Advanced Systems, Inc.

Chromatography Integration and Trouble-shooting

Presented by: Marlene Moore mmoore@advancedsys.com

October 2007

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Agenda Problems Tools Solutions

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Problems Baseline Disturbances Irregular Peak Shapes, Sizes Retention Time Shifts Loss of Separation or Resolution Quantitation Difficulties Rapid Column Deterioration Ghost Peaks Broad Solvent Front

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Baseline Disturbances

spiking noise wander

drift offset

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Spiking Particulate Matter Passing Through

Detector Loose Connections

Cables Circuit boards

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Noise Contaminated Injector/column Physical Defect Detector Defective Detector Board Carrier Gas Leak at Septum or Column FID, NPD, FPD

Column in Flame Incorrect Combustion Gases or Flow Rate/leak

ECD, TCD Air Leak

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Wander Contaminated Carrier Gas

Isothermal Conditions Contaminated Gas Chromatograph Poor Control of Carrier Gas or

Detector Gas Flows Poor Thermal Control of Detector

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Drift Septum Bleed Upward

GC or column contamination Damaged stationary phase

Downward Incomplete conditioning of column Unequilibrated detector

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Offset Contamination:

Injector, column, detector Carrier gas - change/install impurity

traps Column Inserted Into Flame (FID,

NPD, FPD) Malfunctioning or Improperly Set

Recording Device

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QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

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QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Peak Shape

Peak Shape tells the story of your chromatography

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Irregular Peak Shapes

tailing fronting split

rounded negativereduced

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No Peaks Plugged Syringe Broken Column Injecting Sample Into Wrong Injector Column Installed in Wrong Detector Integrator Reading Wrong Signal or Not Connected Detector Not on Temperature

Oven not heated Column temperature too low Injection port temperature too low

Detector Gases Improperly Set or Not on Very Low or No Carrier Gas Flow

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Reduced Peaks Plugged Syringe Change in Injection Technique Large Leak - Injector Split Ratio Too High Too Short of Purge Activation Time for

Splitless Injections Very High Septum Purge Flow Too Low Injector Temperature Column Temperature Too Low Sample Components Absorbed by

Column or Inlet Liner

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Reduced Peaks Initial Temperature Column Too High for

Splitless or On-column Injections High Background Signal -

Contamination Excessive column bleed Check auto zero function and setting

Improperly Operated Detectors Impurities Carrier Gas or Detector Gas Detector Compound Mismatch Excessive Attenuated Integrator Signal Sample Concentration or Integrity Problems

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Tailing Peaks Active Injector Liner or Column Contaminated

Injector liner Column

Dead Volume Caused by Poorly Installed Liner, Column or Union

Poorly Cut Column End Polarity Mismatch - Stationary Phase,

Solute or Solvent Cold Spot in the Flow Path

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Tailing Peaks Solid Debris in Liner or Column Poor Injection Technique - Too Slow Too Low of a Split Ratio Overloading on a PLOT Column

Decrease sample amount Amines and carboxylic acids tail on most

columns Need ph modified stationary phase

Some Peaks Always Exhibit Tailing

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Rounded or Flat Topped Peaks Overloaded Detector Exceeding Range of Integrator

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Split Peaks Detector Overloaded Poor Injection Technique Poorly Installed Column Into Injector Column Temperature Fluctuations Coelution of Two or More Compounds Mixed Sample Solvent for Splitless or

On-column Injections.

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Negative Peaks All Peaks Negative - Polarity Check

Connectors TCD - Select Peaks

Thermal conductivity of compound greater than carrier gas

ECD - After Positive Peak Dirty or old ECD cell

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Retention Time Shifts Different Column Temperature Different Carrier Gas Flow or Linear

Velocity Leak in Injector - Septum Contaminated Column Change in Sample Solvent

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Loss of Separation/Resolution Contaminated Column Damaged Stationary Phase Different Column Temperature,

Carrier Flow Rate, Column Large Changes in Sample

Concentrations Improper Injector Operation

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Quantitation Difficulties Injection Techniques Split Discrimination Different Purge Activation Time for

Splitless Injection Baseline Disturbances Improper Integrator Settings Inconsistent Detector Gas Flows or

Temperatures Column or Liner Activity

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Rapid Column Deterioration Exposure of Column to Air at

Elevated Temperatures Exceeding Upper Temperature

Limit of Column Chemical Damage Contamination of Column With

High Molecular Weight Materials Column Breakage

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Ghost Peaks Contamination

Injector Column

Septum Bleed Dirty Syringe Sample Too Large Previous Run Terminated Too Soon

BOO!

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Broad Solvent Front Poorly Installed Column Leak in the Injector Solvent Interacting with Detector Too Low

Split Ratio (Flow) Injector Temperature

Too Long Purge Activation for Splitless Injections Large Injection Volume Low Column Temperature and High Boiling Solvent High Column Temperature and Low Boiling Solvent

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QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

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Tools Flowmeter Syringe (NEW) Methane or Nonretained Compound Septa, Ferrules, Injection Liners (NEW) Leak Detector Column Test Mixture (Reference) Checkout Column Instrument Manuals

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NO!

WRONG ANSWER!!!

SolutionsQuickest Solution ----

Improve Chromatography ---

Do Manual Integration ---

Get Results out Fast !!

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Solutions Preventive Maintenance

Clean detector Clean injector Clean and repair parts Clean and tighten connections Follow instrument manual suggestions

Allow Time for Optimizing System Integration parameters Programs

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Does anyone have a question?

Question !Where do you document your

trouble shooting?