AR Grade (Analytical Reagent) chemicals

What the grade means

AR grade tells you that the reagent will not add measurable error to an analysis. The specification sets a minimum assay and lists maximum limits for individual impurities such as chloride, sulfate, iron, heavy metals and insoluble matter. Some producers use the labels GR or p.a. for a comparable grade.

AR is a trade grade, not a single published standard. Each producer writes its own limits, often based on ACS or ISO reagent specifications, so compare the actual numbers when you change source.

Typical specification points

For sodium chloride AR you might see assay of 99.5 to 99.9 percent, insoluble matter at or below 0.005 percent, sulfate at a few thousandths of a percent, heavy metals at or below 5 ppm and iron at or below 2 ppm.

When to choose it

Use AR grade for volumetric solutions, titrations, gravimetric work, buffer preparation and wet-chemistry tests in QC. For general synthesis or cleaning, LR grade is usually enough and costs less.

Documentation

Every lot ships with a COA showing results against each limit and a GHS SDS. Browse Lab Reagents for AR products.