Grades and purity
AR grade (analytical reagent)
Definition
High purity laboratory chemical for analytical work, with tight and stated limits on impurities.
AR or analytical reagent grade is a trade grade used by laboratory chemical makers, common in India and the UK. Each maker publishes its own specification, usually with a minimum assay and maximum limits for specific impurities on the label.
AR grade sits above LR grade. For regulated testing, buyers often prefer ACS or pharmacopoeia reagent specifications, because AR has no single public standard behind it.
Related terms
- LR grade (laboratory reagent)General purpose laboratory chemical of reasonable purity, for teaching, synthesis and qualitative work.
- ACS gradeLaboratory reagent that meets or exceeds the specifications in the American Chemical Society's Reagent Chemicals.
- HPLC gradeSolvent of very high purity with low UV absorbance and low residue, made for high performance liquid chromatography.
- Technical grade (industrial grade)Commercial quality for industrial use, with a basic specification and no food, pharma or lab claims.