Peptide HPLC Testing: RP-HPLC Purity Analysis
ShiLai™ Healthcare performs reversed-phase HPLC (RP-HPLC) purity testing on every peptide batch manufactured. HPLC is the industry-standard analytical method for measuring peptide purity and is a mandatory component of the Certificate of Analysis (COA) issued with every shipment.
What Is RP-HPLC for Peptides?
Reversed-phase high-performance liquid chromatography (RP-HPLC) is a chromatographic separation technique that resolves a peptide from synthesis-related impurities, truncated sequences, oxidation products, and other related substances. The sample is injected onto a non-polar stationary phase column and eluted using a gradient of aqueous and organic solvents (typically water and acetonitrile with a trifluoroacetic acid modifier).
Each compound in the mixture elutes at a characteristic retention time and is detected by UV absorbance (typically at 214 nm, which detects the peptide bond). The purity of the target peptide is calculated as the percentage of its peak area relative to the total integrated area of all detected peaks.
What Does Peptide HPLC Purity Mean?
Peptide HPLC purity is expressed as a percentage — for example, 98.5% purity means that 98.5% of the UV-detectable material in the sample is the target peptide, with the remaining 1.5% comprising impurities. A higher purity percentage indicates a cleaner, more consistent batch.
Target peptide peak
The main peak corresponding to the correctly synthesised, full-length peptide at its characteristic retention time.
Related impurities
Truncated sequences, deletion peptides, oxidised forms, and other synthesis by-products that elute at different retention times.
Purity calculation
Target peak area ÷ total peak area × 100. Reported as a percentage on the COA chromatogram.
HPLC vs. LC-MS: Complementary Methods
RP-HPLC and LC-MS answer different analytical questions and are not interchangeable. ShiLai™ Healthcare performs both on every batch because each provides information the other cannot:
| Method | Question answered | What it detects |
|---|---|---|
| RP-HPLC | How pure is the batch? | Separates and quantifies all UV-detectable compounds; reports target peptide as % of total |
| LC-MS | Is it the correct peptide? | Measures molecular mass of the compound; confirms identity by matching theoretical mass |
| COA | What is the complete batch record? | Consolidates HPLC purity, LC-MS identity, batch number, date, and all other test results |
A batch with high HPLC purity but no LC-MS confirmation could theoretically be a highly pure but incorrect compound. A batch with LC-MS identity confirmation but no HPLC purity data could be the correct peptide but heavily contaminated. Both tests together provide complete analytical assurance.
HPLC Testing Across ShiLai™ Healthcare Peptides
RP-HPLC purity testing is applied to every peptide in the ShiLai™ Healthcare manufacturing range without exception. This includes:
- ›Retatrutide (GLP-1/GIP/Glucagon triple agonist)
- ›Eloralintide (LEAP2 analogue)
- ›NAD⁺ high-dose formulations
- ›GHK-Cu peptide (KLOW skin and hair repair)
- ›Custom OEM peptides manufactured for B2B partners
HPLC purity testing is not an optional add-on or premium service at ShiLai™ Healthcare — it is a standard requirement applied to every manufactured batch regardless of order size or product type.
How to Read a Peptide HPLC Result
When reviewing the HPLC section of a ShiLai™ Healthcare COA, the key data points to examine are:
Purity (%)
The percentage of the total UV-detectable area attributed to the target peptide peak. Higher is better; research-grade peptides typically report ≥95% or ≥98% depending on the application.
Retention time (RT)
The time at which the target peptide elutes from the column under the gradient conditions used. Consistent retention time across batches indicates reproducible synthesis.
Chromatogram
The graphical output showing all detected peaks. The main peak should be clearly dominant. Significant secondary peaks indicate impurities that may require investigation.
Column and gradient conditions
The stationary phase, mobile phase composition, and gradient programme used. These are reported on the COA so results can be independently reproduced or verified.
Frequently Asked Questions
Is HPLC testing performed on every batch, or only on request?
RP-HPLC purity testing is performed on every batch manufactured by ShiLai™ Healthcare as a standard quality requirement. It is not an optional or premium service.
Is the HPLC chromatogram included in the COA?
Yes. The RP-HPLC chromatogram showing the peak profile and calculated purity percentage is included in the Certificate of Analysis for every batch.
What HPLC purity level does ShiLai™ Healthcare achieve?
Contact us via WhatsApp or email to request current batch COA data. We report actual measured purity values rather than making general claims, as results vary by batch and product.
Can I request additional HPLC testing beyond the standard COA?
Yes. Additional analytical testing including endotoxin (LAL), Karl Fischer water content, residual solvent analysis, and sterility testing are available on request. Contact us to discuss your specific requirements.
Does HPLC purity confirm that a peptide is Retatrutide specifically?
No. HPLC purity confirms how pure the sample is, but does not confirm the identity of the compound. Identity confirmation requires LC-MS. ShiLai™ Healthcare performs both HPLC and LC-MS on every batch.
Request HPLC Data for a Specific Peptide
Contact ShiLai™ Healthcare via WhatsApp to request sample COA documentation, discuss analytical testing requirements, or enquire about a specific batch.
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