A specification sheet compresses a large amount of analytical work into a single page. The headline number — 98% HPLC, for example — describes the assayed content of the target compound by a specific method. It does not, by itself, describe the whole material.
Assay is a method-bound result
When a specification cites HPLC with a pharmacopoeial method reference such as USP<621>, it is telling you both the technique and the framework used to quantify the compound. A different method can produce a different figure for the same lot, which is why method references matter as much as the number beside them.
The rows that de-risk a purchase
- Identification — confirms the material corresponds to a reference standard, not just that a peak is present.
- Residue on ignition and loss on drying — physical-chemical quality indicators that bound inorganic and moisture content.
- Heavy metals by ICP-MS — typically lead, arsenic, cadmium and mercury with explicit numeric limits.
- Microbiological limits — total plate count, yeast and mould, and specified absent organisms.
- Solvent residue — states whether residual solvents meet the relevant pharmacopoeial requirement.
- Particle size — often expressed as a mesh throughput, which matters for blending and compression.
Specification versus certificate of analysis
A specification defines the limits a material is expected to meet. A certificate of analysis reports the measured result for a specific batch. One describes the promise; the other describes the delivery. When a supplier can provide both, a buyer can verify that a given lot actually met the specification it was sold against.
Read the specification, then read the method column. The method column is where the discipline of a supplier shows.
Chemesis product documentation follows this structure: a one-page specification, an eighteen-page product information package including safety data, and technical profiles where a material requires a longer briefing.