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Method Troubleshooting
This help file is designed to assist you in isolating the cause of changes in performance of an HPLC separation. The initial assumption is that you have either a validated method or a method which has worked in the past, and that you have a specification for "system suitability" (i.e., you know how the method should behave).

To proceed, click on the link below that best describes your problem.

1. Selectivity and/or retention time changes
The retention time of one or more of your peaks is out of specification. 

2. Tailing peaks
The retention times of all your peaks are within specification, but the peak symmetry (asymmetry factor or tailing factor) of one or more of your peaks is out of specification. 

3. Abnormally wide peaks (abnormally low plate count)
The retention times and symmetries of all your peaks are within specification, but the width or plate count of one or more of your peaks is out of specification.

4. Peaks with shoulders
The retention times of all your peaks are within specification, but one or more of your peak shapes is abnormal in the form of a "shoulder."

5. Split peaks
One or more of your peaks is doubled or "split".

6. Flat-top peaks
The retention times of all your peaks are within specification, but one or more of your peak shapes is abnormal in the form of a "mesa" or "flat-topped" peak.

7. Missing peaks
One or more peaks that should be in your chromatogram is missing.

8. Extra peaks
Your chromatogram contains one or more peaks that should not be present.

9. Excessive pressure
Your operating pressure exceeds specifications

10. Noisy or drifting baseline
Your baseline drift and/or noise exceed specifications, but your retention times and peak shapes are within specification

11. Poor peak size repeatability
The repeatability (CV or %RSD) of peak areas for replicate injections does not meet specifications.

12. Poor resolution. The resolution between two critical peaks does not meet specification.

Definitions of key terms.
Diagnostic procedures.
References and further reading.

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