What is the most important value on a black seed oil COA?

For most buyers the thymoquinone (TQ) value, measured by GC-FID, is the headline metric, alongside the fatty-acid profile. Peroxide value and acidity indicate freshness, and microbiology confirms basic safety parameters.

How is thymoquinone measured?

Thymoquinone is measured by GC-FID (gas chromatography with flame-ionisation detection). A reputable COA states the method, the TQ result as a percentage, the batch/lot number and the sample date.

What do peroxide and acidity values tell a buyer?

Peroxide value and free fatty acid / acidity are freshness and oxidation indicators. Lower values generally indicate a fresher, well-handled oil; buyers should compare against their own specification.

Is a COA provided for every batch?

BlackSeedSource provides a batch COA for applicable lots. Buyers can request the current COA and, where available, the GC chromatogram before ordering.

How to Read a Black Seed Oil COA

A practical guide for B2B buyers: what each field on a black seed oil Certificate of Analysis means, and what to check before you order.

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What a COA tells you

A Certificate of Analysis (COA) is the batch-level record that lets a buyer verify what they are actually purchasing. For black seed oil, the fields that matter most are:

COA field	What it means
Thymoquinone (TQ) — GC-FID	Headline quality metric, expressed as %. Confirm the method is GC-FID and note the batch/lot.
Fatty-acid profile	Linoleic, oleic, palmitic and related fractions — confirms the oil is genuine Nigella sativa.
Peroxide value	Oxidation / freshness indicator; lower generally indicates fresher, well-handled oil.
Free fatty acids / acidity	Another freshness and pressing-quality indicator.
Microbiology	Basic safety parameters where included on the panel.
Batch / lot & date	Ties the results to the specific shipment you receive.

What buyers should check

The COA batch/lot number matches the shipment you are quoted or receiving.
The TQ value is measured by GC-FID and stated as a percentage.
The fatty-acid profile is present and consistent with Nigella sativa.
Freshness indicators (peroxide, acidity) fit your specification.
Where available, request the GC chromatogram so your own lab can verify the TQ peak.

This guide is for commercial sourcing decisions only. It does not describe any health, medical or nutritional outcome.

See real examples on our COA & lab testing page, learn more about TQ grades, or request the current batch COA.