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2015-9. LC Column Problems Everywhere

September 1, 2015

No matter where you live or who you work for, you’re likely to encounter one or more of these liquid chromatography (LC) column problems at some point.

LCGC 33(9) 694-699 (2015)

John W. Dolan

Tags: air, column care, column problems, extra peaks, pH, readers' questions

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  • 2022-5. Dealing with Wandering First-Dimension Peaks in 2D-LC Separations 
  • 2022-4. Essentials of LC Troubleshooting, Part II: Misbehaving Retention Times
  • 2022-3. But Why Doesn’t It Get Better? Kinetic Plots for Liquid Chromatography, Part III: Pulling It All Together
  • 2022-2. But Why Doesn’t It Get Better? Kinetic Plots for Liquid Chromatography, Part II: Making and Interpreting the Plots
  • 2022-1. But Why Doesn’t It Get Better? Kinetic Plots for Liquid Chromatography, Part I: Basic Concepts
  • 2021-12. Essentials of LC Troubleshooting, Part I: Pressure Problems
  • 2021-11. But My Peaks Are Not Gaussian! Part III: Physicochemical Causes of Peak Tailing
  • 2021-10. Retention Factor Is Independent of Pressure in LC, Right?
  • 2021-9. But My Peaks Are Not Gaussian! Part II: Physical Causes of Peak Asymmetry
  • 2021-8. But My Peaks Are Not Gaussian! Part I: Basic Concepts in Peak Shape, and the Effect of Extracolumn Connections
  • 2021-7. Where Has My Efficiency Gone? Impacts of Extracolumn Peak Broadening on Performance, Part IV: Gradient Elution, Flow Splitting, and a Holistic View
  • 2021-6. Where Has My Efficiency Gone? Impacts of Extracolumn Peak Broadening on Performance, Part III: Tubing and Detectors
  • 2021-5. Where Has My Efficiency Gone? Impacts of Extracolumn Peak Broadening on Performance, Part II: Sample Injection
  • 2021-4. Where Has My Efficiency Gone? Impacts of Extracolumn Peak Broadening on Performance, Part I: Basic Concepts
  • 2021-3. Surfing on Mobile Phase, Part II: Impact of Mobile-Phase Composition Waves on Retention in LC
  • 2021-2. Surfing on Mobile Phase, Part I: Origins of Mobile-Phase Composition Waves and Their Effects on Detector Baselines
  • 2021-1. LC Troubleshooting Odds and Ends from 2020
  • 2020-12. Tips for Liquid Chromatography Coupled with Charged Aerosol Detection
  • 2020-11. Troubleshooting for Two-Dimensional Liquid Chromatography: Breakthrough in the Second Dimension
  • 2020-10. Troubleshooting 101: Some Essential Principles of Effective Troubleshooting
  • 2020-9. Rules of Thumb for Reversed-Phase LC: What’s In Your Chromatographic Mind?
  • 2020-8. Troubleshooting LC Separations of Biomolecules, Part II: Passivation and Mobile-Phase Additives
  • 2020-7. Recovering from a COVID-19 Shutdown: Tips and Tricks for Starting Up, Part II
  • 2020-6. Recovering from a COVID-19 Shutdown: Tips and Tricks for Starting Up, Part I
  • 2020-5. Liquid Chromatography at Room Temperature: When Should the Column Temperature Be Specified in a Method?
  • 2020-4. Selectivity in Reversed-Phase Liquid Chromatography: 20 Years of the Hydrophobic Subtraction Model
  • 2020-3. Troubleshooting LC Separations of Biomolecules, Part I: Background, and the Meaning of Inertness
  • 2020-2. Effects of Buffer Capacity in LC, Part II: Visualization of pH Changes Inside the Column
  • 2020-1. Effects of Buffer Capacity in Reversed-Phase Liquid Chromatography, Part I: Relationship Between the Sample- and Mobile-Phase Buffers
  • 2019-12. Effects of Flow Rate on UV Detection in Liquid Chromatography
  • 2019-11. Column Re-equilibration Following Gradient Elution: How Long is Long Enough? Part I: Reversed-phase and HILIC Separations of Small Molecules
  • 2019-10. Minimizing Fluctuating Peptide Retention in 2D-LC: How to Address a Moving Target
  • 2019-9. Mind the Diluent: Effects of Sample Diluent on Analyte Recovery in Reversed-Phase and HILIC Separations
  • 2019-8. Pass the Salt: Evolution of Coupling Ion-Exchange Separations and Mass Spectrometry
  • 2019-7. Mobile Phase Buffers in LC: Effect of Buffer Preparation Method on Retention Repeatability
  • 2019-6. Mixing and Mixers in Liquid Chromatography, Part III: Solutions for Problems with Sample Diluents
  • 2019-5. Methods from Mars? Coping with Chromatographic Legacies
  • 2019-4. Reversed-Phase Liquid Chromatography and Water, Part II: Re-equilibration of the Stationary Phase Following Gradient Elution
  • 2019-3. Looking for New Selectivity in Reversed-Phase Liquid Chromatography? A View of the Selectivity Landscape Over the Past Two Years
  • 2019-2. Reversed-Phase Liquid Chromatography and Water, Part I: How Much is Too Much?
  • 2019-1. What’s Trending in LC Troubleshooting?
  • 2018-12. Letting the Chromatograph Talk, Part I: Looking for Troubleshooting Clues in Unexpected Places
  • 2018-11. Mixing and Mixers in Liquid Chromatography—Why, When, and How Much? Part II, Injections
  • 2018-10. Mixing and Mixers in Liquid Chromatography—Why, When, and How Much? Part I, The Pump
  • 2018-9. Tips, Tricks, and Troubleshooting for Separations of Biomolecules, Part II: Contemporary Separations of Proteins by Size-Exclusion Chromatography
  • 2018-8. Contaminants Everywhere! Tips and Tricks for Reducing Background Signals When Using LC–MS
  • 2018-7. Tips, Tricks, and Troubleshooting for Separations of Biomolecules, Part I: Contemporary Reversed-Phase Protein Separations
  • 2018-6. Peak Purity in Liquid Chromatography, Part III: Using Two-Dimensional Liquid Chromatography
  • 2018-5. Fittings and Connections for Liquid Chromatography—So Many Choices!
  • 2018-4. Peak Purity in Liquid Chromatography, Part II: Potential of Curve Resolution Techniques
  • 2018-3. Eluent Preparation for Hydrophilic Interaction Liquid Chromatography, Part II: pH, Buffers, and Gradient Elution
  • 2018-2. Peak Purity in Liquid Chromatography, Part I: Basic Concepts, Commercial Software, and Limitations
  • 2018-1. Eluent Preparation for Hydrophilic Interaction Liquid Chromatography, Part I: Solvent Volumes and Buffer Counterions
  • 2017-12. Resources for LC Practitioners in 2017: What’s on Your Bookshelf and in Your Web Browser?
  • 2017-11s. The Best of LC Troubleshooting: A Farewell to John Dolan
  • 2017-10a. 34 Years of LC Troubleshooting: An Interview with John Dolan
  • 2017-10. All’s Well That Ends Well
  • 2017-9. How to Take Maximum Advantage of Column-Type Selectivity
  • 2017-8. Method Adjustment for Gradient Elution
  • 2017-7. Column Care for the Long Haul — Considerations for Column Storage
  • 2017-6. Method Adjustment the USP Way
  • 2017-5. Count the Cost, Part III: Increasing Resolution by Changing Selectivity
  • 2017-4. Count the Cost, Part II: Increasing Resolution by Increasing Retention
  • 2017-3. Count the Cost, Part I: Increasing Resolution by Increasing Column Efficiency
  • 2017-2. Filters and Filtration in Liquid Chromatography — What to Do
  • 2017-1. Back to Basics: The Role of pH in Retention and Selectivity
  • 2016-12. Failed System Suitability Test: A Case Study
  • 2016-11. Reader’s Question: Early Eluted Peak
  • 2016-10. Reader’s Questions: Gradient Ghost Peaks
  • 2016-9. How Does It Work? Part V: Fluorescence Detectors
  • 2016-8. How Does It Work? Part IV: Ultraviolet Detectors
  • 2016-7. How Does It Work? Part III: Autosamplers
  • 2016-6. How Does It Work? Part II: Mixing and Degassing
  • 2016-5. How Does It Work? Part I: Pumps
  • 2016-4. Retention Time Drift — A Case Study
  • 2016-3. Column Plate Number and System Suitability
  • 2016-2. Detective Work, Part IV: Chemical Problems with the Column — Chemical Attack
  • 2016-1. Detective Work, Part III: Strong Retention and Chemical Problems with the Column
  • 2015-12. Detective Work, Part II: Physical Problems with the Column
  • 2015-11. Detective Work, Part I: Simplify the Choices
  • 2015-10. How to Reduce Mobile-Phase Consumption
  • 2015-9. LC Column Problems Everywhere
  • 2015-8. Overload in Liquid Chromatography
  • 2015-7. Distorted Peaks — A Case Study
  • 2015-6. Internal Standard Calibration Problems
  • 2015-5. Calibration Problems — A Case Study
  • 2015-4. Be Careful of the Flow Rate
  • 2015-3. Listen to the Data
  • 2015-2. Slow Column Equilibration
  • 2015-1. Seven Things to Avoid in the Liquid Chromatography Laboratory
  • 2014-12. Column Protection: Three Easy Steps
  • 2014-11. How Much Can I Inject? Part II: Injecting in Solvents Other than Mobile Phase
  • 2014-10. How Much Can I Inject? Part I: Injecting in Mobile Phase
  • 2014-9. Estimating Resolution for Marginally Separated Peaks
  • 2014-8. How Much Retention Time Variation is Normal?
  • 2014-7. Mobile-Phase Degassing: What, Why, and How
  • 2014-6. UV Detector Problems
  • 2014-5. Readers’ Questions: Calibration
  • 2014-4. Problems with Large-Molecule Separations
  • 2014-3. LC Method Scaling, Part II: Gradient Separations
  • 2014-2. LC Method Scaling, Part I: Isocratic Separations
  • 2014-1. Column Dead Time as a Diagnostic Tool
  • 2013-12. Peak Fronting . . . Some of the Time
  • 2013-11. What’s the Problem with the LLOQ – A Case Study
  • 2013-10. Past, Present, and Future – 30 Years of LC Troubleshooting
  • 2013-9. Variable Retention Times – A Case Study
  • 2013-8. Gradient Elution, Part VI: Ghost Peaks
  • 2013-7. Gradient Elution, Part V: Baseline Drift Problems
  • 2013-6. Gradient Elution, Part IV: Dwell-Volume Problems
  • 2013-5. Gradient Elution, Part III: Surprises
  • 2013-4. Gradient Elution, Part II: Equivalent Separations
  • 2013-3. Gradient Elution, Part I: Intuition
  • 2013-2. The Importance of the Sample Matrix
  • 2013-1. Making the Most of a Gradient Scouting Run
  • 2012-12. Avoiding Refractive Index Detector Problems
  • 2012-11. Evaluation of an LC Method
  • 2012-10. The Role of the Injection Solvent
  • 2012-9. Reader’s Questions
  • 2012-8. Questions from Afar
  • 2012-7. Troubleshooting Basics, Part IV: Peak Shape Problems
  • 2012-6. When Should an Internal Standard Be Used?
  • 2012-5. Extra Chromatographic Peaks – A Case Study
  • 2012-4. Retention Time Changes
  • 2012-3. Why Does an Improvement Make Things Worse?
  • 2012-2. A Case of Sporadic LC Assay Results
  • 2012-1. LC Trouble Everywhere
  • 2011-12. Troubleshooting Basics, Part III: Retention Problems
  • 2011-11. Locating Precision Problems
  • 2011-10. Column Triage
  • 2011-9. Troubleshooting Basics, Part II: Pressure Problems
  • 2011-8. How Fast Can a Gradient Be Run?
  • 2011-7. Troubleshooting Basics, Part I: Where to Start?
  • 2011-6. The Case of the Too Big Little Peak
  • 2011-5. Ghost Peak Investigation in a Reversed-Phase Gradient LC System
  • 2011-4. Selectivity in Reversed-Phase LC Separations, Part IV: Pressure Selectivity
  • 2011-3. Selectivity in Reversed-Phase LC Separations, Part III: Column-Type Selectivity
  • 2011-2. A Picture is Worth a Thousand Words
  • 2011-1. Selectivity in Reversed-Phase LC Separations, Part II: Solvent-Strength Selectivity
  • 2010-12. Selectivity in Reversed-Phase LC Separations, Part I: Solvent-Type Selectivity
  • 2010-11. UHPLC Tips and Techniques
  • 2010-10. Are the Method Requirements Reasonable?
  • 2010-9. Speeding Up Gradients
  • 2010-8. System Contamination
  • 2010-7. Where Did That Peak Come From?
  • 2010-6. 300 and Counting
  • 2010-5. Too Much Scrutiny
  • 2010-4. Getting the Most Out of Calibration Standards
  • 2010-3. Enhancing Signal-to-Noise
  • 2010-2. Column Diameter, Linear Velocity, and Column Efficiency
  • 2010-1. Too Little or Too Much
  • 2009-12. LC Troubleshooting Strategies
  • 2009-11. Kinetic Plots Made Easy
  • 2009-10. Integration Problems
  • 2009-9. Method or System?
  • 2009-8. Too Many Changes
  • 2009-7. Calibration Curves, Part V: Curve Weighting
  • 2009-6. Calibration Curves, Part IV: Choosing the Appropriate Model
  • 2009-5. Calibration Curves, Part III: A Different View
  • 2009-4. Calibration Curves, Part II: What are the Limits?
  • 2009-3. Calibration Curves, Part I: To b or Not to b?
  • 2009-2. Testing Method Performance
  • 2009-1. Problems from East and West
  • 2008-12. LC Pumps
  • 2008-11. Extracolumn Effects
  • 2008-10. Drip, Drip, Drip…
  • 2008-9. Odds and Ends from the Inbox
  • 2008-8. Column Care
  • 2008-7. Peak Shape Problems
  • 2008-6. Check Valves and Acetonitrile
  • 2008-5. How Do I …?
  • 2008-4. Only Three Things
  • 2008-3. Method Transfer Problems
  • 2008-2. Ion Pairing — Blessing or Curse
  • 2008-1. Flow-Rate Adjustment and System Suitability
  • 2007-12. The Perfect Method, Part VII: The Gradient Shortcut
  • 2007-11. The Perfect Method, Part VI: Make It Faster
  • 2007-10. The Perfect Method, Part V: Changing Column Selectivity
  • 2007-9. The Perfect Method, Part IV: Controlling Peak Spacing
  • 2007-8. The Perfect Method, Part III: Adjusting Retention
  • 2007-7. The Perfect Method, Part II: Where to Start?
  • 2007-6. The Perfect Method, Part I: What is Your Goal?
  • 2007-5. How Does Temperature Affect Selectivity?
  • 2007-4. Variability — How to Control It
  • 2007-3. Solvent Conservation
  • 2007-2. How Little Can I See?
  • 2007-1. Questions From India
  • 2006-12. Method Reproducibility — A Case Study
  • 2006-11. On-Column Sample Degradation
  • 2006-10. Making Connections
  • 2006-9. What’s Happening to My Column?
  • 2006-8. Autosampler Carryover
  • 2006-7. Gradient Performance Problems — A Case Study
  • 2006-6. The Power of Mobile Phase Strength
  • 2006-5. Dwell Volume Revisited
  • 2006-4. It’s Gonna Break
  • 2006-3. Chromatography Forum — Use the Braintrust
  • 2006-2. Check Valve Problems
  • 2006-1. Obtaining More Consistent Results
  • 2005-12. The Role of Signal-to-Noise Ratio in Precision and Accuracy
  • 2005-11. Extending Column Life
  • 2005-10. LC Troubleshooting: The Basics
  • 2005-9. A Baker’s Dozen
  • 2005-8. Broad Peaks
  • 2005-7. Reader Questions: Mobile Phase
  • 2005-6. Peak Fronting, Column Life, and Column Conditioning
  • 2005-5. Overload or Minor Peak?
  • 2005-4. The Bermuda Triangle
  • 2005-3. Split Peaks — A Case Study
  • 2005-2. Extracolumn Effects
  • 2005-1. Stay Away from the Cliffs!
  • 2004-12. Retention Time Changes
  • 2004-11. My Favorite Shortcuts
  • 2004-10. Gradient Performance Checks
  • 2004-9. Grandma’s Ham
  • 2004-7. Divide and Conquer
  • 2004-6. But I Can’t Change the Method
  • 2004-5. System Suitability
  • 2004-4. Parallel Chromatography — Double Your Money
  • 2004-3. Success with Evaporative Light-Scattering Detection, Part II: Tips and Techniques
  • 2004-2. Selecting the Best Curve Fit
  • 2004-1. Broad Peaks
  • 2003-12. Understanding Split Peaks
  • 2003-11. Extracolumn Effects
  • 2003-10. How Much Is Enough?
  • 2003-9. Honoring Readers
  • 2003-7. Why Do Peaks Tail?
  • 2003-6. Now What’s Going On?
  • 2003-5. Not Another Leak!
  • 2003-4. Flow Rate and Peak Spacing
  • 2003-3. LC Columns — The Top-10 List
  • 2003-2. Success with Evaporative Light-Scattering Detection
  • 2003-1. Mobile-Phase Buffers, Part III — Preparation of Buffers
  • 2002-12. Mobile-Phase Buffers, Part II — Buffer Selection and Capacity
  • 2002-11. Mobile-Phase Buffers, Part I — The Interpretation of pH in Partially Aqueous Mobile Phases
  • 2002-10. The Hazards of Adjusting Gradients
  • 2002-9. Performance Qualification of LC Systems
  • 2002-7. Resolving Minor Peaks
  • 2002-6. The Importance of Temperature
  • 2002-5. Peak Tailing and Resolution
  • 2002-4. Stability-Indicating Assays
  • 2002-3. The Future of LC Troubleshooting — 10 Years Later
  • 2002-2. Quiet, Please
  • 2002-1. Ion Suppression in LC-MS/MS — A Case Study
  • 2001-12. From the e-Mail Bag
  • 2001-11. Retaining Polar Compounds
  • 2001-10. Attacking Carryover Problems
  • 2001-9. When Ideal Isn’t Practical
  • 2001-7. Communicating with the Baseline
  • 2001-6. Buffers and Baselines
  • 2001-5. Autosamplers, Part II — Problems and Solutions
  • 2001-4. Autosamplers, Part I — Design Features
  • 2001-3. Reproducibility and Carryover — A Case Study
  • 2001-2. Autosampler Carryover
  • 2001-1. Unexpected Peaks
  • 2000-12. Reducing Column Diameter in Gradient Elution — A Case Study
  • 2000-11. The Problem of Late Elution — A Case Study
  • 2000-10. Scaling Gradient LC Methods to LC-MS
  • 2000-9. Reversed-Phase in 100% Water
  • 2000-7. Stainless Steel Surfaces in LC Systems, Part II — Passivation and Practical Recommendations
  • 2000-6. Stainless Steel Surfaces in LC Systems, Part I — Corrosion and Erosion
  • 2000-5. Starting Out Right, Part VI — The Scouting Gradient Alternative
  • 2000-4. Starting Out Right, Part V — Changing Column Conditions
  • 2000-3. Starting Out right, Part IV — Additional Variables to Control Selectivity
  • 2000-2. Starting Out Right, Part III — The Role of the Solvent in Controlling Selectivity
  • 2000-1. Starting Out Right, Part II — Measuring Satisfaction
  • 1999-12. Starting Out Right, Part I — Selecting the Tools
  • 1999-11. Reader’s Questions: Carryover, Mobile-Phase Temperature, and Column Care
  • 1999-10. Mobile-Phase Degassing — Why, When, and How
  • 1999-9. Poor Peak Shape: A Case Study
  • 1999-7. Priming Injections
  • 1999-6. How Much Is Too Much?
  • 1999-5. LC Troubleshooting On-Line with Chromatography Forum
  • 1999-4. Lessons in Column Washing
  • 1999-3. Late Elution and Carryover Peaks — A Case Study
  • 1999-2. Basic Compounds — Starting on the Right Foot
  • 1999-1.UV Detector Noise
  • 1998-12. Column Temperature Effects in Gradient Elution
  • 1998-11. Gradient Background Peaks — A Case Study
  • 1998-10. Autosampler Precision
  • 1998-9. From the Mail Bag — Dirty Loop, Precolumn Use, In-Line Degassing, and Injector Plumbing
  • 1998-7. Useful or Useless? — Part II
  • 1998-6. Useful or Useless? — Part I
  • 1998-5. Sample Overload — Friend or Foe?
  • 1998-4. Column Packing — What’s at the Bottom of It?
  • 1998-3. Extracolumn Band Broadening from Injection and Peak Transfer
  • 1998-2. Ghost Peaks and Aerated Sample Solvent
  • 1998-1. Scaling Gradients
  • 1997-12. Reproducibility Problems
  • 1997-11. A Valuable Source of Help
  • 1997-10. Baseline Problems — A Case Study
  • 1997-9. Retention Time Problems
  • 1997-7. Method Development, Peak Distortion, and Interfering Peaks
  • 1997-6. Maintaining Autosampler Performance
  • 1997-5. Anticipating Problems with a New Method
  • 1997-4. Air: Poison for Liquid Chromatographs
  • 1997-3. The System Logbook
  • 1997-2. Pump Preventive Maintenance
  • 1997-1. Method Quality, Standardization, and Peak Shape
  • 1996-12. When Good Isn’t Good Enough
  • 1996-11. What is the True Temperature?
  • 1996-10. Solvent Changeover and Column Equilibration
  • 1996-9. Improving an Ion-Pairing Method
  • 1996-7. Injection Loop Adsorption
  • 1996-6. Readers’ Questions about Mobile-Phase Additives
  • 1996-5. Noise Problems: A Case Study
  • 1996-4. Problems with Gradient Methods
  • 1996-3. Water Problems: A Case Study
  • 1996-2. Using a Gradient Scouting Run to Get Started
  • 1996-1. Injection Problems
  • 1995-12. A Second Shot at Some Troubleshooting Problems
  • 1995-11. Solvent Selection, Part III: Solvent Life and Degradation
  • 1995-10. Testing Autosampler Performance
  • 1995-9. Internal Standard Problems, Buffer Precipitation, and Column Storage
  • 1995-7. Pump Seal Problems
  • 1995-6. Mobile-Phase Proportioning Problems and Standard Operating Procedures
  • 1995-5. International Liquid Chromatography Problems
  • 1995-4. Odds and Ends from the Mailbox
  • 1995-3. Solvent Selection, Part II: Physical Properties
  • 1995-2. Problems with Water
  • 1995-1. Reader Questions
  • 1994-12. Case Study — Irreproducible Retention Times
  • 1994-11. Questions about Ion Pairing
  • 1994-10. Solvent Selection, Part I: UV Absorption Characteristics
  • 1994-9. Obtaining Separations, Part IV: Putting It All Together
  • 1994-7. Obtaining Separations, Part III: Adjusting Column Conditions
  • 1994-6. Obtaining Separations, Part II: Adjusting Selectivity
  • 1994-5. Obtaining Separations, Part I: A Look at Retention
  • 1994-4. Fixing Problems on the Cheap
  • 1994-3. The Dilemma
  • 1994-2. Choosing the Right Instrument
  • 1994-1. Extra Peaks
  • 1993-12. Worth Repeating
  • 1993-11. To Change or Not to Change?
  • 1993-10. What’s Wrong with Ethylparaben?
  • 1993-9. Readers Respond
  • 1993-7. Gradient Problems at Low Detection Wavelengths
  • 1993-6. Avoiding the Pitfalls of Published Methods
  • 1993-5. Aggressive Mobile Phases — A Case Study
  • 1993-4. Air Problems
  • 1993-3. Recycling Revisited
  • 1993-2. Amine Adsorption — A Case Study
  • 1993-1. Column Care and Feeding
  • 1992-12. Problem Isolation: Three More Things
  • 1992-11. Preventive Maintenance: Just Three Things
  • 1992-10. Ion-Pairing Problems
  • 1992-9. Buffer Precipitation Problems
  • 1992-7. LC Problem Guide
  • 1992-6. Solvent Recycling
  • 1992-5. Column Heating and Resolution — A Case Study
  • 1992-4. The Case of the Mystery Gradient Peak
  • 1992-3. LC Problems – Past, Present, and Future
  • 1992-2. Pump Shutdown, Sparging Problems, Double Peaks: Answers to Readers’ Questions
  • 1992-1. Extracolumn Effects
  • 1991-12. Sample Preparation, Guard Columns: Answers to Readers’ Questions
  • 1991-11. Retention-Time Problems: Answers to Readers’ Questions
  • 1991-10. NISA A Service Alternative
  • 1991-9. Electrochemical Detector and System Pressure Problems
  • 1991-7. Using Dead Time, Retention, and the Capacity Factor as Diagnostic Tools
  • 1991-6. Changing System Conditions
  • 1991-5. Liquid Chromatography Pump Refinements
  • 1991-4. Pumps: Operation and Maintenance
  • 1991-3. Retention-Time Drift A Case Study
  • 1991-2. Method Reproducibility, Leaks, and Check-Valve Problems
  • 1991-1. Sample Adsorption in Liquid Chromatography Injection Valves
  • 1990-12. Pump Problems
  • 1990-11. Retention-Time Variation: A Case Study
  • 1990-10. Column and Mobile Phase Problems
  • 1990-9. Baseline Noise: A Case Study
  • 1990-7. Ghost Peaks and Column Problems
  • 1990-6. Peak Tracking
  • 1990-5. Column and Detector Problems
  • 1990-4. Problems in Size-Exclusion Chromatography
  • 1990-3. Mobile Phase Buffer Problems
  • 1990-2. Problems with Small-Volume Columns
  • 1990-1. System-to-System Variation
  • 1989-12. Isolating and Correcting LC Problems
  • 1989-11. Preventive Maintenance of Sample-Injection Valves
  • 1989-10. Readers’ Questions
  • 1989-9. Passivation of Liquid Chromatography Components
  • 1989-7. Column Flushing Demystified
  • 1989-6. Peak Tailing
  • 1989-5. Readers’ Questions
  • 1989-4. Peak Problems
  • 1989-3. Troubleshooting Pump Problems
  • 1989-2. Readers’ Questions
  • 1989-1. Mobile Phase Proportioning Problems: A Case Study
  • 1988-12. Method Optimization and Maintenance Using a Resolution Map
  • 1988-11. Recognizing and Eliminating Noise Problems in Liquid Chromatography
  • 1988-10. Troubleshooting LC Fittings, Part II
  • 1988-9. Troubleshooting LC Fittings, Part I
  • 1988-7. Mobile Phase Proportioning Problems
  • 1988-6. Blocked Columns and Tubing
  • 1988-5. Late Peaks and Gradient Reproducibility
  • 1988-4. Rules of Thumb
  • 1988-3. Readers’ Questions
  • 1988-2. Ghost and Vacancy Peaks
  • 1988-1. More on Solvents
  • 1987-12. Shortcuts for LC Measurements
  • 1987-11. Column Stability: A Case Study
  • 1987-10. Mobile Phase Problems
  • 1987-9. Capacity Factor, Plate Number, Extracolumn Effects, and More
  • 1987-7. Readers’ Questions
  • 1987-6. Gradient Elution Separation Problems, Part II
  • 1987-5. Gradient Elution Separation Problems, Part I
  • 1987-4. Potpourri
  • 1987-3. Troubleshooting Autosamplers, Part II
  • 1987-2. Troubleshooting Autosamplers, Part I
  • 1987-1. Maintaining an LC System with Ease
  • 1986-12. Problems Resulting from Normal System Variability
  • 1986-11. Extracolumn Effects: Two Case Studies
  • 1986-10. Readers’ Questions
  • 1986-9. Readers’ Questions
  • 1986-7. LC User Survey: Data-System Problems
  • 1986-6. LC User Survey: Detector Problems
  • 1986-5. LC User Survey: Autosampler Problems
  • 1986-4. Readers’ Questions
  • 1986-3. Separation Artifacts III: Secondary-Retention Effects in Reversed-Phase Chromatography
  • 1986-2. Separation Artifacts II: Extracolumn Effects, Tailing, and Strong Retention Sites
  • 1986-1. Separation Artifacts I: Sample Overload and Injection-Solvent Problems
  • 1985-12. Sample Injection Valves
  • 1985.11 Equipment Usage
  • 1985-10. Troubleshooting
  • 1985-9. Troubleshooting
  • 1985-7. Troubleshooting
  • 1985-6. Troubleshooting
  • 1985-5. Common Column Problems
  • 1985-4. Troubleshooting
  • 1985-3. Troubleshooting
  • 1985-2. Connecting Tubing
  • 1985-1. Peak Shape
  • 1984-11. Autosamplers
  • 1984-10. Chromatographic Theory as a Problem-Isolation Aid: Part II
  • 1984-9. Chromatographic Theory as a Problem-Isolation Aid: Part I
  • 1984-8. Mobile Phase Preparation
  • 1984-7. Service Contracts
  • 1984-6. Optical Detectors Part III: Variable-Wavelength UV Detectors
  • 1984-5. Optical Detectors Part II: Fixed-Wavelength UV Detectors
  • 1984-4. Optical Detectors, Part I: General Principles
  • 1984-3. Piston-Diaphragm Pumps
  • 1984.2 Reciprocating Piston Pumps
  • 1984-1. Chromatographic Fittings: Proper Use to Minimize Dead Volume
  • 1983-8. Problem Isolation: Shortening Troubleshooting Time
  • 1984-7. Recordkeeping: Plan Ahead to Minimize Downtime
  • 1983-3. Troubleshooting: HPLC Sample Preparation and Introduction
  • 1983-2. Troubleshooting the Mobile Phase of Your HPLC System
  • 1983-1. An HPLC Troubleshooting Guide