LC*GC

December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
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April 2018
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2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
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1995 - 1996

COLUMNS

• COLUMN WATCH
  Drawing A Better Map: Recent Advances in Protein Digestion and Peptide Mapping
  Cory E. Muraco
  New strategies for “bottom-up” analysis of therapeutic proteins, using faster enzymes, new buffer systems, and optimal column chemistries, enable analysts to perform these studies much faster and with fewer artifacts.
  
• LC TROUBLESHOOTING
  Letting the Chromatograph Talk, Part I: Looking for Troubleshooting Clues in Unexpected Places
  Dwight R. Stoll
  An ultraviolet (UV) detector signal can be an excellent source of clues for troubleshooting problems with your LC—even if you are using a mass spectrometer. We also share another good source of clues.
  
• THE ESSENTIALS
  How It Works: UV Detection for HPLC
  The fundamental principles of UV detection are explained, in a single page.
  

PEER-REVIEWED ARTICLES

• Development of a Multi-Product SE-UHPLC Method for the Determination of Size-Variants in Bispecific Antibody Formats
  Tobias Graf, Raphael Ruppert, Alexander Knaupp, Georg Hafenmair, Sebastien Violini, Steffen Kiessig, Markus Haindl, Harald Wegele, and Michael Leiss
  The versatile size-exclusion ultrahigh-performance liquid chromatography (SE-UHPLC) platform method described here provides superior separation for bispecific monoclonal antibody formats compared to a previous method.
  
• Statistics for Analysts Who Hate Statistics, Part VII: Sum of Ranking Differences (SRD)
  Caroline West
  The sum of ranking differences (SRD) is a useful statistical tool for comparing methods, models, columns, or samples. It is also simple and straightforward.
  

FEATURES

• Lloyd R. Snyder (1931-2018)–A Personal Tribute
  John W. Dolan
  Lloyd Snyder was one the “founding fathers” of high performance liquid chromatography (HPLC). He was one of the most widely cited chromatographers with many important contributions to the field of separation science.
  
• Deep in the Heart of Texas, Chromatography Advances
  Kevin A. Schug
  The 2019 ISCC and GCxGC Symposia, May 12–17, 2019, in Fort Worth, Texas, promise to provide an exciting and relevant venue for discussions of the latest developments in chromatography.
  

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index

COLUMNS

• LC TROUBLESHOOTING
  Mixing and Mixers in Liquid Chromatography—Why, When, and How Much? Part II, Injections
  Dwight R. Stoll
  What happens when we inject a sample into the mobile-phase stream? Many LC practitioners are surprised to learn just how serious the effect of the injected sample solvent can be.
  
• SAMPLE PREP PERSPECTIVES
  A Look Back and A Look Forward—An Annual Check-up on the State of Sample Preparation
  Douglas E. Raynie
  We assess the state of the field, first looking back at developments presented at conferences this year, reader questions, and the passing of a pioneer in solidphase extraction. Then, we look to the future of sample preparation.
  
• GC CONNECTIONS
  Stationary Phase Selectivity: The Chemistry Behind the Separation
  Nicholas H. Snow
  Here, we focus on selectivity: its definition, its importance for generating separations and resolution; and its role in column polarity.
  
• FOCUS ON BIOPHARMACEUTICAL ANALYSIS
  Analytical Characterization of Biotherapeutic Products, Part II: The Analytical Toolbox
  Anurag S. Rathore, Ira S. Krull, and Srishti Joshi
  The analytical techniques used for characterizing biotherapeutics have evolved. We review the utility of the traditional tools and discuss the new, orthogonal techniques that are increasingly being used.
  
• THE ESSENTIALS
  HPLC Column Maintenance: Tips for Extending HPLC Column Lifetime
  Follow these tips to protect your columns and extend their useful lifetime.
  

PEER-REVIEWED ARTICLES

• Instrument Considerations in the Transfer of Chromatographic Methods, Part II: System Considerations
  Thomas E. Wheat
  Scientists executing a method transfer often do not have access to the originating system. Thus, alternative approaches to matching chromatographic results must be considered.
  
• Chromatography Fundamentals, Part V: Theoretical Plates: Significance, Properties, and Uses
  Howard G. Barth
  The number of theoretical plates forms the basis of chromatographic theory, and is a key parameter used in all modes of chromatography for measuring column efficiency. Fortunately, it’s easy to measure.
  

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index

ADVANCES IN FOOD AND BEVERAGE ANALYSIS

• Rapid Classification of Beef Aroma Quality Using SIFT-MS
  Vaughan S. Langford, Murray J. McEwan, Tracey Cummings, Nicola Simmons, and Clyde Daly
  Application of multivariate statistical analysis to a combined data set demonstrated that SIFT-MS discriminates premium quality beef from eight sensory defects, and, therefore, could be applied as an instrumental grading tool, obviating sensory panel grading.
  
• A Simple and Effective ICP-MS Method Capable of Detecting Trace and Major Elements in Milk Samples
  Helmut Ernstberger and Fadi Abou-Shakra
  The method described here is a simple method for detection of a wide spectrum of metals and for quantitative analysis over a wide dynamic range of elements, including both toxic metals and those metals essential for health and well-being.
  
• Comprehensive Identification of Migrating Compounds from Plastic Food Packaging Materials Using High-Resolution Mass Spectrometry
  Ashley Sage, Jianru Stahl-Zeng, Amadeo Fernández-Alba, Maria José Gómez Ramos, and Anna Lozano
  This study assesses whether two commonly used plastic packaging materials are safe for use. Their potential migrants are analyzed using data-independent acquisition and liquid chromatography coupled with high-resolution, accurate-mass mass spectrometry.
  
• Immunoaffinity Solid-Phase Extraction with HPLC-FLD Detection for the Determination of Aflatoxins B2, B1, G2, and G1 in Ground Hazelnut
  Sylvia Grosse, Mauro De Pra, and Frank Steiner
  Using highly specific immunoaffinity solid-phase extraction to selectively extract and enrich aflatoxins prior to HPLC-FLD analysis, without derivatization, low LOQ values— far below the European regulations—can be achieved even in highly complex and fatty matrices.
  
• Detection and Quantitation of Pyrrolizidine Alkaloids in Diverse Food Matrices
  An interview with Jean-François Picron
  A new method enables quantification of pyrrolizidine alkaloids in a range of food matrices.
  
• Measuring Mycotoxins
  An interview with Rudolf Krska
  A discussion of challenges in mycotoxin analysis, a new multi-analyte method that does not require sample cleanup, and how analytical chemistry can help reduce contamination by these toxins along the food chain.
  

COLUMNS

• COLUMN WATCH
  Highlights from the HPLC 2018 Symposium
  David S. Bell, Cory E. Muraco, and Connor Flannery
  Topics that stood out at HPLC 2018 include advances in large-molecule separations, multidimensional separations, 3D printing, chiral separations, and HILIC. Also, many speakers addressed separation fundamentals, including ways to increase speed, generate higher throughput, and add selectivity.
  
• LC TROUBLESHOOTING
  Mixing and Mixers in Liquid Chromatography—Why, When, and How Much? Part I, The Pump
  Dwight R. Stoll
  Many LC users are unclear what happens when we combine two (or more) flow streams in LC systems, and when mixers are needed to blend the fluids. This discussion explains why mixers are needed, and when and how you might consider using something other than the default mixer setting.
  
• PERSPECTIVES IN MODERN HPLC
  Modern Trends and Best Practices in Mobile-Phase Selection in Reversed-Phase Chromatography
  Michael W. Dong and Barry E. Boyes
  Modern trends in LC mobile-phase selection and preparation include using simpler mobile phases, increased use of MS-compatible mobile phases, and eliminating filtration and certain mobile-phase additives. Here, we discuss those and other trends and best practices, as well as the fundamentals behind them.
  
• FOCUS FOOD ANALYSIS
  The Quest for Greener Sample Preparation in Food Analysis
  Laura Bush
  Elena Ibañez is determined to make sample preparation for food analysis not only more environmentally friendly but also more efficient, as she explores approaches that simplify solvent selection, increase solvent selectivity, and lessen the role of chemical solvents.
  
• THE ESSENTIALS
  Tips for Successful GC–MS Tuning and Optimization
  Proper tuning and calibration of instruments ensure their peak response and an exact mass-to-charge ratio and ion abundance measurement.
  

PEER-REVIEWED ARTICLE

• Molecular Imprinting for Sample Preparation
  Dimitrios Bitas and Victoria Samanidou
  Molecularly imprinted polymers can replace conventional sorbent materials in sample preparation techniques such as solid-phase extraction (SPE), solid-phase microextraction (SMPE), and matrix solid-phase dispersion (MSPD), offering increased selectivity over the target analytes.
  

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• EAS Conference Preview
• Ad Index

Current Trends in MASS Spectrometry

• Articles
  • Epitope Mapping of an Interleukin Receptor for Three Therapeutic Antibodies by Hydrogen-Deuterium Exchange Mass Spectrometry
    Eric Largy, Caroline Cajot, and Arnaud Delobel
    Among all the analytical techniques available for epitope mapping studies, hydrogen–deuterium exchange mass spectrometry (HDX-MS) is usually the fastest and easiest to carry out. We present here the epitope mapping of three distinct monoclonal antibody (mAb) candidates targeting the same antigen, an interleukin receptor. The goal is to establish the binding mode of these mAbs, and explain possible differences observed for in vitro binding and in vivo function.
    
  • Enhancing the Sensitivity of Atmospheric Pressure Ionization Mass Spectrometry Using Flow Modulated Gas Chromatography
    Karl J. Jobst, John V. Seeley, Eric J. Reiner, Lauren Mullin, and Adam Ladak
    The past decade has witnessed resurgent interest in coupling GC to atmospheric-pressure chemical ionization (APCI), which is suitable for the high column flows required for using flow modulation. This study assesses the use of GP-APCI with flow modulation for sensitive detection of selected trace organics.
    
  • Peptide Mapping of Monoclonal Antibodies and Antibody–Drug Conjugates Using Micro-Pillar Array Columns Combined with Mass Spectrometry
    Koen Sandra, Jonathan Vandenbussche, Isabel Vandenheede, Bo Claerebout, Jeff Op de Beeck, Paul Jacobs, Wim De Malsche, Gert Desmet, and Pat Sandra
    The structural complexity of monoclonal antibodies (mAbs) challenges the capabilities of even the most advanced chromatography and mass spectrometry techniques. This study examines the use of micro-pillar array columns in combination with mass spectrometry for peptide mapping of both mAbs and antibody–drug conjugates (ADCs).
    
• Departments
  • Product Profiles
  • Application Notes

COLUMNS

• COLUMN WATCH
  LC–MS Sensitivity: Practical Strategies to Boost Your Signal and Lower Your Noise
  Sharon Lupo
  By understanding the relationship between various parameters and ionization efficiency, analysts can realize the full potential of the LC–MS technique.
• LC TROUBLESHOOTING
  Tips, Tricks, and Troubleshooting for Separations of Biomolecules, Part II: Contemporary Separations of Proteins by Size-Exclusion Chromatography
  Szabolcs Fekete, Davy Guillarme, and Dwight R. Stoll
  How do I know which column to choose for size-exclusion separations of proteins, and which separation conditions will be the best for my separation?
• GC CONNECTIONS
  Safely Delivering the Best Possible Carrier and Detector Gases to Your GC System
  John Hinshaw
  A laboratory relocation yielded insights as to how to deliver gases that are up to the requirements of the separations at hand, within a safe working atmosphere.
• THE ESSENTIALS
  LC–MS Peptide Mapping: Where to Start, and What It Can Tell Us
  In peptide mapping, the enzymes and conditions used in digestion affect not only the number of peptides liberated, but also the stability of associated PTMs.

PEER-REVIEWED ARTICLES

• Chemical Fingerprinting of Mobile Volatile Organic Compounds in Soil by Dynamic Headspace–Thermal Desorption?Gas Chromatography?Mass Spectrometry
  Peter Christensen, Majbrit Dela Cruz, Giorgio Tomasi, Nikoline J. Nielsen, Ole K. Borggaard, and Jan H. Christensen
  This method was used to compare VOCs in soil samples from the three forest areas and was able to detect potential biomarkers for land use.
• Data Integrity in the Chromatography Laboratory, Part VI: Open Culture, Training, and Monitoring Metrics
  Mark E. Newton and R.D. McDowall
  In this final part of the series, we look at three requirements for establishing and supporting data integrity in a regulated laboratory.
• Instrument Considerations in the Transfer of Chromatographic Methods, Part I: Method Considerations
  Thomas E. Wheat
  In this first of a three part series, we focus on the method as a whole and considerations for avoiding ambiguities and inconsistencies between laboratories.

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index
• The Application Notebook

COLUMNS

• SAMPLE PREP PERSPECTIVES
  The Vital Role of Blanks in Sample Preparation
  Douglas E. Raynie
  Blanks are important in the pursuits of quality control and robust quantitative analytical methods, but many analysts don’t fully understand their value, or how to use them correctly.
  
• LC TROUBLESHOOTING
  Contaminants Everywhere! Tips and Tricks for Reducing Background Signals When Using LC–MS
  Dwight R. Stoll
  We examine instances where contaminants are problematic in LC–MS, as well as successful methods to decrease their influence.
  
• PERSPECTIVES IN MODERN HPLC
  Ten Common-Sense Corollaries in Pharmaceutical Analysis by HPLC
  Michael W. Dong
  These ten propositions are widely acknowledged, but frequently neglected, by practitioners of high performance liquid chromatography (HPLC).
  
• THE ESSENTIALS
  Advantages of Supported Liquid Extraction
  We look at a process that can overcome the shortcomings associated with liquid–liquid extraction.
  

PEER-REVIEWED ARTICLES

• Frontiers in Ultrafast Chiral Chromatography
  Daipayan Roy, Choyce A. Weatherly, M. Farooq Wahab, and Daniel W. Armstrong
  We explore the developments that have made it possible to produce sub-minute, and, more recently, even sub-second enantiomeric separations. We also look at the questions that remain unanswered.
  
• Biomimetic Chromatography to Accelerate Drug Discovery: Part II
  Klara Valko
  Biomimetic HPLC retention data can be used to measure how a compound will bind to proteins and phospholipids in vivo.
  
• Data Integrity in the Chromatography Laboratory, Part V: Second-Person Review
  Mark E. Newton and R.D. McDowall
  The series continues with a crucial scientific and regulatory necessity in ensuring reliable information—the second-person review.
  
• Chromatography Fundamentals, Part IV: Origin of Theoretical Plates—Fractional Distillation and Countercurrent Distribution Extractions
  Howard G. Barth
  The theoretical plate concept forms the basis of chromatographic theory. Here is where it came from.
  

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Calendar
• Short Courses
• Ad Index

COLUMNS

• COLUMN WATCH
  When Do We Need Sub-2-µm Superficially Porous Particles for Liquid Chromatography Separations?
  David S. Bell, Landon Wiest, Shun-Hsin Liang, and Dan Li
  Many manufacturers now offer columns using superficially porous particles that are 2-µm and smaller. When should you use them?
  
• LC TROUBLESHOOTING
  Tips, Tricks, and Troubleshooting for Separations of Biomolecules, Part I: Contemporary Reversed-Phase Protein Separations
  Szabolcs Fekete, Davy Guillarme, and Dwight R. Stoll
  For reversed-phase separations of proteins, you must consider pore size, column temperature, and stationary-phase chemistry. Here are some guidelines.
  
• GC CONNECTIONS
  Split, Splitless, and Beyond—Getting the Most from Your Inlet
  Nicholas H. Snow
  We discuss the challenges of split and splitless injections, ideas for mitigating them, and the case for renewed exploration of cool inlets and injection techniques.
  
• THE ESSENTIALS
  GC Column Maintenance: Tips for Extending GC Column Life
  To extend the life of your GC columns, follow these best practices.
  

PEER-REVIEWED ARTICLES

• Data Integrity in the GXP Chromatography Laboratory, Part IV: Calculation of the Reportable Results
  Mark E. Newton and R.D. McDowall
  You need to ensure that your calculations of reportable results don’t get you into data integrity trouble. Here’s how.
  
• Determination of Polycyclic Aromatic Hydrocarbons in Environmental Waters Using Heterogeneous Magnetic Materials Based on Metal–Organic Frameworks
  Priscilla Rocío-Bautista, Verónica Pino, Jorge Pasán, Juan H. Ayala, Catalina Ruiz-Pérez, and Ana M. Afonso
  This study of PAHs makes it easy to compare this microextraction procedure to conventional approaches and to other procedures using magnetic composites.
  
• Chromatography Fundamentals, Part III: Retention Parameters of Liquid Chromatography
  Howard G. Barth
  We review different approaches for measuring solute retention.
  
• Marjorie Groothuis Horning: Biochemist, Pharmacologist, and GC Pioneer
  Werner Engewald and Hartmut Frank
  A look back at this innovator’s career and her efforts to develop and popularize gas chromatography (GC), particularly for biomedical research.
  

DEPARTMENTS

• Peaks of Interest
• Chromatography Corner: Data-Independent Acquisition
• Chromatography Corner: Rapid Trace Analysis
• Calendar
• Short Courses
• Products & Resources
• Ad Index

COLUMNS

• COLUMN WATCH
  The Promise of Metal–Organic Frameworks for Use in Liquid Chromatography
  David S. Bell
  What can metal–organic frameworks offer for liquid chromatography?
  
• LC TROUBLESHOOTING
  Peak Purity in Liquid Chromatography, Part III: Using Two-Dimensional Liquid Chromatography
  Dwight R. Stoll, C.J. Venkatramani, and Sarah C. Rutan
  Here, we see how 2D-LC can solve coelution problems that are difficult or impossible to address using peak purity tools or curve resolution methods.
  
• PERSPECTIVES IN MODERN HPLC
  Antibody–Drug Conjugates: Perspectives and Characterization
  Rowan E. Moore, Kelly Broster, Ken Cook, Kyle D’Silva, Eric Niederkofler, Aaron O. Bailey, Jonathan Bones, and Michael W. Dong
  Comprehensive characterization of ADCs requires increasingly powerful approaches consisting of small- and large-molecule techniques.
  
• FOCUS ON BIOPHARMACEUTICAL ANALYSIS
  Analytical Characterization of Biotherapeutic Products, Part I: Quality Attributes
  Anurag S. Rathore, Ira S. Krull, and Srishti Joshi
  To ensure the reliable and accurate characterization of biotherapeutics, an arsenal of orthogonal analytical techniques is needed.
  
• THE ESSENTIALS
  HPLC Troubleshooting: Autosampler Contamination
  With autosamplers, we need to be extra careful to avoid contamination.
  

PEER-REVIEWED ARTICLES

• Profiling Nonionic Surfactants Applied in Pharmaceutical Formulations by Using Comprehensive Two-Dimensional LC with ELSD and MS Detection
  Gerd Vanhoenacker, Mieke Steenbeke, Koen Sandra, and Pat Sandra
  Comprehensive 2D-LC using HILIC and reversed-phase LC is a robust tool to characterize nonionic ethoxylated surfactants in pharmaceutical formulations.
  
• Chromatography Fundamentals, Part II: Thermodynamics of Liquid Chromatography: Energetics
  Howard G. Barth
  We examine the connection between the distribution coefficient and Gibbs free energy, and contributions from enthalpy and entropy.
  
• Biomimetic Chromatography to Accelerate Drug Discovery: Part I
  Klara Valko
  Drug discovery can be accelerated by chromatographic profiling of analogs by measuring their nonspecific binding to proteins and lipids.
  
• THE APPLICATION NOTEBOOK
  

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index

COLUMNS

• SAMPLE PREP PERSPECTIVES
  New Sample Preparation Products and Accessories
  Douglas E. Raynie
  Our yearly report on new products covers sample preparation instrumentation, supplies, and accessories. New sample preparation technologies introduced in the past year, while not necessarily disruptive, take giant leaps in that direction.
  
• LC TROUBLESHOOTING
  Fittings and Connections for Liquid Chromatography—So Many Choices!
  Dwight R. Stoll
  A bad connection between an LC column and the rest of the system can ruin a good separation. New technologies may improve the quality of these connections and the likelihood of establishing a good connection in the first place. Understanding the issues will help you choose the best option for you.
  
• GC CONNECTIONS
  New Gas Chromatography Products for 2017–2018
  John V. Hinshaw
  We present our annual review of new developments in the field of gas chromatography, which this year includes eight new GC and GC–MS laboratory benchtop systems as well as numerous new columns and accessories.
  
• THE ESSENTIALS
  A Step-by-Step Guide to Inlet Maintenance
  Good maintenance of the GC inlet can prevent a host of problems from compromising the quality of your results.
  

PEER-REVIEWED ARTICLES

• Quantitating Toxaphene Parlar Congeners in Fish Using Large Volume Injection Isotope Dilution GC with Electron-Capture Negative Ion MS
  Paul R. Loconto
  A novel automated ultratrace gas chromatography–mass spectrometry (GC–MS) method has been developed that quantitates the eight toxaphene Parlar congeners designated in U.S. Environmental Protection Agency Method 8276. This method, combined with an efficient extraction, cleanup, and fractionation technique, makes is possible to extend instrument detection limits to the low parts-per-trillion concentration level for these toxaphene Parlar congeners.
  
• Data Integrity in the GxP Chromatography Laboratory, Part III: Integration and Interpretation of Data
  Mark E. Newton and R.D. McDowall
  Integration is the heart of the chromatographic process and is subject to regulatory scrutiny. What should be done to control integration and interpretation of the chromatographic runs?
  

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index

COLUMNS

• COLUMN WATCH
  New Chromatography Columns and Accessories for 2018
  David S. Bell
  Our annual review of new liquid chromatography columns and accessories, including columns for reversed-phase, HILIC, chiral, SEC, GPC, ion-exchange, and SFC separations of small and large molecules.
  
• LC TROUBLESHOOTING
  Peak Purity in Liquid Chromatography, Part II: Potential of Curve Resolution Techniques
  Daniel W. Cook, Sarah C. Rutan, C.J. Venkatramani, and Dwight R. Stoll
  In part II of this series, we explore how curve resolution methods advance purity assessments and illustrate one of the most popular techniques, which adds a powerful tool to the chromatographer’s arsenal.
  
• PERSPECTIVES IN MODERN HPLC
  New HPLC Systems and Related Products Introduced in 2017–2018: A Brief Review
  Michael W. Dong
  An overview and assessment of the latest HPLC and mass spectrometry instruments, modules, chromatography data systems, and related software.
  
• FOCUS ON ENVIRONMENTAL ANALYSIS
  Best Practices for Analyzing Pesticides and Their Metabolites in Environmental Samples
  Laura Bush
  James Stry of FMC Agricultural Solutions talks about best practices for developing robust environmental analysis methods, including simplifying sample preparation and dealing with matrix effects.
  
• THE ESSENTIALS
  Making HILIC Work for You—Column Selection
  Ligands capable of undergoing electrostatic interactions can add an extra dimension to separations of ionizable compounds.
  

PEER-REVIEWED ARTICLE

• Data Integrity in the GxP Chromatography Laboratory, Part II: Setting up a Chromatograph and Acquiring Data
  Mark E. Newton and R.D. McDowall
  Part II of this series on practical perspectives on data integrity focuses on instrument setup, system suitability test samples, and data acquisition.
  

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index

COLUMNS

• SAMPLE PREP PERSPECTIVES
  Recent Advances in Solid-Phase Microextraction, Part I: New Tricks for an Old Dog
  Douglas E. Raynie
  A look at recent advances in SPME, such as increasing the sorbent surface area available for extraction, accommodating direct analysis by mass spectrometry, and sorbent overcoating to resist fouling by sugars and lipids
  
• LC TROUBLESHOOTING
  Eluent Preparation for Hydrophilic Interaction Liquid Chromatography, Part II: pH, Buffers, and Gradient Elution
  Dwight R. Stoll and Claudia Seidl
  Certain details related to mobile-phase preparation that can be assumed in reversed-phase LC separations can be much more consequential in HILIC.
  
• GC CONNECTIONS
  A Compendium of GC Detection, Past and Present
  John V. Hinshaw
  Gas chromatography makes use of a wide variety of detection methods, which really shine when deployed properly. Here’s guidance for how to choose the right one for your analysis.
  
• THE ESSENTIALS
  Optimizing SEC for Biologics Analysis
  Parameters such as pore size, column dimensions, temperature, flow rate, and mobile phase are important to consider when developing SEC methods.
  PEER-REVIEWED ARTICLES

PEER-REVIEWED ARTICLES

• Scaling LC Methods Using Superficially Porous Particle Stationary Phases
  Gregory K. Webster and Mathew A. Gragg
  Because not all laboratories have UHPLC systems, reverse scaling of methods from UHPLC to HPLC is often needed, particularly in the pharmaceutical industry. The use of superficially porous particles can facilitate this process.
  
• Chromatography Fundamentals, Part I: Thermodynamics of Liquid Chromatography: The Distribution Coefficient
  Howard G. Barth
  This article, the first in a series on chromatography fundamentals, discusses the cornerstone of all chromatographic techniques—the distribution or equilibrium coefficient—and its influence on liquid chromatographic separations.
  SPECIAL FEATURE

SPECIAL FEATURE

• Highlights of HPLC 2017 Jeju
  Ronald E. Majors
  A summary of the findings presented at the HPLC 2017 Jeju conference, reviewing how they fit into overall liquid-phase separation trends and the outlook for the future of these technologies
  

DEPARTMENTS

• Peaks of Interest
• Chromatography Corner
• Products & Resources
• Calendar
• Short Courses
• Ad Index

COLUMNS

• COLUMN WATCH
  Understanding the Science Behind Packing High-Efficiency Columns and Capillaries: Facts, Fundamentals, Challenges, and Future Directions
  Fabrice Gritti and M. Farooq Wahab
  Despite the theoretical promise of reduced plate heights (h) < 1, most modern UHPLC columns can only deliver plate heights in the range from 1.4 to 2.5. However, improved packing procedures, a better understanding of the colloidal properties of particle suspensions, and the study of the rheological behavior of packed beds and the final bed structure should lead us to practical solutions that can double the column efficiencies.
  
• LC TROUBLESHOOTING
  Peak Purity in Liquid Chromatography, Part I: Basic Concepts, Commercial Software, and Limitations
  Sarah C. Rutan, C.J. Venkatramani, and Dwight R. Stoll
  Is that peak “pure”? How do I know if there might be something hiding under there? In part I of this series, we explore some of the concepts behind peak purity assessments, describe some tools that are used in commercially available software for these assessments, and highlight some of the limitations of these tools using real-world examples.
  
• THE ESSENTIALS
  How to Avoid Problems in LC–MS
  Five tips to help you get the most out of your LC–MS instruments and methods
  

FEATURES

• The 2018 LCGC Awards
  Megan L’Heureux
  We explore the careers and achievements of the winners of LCGC’s 11th annual awards: Ronald E. Majors and Zachary S. Breitbach.
  
• Pittcon 2018: The LCGC Awards Symposium Preview
  In advance of Pittcon 2018, leading scientists—Ronald Majors, Richard Henry, John W. Dolan, Zachary S. Breitbach, and Daniel W. Armstrong—who will be speaking at the LCGC awards symposium give us a preview of their talks.
  

PEER-REVIEWED ARTICLE

• Accuracy Validation of Size-Exclusion Chromatography
  Howard G. Barth
  Here, a procedure is described for preparing polydisperse polymer standards to validate the accuracy of any SEC method for aqueous or organic mobile phases. This approach can be used for all calibration procedures with the exception of online light scattering and viscometric detection.
  

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index

COLUMNS

• SAMPLE PREP PERSPECTIVES
  Analyte Derivatization as an Important Tool for Sample Preparation
  Douglas E. Raynie
  There is a resurgence of interest in chemical derivatization schemes in separation science, particularly in sample preparation. Here’s why.
• LC TROUBLESHOOTING
  Eluent Preparation for Hydrophilic Interaction Liquid Chromatography, Part I: Solvent Volumes and Buffer Counterions
  Charles A. Lucy, Caley B. Craven, Claudia Seidl, and Dwight R. Stoll
  Paying attention to the details of mobile-phase preparation can have a big impact on the reproducibility of HILIC separations.
• FOCUS ON BIOPHARMACEUTICAL ANALYSIS
  Charge-Variant Profiling of Biopharmaceuticals
  Jared R. Auclair, Anurag Rathore, and Ira Krull
  A look at techniques for charge-variant analysis of monoclonal antibodies and the question of whether pH gradients are really better than salt gradients
• GC CONNECTIONS
  Tips and Tricks for New Gas Chromatographers
  Nicholas H. Snow
  Three main points summarize the best ways to be successful in GC: capillary GC is clean GC; practice, practice, practice; and be a student of GC.
• THE ESSENTIALS
  How It Works: Ion-Exchange SPE
  The fundamental principles of ion-exchange solid-phase extraction

PEER-REVIEWED ARTICLES

• Data Integrity in the GxP Chromatography Laboratory, Part I: Sampling and Sample Preparation
  Mark E. Newton and R.D. McDowall
  Part I of this series on practical perspectives of data integrity focuses on sample management, transport, and preparation.
• Headspace Solid-Phase Microextraction Coupled with Gas Chromatography–Mass Spectrometry for the Characterization of Polymeric Materials
  Peter Kusch
  HS-SPME-GC–MS is a valuable technique for identifying volatile organic compounds, additives, and degradation products in industrial rubber, car labeling reflection foil, and bone cement materials.

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index