LC*GC

December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1995 - 1996

COLUMNS

• SAMPLE PREP PERSPECTIVES
  Immunosorbents for Selective Sample Preparation of Complex Mixtures
  Ronald E. Majors
  In this month’s installment, columnist Ron Majors covers the field of immunoextraction, a technique that employs immobilized antibodies to selectively capture specific analytes using molecular recognition via antibody–antigen interactions. Recently, the introduction of commercial products for specific high-volume environmental and food safety applications has spurred further applications of this technique.
  
• LC TROUBLESHOOTING
  The Perfect Method, Part VII: The Gradient Shortcut
  John W. Dolan
  For the last six months, “LC Troubleshooting” has been concentrating on the process for the development of isocratic methods (those for which the mobile phase composition is constant throughout the run). The use of a gradient scouting run to speed isocratic method development is the subject of this month’s “LC Troubleshooting.”
  
• MS — THE PRACTICAL ART
  Incipient Technologies: Desorption and Thermal Desorption Techniques
  Michael P. Balogh
  Nearly a dozen incipient technologies have appeared in recent years. Which will survive? Which will find extensive, robust usage as did electrospray ionization? Which are fated to become footnotes in mass spectrometry practice?
  
• VALIDATION VIEWPOINT
  Impurity Determinations for Biotechnology-Derived Biopharmaceuticals and Related Products
  Michael Swartz and Ira Krull
  This installment of “Validation Viewpoint” column addresses, in the hopes of clarifying what the biopharmaceutical industry is required to do today to identify and quantify impurities in their biotech, proteinaceous products.
  

EDITORIAL INDEX

• 2007 Index of Authors and Subjects
  

DEPARTMENTS

• Peaks of Interest
• Products
• Literature
• Classified Directory
• Ad Index

COLUMNS

• COLUMN WATCH
  Column Pressure Considerations in Analytical HPLC
  Ronald E. Majors
  In this installment of “Column Watch,” columnist Ron Majors examines the role of pressure in high performance liquid chromatography (HPLC) from two viewpoints: the impact of the ultrahigh pressures encountered in ultrahigh-pressure liquid chromatography (UHPLC) on chromatographic parameters and increases in column pressure encountered in normal daily use. The latter is of more practical consequence to HPLC users because increased back pressure usually implies that something has gone wrong with the column. Pressure increases due to physical and chemical contamination are explored and practical approaches to solve these problems are suggested.
  
• LC TROUBLESHOOTING
  The Perfect Method, Part VI: Make It Faster
  John W. Dolan
  In the previous installments of this series on efficient development of LC methods (1–5), we have concentrated on improving resolution by modifying the mobile phase, choosing a different stationary phase, or changing some other condition, such as column temperature. In this month’s “LC Troubleshooting” installment, we take a look at trading some of that resolution for a faster separation.
  
• GC CONNECTIONS
  Using Computerized Pneumatics
  John V. Hinshaw
  In this month’s “GC Connections” installment, John Hinshaw discusses computerized pneumatics for gas chromatography. This is the first of a two-part series that reviews computerized pneumatics and some important considerations that arise in the course of normal use.
  

ARTICLE

• A Strategy for Developing HPLC Methods for Chiral Drugs
  Satinder (Sut) Ahuja
  Basic information on stereochemistry is provided in this article to help readers develop a better understanding of the separation mechanisms that come into play in various separation methods used for chiral compounds. This knowledge can allow readers to select a desirable chiral separation method, based upon the molecular structure of the chiral compound of interest. Logical reasons for the selection process are discussed later in this article.
  

DEPARTMENTS

• Peaks of Interest
• Products
• Literature
• Classified Directory
• Ad Index

COLUMNS

• COLUMN WATCH
  Technology and Application Highlights of HPLC 2007
  Ronald E. Majors
  HPLC 2007 was held in Ghent, Belgium in June. Last month, columnist Ron Majors summarized some the important column developments as well as other Symposium highlights. This month, he winds up coverage with additional highlights in the areas of technology and applications.
  
• LC TROUBLESHOOTING
  The Perfect Method, Part V: Changing Column Selectivity
  John W. Dolan
  This month’s installment of “LC Troubleshooting” will focus on changing the column as a means to change the peak spacing in a chromatogram. We will consider two approaches — a traditional one of selecting the column by bonded phase type and a newer technique based upon the chromatographic properties of the column.
  
• MS — THE PRACTICAL ART
  Collecting Wisdom
  Michael P. Balogh
  Micahel Balogh takes a glance at how discussions at conferences, “for-a-fee” LC–MS courses, and postings of moderated websites and blogs are other primary means to examine not only suiting a mass spectrometer to a given purpose but the art of employing the devices.
  
• DIRECTIONS IN DISCOVERY
  Quantitative Proteomics: Available Tools and Results of a Collaborative Study
  Tim Wehr
  Many methods are currently in use to address protein quantification. This installment of “Directions in Discovery” reviews several of the more popular ones and reports on a collaborative study organized by the Association of Biomolecular Resource Facilities.
  

ARTICLE

• Development and Validation of a UHPLC Method for Paroxetine Hydrochloride
  Christopher J. Messina, Eric S. Grumbach, and Diane M. Diehl
  The authors discuss how a UHPLC method was developed to separate paroxetine from several of its related compounds using a systematic screening protocol that monitors combinations of selectivity factors including column chemistry, organic modifier, and pH.
  

DEPARTMENTS

• Peaks of Interest
• Products
• Literature
• Classified Directory
• Ad Index

COLUMNS

• COLUMN WATCH
  Column Highlights of HPLC 2007
  Ronald E. Majors
  HPLC 2007 was held in Ghent, Belgium in June. The symposium had the largest numbers of submitted papers in the history of the meeting. Columnist Ron Majors covers some of the highlights of the meeting including honorary sessions, best poster awards, and highlights of the technologies, applications, and detection techniques reported. In particular, the latest developments in HPLC column technology are covered including monoliths, sub-2-mm and UHPLC columns, chiral separations, HILIC, and other important topics.
  
• LC TROUBLESHOOTING
  The Perfect Method, IV: Controlling Peak Spacing
  John W. Dolan
  This is the fourth installment in a series on method development for liquid chromatography (LC), with an emphasis on developing trouble-free methods quickly. John Dolan started out by considering some of the goals we might have and some method development strategies. Next, he selected starting conditions for reversed-phase separations. This was followed by a discussion of how to control retention for good chromatographic performance. This month’s installment considers how to pull apart those troublesome peak pairs.
  
• GC CONNECTIONS
  A Split Decision
  John V. Hinshaw
  This month’s installment of “GC Connections” discusses factors that can help determine which type of liquid injection technique is appropriate for specific samples, including having to use existing inlet systems that are on-hand in the laboratory with samples for which they might not be ideally suited.
  

ARTICLE

• HPLC with Charged Aerosol Detection for Pharmaceutical Cleaning Validation
  Brian Forsatz and Nicholas H. Snow
  Cleaning validation is a major analytical application in the pharmaceutical industry. Here, high performance liquid chromatography (HPLC) with charged aerosol detection is compared and contrasted to HPLC with UV detection showing comparable performance and several advantages for charged aerosol detection, especially for analytes that do not contain a chromophore.
  

DEPARTMENTS

• From the Editor
• Peaks of Interest
• Products
• Literature
• Classified Directory
• Ad Index

COLUMNS

• COLUMN WATCH
  HPLC Column Expert Predictions — Revisited
  Ronald E. Majors
  Ron Majors revisits expert predictions from an HPLC survey conducted 20 years ago. Looking back, some of the answers might surprise you.
  
• LC TROUBLESHOOTING
  The Perfect Method, Part III: Adjusting Retention
  John W. Dolan
  This is the third installment in a series on method development for liquid chromatography (LC) that focuses on developing new reversed-phase methods.
  
• MS — THE PRACTICAL ART
  Identifying Packaging-Related Drug Product Impurities
  John D. Lennon III, Alan D. Hendricker, and Thomas N. Feinberg
  Three guest contributors provide a different take on how practitioners employ the skills of interpretation that have been the focus in recent columns.
  
• VALIDATION VIEWPOINT
  Glossary of Terms Related to Chromatographic Method Validation
  Michael Swartz and Ira Krull
  In this month’s installment of “Validation Viewpoint,” the duo have compiled a glossary of method validation terms as they pertain to chromatography.
  

ARTICLES

• Isolation and Recovery of Triclosan from Liquid Hand Soap Using Reversed-Phase Solid-Phase Disk Extraction and a Capillary GC–AED Determinative Technique
  Paul R. Loconto
  This article demonstrates that triclosan can be quantitatively determined in commercial hand soaps using reversed-phase solid-phase disk extraction coupled to quantification using capillary gas chromatography–atomic emission detection
  
• Different Approaches to Synthesizing Molecularly Imprinted Polymers for Solid-Phase Extraction
  Faten BelHadj Kaabi and Valérie Pichon
  The authors look at different polymerization methods to offset the common bulk process drawbacks.
  

DEPARTMENTS

• From the Editor
• Peaks of Interest
• Products
• Literature
• Calendar
• Classified Directory
• Ad Index

COLUMNS

• COLUMN WATCH
  The Art and Science of GC Capillary Column Production
  Allen K. Vickers, Daron Decker, and Ronald E. Majors
  Fused silica capillary columns have dominated the gas chromatography applications field for years. This installment of “Column Watch” will cover the basics of column production from the bare fused silica tubing to the final tested product.
  
• LC TROUBLESHOOTING
  The Perfect Method, Part II: Where to Start?
  John W. Dolan
  This is the second installment in a series on how to develop liquid chromatographic (LC) methods in an efficient manner. Last month, John Dolan considered how to set goals for new methods. This month, he looks at some of the factors involved in selecting a starting point for method development.
  
• MILESTONES IN CHROMATOGRAPHY
  The Rebirth of Chromatography 75 Years Ago
  Leslie S. Ettre
  After a 25-year dormant period, chromatography was finally reborn in the first years of the 1930s. The present column deals with this important step in the evolution of chromatography; the start of the meteoric rise of its application.
  

ARTICLE

• Improving Injection Consistency Using N Methyl-2-Pyrrolidone as a GC Syringe Wash
  Michael W. Dong
  This article describes the use of ultrahigh-pressure liquid chromatography (UHPLC) in pharmaceutical analysis of drug substances and drug products with UV absorption detection. The fundamentals and benefits of UHPLC in increasing analysis speed and resolution are reviewed. Its performance (precision, extracolumn dispersion, sensitivity, and column life) in pharmaceutical analysis was assessed.
  

DEPARTMENTS

• Peaks of Interest
• Products
• Literature
• Classified Directory
• Ad Index

COLUMNS

• COLUMN WATCH
  Current Trends in HPLC Column Usage
  Ronald E. Majors
  LCGC recently conducted a survey of readers on their use of analytical and preparative HPLC columns and guard columns. The last columns survey was performed in 1997. From the recent survey, Ron Majors compares some of the usage factors to those of the 1997 survey in order to understand trends in particle size, column dimensions, mode and phase usage, column lifetime, number used, buying trends, and other data.
  
• LC TROUBLESHOOTING
  The Perfect Method, Part I: What Is Your Goal?
  John W. Dolan
  Over the next several months, “LC Troubleshooting” will look at the subject of LC method development in detail. A few years ago this topic was covered with a little different emphasis, and in terms of reader feedback, the series was one of the most popular discussions in this column. So we’ll look at method development again with a little different twist.
  
• MS — THE PRACTICAL ART
  Techniques for Structure Elucidation of Unknowns: Finding Substitute Active Pharmaceutical Ingredients in Counterfeit Medicines
  Michael P. Balogh
  This month’s column brings much of the previous discussion on how to interpret mass spectra to a practical examination of detecting substitutions in counterfeit pharmaceuticals. The approaches used are practical “take home” lessons readers can apply to any analyze unknowns in any mixture.
  

ARTICLE

• Improving Injection Consistency Using N Methyl-2-Pyrrolidone as a GC Syringe Wash
  Bryan E. Bell
  In this study, Three GC–FID residual solvent methods were examined. The consistency of injections on GC–FID instruments was improved, including reproducibility of peak tailing and standard %RSD, by using N-methyl-2-pyrrolidone as an additional syringe wash.
  

DEPARTMENTS

• Peaks of Interest
• Products
• Literature
• Calendar
• Short Courses
• Classified Directory
• Ad Index

COLUMNS

• SAMPLE PREP PERSPECTIVES
  QuEChERS — A New Sample Preparation Technique for Multiresidue Analysis of Pesticides in Foods and Agricultural Samples
  Ronald E. Majors
  Ron Majors discusses an emerging sample prep technique becoming increasingly popular in the area of multiresidue pesticide analysis in food and agricultural products.
  
• LC TROUBLESHOOTING
  How Does Temperature Affect Selectivity?
  John W. Dolan
  Column temperature plays an important role in controlling peak spacing (selectivity) in re versed-phase LC separations. This month’s “LC Troubleshooting” examines temperature selectivity and its relationship to pH selectivity.
  
• GC CONNECTIONS
  GC Connections: New Gas Chromatography Products at Pittcon 2007
  John V. Hinshaw
  John Hinshaw presents his annual review of GC instruments and accessories from the 58th Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy.
  
• VALIDATION VIEWPOINT
  Validation and Peptide Mapping
  Michael Swartz and Ira Krull
  Peptide mapping is the preferred technique for the comprehensive characterization of biopharmaceutical products and is the analytical method of choice for studying a protein’s primary structure. Method validation approaches specifically for these complex samples are looked at here.
  

ARTICLES

• Solid-Phase Extraction Pipette Tip Sample Preparation for Membrane Protein Intact Mass
  Analysis by MALDI–MS Yibai Chen and Anthony Yeung
  This article describes a new sample preparation protocol favoring the analysis of the intact mass of membrane (and potentially other hyd rophobic) proteins by using MALDI-MS.
  
• A Comparison of Two Separation Modes: HILIC and Aqueous Normal Phase Chromatography
  Joseph Pesek and Maria T. Matyska
  A more precise definition of ANP and HILIC is proposed here that enables chromatographers to distinguish between the two and select columns suitable for particular applications.
  

DEPARTMENTS

• Peaks of Interest
• Letters to the Editor
• Letter from the Editor
• Products
• Literature
• Calendar
• Short Courses
• Classified Directory
• Ad Index

COLUMNS

• COLUMN WATCH
  New Chromatography Columns and Accessories at Pittcon 2007: Part II
  Ronald E. Majors
  This month's installment of “Column Watch” is the conclusion of a two-part series in which columnist Ron Majors examines trends in column and sample prep introductions at Pittcon 2007.
  
• LC TROUBLESHOOTING
  Variability — How to Control It
  John W. Dolan
  Prompted by a recently re v i ewed manuscript and a question f rom a reader, John Dolan examines the variability of retention times observed in LC methods in this month’s installment of “LC Troubleshooting.”
  
• MS — THE PRACTICAL ART
  Alternatives in the Face of Chemical Diversity
  Michael P. Balogh
  In this month’s “MS—The Practical Art,” Michael Balogh takes a closer look at insight provided by Chuck McEwen regarding obstacles while using solvents.
  
• MILESTONES IN CHROMATOGRAPHY
  Emanuel Gil-Av and the Separation of Enantiomers on Chiral Stationary Phases by Chromatography
  Leslie S. Ettre
  Guest columnist Volker Schurig discusses the achievements of Emanuel Gil - Av in introducing enantioselectivity into chromatographic analysis.
  

ARTICLE

• High-Throughput Quantitative LC–MS-MS Assays by On-Line Extraction Using Monolithic Support
  Raymond N. Xu, Grace E. Kim, Brian Boyd, Jill Polzin, Matthew J. Rieser, and Tawakol A. El-Shourbagy
  LC–MS-MS) has become a widely used technique for the fast and sensitive quantitation of small molecules.
  In this article, this approach has been extended to high-throughput quantitative LC–MS-MS analysis under GLP applications for a drug candidate in development from preclinical animal studies through clinical development.
  

DEPARTMENTS

• Peaks of Interest
• Products
• Literature
• Classified Directory
• Ad Index

COLUMNS

• COLUMN WATCH
  New Chromatography Columns and Accessories at Pittcon 2007: Part I
  Ronald E. Majors
  This month's installment of “Column Watch” is the first of a two-part series in which Ron Majors examines the trends and highlights in columns and consumables at Pittcon 2007.
  
• LC TROUBLESHOOTING
  Solvent Conservation
  John W. Dolan
  It has been more than 10 years since solvent recycling has been the main subject of an “LC Troubleshooting column,” so this month, John Dolan revisits this subject.
  
• GC CONNECTIONS
  How Close is Close Enough? Accuracy and Precision: Part II
  John V. Hinshaw
  In this month’s “GC Connections,” John Hinshaw continues a discussion of accuracy and precision begun in an earlier installment.
  
• DIRECTIONS IN DISCOVERY
  HPLC-Based Measurements of Various Lipophilicity Parameters to Aid Drug Design
  Klara Valko
  Fast, reliable measurement of lipophilicity has a great impact on the compounds’ selection process at an early stage of drug discovery. The guest columnist examines HPLC methods for this purpose.
  

ARTICLE

• CE–MS-MS for the Identification of Chemical Warfare Agent Degradation Products
  Mélanie Lagarrigue, Anne Bossée, Arlette Bégos, Anne Varenne, Pierre Gareil, and Bruno Bellier
  With the threat of terrorism growing, the development of analytical techniques for the detection and identification of chemical warfare agent degradation products has increased. With this in mind, capillary electrophoresis (CE) presents interesting features such as high separation efficiency, low sample consumption, and electrophoretic separation principles that are very complementary to those of the most commonly used chromatographic techniques.
  

DEPARTMENTS

• Peaks of Interest
• Products
• Literature
• Calendar
• Short Courses
• Classified Directory
• Ad Index

COLUMNS

• SAMPLE PREP PERSPECTIVES
  Removal and Depletion of High-Abundance Proteins from Biological Fluids
  Nina Zolotarjova, Peter Mrozinski, and Ronald E. Majors
  This installment of “Sample Prep Perspectives” discusses techniques for the reduction–depletion of high-abundance proteins.
  
• LC TROUBLESHOOTING
  How Little Can I See?
  John W. Dolan
  John Dolan considers some techniques to improve detection limits, no matter what the application is.
  
• MS — THE PRACTICAL ART
  The Future of Drug Lead Development and Analysis
  Michael P. Balogh
  This month’s installment of “MS — The Practical Art” reprises a talk from Chris Lipinski that examines the analytical road ahead in drug discovery and the quest to expand the chemistry landscape and its inherent analytical demands.
  
• MILESTONES IN CHROMATOGRAPHY
  The Saga of the Electron-Capture Detector
  Peter J.T. Morris and Leslie S. Ettre
  Leslie Ettre is joined by Peter J.T. Morris as the duo discusses the work of James E. Lovelock, which eventually led to the invention of the electron-capture detector.
  

ARTICLES

• Improvement of GC Sensitivity for Polar and Nonpolar PAHs by Using a Deactivated Liner
  Dietmar Meyer, Hella Dressler, and Wolfgang Ruck
  This article presents the findings from an analysis conducted on sensitivity in GC on the basis of the complex group of polycyclic aromatic hydrocarbons and PAH derivatives.
  
• Application of SEC–MALS in Paint Manufacturing
  Stepan Podzimek and Daniela Vareckova
  The authors explore how the development of improved lightscattering detection, methodology, and data interpretation has allowed detailed characterization of polymers used in the paint industry.
  

DEPARTMENTS

• From the Editor
• Peaks of Interest
• Products
• Literature
• Calendar
• Short Courses
• Classified Directory
• Ad Index

COLUMNS

• SAMPLE PREP PERSPECTIVES
  Advanced Topics in Solid-Phase Extraction: Chemistries
  Ronald E. Majors
  Solid-phase extraction, single-drop microextraction, matrix solid-phase dispersion, and supported liquid-liquid extraction are all covered by Ron Majors in this review article.
  
• LC TROUBLESHOOTING
  Questions from India
  John W. Dolan
  John Dolan reconfirms his belief that LC problems have no regard for company or national boundaries as he discusses some of the LC problems brought up by his Indian colleagues.
  
• GC CONNECTIONS
  Laboratory Gas Safety
  Chuck Hollenbeck and Derek F. Gill
  Laboratory gases have risks that must be understood to use them effectively. This column provides an overview of safety information, especially for the gases used in GC.
  
• VALIDATION VIEWPOINT
  21 CFR Part 11 and Risk Assessment: Adapting Fundamental Methodologies to a Current Rule
  Victoria Lander
  Guest columnist Victoria Lander examines the issues surrounding a new FDA regulation under which the agency will accept information in electronic form.
  

ARTICLES

• The Expanding Role of LC-ICP-MS Speciation Analysis in the Life Sciences: Element-Selective Screening and Species-Independent Quantification
  Zheng Yang and Kenneth Neubauer
  This article discusses the important roles LC-ICP-MS speciation analysis can play in meeting exploratory analytical challenges in the life sciences.
  
• The Possibilities and Limitations of Capillary Extraction (CEx): The Case Study of Polycyclic Aromatic Hydrocarbons (PAHs) in Clean-Water Samples
  Luigi Nardi
  The performance of CEx for the extraction-preconcentration and subsequent GC analysis of PAHs covering a wide range of physiochemical properties is explored.
  

DEPARTMENTS

• Peaks of Interest
• Products
• Literature
• Calendar
• Short Courses
• Classified Directory
• Ad Index