What a measurement can support, and what it cannot.
A figure is only as good as the method behind it and the conditions it was run under. This page is about both: what each determination we make actually establishes, and which of the controls standing behind it a certificate can show you.
- 5
- Methods cited on certificates
- 4
- Determinations per certificate
- ≥ 98.00%
- Purity specification
- ± 1.00 g/mol
- Mass tolerance
Reading a chromatogram
The purity figures on these certificates almost always begin as a separation. A mixture is pushed through a column that retains its components for different lengths of time, and a detector records what comes off and when. This happens in whichever laboratory produced your data, not here.
The large peak is the main component. Its area relative to everything else is the purity figure. The small peaks are related substances — impurities, degradation products, residues from synthesis — and each is integrated and reported rather than dismissed as noise.
5 methods run here.
These are the method codes our results cite. Each line on a certificate names the one that produced it, because two techniques can answer the same question to different depths and the name is how a reader tells which was used.
What has to sit behind a number, and who can show it to you.
Six controls that decide whether a figure can be defended later or only asserted now. They are ours, and they run whether or not a document mentions them — so each one also says plainly whether a certificate can show it to you, which is a different question from whether it happened.
Certified reference standards
A quantity is only meaningful against certified material of known purity, traceable to its supplier and lot. A figure calculated against a previous batch measures consistency, not truth.
On a ZEIKKA certificate
Not printed. The certificate names the method, and the standard that method answers to is stated on its own page.
System suitability before the run
Resolution, peak symmetry and repeatability checked against acceptance criteria before any sample data is accepted. A run that fails suitability should be repeated, not reported.
On a ZEIKKA certificate
Not printed. Suitability is a condition of accepting a run, not a line on the document it produces.
Blanks and controls in the sequence
Solvent blanks detect carryover; a control at known concentration confirms the calibration held for the whole sequence.
On a ZEIKKA certificate
Not printed. Ask for the sequence, not just the result, if a figure matters enough to question.
A named instrument and analyst
A figure that cannot be traced to an instrument and a person cannot be investigated later.
On a ZEIKKA certificate
Recorded, not published. The snapshot carries an analyst code and an instrument reference; the public page prints neither, and the code is a code rather than a name.
Retained material
Material held after the analysis lets a questioned figure be re-examined rather than argued about.
On a ZEIKKA certificate
Not stated on the certificate. If you need material held after the analysis, say so before sending rather than after.
Release by a second person
The person who produces a figure should not be the one who signs it off.
On a ZEIKKA certificate
Recorded where it applies: the snapshot carries a reviewer code beside the analyst code. Not printed publicly.
Every figure names the method that produced it.
Choose the analysis that answers your question, or check a certificate you already hold.