When this test applies
Chemical characterisation is how endpoints get addressed with data rather than with animals under ISO 10993-1:2025. This particular arm is one cell of a grid — volatility on one axis, solvent polarity on the other. It targets the heavy end — larger oligomers, non-volatile antioxidant degradants, colourants and anything that would decompose rather than elute on a GC column, and in isopropyl alcohol (IPA) specifically it is moderately polar organics — many plasticisers, alcohol-soluble antioxidants and their breakdown products, and low-molecular-weight oligomers that come out. IPA covers the middle of the polarity range, and it is the arm that most often turns up the additive package — the compounds a formulator actually put there on purpose.
When to run it
Early, and commissioned as a solvent set rather than one arm at a time — the same extraction campaign supports all of them, and a partial profile usually has to be repeated. Before any of it, get the protocol and the analytical evaluation threshold agreed (GRK-2005): an AET set too high means the study missed things it should have found, and that is a finding a reviewer makes, not you.
What the result gives you
A GLP report giving each recovered compound identified and semi-quantified against its reporting limit, by liquid chromatography rather than gas, with the extraction conditions documented. If your own toxicologist writes the assessment, this is the dataset they need and the documentation trail a reviewer asks for. If you would rather we reached the conclusion, the ISO 10993-17 assessment (GRK-2001) is the next line item.
What it does not settle
HPLC/MS is the arm for the heavy end, and its identifications are typically less definitive than GC/MS library matches — an unknown here often needs follow-up work to name. IPA sits between the extremes and is therefore strongest in the middle: strongly ionic species stay in the water arm and the most lipophilic stay in hexane. IPA also swells some polymers, which raises recovery but means the result is not a simple surface measurement. And chemical characterisation has no independent pass or fail at all: compounds are reported against analytical reporting limits, not against a safety threshold, so the judgment about patient safety is made in the ISO 10993-17 assessment rather than here.
Method
Testing per ISO 10993-18:2020/Amd 1:2022. A single extract is prepared in isopropyl alcohol (IPA) at 10 mL, with the extraction ratio per ISO 10993-12: 6 cm²/mL for material under 0.5 mm thick, 3 cm²/mL at 0.5 mm or thicker, or 0.1 to 0.2 g/mL where surface area is indeterminate. The extract is analysed by HPLC/MS.
Where it runs
This analysis is subcontracted to an ISO/IEC 17025 accredited, GLP certified laboratory, and the report is issued under Groenakker cover, in Groenakker’s report template or in your document template on request at no extra cost. Turnaround is 4 to 5 weeks.
Usually ordered alongside
The semi-volatile arm in IPA, and the water and hexane non-volatile arms. IPA plus HPLC/MS is the combination that most often surfaces oligomer series. And — critically — an ISO 10993-17 toxicological risk assessment to interpret the numbers. Chemistry without the assessment is data without a conclusion; ChemTox bundles the two.
