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Sample Preparation Tip

Level: Advanced

SPE Troubleshooting - Extra Peak

Welcome to our new SPE technical tip!

What is the cause when you encounter interferences post-extraction regardless of the analytical or detection method? Possible sources of the mystery peak(s) are listed in the table below.

Possible Cause/Source Suggested Remedy
Contaminated reagents Analyze the purity of reagents and additives or try using these from a different supplier.
Sample pre-treatment Compare chromatograms of pre-treated and non-pre-treated sample.
Mismatched injection solvent Analytes that are dissolved in a strong injection solvent may retain poorly and thus appear as extra peaks. Using the initial mobile phase as the injection solvent is recommended.
Incorrect SPE method The SPE sorbent might not have been properly conditioned and equilibrated. Typically, the strongest solvent used in the method should be used to condition the sorbent. Analyze the conditioning, loading and washing fractions to check if the same interferences appear.
SPE tube leaching Before conditioning, clean the tube with elution solvent. If reagents or the nature of the sample are too harsh for the polypropylene SPE tube, a glass tube or PTFE tube could be used instead.
Degradation/side reaction Check the reactivity and stability of all components in your sample. Degradation can happen if compounds are sensitive to factors such as heat, light, acids, bases, etc. Sample components may be reacting with each other or with reagents/additives.

We hope this tip was useful. See you soon for another tip!


SPE Method Optimization Poster

Learn how polymeric SPE selectivities can help improve your sample clean up with this polymeric SPE method development poster.

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Vial Finder Tool

Easily find the right vial or vial kit for your sample collection needs. Whether you are looking for an amber vial, crimp-top vial, autosampler vial, or headspace vial, use our online vial finder tool to make your selection.

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