标准归口哪个标准化分会或部门，起草人是哪个单位的？他应该最清楚

从不知道r是表示纯度的，学习了。

nitric acid 硝酸 r 来自于Reagent, 表示硝酸的级别是试剂的级别。

Grades of Chemicals
Reagent A.C.S. - This designates a high quality chemical for laboratory use. The abbreviation "A.C.S.," means the chemical meets the specifications of the American Chemical Society. A Certificate of Analysis is available upon request.
Guaranteed Reagent (GR) - Suitable for use in analytical chemistry, products meet or exceed American Chemical Society (ACS) requirements where applicable. (EMD trademark)
AR - The standard Mallinckrodt grade of analytical reagents; suitable for laboratory and general use. If the reagent also meets the requirements of the American Chemical Society Committee on Analytical Reagent, it will be denoted as an AR (ACS) reagent. (MBI trademark)
Primary Standard - Analytical reagent of exceptional purity that is specially manufactured for standardizing volumetric solutions and preparing reference standards.
Reagent - The highest quality commercially available for this chemical. The American Chemical Society has not officially set any specifications for this material.
OR - Organic reagents that are suitable for research applications.(MBI trademark)
Purified - Defines chemicals of good quality where there are no official standards. This grade is usually limited to inorganic chemicals.
Practical - Defines chemicals of good quality where there are no official standards. Suitable for use in general applications. Practical grade organic chemicals may contain small amounts of isomers of intermediates.
Lab Grade - A line of solvents suitable for histology methods and general laboratory applications.
USP - Chemicals manufactured under current Good Manufacturing Practices and which meet the requirements of the US Pharmacopeia.
USP/GenAR - A line of chemicals manufactured under cGMP, meet the requirements of the 1995 USP 23, meet European Pharmacopeia (PhEur, EP) and British Pharmacopeia (BP) specifications where designated, and are Endotoxin (LAL) tested where appropriate. (MBI trademark)
NF - Chemicals that meet the requirements of the National Formulary.
FCC - Products that meet the requirements of the Food Chemical Codex.
CP (Chemically Pure) - Products of purity suitable for use in general applications.
Technical - A grade suitable for general industrial use.

Reagent - The highest quality commercially available for this chemical. The American Chemical Society has not officially set any specifications for this material.

没注意过，还有这要的标号

r？？？有点迷糊