> For the complete documentation index, see [llms.txt](https://docs.rplpeptides.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rplpeptides.com/docs/glossary/documentation-terms/certificate-of-analysis.md).

# Certificate of Analysis

## Definition

A Certificate of Analysis (COA) is an official batch-specific document that reports quality testing results for a peptide product, confirming that it meets established specifications.

## Overview

The COA is the definitive quality document for a specific batch of peptides. Unlike the TDS (which describes general specifications), the COA provides actual test results for that particular batch, along with HPLC chromatograms and mass spectra.

## Technical Explanation

**Standard COA Sections:**

| Section            | Content                                        |
| ------------------ | ---------------------------------------------- |
| Header             | Company name, document title, document ID      |
| Product Info       | Product name, catalog #, batch/lot #, quantity |
| Testing Summary    | Parameter, specification, result, method       |
| Analytical Data    | HPLC chromatogram, mass spectrum               |
| Certifying Section | Authorized signature, date, stamp              |

**Common Tests on a Peptide COA:**

* Appearance (visual inspection)
* Identity (mass spectrometry)
* Purity (HPLC area %)
* Assay (peptide content %)
* Water content (KF or LOD)
* Counter-ion content (HPLC or IC)
* Endotoxin (LAL test) — if applicable

## Importance in Peptide Documentation

The COA is the document that substantiates product quality claims. Researchers should always request and review the batch-specific COA before using peptide products.

## Related Terms

* [Technical Data Sheet](/docs/glossary/documentation-terms/technical-data-sheet.md)
* [Specification](/docs/glossary/quality-control/specification.md)
* [Batch Number](/docs/glossary/quality-control/batch-number.md)

## Frequently Asked Questions

**Q: Should I request the COA before or after purchasing?** A: Reputable suppliers provide COAs with every shipment. For evaluation purposes, representative COAs are typically available upon request before purchase.

**Q: Can a COA be falsified?** A: Unfortunately, yes. Always verify COA authenticity by checking batch numbers, document formatting, and supplier credentials. Requesting LC-MS data makes falsification more difficult.


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