Keep the assay method beside every percentage. The UV ≥90% reference is not an HPLC90 offer; a dual UV ≥90% / HPLC ≥30% request needs two separately stated requirements and matching records.
View the product reference scope ↗Read the two reference specifications literally
The source identity in the published references is Cyanotis arachnoidea root extract. The UV-only reference and the separate dual-method reference are not the same purchasing requirement. Write the UV and HPLC limits on separate lines, with each reporting basis stated.
| Published reference | UV requirement | HPLC requirement | Purchasing consequence |
|---|---|---|---|
| UV reference | ≥90% | Not specified by this reference | Do not describe it as HPLC ≥90% |
| Separate dual-method reference | ≥90% | ≥30%, reported separately | Ask for both results and their applicable procedures |
For a dual-method requirement, ask the source to report both applicable results for the proposed lot. Meeting one stated method limit does not establish that the other method was performed or its limit met.
Compare the actual procedures on record
The HPLC procedure specifies C18 (4.6 × 250 mm, 5 μm), methanol–water (43:57, v/v), flow 1 mL/min, detection at 250 nm, 30°C, 10 μL injection and external-standard calculation. The separate UV procedure measures absorbance in ethanol at 242 ±2 nm. These are different measurement procedures: a UV percentage must not be presented as an HPLC result. Request the full method and confirm reference-standard identity and reporting basis.
Request the controlled revision used for the offered grade, the named reference substance and its traceability, sample preparation and calculation basis. The conditions above describe separate supplier procedures; this guide does not independently validate them for every material or lot.
Do not convert UV percentages into HPLC percentages
The two procedures produce method-specific results. The available records do not establish a universal conversion between UV and HPLC percentages. Do not rename a UV ≥90% reference as HPLC ≥90%, add the two percentages, or present them as two independent ingredient fractions.
When a supplier sends a chromatogram, ask which sample, grade and lot it represents and which calculation supports the reported assay. A peak image or an unqualified “90%” label does not answer those questions.
Review the rest of the material on the same basis
The existing product page provides these physical and chemical reference limits. They remain supplier-document references and require confirmation against the proposed material and current-lot records.
| Parameter | UV ≥90% reference | Dual UV ≥90% / HPLC ≥30% reference | Recorded method |
|---|---|---|---|
| Appearance | Brown-yellow powder | Brown powder | Visual |
| Moisture | ≤5.0% | ≤5.00% | CP2015; 105°C, 4 h |
| Ash | ≤5.0% | ≤5.0% | CP2015 |
| Particle size | 95% through 80 mesh | 95% through 80 mesh | CP2015 |
| Total heavy metals | <10 ppm | <10 ppm | CP2015 |
Ask for the full composition, process information, applicable residual-solvent requirements and other relevant contaminant or microbiological records. A matching assay does not establish that unspecified requirements were evaluated.
Worked example: a method mismatch in a quotation
Illustrative purchasing example, not an actual quotation: your brief requires UV ≥90% and HPLC ≥30%, reported separately. One proposal provides only a UV90 reference and a generic assurance that the material is “high purity”. Another names both limits but supplies an unlabeled chromatogram.
The first proposal leaves the HPLC requirement unanswered. For the second, request the relevant lot COA, both applicable methods and a traceable sample identifier. Neither a lower price nor the presence of a chromatogram resolves the missing information. Obtain matching records or agree a documented specification change.
Carry one clear brief into sample and order review
Specify source plant and root, required analyte and method, composition restrictions, quantity, application, destination and document list. Confirm the sample identity, evaluation criteria, costs and proposed delivery arrangements before comparing quotations.
Record which documents apply to the sample and eventual offered lot. Published references do not establish stock, a fixed MOQ, a shipment schedule, suitability for every application or destination-market approval.
Reference scope
This guide uses the supplier-document references, source identity, separate assay procedures and physical limits already published on our ecdysterone product page. Examples are document-review exercises, not new results or current-stock statements.