needs - income, diversity, growth.

      The panel will also broaden this out into a wider discussion of the current market environment and how new issuance meets the needs of that environment - for example, the spike in bond yields, or the improving equity markets.

      Moderator: Jackie Beard, Morningstar UK
      John Yakas, Polar Capital
      Robert Worthington, J.P. Morgan Asset Management

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    • Rapid LC/MS/MS-Based Methods For Opiates & Benzodiazepines Rapid LC/MS/MS-Based Methods For Opiates & Benzodiazepines Dwight R. Stoll, Ph.D., Assistant Professor - Gustavus Adolphus College Recorded: May 18 2011 3:00 pm UTC 26 mins
    • Increasing case loads and budget and staffing cuts in forensic laboratories continue to motivate the development of higher throughput methods, particularly for confirmatory analysis of regulated intoxicants. In this work, we have focused on the development of rapid LC/MS/MS methods for the determination of nine opiates including two glucuronide metabolites, and 16 benzodiazepines, including two amino- metabolites. Here we aim to analyze both the parent compounds and important polar metabolites in a single analysis. To this end we have compared the retention of the target compounds on two different reversed-phase HPLC stationary phases: a conventional C18 type phase, and a perfluorinated phenyl (PFP or F5) phase built upon the increasingly popular Fused-Core particle morphology. We see that the F5 phase not only generally exhibits higher retention than the C18 type phase, but also exhibits very different selectivity such that the nine opiates can be nearly completely resolved in under four minutes. We find that the mixture of 16 benzodiazepines cannot be completely resolved in a reasonable (i.e., less than 20 min.) time, however we have developed a separation with no more than three overlapping peaks in an analysis time of five minutes.

      Full Title
      DEVELOPMENT OF RAPID LC/MS/MS-BASED METHODS FOR CONFIRMATORY ANALYSIS OF OPIATES AND BENZODIAZEPINES

      Authors
      SPENCER BONNERUP, D. CHRISTOPHER HARMES, TOMAS LISKUTIN, JONNA BERRY, AND DWIGHT R. STOLL

      Department of Chemistry
      Gustavus Adolphus College
      800 West College Avenue
      St. Peter, MN 56082

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