2021-12. Essentials of LC Troubleshooting, Part I: Pressure Problems | LCTSBIBLE.COM

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2021-12. Essentials of LC Troubleshooting, Part I: Pressure Problems

December 1, 2021

Deviations from the expected pressure in modern LC systems (too low, too high, or fluctuating) can be diagnosed and more quickly resolved using the streamlined troubleshooting practices shown here.

LCGC 39(12), 572–574,585 (2021).

Dwight R. Stoll

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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