LC*GC

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COLUMNS

• LC TROUBLESHOOTING
  Pass the Salt: Evolution of Coupling Ion-Exchange Separations and Mass Spectrometry
  Dwight R. Stoll
  The high levels of non-volatile salts typically used in ion-exchange separations are incompatible with mass spectrometry. But the desire to directly couple these two powerful techniques has prompted researchers find solutions to this problem. Here are three approaches.
  
• SAMPLE PREP PERSPECTIVES
  Looking at the Past to Understand the Future: Soxhlet Extraction
  Douglas E. Raynie
  To better understand modern sample preparation techniques—such as ultrasound-assisted extraction, microwave-assisted extraction, and pressurized solvent extraction—we should look at the lessons these methods took from Soxhlet extraction.
  
• PERSPECTIVES IN MODERN HPLC
  HPLC Autosamplers: Perspectives, Principles, and Practices
  Carsten Paul, Frank Steiner, and Michael W. Dong
  We explain recent trends in HPLC autosampler design, provide recommendations for selecting one, and offer guidelines for operation and troubleshooting.
  
• THE ESSENTIALS
  The Importance of Tuning and Calibration in Liquid Chromatography–Mass Spectrometry (LC–MS)
  In LC–MS, the importance of tuning and calibrating the mass spectrometer cannot be overemphasized. There are six main aspects to address.
  

FEATURE

• Data Integrity Focus, Part VII: A Data Life Cycle for Chromatography
  R.D. McDowall
  Several regulatory data integrity guidance documents require that laboratories understand the data life cycle of their processes, but provide only vague definitions of what a data life cycle is. Here is a practical interpretation.
  

PEER-REVIEWED ARTICLE

• HILIC to the Rescue: Pharmaceutical Development Case Examples
  Jonathan G. Shackman
  HILIC has rapidly evolved into a practical technique. For analyzing highly polar compounds, HILIC can be far more straightforward than GC or reversed-phase LC with derivatization, and can lead to a simpler final method with robustness comparable to that of reversed-phase LC.
  

DEPARTMENTS

• Peaks of Interest
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ANNUAL INDUSTRY TRENDS AND DIRECTORY ISSUE

• 2019 Salary Survey: Some Slight Gains and the Gender Gap Narrows
  
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COLUMNS

• COLUMN WATCH
  Hybrid Particle Columns: The First Twenty Years
  Thomas H. Walter
  We examine the evolution of hybrid particle columns, highlighting examples of separations enabled by this technology.
  
• LC TROUBLESHOOTING
  Mobile Phase Buffers in LC: Effect of Buffer Preparation Method on Retention Repeatability
  Dwight R. Stoll and Devin M. Makey
  Many analysts have strongly held beliefs about buffer preparation methods, but these positions are not always supported by experimental evidence.
  
• GC CONNECTIONS
  Temperature Programmed GC: Why Are All Those Peaks So Sharp?
  Nicholas H. Snow
  Temperature programming is used in most capillary GC separations, but many analysts lack a good understanding of the principles behind this approach.
  
• FOCUS ON ENVIRONMENTAL ANALYSIS
  Environmental Method Development: Key Challenges and Unmet Needs
  Michael MacRae
  The environmental analysis community sorely needs a system by which new and up-to-date methods are more easily developed, shared, and adopted.
  
• THE ESSENTIALS
  Electron Capture Detectors
  The fundamentals of electron capture detectors, explained.
  

PEER-REVIEWED ARTICLES

• The Determination of Trace Per- and Polyfluoroalkyl Substances and Their Precursors Migrated into Food Simulants from Food Contact Materials by LC–MS/MS and GC–MS/MS
  Dan Li, Zi-hao Zhang, Huai-ning Zhong, Lei Zhu, Jing-jing Pan, Jian-guo Zheng, Qin-bao Lin, and Hui Liu
  This integrated analytical approach combines HPLC–MS/MS and GC–MS/MS to detect 36 PFAS migrating into food simulants from packaging.
  
• Chromatography Fundamentals, Part VII: Influence of Peak Broadening on Detection Sensitivity, Solute Dilution, and Efficiency of Coupled Columns
  Howard G. Barth
  With these equations, you can predict how solute dilution will affect sensitivity.
  

FEATURE ARTICLE

• Under Pressure to Perform: Impact of UHPLC Technology on Pharmaceutical Research and Development
  Christopher J. Welch
  How has UHPLC has affected pharmaceutical research? The answer depends on your point of view.
  

DEPARTMENTS

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

CURRENT TRENDS IN MASS SPECTROMETRY

• Articles
  • High-Throughput Experimentation: Where Does Mass Spectrometry Fit?
    Jessica Lin, Colin Masui, Raymond Lieu, and Kelly Zhang
    In the pharmaceutical industry, the use of mass spectrometry in high-throughput experimentation (HTE) has increased, thanks to the technique’s speed, sensitivity, and selectivity. We systematically evaluate the applicability of multiple MS techniques for different types of HTE samples and purposes, reviewing the pros and cons, and provide practical recommendations, Illustrated by application case studies.
    
  • Laser Thermal Desorption and GC×GC for Harsh Environment and Planetary Mass Spectrometry
    Mark Libardoni and Ryan Blase
    The development of analytical instrumentation for harsh terrestrial environments and outer planet space exploration exponentially increases instrument requirements—for features such as robustness, autonomous operation, and speed—and poses unique system integration challenges. Here, we explore the use of laser thermal desorption coupled to comprehensive two-dimensional gas chromatography (LTD-GC×GC) for use with a compact, high-resolution mass spectrometer for challenging applications.
    
  • A Brief Review of Recent Advances in Isomeric N- and O-Glycomics
    Yehia Mechref, Wenjing Peng, and Yifan Huang
    Glycan isomer expressions have not been well studied, due to inefficient separation and structural identification techniques. Fortunately, with the development of novel separation techniques and liquid chromatography–mass spectrometry (LC–MS) based glycan isomer identification strategies, new efforts have been made to investigate the glycan isomers in various diseases. Here, we review the recent advances of several isomeric separation techniques for both N- and O-linked glycans.
    
• Departments
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COLUMNS

• COLUMN WATCH
  Making the Most of Size-Exclusion Bioseparations Using Sub-2-µm Column Technology
  Te-Wei Chu, Veronica Qin, Andrew Coffey, Eric Lyster, Wu Chen, and Gregory Staples
  With SEC, special care is required to achieve in practice the chromatographic efficiency that is expected from theory.
  
• LC TROUBLESHOOTING
  Mixing and Mixers in Liquid Chromatography, Part III: Solutions for Problems with Sample Diluents
  Zachary Breitbach, Corianne Randstrom, Jean Chang, Michael Lesslie, Gregory Webster, and Dwight R. Stoll
  An in-line mixer between the sample injector and column may resolve problems with peak shape caused during sample dilution.
  
• PERSPECTIVES IN MODERN HPLC
  Modern HPLC Pumps: Perspectives, Principles, and Practices
  Konstantin Shoykhet, Ken Broeckhoven, and Michael W. Dong
  Gaining a solid understanding of how HPLC instrumentation works will help you achieve success in the analytical laboratory. This four-part series is here to guide you, starting with pumps.
  
• FOCUS ON BIOPHARMACEUTICAL ANALYSIS
  Practical Considerations of Capillary Electrophoresis–Mass Spectrometry for Analysis of Biotherapeutics
  Anurag S. Rathore, Ramesh Kumar, and Ira S. Krull
  Coupling CE with MS presents some challenges. Here, we discuss the advantages of CE–MS over LC–MS, and the parameters that are important to obtain a stable CE–MS profile.
  
• THE ESSENTIALS
  Solving Recovery Problems in Solid-Phase Extraction
  Improved practices in chemistry selection and sample processing may resolve recovery issues related to target analytes or internal standards.
  

FEATURE ARTICLES

• Data Integrity Focus, Part VI: Who Is Looking Over Your Shoulder? Quality Oversight for Data Integrity
  R.D. McDowall
  What are the roles and responsibilities of quality assurance staff for ensuring data integrity in an organization?
  
• Evaluation of Achiral Stationary Phases for Gradient Screening with Supercritical Fluid Chromatography
  Raffeal Bennett, Matthew Przybyciel, Erik L. Regalado, and Mirlinda Biba
  Unlike reversed-phase liquid chromatography, SFC lacks a universal stationary phase. Thus, it is important to re-evaluate the default column screening library used with SFC. In this study, three uncommon achiral SFC columns were investigated and compared to three popular stationary phases.
  

THE APPLICATION NOTEBOOK

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index

Recent Developments in HPLC and UHPLC

• Looking To The Future
  Gert Desmet
  An introduction to this special issue from the guest editor.
  
• Vacuum-Jacketed Columns: Maximum Efficiency, Easy Deployment Without Oven, and Improved LC–MS Performance
  Fabrice Gritti
  The design of a user-friendly vacuum-jacketed column (VJC) is described for improved LC–MS performance, which does not require a large vacuum chamber with multiple vacuum pumps. Using this configuration, the experimental peak capacities measured for a 2.1 mm × 100 mm column packed with sub-2-µm particles and placed in the VJC-MS probe are doubled with respect to standard LC–MS systems.
  
• Recycle Reversed-Phase Liquid Chromatography to Achieve Separations Based on One H/D Substitution on Aromatic Hydrocarbons
  Kazuhiro Kimata, Tsunehisa Hirose, Eisuke Kanao, Takuya Kubo, Koji Otsuka, Ken Hosoya, Kohei Yoshikawa, Eiichiro Fukusaki, and Nobuo Tanaka
  Ultrahigh efficiency separations based on the presence of one deuterium in benzene, toluene, and naphthalene were achieved by recycle chromatography using C18 silica columns. The discrimination mechanism of H/D isotopic species is discussed based on the dispersion interactions of a CH/CD group of the solute with the stationary phase as well as the mobile phase.
  
• Progress in Peak Processing
  M. Farooq Wahab, Garrett Hellinghausen, and Daniel W. Armstrong
  The advantages and limitations of several recently introduced mathematical procedures for enhancing peak resolution in liquid chromatography (LC) are described. Despite advanced separation technologies and extensive knowledge in method development, peak overlap is still commonly observed. This article gives a brief overview of the advantages and limitations of recently introduced mathematical procedures for enhancing resolution.
  
• Optimization of MS-Compatible Mobile Phases for IEX Separation of Monoclonal Antibodies
  Evelin Farsang, Amarande Murisier, Krisztián Horváth, Olivier Colas, Alain Beck, Davy Guillarme, and Szabolcs Fekete
  The impact of ionic strength, buffer capacity, and pH-response on the retention behavior and peak shape of mAb species characterization is evaluated for IEX-MS. The aim of the present study was to understand the impact of ionic strength, buffer capacity, and pH-response on the retention behavior and peak shape of mAb species.
  

COLUMNS

• LC TROUBLESHOOTING
  Methods from Mars? Coping with Chromatographic Legacies
  Dwight R. Stoll and Tony Taylor
  Legacy LC methods seem like they come from a different planet. This month, we look at which conditions to keep, and which ones to let go.
  
• SAMPLE PREP PERSPECTIVES
  New Sample Preparation Products and Accessories
  Douglas E. Raynie
  Our annual report of sample preparation instrumentation, supplies, and accessories for gas and liquid chromatography
  
• GC CONNECTIONS
  New Gas Chromatography Products for 2018–2019
  John V. Hinshaw
  Our annual review of new developments in the field of gas chromatography, as seen at Pittcon and other venues
  
• THE ESSENTIALS
  Modern Mobile Phase Design for HPLC
  In recent years, there has been a paradigm change in the way we approach mobile phase design for high performance liquid chromatography (HPLC). What are the trends?
  

FEATURE ARTICLES

• Data Integrity Focus, Part V: How Can USP <1058> Help Data Integrity?
  R.D. McDowall
  USP chapter <1058> can help ensure data integrity of a chromatography data system. Here’s how.
  
• Statistics for Analysts Who Hate Statistics, Part VIII: Decision Trees
  Caroline West
  Decision trees offer great visuals to observe complex data sets and to classify data according to simple decision rules.
  

PEER-REVIEWED ARTICLE

• Development of Fully Automated Bubble-in-Drop Microextraction–Gas Chromatography–Mass Spectrometry of Organochlorine Pesticides in Environmental Waters
  Claire A. Taylor, Hui Min Lee, and Hian Kee Lee
  By optimizing and fully automating the bubble-in-drop microextraction process, this sample preparation technique, combined with gas chromatography–mass spectrometry (GC–MS) analysis, provides high precision and good figures of merit, as shown for selected organochlorine pesticides in the analysis of tap water and reservoir water samples.
  

DEPARTMENTS

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

CURRENT TRENDS IN MASS SPECTROMETRY

• Articles
  • Determination of the Relative Prevalence of Lurasidone Metabolites in Urine Using Untargeted HRMS
    Erin C. Strickland, Jeffrey R. Enders, and Gregory L. McIntire
    For lurasidone treatment adherence testing, an untargeted high-resolution mass spectrometry method was employed, using known positive human urine samples to identify the lurasidone metabolites and their relative abundance in urine.
    
  • Quantitation and Nontargeted Identification of Pesticides in Spinach Extract with GC×GC–TOF-MS
    Todd Richards and Joseph Binkley
    In this study of pesticides in spinach extract, the use of GC×GC–TOF-MS is demonstrated as a methodology to overcome matrix interferences and quickly quantify suspected contaminants. The approach also allows nontargeted analysis using a single sample injection.
    
  • High-Throughput Structure-Based Profiling and Annotation of Flavonoids
    Simon Cubbon
    A novel mass spectrometry-based flavonoid profiling workflow is applied to characterize and structurally annotate a large number of unknown flavonoids in fruit juice and vegetable juice samples.
    
• Departments
  • Products
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COLUMNS

• COLUMN WATCH
  New Liquid Chromatography Columns and Accessories for 2019
  David S. Bell
  Our annual review of new liquid chromatography columns and accessories.
  
• LC TROUBLESHOOTING
  Reversed-Phase Liquid Chromatography and Water, Part II: Re-equilibration of the Stationary Phase Following Gradient Elution
  Dwight R. Stoll
  Re-equilibrating a reversed-phase stationary phase following aqueous gradient elution can be achieved much faster than you think.
  
• PERSPECTIVES IN MODERN HPLC
  New HPLC Systems and Related Products Introduced in 2018–2019: A Brief Review
  Michael W. Dong
  New HPLC and MS systems: A review of instrumentation trends and the current market along with new instruments, modules, chromatography data systems, and related software.
  
• FOCUS ON ENVIRONMENTAL ANALYSIS
  Trends in Water Analysis
  Laura Bush
  In this interview, Thomas Letzel of the Technical University of Munich considers the current state of water analysis, looking at recommended techniques, thegrowth of nontargeted screening, and multi-disciplinary collaboration.
  
• THE ESSENTIALS
  Electron Ionization in GC–MS
  We provide a succinct explanation of electron ionization for GC–MS and illustrate the fundamentals of ion formation.
  

FEATURE

• Data Integrity Focus, Part IV: Are Raw Data and Complete Data the Same?
  R.D. McDowall
  The meaning of the terms raw data and complete data are explored. One term is from EU GMPs and the other is from US GMPs. Do they mean the same thing?
  

PEER-REVIEWED ARTICLE

• Chromatography Fundamentals, Part VI: The Gaussian Distribution and Moment Analysis
  Howard G. Barth
  How well do Gaussian-shaped profiles represent injected solute peaks after they are eluted through a chromatographic column? This question is explored along with a discussion of moment analysis for determining retention time, variance, and shapes of peaks.
  

DEPARTMENTS

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

RECENT DEVELOPMENTS IN SAMPLE PREPARATION

• Articles
  • Advancing Chromatographic Analysis Using Selective and Robust Sample Preparation
    Jared L. Anderson
    The field of sample preparation is undergoing revolutionary change, largely governed by the need for miniaturization while maintaining high selectivity and high analyte enrichment. How up-to-date are you in the advances of sample preparation for chromatographic analysis?
    
  • Dispersive Miniaturized Solid-Phase Extraction Using the CIM-81 Metal-Organic Framework and Gas Chromatography–Mass Spectrometry to Determine Personal Care Products in Waters
    Providencia González-Hernández, Ana B. Lago, Jorge Pasán, Juan H. Ayala, Ana M. Afonso, and Verónica Pino
    In this study, the analysis of contaminants found in environmental waters and originating from personal care products is addressed using metalorganic frameworks (MOFs) in combination with liquid chromatography (LC). This work expands the use of MOFs from gas chromatography to LC and also meets the requirements of green analytical chemistry.
    
  • Solid-Phase Microextraction Combined with Flow-Modulated Comprehensive Two-Dimensional Gas Chromatography for Screening Leachables in the Pharmaceutical Industry
    Juliana Crucello, Andre Cunha Paiva, and Leandro W. Hantao
    A simple, fully-automated method is proposed to analyze extractables and leachables—compounds that are released from packing materials into drugs during storage—using SPME-GC×GC–MS. This method avoids the use of sample preparation solvents and reduces sample handling, and is ideal for routine use in quality control.
    
  • Nanomaterials Have Come to Stay: An Overview of their Use as Sorbents in Sample Preparation
    Javier González-Sálamo, Diana Angélica Varela-Martínez, Carlos Cairós, Miguel Ángel González-Curbelo, and Javier Hernández-Borges
    Nanomaterials are extremely useful as sorbents for sample preparation, because of their varied morphologies, high surface area, surface-tovolume ratio, porosity, and ability to interact with samples in a variety of ways. Here, we review how nanomaterials are being used in a variety of sample preparation techniques, such as dispersive solid-phase extraction (dSPE), solid-phase microextraction, stir-bar sorptive extraction, and matrix solid-phase dispersion.
    
  • Exploring the Efficiency of Various Extraction Approaches for Determination of Crude (4-methylcyclohexyl)methanol (MCHM) Constituents in Environmental Samples
    Ronald V. Emmons, Amila M. Devasurendra, Nipunika H. Godage, and Emanuela Gionfriddo
    Crude (4-methylcyclohexyl)methanol (MCHM) is a chemical contaminant that must be monitored in fresh water environments, because of significant health risks to surrounding human populations. A new method for MCHM analysis was developed using solid-phase microextraction (SPME) and thin film microextraction (TFME) combined with GC–MS. Both methods achieved limits of quantitation lower than standard methods using SPE.
    
  • “Truly Natural”: Fully Automated Stir-Bar Sorptive Extraction with Enantioselective GC–MS Quantitation of Chiral Markers of Peach Aroma
    Cecilia Cagliero, Alessandro Guglielmetti, Chiara Cordero, Erica Liberto, Arianna Marengo, Barbara Sgorbini, Patrizia Rubiolo, and Carlo Bicchi
    A simple, automated, and fast method to quantify complex odorants in foods is described using stir-bar sorptive extraction (SBSE) combined with fast enantioselective GC–MS analysis. The total analytical method takes only 30 minutes and does not require any sample pretreatment.
    

COLUMNS

• COLUMN WATCH
  Perspectives on the Adoption and Utility of 1.0-mm Internal Diameter Liquid Chromatography Columns
  David S. Bell
  We assess the advantages and disadvantages of 1.0-mm diameter columns.
  
• LC TROUBLESHOOTING
  Looking for New Selectivity in Reversed-Phase Liquid Chromatography? A View of the Selectivity Landscape Over the Past Two Years
  Dwight R. Stoll
  How many new columns truly offer new selectivity?
  
• SAMPLE PREP PERSPECTIVES
  Recent Advances in Solid-Phase Microextraction, Part II: Bio-SPME
  Douglas E. Raynie
  Bioanalysis with SPME has advanced greatly over the past decade.
  

PEER-REVIEWED ARTICLES

• Data Integrity Focus, Part III: What Is the Problem with Hybrid Systems?
  R.D. McDowall
  A hybrid system is the worst possible choice for managing your regulated data.
  
• Instrument Considerations in the Transfer of Chromatographic Methods, Part III: Aligning Performance of Modules
  Thomas E. Wheat
  In method transfer, carefully aligning the modules of the two systems is essential.
  
• Determination of Diclofenac in Water Samples from Wastewater Treatment Plants by Large Volume Injection-Gas Chromatography–Mass Spectrometry
  Álvaro Aragón, Rosa M. Toledano, Ana Vázquez, Jesús Villén, and José M. Cortés
  A new method to analyze low concentrations of the drug diclofenac in wastewater.
  
• Pressure Tuning: Increasing the Flexibility of Comprehensive Two-Dimensional Gas Chromatography
  Mohammed Sharif Khan and Philip John Marriott
  Pressure tuning makes it easy to change the orthogonality in the 2D space.
  

THE LCGC AWARDS: INTERVIEWS

• The 2019 Lifetime Achievement in Chromatography Award: Professor Milos V. Novotny on His Chromatographic Journey
  Jerome Workman, Jr.
  Prof. Novotny discusses the joys of mentoring and the future of separation science.
  
• The 2019 Emerging Leader in Chromatography Award: Ken Broeckhoven on Investigating the Performance Limits of HPLC Separations
  Jerome Workman, Jr.
  Ken Broeckhoven explains his pursuit of ever higher performance in HPLC.
  

DEPARTMENTS

• Peaks of Interest
• ISCC and GCxGC Preview: Honey I Shrunk the HPLC.
• Calendar
• Short Courses
• Products & Resources
• Ad Index
• The Essentials

Current Trends in MASS Spectrometry

• Articles
  • Plant Metabolomic Workflows Using Reversed-Phase LC and HILIC with ESI-TOF-MS
    Rofida Wahman, Johanna Grassmann, Peter Schröder, and Thomas Letzel
    In plant metabolomics, molecular fingerprints and additional molecular descriptors can be identified using recent developments in polarity-extended separations with serial coupling of reversed-phase LC and HILIC combined with ESI-TOF-MS.
    
  • A Robust and Sensitive Method for Detecting Glyphosate and Other Polar Pesticides in Food and Water: Multiple Analytes in a Single Injection without Derivatization
    Wim Broer, Ugo Chiuminato, Jianru Stahl-Zeng, Daniel McMillan, and Phil Taylor
    A new high-throughput LC–MS/MS method meets the challenge of eliminating matrix effects for monitoring, with high specificity, polar organic pesticides such as glyphosate in food and water, while meeting targeted limits of detection.
    
  • GC×GC–MS for Forensic Analysis
    Candice M. Bridge, Mark Maric, and Kaitlin Jones
    Forensic scientists often encounter highly complex analytical problems related to crime scenes that would benefit from the capabilities of GC×GC–MS. However, this technique has not been fully explored to help benefit forensic laboratories.
    
  • The Benefits of Data-Independent Acquisition in Metabolomics
    Alasdair Matheson
    Data-independent acquisition (DIA) makes it possible to re-interrogate data from earlier analyses to determine if new compounds have appeared in a sample previously analyzed. In this interview, Craig Wheelock of the Karolinska Institute discusses the use of DIA in metabolomics.
    
• Departments
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COLUMNS

• LC TROUBLESHOOTING
  Reversed-Phase Liquid Chromatography and Water, Part I: How Much is Too Much?
  Dwight R. Stoll
  In reversed-phase separations, retention generally increases as the fraction of water in the eluent increases. When we encounter situations where retention is too low for an analyte of interest, we tend to use eluents with higher and higher levels of water. But how much water is too much?
  
• GC CONNECTIONS
  GCxGC: From Research to Routine
  Nicholas H. Snow
  Two-dimensional gas chromatography (GCxGC) is becoming the technique of choice for analysis of highly complex samples such as petroleum, pharmaceuticals, biological materials, food, flavors, and fragrances. Here, we explain how GCxGC works and provide examples that illustrate its advantages.
  
• THE ESSENTIALS
  Optimizing Sensitivity in GC–FID Analysis
  It is often possible to achieve better sensitivity and lower limits of detection and quantitation using standard gas chromatography instrumentation. Paying attention to fundamental variables—like sample solvent, initial oven temperature hold, carrier gas operating mode, and thermal gradients— can lead to much improved method performance.
  

FEATURE ARTICLES

• The 2019 LCGC Awards
  Jerome Workman Jr.
  The contributions of Milos V. Novotny and Ken Broeckhoven, the winners of the 2019 LCGC Lifetime Achievement and Emerging Leader in Chromatography Awards, are presented.
  
• Data Integrity Focus, Part II: Using Data Process Mapping to Identify Integrity Gaps
  R.D. McDowall
  Data integrity is paramount when working in a regulated environment. Data process mapping is an excellent way to identify and mitigate data gaps and record vulnerabilities in a chromatographic process. This approach is simple and practical.
  

THE APPLICATION NOTEBOOK

DEPARTMENTS

• Peaks of Interest
• Products & Resources
• Ad Index

COLUMNS

• SAMPLE PREP PERSPECTIVES
  Is Headspace Sampling Quantitative?
  Douglas E. Raynie
  Whether or not headspace sampling is quantitative depends on the information gleaned from the analysis.
  
• LC TROUBLESHOOTING
  What’s Trending in LC Troubleshooting?
  Dwight R. Stoll
  We look at problems in LC that can be traced to contaminated solvents or reagents, and how sample solvent effects can lead to poor performance in HILIC.
  
• GC CONNECTIONS
  Stopping GC and GC–MS Problems Before They Start
  Nicholas H. Snow
  By taking simple proactive troubleshooting steps, GC users can ensure that instruments will operate correctly over time, thus avoiding workflow disruptions.
  
• FOCUS ON BIOPHARMACEUTICAL ANALYSIS
  Methods and Purposes for Determining Higher Order Structures of Biopharmaceuticals
  J. Auclair, A. Rathore, and Ira S. Krull
  Determining the higher order structure of a protein pharmaceutical is important. Here, we review the approaches for HOS determination that are currently receiving the most attention in the literature and at scientific meetings.
  
• THE ESSENTIALS
  Essential Theory of HPLC
  The elution mechanisms for gradient and isocratic HPLC are fundamentally different from each other. Here is what you should understand about both.
  

FEATURE ARTICLE

• Data Integrity Focus, Part 1: Understanding the Scope of Data Integrity
  R.D. McDowall
  There are many factors to consider in a data integrity and governance program. Fortunately, a simple diagram can help us understand what needs to be covered.
  

PEER-REVIEWED ARTICLE

• Suspect Screening of Chemicals in Food Packaging Plastic Film by Comprehensive Two-Dimensional Gas Chromatography Coupled to Time-of-Flight Mass Spectrometry
  Yelena Sapozhnikova and Eunha Hoh
  The occurrence of additives like plasticizers in plastic food packaging has been documented, but information on their potential migration into foods is limited. In this pilot study, 2D GC–MS was used to identify chemicals extracted from a common stretch plastic film with a series of organic solvents. In total, 91 compounds were tentatively identified, including five PCBs.
  

DEPARTMENTS

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