MANUFACTURING / JAPAN SOURCING
The same chemical purity figure can answer a different question
Keep the percentage with its assay method, reporting basis and controlled impurities. Then connect the specification and lot report to the material actually offered.
Ask what the quoted percentage measures
Imagine comparing two offers for an organic chemical raw material. Both show the same purity percentage, but one names a chromatographic method while the other gives a different assay description. The shared number does not yet establish an interchangeable material.
Shimadzu explains GC area normalization as a proportion of measured peak areas and identifies assumptions about detection and relative response.[1] Ask what method and reporting basis the supplier uses before interpreting the figure as a mass content. The responsible analyst should explain what the method covers and which conclusions it supports.
Keep the substance identity, relevant chemical form and grade alongside the percentage. Ask the supplier to identify proposed differences, not just repeat that the purity is “equivalent”. Intended use and the buyer’s process requirements determine which differences need technical review.
Read the other specification lines as well
Watanabe Chemical’s specification FAQ lists chromatographic purity, titration content and water as separate kinds of entry.[2] It is a useful example of why one headline figure does not describe every controlled property. Ask for the current full specification for the proposed product, not only its purity line.
For the intended use, ask the technical team which water, residual solvent, particular impurity or other property needs to be controlled and by which evidence. An omitted result should remain unknown. If a result says “not detected”, ask for the reporting limit and basis rather than replacing the statement with zero.
- 1Material identity: identify the proposed product and supplied lot
- 2Analytical scope: identify the assay and separately required properties
- 3Lot evidence: match the report to the specification and delivery
The traces are illustrative symbols, not chromatograms or acceptance limits for a real material. The connections identify questions to resolve, not approval of a substitution.
Request one comparison against the intended use
Use a comparison sheet that keeps the requested requirement and the offered evidence side by side. Ask the responsible technical buyer or analyst to resolve method differences and decide what evidence is adequate for this product.
Separate a specification limit from a result for an identified lot and from a typical value. Ask which will form the order requirement and which document will accompany supply. If the offer changes the assay method, the same numerical limit should go back to the technical reviewer rather than silently being copied into the comparison.
| Compare | Request or identify | Supplier states |
|---|---|---|
| Identity and form | Request or identifySubstance reference, relevant form, grade and intended use | Supplier statesProposed product, origin and deviations |
| Assay | Request or identifyRequirement, reporting basis, method/version and units | Supplier statesSpecified limit or sample result; scope of the method |
| Other properties | Request or identifyUse-relevant water, impurities or other required controls | Supplier statesSeparate specifications/results and information not available |
| Lot evidence | Request or identifyOffered lot, sample/report reference and date | Supplier statesWhich delivery the report covers and remaining verification |
| Supply condition | Request or identifyQuantity, packaging, storage requirements and receiving point | Supplier statesActual pack and supplied records; proposed changes |
Carry the decision into the lot and delivered pack
Once the comparison is resolved, retain the accepted specification revision, product identity, lot and agreed evidence with the order. Ask the supplier to flag changes to the grade, method, controlled properties or packaging that require review. A small evaluation sample and the later commercial lot need an explicit link.
Ask for the current safety and handling information for the proposed product and confirm the storage/transport arrangements with the responsible parties. Quality acceptance and safe handling are separate decisions. Do not arrange a material substitution from the purity figure alone.
Send HAM the product reference, destination, intended use and the unresolved specification or evidence question. A Japanese supplier can then respond to a defined request rather than an unexplained percentage. The related report-traceability guide can help keep the document connected to the delivered lot.
Questions to send your supplier
Open supplier questions
Product/substance reference, relevant form and requested grade: Intended use, destination and responsible technical reviewer: Purity/assay requirement, reporting basis, units and method/version: Other properties required for the use and their evidence: Please separate specification limits, typical values and lot results. Offered lot, sample/report reference and date: What is not measured or not available in the supplied records? Quantity, packaging, storage/transport and receiving point: Current safety/handling documents and changes requiring review:
Sources
- Shimadzu — GC quantitation methods
Read sections 2.4.1–2.4.2 on peak-area normalization and its assumptions. Supports asking about the reporting basis and method scope, not selecting or operating a method for a particular chemical.
- Watanabe Chemical — Product specification FAQ
Read the quality-specification table: purity, titration content, water and other specified items are separate fields. This is a supplier-specific example; absent fields are not assumed tested or zero.