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A blog on the latest applications, articles, & research on chromatography solutions in sample preparation, Ion Chromatography (IC),
High Pressure Liquid Chromatography (HPLC), Ion Chromatography-Mass Spectrometry (IC-MS), Gas Chromatography (GC),
Gas Chromatography-Mass Spectrometry (GC-MS and GC-MS/MS), and software (Chromeleon CDS, LIMS, and ProteinCenter).

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Liquid Chromatography: Troubleshooting WallChart!

  
  
  
  
  
  

LC Troubleshooting WallChart Icon 200 200What do you do when you run into liquid chromatography (LC) problems? Refer to this complimentary poster for troubleshooting! Supplies are limited so get your wallchart today by clicking the image on the right and filling out a brief form so that the wallchart can be mailed to you.

Here is a brief list of the troubleshooting areas covered in this wallchart. (For solutions, you will need the wallchart!)

Sensitivity Problems

Several possible causes of lack of sensitivity are described including problems with the detector attenuation, the injector sample loop, detector linear ranges, sample losses during sample preparation or on the column, UV detector wavelengths, and the column internal diameter.

Poor Sample Recovery

This could be caused by absorption or adsorption of proteins; hydrophobic interactions between stationary phase and biomolecules; adsorption on column packing, tubing and other hardware components; chemisorptions (link to Wikipedia page) on the column packing; or, less than 90% yield for acidic or basic compounds.

Baseline Problems

These could be caused by disturbance at void time, a drifting baseline, or noise from a variety of sources, such as lack of solvent mixing, malfunctioning proportioning valves, external electrical interference, contamination, or by air bubbles.

Leaks

Four types of leaks are listed: catastrophic and non-catastrophic leaks at the column or fittings, catastrophic leaks at the detector, catastrophic leaks at injection valve, and catastrophic leaks at the pump seal.

Retention

Four retention areas are covered: changing retention times, decreasing retention times, increasing retention times, and retention beyond total permeation volume for size exclusion chromatography.

Pressure

The pressure section covers possible causes and fixes for decreasing (or lower-than-expected) or increasing pressure, fluctuating, and high back pressure.

Peaks

This section –the longest section--lists possible causes and fixes for no or broad peaks, ghost peaks, negative peaks, peak doubling or splitting, peak fronting and tailing, and peak spikes.

Let us know if this wallchart is helpful in your work in the Comments box below. Also, let us know troubleshooting areas not covered in the wallchart. Our experts will be pleased to answer your questions.

Comments

Good idea!!!
Posted @ Friday, August 31, 2012 12:28 AM by Merey
A good instrument for removing ghost peaks in gradient HPLC is the use of a trap column like the Ghost-Guard-LC: 
The Ghost-Guard-LC increases reliability of gradient trace impurity analysis by eliminating Ghost Peaks caused by mobile Phase or hardware components. 
In gradient elution analysis using a HPLC system, impurities from the mobile phase solvents, mobile phase containers, flow lines, pump, gradient mixer etc., can cause peaks to appear in chromatograms. If such ghost peaks appear, it can be difficult to distinguish them from peaks corresponding to trace sample components, reducing analysis reliability. 
Furthermore, identifying the source of ghost peaks can be extremely time-consuming, and has been a source of frustration for chromatographers, particularly in trace analysis work. The Ghost-Guard-LC column enabled efficient removal of impurities from mobile phase solvents and other sources by adsorption to easily avoid the effects of ghost peaks in analysis.  
Ghost-Guard-LC columns can be used to efficiently adsorb impurities in both aqueous and organic solvents. Using the Ghost-Guard-LC in reverse-phase gradient elution, which is widely used in liquid chromatography, allows adsorbing and removing all components that cause ghost peaks from mobile phases and their flow lines. This can significantly increase the analytical accuracy of trace analysis. Previously, if ghost peaking interfered with analysis, it was necessary to identify the causes and implement countermeasures, which was extremely time-consuming. In contrast, using the Ghost-Guard-LC easily removes the causes without any need to investigate their source.  
http://ghost-guard.iip.de/?page_id=40 
Posted @ Thursday, January 30, 2014 6:30 AM by Dr. M. Statz
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