Recently, some classmates often ask what is pure grade, which is actually the purity grade of chemical reagents.
Purity grade
Premium grade
Analytically pure
Chemically pure
Experimental reagent
English code
G. R.
Guarantee Reagent
A. R.
Analytical Reagent
C. P.
Chemical Pure
L. R.
Laboratory Reagent
Bottle label color
green
red
blue
yellow
Scope of application
Used as a reference substance, mainly used for precise scientific research and analytical experiments.
Used for general scientific research and analytical experiments.
It is used for higher inorganic and organic chemistry experiments or less demanding analytical tests.
Used for general experiments and less demanding scientific experiments.
Chemical reagent purity
China's reagent specifications are basically divided by purity (how much impurity content), there are 7 types of high purity, spectral purity, benchmark, spectroscopic purity, superior purity, analytical and chemical purity. The state and the competent authority have promulgated three main types of quality indicators: superior grade, graded grade, and chemical grade.
(1) Excellent grade pure (GR: Guaranteed reagent), also known as first-class product or guaranteed reagent, 99.8%, this reagent has the highest purity and the lowest impurity content, suitable for important precision analysis work and scientific research work, using green bottles sign.
(2) Analytical purity (AR), also known as secondary reagent, has a very high purity of 99.7%, which is slightly inferior to superior purity, and is suitable for important analysis and general research work, using red bottle labels.
(3) Chemically pure (CP), also known as tertiary reagent, ≥ 99.5%, the purity is quite different from analytical purity, and is suitable for general analysis in industry, mines and schools. Use blue (dark blue) labels.
(4) Laboratory reagent (LR: Laboratory reagent), also known as grade four reagent.
In addition to the above four levels, there are still:
Reference Reagent (PT: Primary Reagent): It is specially used as a reference substance, and a standard solution can be directly prepared.
Spectral pure reagent (SP: Spectrum pure): indicates spectral purity. However, because the organic substance does not show up in the spectrum, sometimes the main component is less than 99.9%, and it must be noted when using it, especially when it is used as a reference substance, it must be calibrated.
Reagents whose purity is much higher than that of superior-grade pure are called high-purity reagents (≥ 99.99%). High-purity reagents are developed on the basis of general-purpose reagents. It is the reagent with the highest purity produced by a special method for special use purposes. Its impurity content is 2, 3, 4 or more orders of magnitude lower than the superior reagent. Therefore, high-purity reagents are particularly suitable for some trace analysis, and the usual high-grade pure reagents can not meet the requirements of this precise analysis. At present, except for the establishment of national standards for a small number of products (such as high-purity boric acid, high-purity glacial acetic acid, high-purity hydrofluoric acid, etc.), the quality standards of most high-purity reagents are still not uniform. ), Ultrapure, spectrally pure, etc. According to the different scope of high-purity reagent industry, it can be divided into the following types:
(1) High-purity chemicals for optics and electronics, namely EIectronicgrade reagents.
(2) Metal-oxide-semiconductor (Metal-Oxide-Semiconductor) electronic industry special high-purity chemicals, namely UP-S grade or MOS reagent (read: Morse reagent). Generally used in semiconductors, electronic tubes, etc., the highest impurity content is 0.01-10ppm, some can be reduced to ppb order, the metal impurity content is less than 1ppb, the dust level reaches 0-2ppb, suitable for 0.35-0.8 micron integrated circuit processing technology.
(3) High-purity chemicals for single crystal production.
â‘·High-purity chemicals for optical fiber.
In addition, there are instrumentation reagents, ultra-pure reagents (impurity content less than 1/1000000 ～ 1/1000000000), special high-purity organic materials, etc.
(5) ICP-Mass Pure Grade reagent: The content of most impurity elements is less than 0.1ppb, which is suitable for the daily analysis of plasma mass spectrometer (ICP Mass).
(6) Plasma emission spectrum pure grade reagent (ICP Pure Grade): The content of most impurity elements is less than 1ppb, which is suitable for the daily analysis work of plasma emission spectrometer (ICP).
(7) AA Pure Grade Reagents: The content of most impurity elements is less than 10 ppb, which is suitable for the daily analysis work of AA.
At present, the specifications of chemical reagents produced by foreign reagent factories tend to be divided according to usage, the common ones are as follows:
Biochemical reagents (BC: Biochemical)
Biological reagent (BR: Biological reagent)
Biological stain (BS: Biological Stain)
For complex titration (FCM: For Complexometry)
0S-J1 [j; B2 ~ (F1v7G analytical chemistry, forum, chemical analysis, instrumental analysis, analytical testing, chromatography, electrophoresis, spectroscopy (FCP: For chromatography purpose)
Fluorescence analysis (FIA)
For microbes (FMB)
For Microscope (FMP: For microscopic purpose)
For synthesis-[6] #f! G6M # s.u5)] ^ (FS: For synthesis)
Gas chromatography 0S, ~ .L1t3k7`-{"E (GC: Gas chromatography)
High pressure liquid chromatography (HPLC: High Pressure Liquid chromatography)
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Infrared absorption (IR)
Liquid Chromatography (LC)
Nuclear Magnetic Resonance (NMR)
Organic Analysis Standard 6a1Z2m: d * A7K + x Forum for Analytical Chemistry
For analysis (PA: Pro analysis)
Pract: Practical use
(\ (T & e-Y5G-N% MPur (Pure purum pure)
Puriss (Purissmum Extra Pure)
Synthesis (SYN)
Industrial Tech: Techincal grade)
Thin layer chromatography (TLC: Thin Layer chromatography)
Spectroscopically pure, optically pure, purple analysis spectrophotometrically pure $ v7) (UV: Ultra violet pure)
For example, the nitric acid produced by the German Imerk company has 13 specifications: the minimum concentration of 65% (density of about 1.40) of the ultra-pure reagent dithizone nitrate test passed the minimum concentration of 65% (density of about 1.40, Hg maximum concentration of 0.0000005 %) Guaranteed reagent (GR) nitric acid, dithizone tested with a minimum concentration of 65% (density about 1.40) guaranteed reagent (GR) nitric acid, minimum concentration of 65% (density about 1.40) for optical and electronics Special pure (Selectipur) nitric acid, 100% (density about 1.52) guarantee reagent (GR) nitric acid, 100% (density about 1.42) special pure optical (Seletipur) fuming nitric acid, heavy hydrogen degree less than 99 % Heavy hydrogen reagent nitric acid-di (in D2O, not less than 65% DNO3), 0.1mo1 / L nitric acid solution for titration and 1mo1 / L nitric acid solution for titration. Imok also produces reagents of various specifications according to the needs of users, such as biochemical reagents, Merck diagnostic reagents, medical research, agricultural and environmental monitoring reagents, etc.
The advantages of reagent specifications divided by use are simple and clear. From the specifications, the purpose of this reagent can be known, and the user does not have to repeatedly consider which purity level and reagent to use.
Attachment: Description of purity grade of foreign reagents
Ultra Pure: Ultra pure, similar to GR grade.
High Purity: High purity, similar to AR level.
Biotech: Biotech grade, similar to BR grade.
Reagent: Reagent grade, similar to CP grade.
ACS: American Chemical Society standard, similar to AR level.
USP: Medicinal grade
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