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Chromatography Integration and Trouble-shooting

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Presentation on theme: "Chromatography Integration and Trouble-shooting"— Presentation transcript:

1 Chromatography Integration and Trouble-shooting
Presented by: Marlene Moore October 2007 Advanced Systems, Inc.

2 Agenda Problems Tools Solutions Advanced Systems, Inc.

3 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 Advanced Systems, Inc.

4 Baseline Disturbances
spiking noise wander drift offset Advanced Systems, Inc.

5 Spiking Particulate Matter Passing Through Detector Loose Connections
Cables Circuit boards Advanced Systems, Inc.

6 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 Advanced Systems, Inc.

7 Wander Contaminated Carrier Gas Contaminated Gas Chromatograph
Isothermal Conditions Contaminated Gas Chromatograph Poor Control of Carrier Gas or Detector Gas Flows Poor Thermal Control of Detector Advanced Systems, Inc.

8 Drift Septum Bleed Upward Downward GC or column contamination
Damaged stationary phase Downward Incomplete conditioning of column Unequilibrated detector Advanced Systems, Inc.

9 Offset Contamination: Column Inserted Into Flame (FID, NPD, FPD)
Injector, column, detector Carrier gas - change/install impurity traps Column Inserted Into Flame (FID, NPD, FPD) Malfunctioning or Improperly Set Recording Device Advanced Systems, Inc.

10 Advanced Systems, Inc.

11 Peak Shape Peak Shape tells the story of your chromatography
Advanced Systems, Inc.

12 Irregular Peak Shapes tailing fronting split reduced rounded negative
Advanced Systems, Inc.

13 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 Advanced Systems, Inc.

14 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 Advanced Systems, Inc.

15 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 Advanced Systems, Inc.

16 Tailing Peaks Active Injector Liner or Column Contaminated
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 Advanced Systems, Inc.

17 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 Advanced Systems, Inc.

18 Rounded or Flat Topped Peaks
Overloaded Detector Exceeding Range of Integrator Advanced Systems, Inc.

19 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. Advanced Systems, Inc.

20 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 Advanced Systems, Inc.

21 Retention Time Shifts Different Column Temperature
Different Carrier Gas Flow or Linear Velocity Leak in Injector - Septum Contaminated Column Change in Sample Solvent Advanced Systems, Inc.

22 Loss of Separation/Resolution
Contaminated Column Damaged Stationary Phase Different Column Temperature, Carrier Flow Rate, Column Large Changes in Sample Concentrations Improper Injector Operation Advanced Systems, Inc.

23 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 Advanced Systems, Inc.

24 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 Advanced Systems, Inc.

25 Ghost Peaks Contamination Septum Bleed Dirty Syringe Sample Too Large
Injector Column Septum Bleed Dirty Syringe Sample Too Large Previous Run Terminated Too Soon BOO! Advanced Systems, Inc.

26 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 Advanced Systems, Inc.

27 Advanced Systems, Inc.

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

29 Solutions Quickest Solution ---- Improve Chromatography ---
Do Manual Integration --- Get Results out Fast !! NO! WRONG ANSWER!!! Advanced Systems, Inc.

30 Solutions Preventive Maintenance Allow Time for Optimizing System
Clean detector Clean injector Clean and repair parts Clean and tighten connections Follow instrument manual suggestions Allow Time for Optimizing System Integration parameters Programs Advanced Systems, Inc.

31 Does anyone have a question?
Where do you document your trouble shooting? Advanced Systems, Inc.

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