Reagent Level Classification and Analytical Purification
There are many types of chemical reagents, and the classification and grading standards of chemical reagents in countries around the world are inconsistent. IUPAC classifies chemical standard substances as: Class A: Atomic Weight Standard.
Class B: The closest reference substance to Class A
Class C: Standard reagent with 100 + -0.02% content Class D: Standard reagent with 100 + -0.05% content
Grade E: A reagent whose purity is determined by comparison with grade C or D as the standard
Chemical reagents can be divided into standard reagents, general reagents, biochemical reagents, etc. Our country is accustomed to calling the C-grade and D-grade reagents equivalent to IUPAC standard reagents.
Superior purity, analytical purity, and chemical purity are the Chinese names of general reagents:
Grade 1: GR (Guaranteed Reagent), labeled dark green, for precision analytical testing.
Level 2: Analytical pure (AR), labeled golden red, used for general analytical tests.
Grade 3: That is, chemically pure (CP, Chemicalpure), labeled medium blue, used for general chemical tests. In terms of reagent purity:
Ultra-high purity ≥ 99.99% Premium purity ≥ 99.8% Analytical purity ≥ 99.7% Chemical purity ≥ 99.5%
Level 4: High Purity > 99% Level 5: Industrial Grade "98.5%
The difference between chemical purity, analytical purity, and chromatographic purity
Chemical purity refers to the purity of the reagent that meets the general production or analytical test. The purity of analytical purity is higher than that of chemical purity. It is generally used in more demanding places, such as reagents used in hospitals. Chemical purity, analytical purity, and chromatographic purity refer to the purity level of the reagent. Chemical purity refers to the purity level of the reagent used in general chemical tests. There are fewer impurities. It may be required for your experiment. Analytical purity refers to the reagent used for analytical determination with fewer impurities and does not hinder the analytical determination. Chromatographic purity refers to the standard reagent used in chromatographic analysis. Under chromatographic conditions, only the peaks of the specified compounds appear, and no impurity peaks appear.
