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Peptide Residual Solvent Testing

What Residual solvents testing checks

Leftover solvents from synthesis can be toxic if they weren’t fully purged.

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This test is currently unavailable for online ordering.

Peptide synthesis and purification use organic solvents — acetonitrile, methanol, and others. Residual-solvent testing measures how much of them is left in the finished product, using headspace gas chromatography (GC), the standard method for volatile-solvent analysis.

When available, it can be ordered as a Custom add-on, on top of required Basic analysis and any product surcharge. Extra tests other than endotoxins require Custom rather than Standard.

Why it matters for peptides

Solvents are supposed to be driven off during drying and purification. When that step is rushed or incomplete, toxic solvent can remain in the vial. Because these solvents are volatile and present in small amounts, HPLC won’t flag them — a dedicated GC method is what catches them.

It’s the test that tells you whether the manufacturing process was actually finished, not just started.

Peptides we test the most

Residual solvents testing availability depends on the compound and selected lab. These are the peptides Finnrick has published the most results for:

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Run at our partner labs

Other tests you can run

How Finnrick publishes results

Finnrick publishes results when we can establish sample provenance and have enough evidence that the sample represents the product sold by the named vendor. Published results include vendor and product details, helping customers evaluate the available evidence and encouraging better supply-chain decisions.

Results that do not meet these requirements are shared with the requester and kept outside the public record. Read how Finnrick decides which results to publish →

Don’t want to share sample details?

The Confidential option is currently unavailable as a Custom add-on. Standard already includes Confidential. Results are shared with you and not published publicly.

Frequently asked questions

What are residual solvents?

Organic solvents used during peptide synthesis and purification (such as acetonitrile or methanol) that can remain in the finished product if they aren’t fully purged.

Why can’t the standard HPLC test catch them?

Residual solvents are volatile and present at low levels, so they call for a dedicated gas-chromatography method (headspace GC) rather than the HPLC used for identity, purity, and quantity.

Is residual-solvent testing an add-on?

Yes. It is layered on top of the identity, purity, and quantity analysis every sample receives.

Review available testing options →

This test is currently unavailable for online ordering.

Do you distribute peptides?

Finnrick offers professional testing services for vendors who want to verify their supply chain and build trust with customers through independent quality assurance.

Learn about vendor services