> 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/retatrutide/analytical-methods/retatrutide-analytical-methods.md).

# retatrutide-analytical-methods

RPL Peptide

Official Technical Documentation

Analytical Methods

***

## Analytical Methods — Retatrutide

### Method Overview

| Method           | Purpose               | Specification |
| ---------------- | --------------------- | :-----------: |
| **HPLC**         | Purity Analysis       |     ≥99.0%    |
| **LC-MS**        | Identity Confirmation |    ±0.5 Da    |
| **Karl Fischer** | Water Content         |     <5.0%     |
| **LAL Test**     | Endotoxin             |    <5 EU/mg   |

### 1. HPLC Method

| Parameter        | Specification           |
| ---------------- | ----------------------- |
| **Column**       | C18, 4.6 × 250 mm, 5 μm |
| **Detection**    | UV at 214 nm            |
| **Mobile Phase** | 0.1% TFA in H₂O / ACN   |
| **Gradient**     | 20–60% B, 30 min        |
| **Flow Rate**    | 1.0 mL/min              |

### 2. LC-MS Method

| Parameter         | Specification      |
| ----------------- | ------------------ |
| **Ionization**    | ESI, Positive Mode |
| **Mass Accuracy** | ±0.5 Da            |
| **Scan Range**    | m/z 500–2500       |

### 3. Karl Fischer (KF)

* Coulometric titration
* Acceptance: <5.0%

### 4. LAL Endotoxin

* Kinetic Turbidimetric
* Acceptance: <5 EU/mg

### Document Control

| Version |    Date   | Author              |
| :-----: | :-------: | ------------------- |
|   1.0   | July 2026 | RPL Peptide Quality |

***

© 2026 RPL Peptide

Official Technical Documentation

rplpeptides.com


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