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    • Enabling Reliable Compound Identification using LC-MSn Enabling Reliable Compound Identification using LC-MSn Herbert Oberacher Recorded: Nov 10 2015 3:00 pm UTC 53 mins
    • Enabling Reliable Compound Identification using LC-MSn

      Reliable compound identification with non-targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a major challenge. It involves matching against reference data. For fast and automated identification, tandem mass spectral libraries are queried with appropriate search tools. Reliability of search as well as time and efforts spent for data reviewing very much depend on the quality of the database involved. In this presentation, we will give an overview on our efforts towards the development of a reliable, robust, and transferable tandem mass spectral database, and how such a database can successfully be implemented in workflows for comprehensive drug analysis.

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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.

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

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    • Ultra-Fast LC/MS/MS in Bioanalysis Using Fused-Core Columns Ultra-Fast LC/MS/MS in Bioanalysis Using Fused-Core Columns Ethan R. Badman, Ph.D. Recorded: Feb 16 2011 4:00 pm UTC 39 mins
    • With recent advances in HPLC columns and LC/MS hardware, it is possible to increase the throughput of bioanalytical assays without sacrificing quality. By using fused-core columns, it is possible to decrease the run time from ~4 min to 1 min or less, without the use of UHPLC hardware. High quality methods at high flow rates (1-3 mL/min) using non-ballistic gradients as short as 20 seconds were developed that provide comparable or better performance for accuracy, precision, sensitivity, and specificity than traditional slower LC methods. Data will be presented that show that these assays meet regulatory requirements for bioanalytical work. Limitations in the ultimate speed possible for these assays will also be discussed.

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    • Harnessing the Power of High-Res, Accurate Mass LC/MS Technology Harnessing the Power of High-Res, Accurate Mass LC/MS Technology Dipankar Ghosh, Ph.D., Tina Hemenway, Ph.D.,Thermo Fisher Scientific Recorded: Jan 25 2011 4:00 pm UTC 63 mins
    • Harnessing the Power of High-Resolution, Accurate Mass LC/MS Technology in Food Safety Laboratories

      In this webinar, you will learn the advantages of high-resolution, accurate mass LC/MS technology and how it can be applied in the food safety laboratory. Instrumentation that offers high resolving power and ultimate mass accuracy provide unique advantages in screening and quantifying low levels of contaminants in complex food matrices. Software is the key to efficient processing of this data to obtain quantitative and qualitative results. Attend this webinar to learn what features to look for in a high-resolution solution for your lab:

      -- What do you need to streamline your workflow and increase throughput?
      -- How are results verified so you have a high level of confidence in your results?
      -- How can you screen for unknowns?

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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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    • New! Introducing Ascentis Express 5 um HPLC Columns with Fused-Core Technology New! Introducing Ascentis Express 5 um HPLC Columns with Fused-Core Technology R. A Henry Recorded: Sep 21 2012 3:00 pm UTC 53 mins
    • Core-type particles are competing strongly with small porous particles to improve the speed and resolution of HPLC and UHPLC experiments. The pioneering Ascentis Express column with Fused-Core® 2.7µm particles has exploded in popularity because it operates more ruggedly at much lower pressure than current sub-2µm porous particles, yet delivers the same ultra-high performance. This unique performance has been largely attributed to very narrow particle size distribution. Fused-Core® design advantages have also become popular for LC-MS because Ascentis Express columns surpass performance of columns with 3µm porous particles and operate ruggedly at higher velocities and similar pressures.

      With new, narrow-distribution 5µm Fused-Core® particles, the same design advantages can now be realized over traditional 5µm and 3µm porous particles that remain very popular for HPLC columns. An Ascentis Express 5µm column brings 3µm performance and extreme ruggedness at 5µm pressures to your laboratory. Like Ascentis Express 2.7µm particles, the 5µm particles show flatter van Deemter plots than same-size porous particles and allow separation speed to be maximized with minimal loss of resolution. Extremely high plates per pressure are observed. The core-type 5µm design should replace porous 5µm columns in routine HPLC applications with traditional instruments, and should also compete with porous 3µm columns in many LC-MS applications. Performance will be compared to 5µm and 3µm particle columns, and examples of method transfer will be shown. Ascentis Express 5µm will be available in the same phase modifications as the original Ascentis Express 2.7µm ultra-high performance column. Highly stable columns are available in various IDs and lengths up to 25cm.

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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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    • HPLC of Peptides:  Speed and Resolution with Fused-Core Columns HPLC of Peptides: Speed and Resolution with Fused-Core Columns Hillel Brandes, Ph.D. Recorded: Jan 25 2011 7:45 pm UTC 24 mins
    • HPLC columns featuring 2.7 µm Fused-Core (superficially porous) particles with 90 Å pores demonstrate very fast separations of small molecules because of high efficiency and a flat van Deemter plot. These particles rival the efficiency of sub-2 µm totally porous UHPLC particles, but show only about one-half the backpressure. Fused-Core 2.7 µm particles with wider (160 Å) pores have been optimized for the rapid separation of peptides and small proteins. The higher efficiency and lower pressure drop of Fused-Core particles allows preparation of longer columns with very large numbers of theoretical plates. This dramatically increases the peak capacity of the column system, which facilitates qualitative and quantitative HPLC and LC-MS analysis.

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