Chromatography Theory and Applications: A Virtual Symposium

Register free: https://www.chromatographyonline.com/lcgc_w/theory_and_applications_symposium​

Day One, Thursday, October 22, 2020: Gas Chromatography

Morning session, 10:00 am–11:30 am EDT

Gas Chromatography Theory and Applications, I

Session chair: Emanuela Gionfriddo, Assistant Professor, Department of Chemistry, Biochemistry, University of Toledo

10:00 am Welcome and Introductions

10:05 am Natural or Synthetic? Determining the Integrity of Flavors and Fragrances for Consumer Products with GC–MS—An Example from the Analysis of Lavender Essential Oil
Prabodh Satyal, PhD, Chief Scientific Officer, Aromatic Plant Research Center (APRC)
Lavender essential oil contains linalool and linalyl acetate as major components. Our studies showed that some commercial lavender samples contain unidentified trace molecules (linalool oxide acetate cis trans furanoids), which we later confirmed as markers of synthetic linalyl acetate. Before confirming that the markers indicated the presence of the synthetic linalyl acetate, three possible scenarios were considered for the marker molecules: 1, that they were process-derived or auto-oxidized artifact molecules; 2, that they were natural compounds; and 3, that synthetic linalyl acetate had been added. In this talk, I explain the analytical process we followed, using gas chromatography–mass spectrometry (GC–MS) methods, to explore these hypotheses.

10:25 am FAME Analysis:Solvent-Mediated (SM) Covalent Adduct Chemical Ionization (CACI-)MS/MS for Complete Assignment of Double Bond Position Using Triple-Quadrupole Mass Spectrometry
J. Thomas Brenna, Professor, Depts. of Pediatrics, of Chemistry, and of Nutrition, The University of Texas at Austin, and Cornell University, Ithaca, New York, USA
Double bond location, along with geometry and chain branching, are the key structural elements determining fatty acid function, but are not available from conventional electrospray tandem mass spectrometry (MS/MS) or by any widely available MS technique applied to fatty acid methyl esters (FAME). Nearly 20 years ago we introduced chemical Ionization (CACI-)MS/MSbased on an ion-molecule reaction between CH2=C=N+=CH2 derived from an CH3CN self-reaction and neutral FAME and developed it for location of double bonds in most unsaturated FAME at GC rates. We report modification of a commercial triple-quadrupole MS instrument that enables high sensitivity CACI-MS/MS enabled by solvent-mediated chemical ionization (SM-CI). We used a prototype SM-CI gas inlet system consisting of a pressurized flow inlet for low volatility solvents. Using the CACI-MS/MS approach, M+54 ions were tested for a wide range of homoallylic FAME with 1-6 double bonds, with monoenes of unknown double bond position derived from cell culture experiments with genetically modified human cells, and with conjugated polyenes derived from seed oil extracts. We also looked at signal response consistency for quantitative analysis. We discuss the results of this study, which demonstrate that the novel source enables structural assignments without standards for nearly all unsaturated fatty acids, offering the sensitivity advantages of a triple-quadrupole MS instrument for high sensitivity applications, including true selected ion monitoring.

10:45 am Identifying Key Drivers of Toxicity in Drinking Water: Sensitive GC–MS Methods Push the Envelope
Susan Richardson, Arthur Sease Williams Professor of Chemistry, University of South Carolina
This study identifies important drivers of toxicity for disinfection by-products (DBPs) in drinking water. DBPs are by far the dominant organic contaminants found in drinking water, are formed by the reaction of disinfectants with natural organic matter (NOM) and are an untended consequence of trying to make water microbially safe to drink. However, DBPs are linked to several adverse effects, including bladder cancer, miscarriage, and birth defects. Our goal is to understand which DBPs are the drivers of toxicity so that they can ultimately be minimized in drinking water. For this research, improved analytical methods using gas chromatography–mass spectrometry (GC–MS) were developed, allowing ng/L quantification limits for nearly 60 priority, unregulated DBPs with different chemical properties. Many of these compounds are more toxic than the DBPs currently regulated. Drinking water samples from across the United States were studied, including those with saltwater intrusion and wastewater impacts. Results revealed that regulated DBPs were not the big drivers of toxicity, but that several priority, unregulated DBPs are. Our study highlights the power of highly sensitive GC–MS methods and how they can be used to improve the safety of drinking water.

11:05 am Question-and-answer (Q&A) period with all speakers in the session

Lunchtime tutorial session: 12:30–1:30 pm EDT

12:30 - 1:30 pm EDT TUTORIAL: From Petroleum to Cannabis—Comprehensive Two-Dimensional Gas Chromatography (GC×GC) Solutions for Complex Sample Analysis
Michelle Misselwitz, Chemist Consultant, Chemistry Matters Inc.
One-dimensional gas chromatography (GC) analysis is challenging for many petroleum, cannabis, food, environmental, and biological samples. The massive amounts of components with a wide range of concentrations results in numerous overlapping peaks. It is often difficult to achieve fundamental knowledge about the sample, discover impurities, or identify indicative biomarkers without further separation. While emphasis has been placed on mass spectrometry (MS) to achieve another dimension of separation, comprehensive two-dimensional gas chromatography (GC×GC) has proven successful when 1D GC-MS is insufficient. There is an outstanding need to educate and inform the broad analytical community about the established technique of GC×GC. This tutorial session will provide examples of the successful implementation of GC×GC to overcome obstacles in complex sample analysis. Specifically, the talk will explain:

• the benefits of GC×GC for challenging sample analysis
• fundamental operation and considerations of GC×GC systems
• resources for method development and data processing with GC×GC

Afternoon session, 2:00–4:00 pm EDT

Gas Chromatography Theory and Applications, II

2:00 pm Welcome and Introductions

2:05 pm Comprehensive Analysis of Cannabis Using Two-Dimensional Gas Chromatography with High Performance Time-of-Flight Mass Spectrometry (GCxGC–TOF-MS)
David E. Alonso, PhD, Applications Chemist, LECO Corporation, St. Joseph, Michigan
Hemp characterization is not only important for determining its legality in the United States, but also critical for determining the effectiveness and safety of its many products. Regrettably, reported test results are often incomplete or inaccurate. In this study, gas chromatography–mass spectrometry (GC–MS) and comprehensive GCxGC–MS technology were used for untargeted analysis of cannabis botanicals. The methodology included pesticide analysis, potency determination, and terpene profiling. Data collection was comprehensive; however, both targeted and untargeted data processing methods were utilized for the quantitative and qualitative analysis of samples. The analytical methodology provided data with superior chromatographic resolution and increased peak signal to noise values, which dramatically improved compound detection and identification. Enhanced chromatographic plots and high-performance TOF-MS facilitated chemical classification and differentiation of cannabis samples.

2:25 pm Rapid Rinse and Shoot: A Screening Method for Pesticides in Fruit by GC–MS in Under Six Minutes
Bruce D. Quimby, PhD (presenter), Senior GC/MS Applications Scientist, and Anastasia A. Andrianova, PhD, GC/MS Applications Scientist, both at Agilent Technologies, Inc., Wilmington, Delaware
A gas chromatography-mass spectrometry (GC–MS) system has been configured for fast screening of residual pesticides present on the surface of fruits. The method uses a GC oven with direct heating technology and mass spectrometry (MS) spectral deconvolution. Residual pesticides are rinsed from the tested commodity surface with acetone. The rinsate is collected and injected into the GC–MS system. The direct heating oven allows a very high temperature program rate (250 °C/min) to complete the GC–MS analysis in 3.4 minutes. Deconvoluted spectra are searched against a user created library and NIST 17 using retention indices for time filtering, resulting in rapid and confident identification of pesticides present on the fruit. The entire analysis from sample rinsing to reporting takes under 6 minutes. This talk will describe application of the method to fresh fruits. The approach is particularly useful for prioritizing samples (triage) for more in-depth analysis.

2:45 pm Use of Barrier Discharge Ionization Detection for the Analysis of Water in Liquefied and Gaseous Petroleum Samples
Allison Mason (presenter), Product Manager, System Gas Chromatography, Ian Shaffer, Product Specialist, Gas Chromatography, Andrew Fornadel, Marketing Manager, Energy and Petrochemicals, all at Shimadzu Scientific Instruments
Barrier discharge ionization detection for gas chromatography (GC-BID) is a novel universal detector capable of detection of nearly any volatile analyte with the exception of helium and neon. Traditional analyses of moisture in hydrocarbon samples are labor intensive and error prone. Here we will explore the use of GC-BID for detection of moisture (water) in liquified petroleum gas and gaseous hydrocarbon samples. It is critical to understand the moisture content of hydrocarbon mixtures as it will affect their processing characteristics and utility as fuels. GC-BID coupled with an ionic liquids column has proven to be an easy and reliable method of separating and quantifying trace (ppm) levels of water in those samples.

3:05 pm Qualitative Analysis of Meat Aroma with SPME-GC­–MS
Madeleine DiGregorio, GCMS Product Specialist at Shimadzu Scientific Instruments
Solid-phase microextraction (SPME) is a solvent-less extraction technique which makes use of a sorbent fiber to ad/absorb compounds from a headspace or liquid sample. Headspace SPME improves selectivity and sensitivity for volatile compounds and reduces matrix effects. Because aroma is responsible for most of what we know as flavor, looking at volatile odorants is critical for any food product. This work describes the development of a SPME-GCMS method suitable for qualitative analysis of cooked-meat aroma, and an optimization of several different fiber coatings to assess the wide range of odorants present in cooked-meat.

3:25 pm Low-Pressure Gas Chromatography (LPGC)–The Fast Way to Your Pesticide Analysis
Jana Rousova, Applications Scientist, Restek
Saving time while ensuring the same level of performance is a goal of every analytical chemist. The technique of gas chromatography under low pressure (LPGC), or near vacuum GC, can provide that for your analysis. In this webinar, we will explain how this technique works and what the advantages and drawbacks are. We will then discuss its application to the analysis of pesticides in food commodities.

3:45 pm Choosing and Maintaining Your GC Gas System
Aria Reynolds, Global Product Manager, Parker Analytical Gas Systems
How does the carrier gas impact your gas chromatography analysis? Please join us for an in-depth discussion about:

• how a carrier gas can affect your lab’s throughput and quality of results
• how to select the appropriate gas and gas delivery system for your needs
• how to evaluate gas purity and understand your GC instrument’s needs
• maintenance and cost of ownership of gas choices
• ensuring safety of personnel and equipment in today’s lab environment
• Whether you’re a GC expert or just learning the basics, this talk will provide a solid foundation in everything related to carrier, fuel, and make-up gas!

Day Two, Friday, October 23, 2020: Liquid Chromatography

Morning session, 10:00 am–11:30 am EDT

Liquid Chromatography Theory and Applications, I
Session chair: James Grinias, Associate Professor, Department of Chemistry & Biochemistry, Rowan University

10:00 am Welcome andIntroductions

10:05 am Experimental Investigation of the Retention Factor Dependency to Eddy Dispersion in Packed Bed Columns and Relation to Knox’s Empirical Model Parameters
Deirdre Cabooterand Huiying Song, KU Leuven, Leuven, Belgium; Devin Makey and Dwight R. Stoll, Gustavus Adolphus College, Saint Peter, Minnesota, United States; and Gert Desmet, Vrije Universiteit Brussel, Brussels, Belgium
We report on a systematic and comprehensive (0.7£k’’ £ 122)
experimental study of the effect of the zone retention factor k’’ on eddy-dispersion (heddy) in packed-bed columns for liquid chromatography. The values for heddy are obtained by subtracting the known contributions from the longitudinal diffusion (hB) and the mobile (hCm) and stationary zone (hCs) mass transfer resistance from the total plate height values. For the first time, hCm-values are calculated using an expression for the Sherwood-number (Sh) that has been established and validated in the relevant velocity range. Experiments were carried out on both fully porous and a superficially porous particle columns. In both cases, the eddy-dispersion systematically decreased with increasing retention factor k’’, decreasing with 0.5 to 0.8 reduced plate height units when going from the lowest to the highest k’’. To establish a simple empirical fitting equation that can represent the observed effects, the widely used power-law Knox model has been extended to express the dependency of its A- and n-parameters on the retention factor.

10:25 am Fourier-Transform and Wavelet Techniques for Chromatography: Simple and Practical Approaches to Enhance Resolution, Improve Peak Shapes, and Denoise the Data
M. Farooq Wahab, Research Engineering Scientist, the University of Texas at Arlington
Separation scientists often question the future directions of chromatography. Chemists have spent decades optimizing surface chemistry and reducing the particles. Still, no column can resolve every mixture. As the number of components increases, peak resolution continues to degrade rather rapidly. Peak integration becomes more challenging as chromatographic resolution decreases, especially with asymmetric tailing peaks. Therefore, post-acquisition signal processing, well established in optical vibrational spectroscopy and NMR, should now be utilized in liquid chromatography. Given the fact that all current chromatographic data is now acquired digitally, it is possible to apply simple mathematical techniques on the raw detector output to enhance resolution, improve peak shapes, and denoise the data without broadening the peaks. In this presentation, the theory and applications of Fourier transform (FT) will be discussed, explaining its use in chromatography. Real and simulated examples will be shown. The denoising power of wavelets also will be discussed. The main goal of these techniques is to resolve the data in such a way that the original peak areas are not affected. Surely, high-throughput analyses in gas, liquid, and supercritical fluid chromatography will benefit from these simple and practical approaches in many challenging separations and the implementation of these techniques in chromatography data software will undoubtedly be feasible soon.

10:45 am Fast Chiral and Achiral Profiling of Compounds with Multiple Chiral Centers by a Versatile Two-Dimensional Multicolumn Liquid Chromatography (LC–mLC) Method
Jessica Lin, Scientist, Small Molecule Analytical Chemistry, Genentech Inc.
Chiral analysis of drug molecules with multiple chiral centers has proven to be a tremendous analytical challenge. The traditional chiral HPLC methods can take a gruelingly long time to develop yet may not offer sufficient resolution for all stereoisomers. We have developed an effective and fast multiple heart-cutting (MHC) multicolumn two-dimensional liquid chromatography (LC–mLC) platform approach. A short achiral HPLC method in the first dimension ( 1D) allows the separation of diastereomers and other achiral impurities, followed by 2D analysis enabling different chiral columns and different mobile phases on each coeluted 1D peak for maximum resolution. This LC–mLC methodology dramatically reduces chiral method development time and sample analysis turnaround, and enables quick stereoselective synthetic route development.

12:05 pm Question-and-answer (Q&A) period with all speakers in the session

Afternoon Session, 2:00–3:30 pm EDT

Liquid Chromatography Theory and Applications, II

2:00 pmWelcome and Introductions

2:05 pm 20 Minutes to Improve Your LC Method Sensitivity
GenevieveHodson,Senior Technical Specialist, Phenomenex
Join us as we jump into some fundamental ways to improve your method sensitivity without a new system or detector. While new equipment can increase your relative sensitivity there are several chromatographic aspects that can be easily adjusted to help maximize your relative sensitivity. From leveraging different HPLC/UHPLC particle architectures, to selecting specific mobile phase additives, to optimizing the power of flow rate, to changing your column internal diameter, this quick webcast will focus on multiple routes to improve your method sensitivity.

2:25 pm Investigation of the Possibilities and Limitations of a Sample Feed Injector for SFC and LC
Kim Vanderlinden, Gert Desmet, Ken Broeckhoven (presenter), Vrije Universiteit Brussel (VUB), Belgium
The properties of a novel type of sample injector (“feed injector”) for both supercritical fluid chromatography (SFC) and liquid chromatography (LC) was investigated in detail. This injector differs from standard injectors in that the sample volume is not switched in line with the mobile phase flow, but directly injected or added to the mobile phase flow (F). The subsequent mixing inherently results in a dilution of the sample, reducing the solvent mismatch, but at the cost of an increased sample volume. To ensure full sample injection, an additional overfeed volume Vov needs to be injected. A wide range conditions was investigated by varying the Finj/F-ratio, Vov, overfeed solvent etc. in supercritical fluid chromatography conditions. It was found that an optimal Finj/F exists which is independent of F, but varies with sample compound. Smaller Vov decreases peak dispersion, but results in only partial sample injection. The possibility to apply this feed injection technique for liquid chromatography separations will be discussed as well.

2:45 pm Wide Compound Coverage for Confident Analyte Identification in LC–MS/MS Workflows Using the Wiley Forensic Libraries
Pierre Negri, Global Technical Marketing Lead, Forensic Market, SCIEX
The use of high-resolution mass spectrometry combined with supporting software allows fast, comprehensive analysis of forensics samples. In this presentation, we will discuss how to use the Wiley Forensic Libraries to support accurate detection and identification of a large number of novel psychoactive substances (NPS) and other related drugs of abuse through library spectral matching. We will demonstrate how automated processing matches the MS data to the analyte mass and how the MS/MS is matched to the analyte fragmentation pattern in the library, providing a “fit score” for assessment of confidence of compound identification. Several examples will be provided to demonstrate how the use of the spectral libraries increases selectivity for accurate screening of drugs and drug metabolites, provides confident identification of NPS in real case samples, and overall enhances the screening accuracy of illicit substances and other drugs of abuse present in biological samples.

3:05 pm Increased Sensitivity in Multi-Angle Light Scattering and Size-Exclusion Chromatography for the Determination of Molecular Weight and Rg of Macromolecules in Solution
Philip Hoang, Technical Marketing Specialist, Analytical Chromatography, Tosoh Bioscience LLC
Advancements in analytical technologies are critical as research and development of polymers and biomolecules continue to grow in complexity. In recent years, significant innovations have been seen in multi-angle light scattering (MALS) and the stationary phases of analytical size-exclusion chromatography (SEC) columns and their applications. When coupled together, SEC-MALS is a common analytical technique used for the determination of the molecular weight of polymers and biomolecules in solution, such as proteins and their higher order aggregates. By measuring angular dependence, the utility of this technique is extended and provides the radius of gyration of complex polymers. New applications now have improved sensitivity, lower limits of detection, and an extended range for size determination far below 10 nm. This presentation will review both the theory behind SEC-MALS and the methods of polymers and bioapplications including proteins, mAbs, and oligonucleotides.

Time and Date:

Day One: Thursday, Oct. 22, 2020 10am EDT | 12:30pm EDT | 2pm EDT

Day Two: Friday, Oct. 23, 2020 10am EDT | 2pm EDT

On demand available after final airing until Oct. 23, 2021

Sponsor: Agilent, Leco, Parker, Restek, Shimadzu, Wiley, Hamilton, Phenomenex, SCIEX, Tosoh Bioscience

Register free: https://www.chromatographyonline.com/lcgc_w/theory_and_applications_symposium​

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