Liquid Chromatography: Troubleshooting WallChart!
What 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!)
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.
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.
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.
Four retention areas are covered: changing retention times, decreasing retention times, increasing retention times, and retention beyond total permeation volume for size exclusion chromatography.
The pressure section covers possible causes and fixes for decreasing (or lower-than-expected) or increasing pressure, fluctuating, and high back pressure.
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.