Chemical reagents produced in China are generally divided into four levels according to their purity:
1, Premium pure (GR); 2, analytical pure (AR); 3, chemical pure (CP); 4. Experimental reagent (LR). In addition, there are spectral pure reagents.
Chemical pure reagent: It is a third-grade product, its purity is worse than that of analytical pure, but it is higher than that of experimental reagent, and it is suitable for general analytical work in factories and schools, often expressed by CP. Experimental reagent: for the fourth grade, purity is worse than chemical pure, but higher than industrial purity, mainly used for general chemical experiments, can not be used for analytical work, often expressed by LR.
Classification of chemical grades
Chemicals are usually classified into different classes according to their use, nature and safety level. The following are the classification of chemical classes.
Industrial grade
It is mainly used in industrial production and manufacturing and usually contains high impurities and residues, but the purity and quality are not guaranteed.
Laboratory grade
Usually used for laboratory research, purity and quality requirements are high, but food or drug grades are not guaranteed.
Food grade
Chemicals intended for human consumption that are of high purity and quality and do not contain carcinogenic, toxic or harmful substances.
Pharmaceutical grade
Chemicals suitable for the production of pharmaceuticals, with higher purity and quality requirements, must not contain any harmful substances.
Agricultural grade
Chemicals suitable for agricultural production, usually containing hazardous substances, need to be diluted in accordance with regulations.
Medical grade
Chemicals suitable for clinical treatment or medical care, with higher purity and quality requirements, must not contain any harmful substances.
Electronic grade
Chemicals suitable for the manufacture of electronic products require extremely high purity and quality and contain impurities that must be controlled at very low levels.
In general, the different levels of chemicals are mainly to meet different uses and safety requirements, when using chemicals should carefully read the label and instruction manual, choose the level and quality of products that meet their own needs.
Chemical reagent classification
National standard reagent
National standard reagent (this kind of reagent is stipulated by China’s national standard, suitable for inspection, identification, detection) classification as (requirements from high to low ranking) :
1, the work reference reagent (national standard without shorthand mark, indicated in Chinese, green label) : as the reference material, calibration standard solution.
2, excellent grade pure (GR, green label) : the principal component content is very high, high purity, suitable for accurate analysis and research work, and some can be used as a reference material.
3, analytical pure (AR, red label) : the principal component content is high, the purity is high, the interference impurity is very low, suitable for industrial analysis and chemical experiments. This is the grade most commonly used in laboratories.
4, chemical pure (CP, blue label) : high principal component content, high purity, there are interference impurities, suitable for chemical experiments and synthetic preparation.
5, experimental reagent (LR, yellow label) : the main component content is high, the purity is poor, the impurity content is not selected, and it is only suitable for general chemical experiments and synthesis.
other
Others can be divided into many specific grades according to the requirements of different uses. The quality of this type of reagent focuses on the content of impurities that may cause deviations in the analytical results during the analysis of a particular method and interfere with the composition analysis or content analysis, but the main content is not very demanding. The sections are as follows:
1, pure chromatography (GC, LC) : gas chromatography, liquid chromatography analysis. Quality indicators focus on impurities that interfere with chromatographic peaks. High principal component content.
2, indicator (ID) : preparation of indicator solution. The quality index is color change range and color change sensitivity. It can replace CP and is also suitable for organic synthesis.
3, biochemical reagent (BR) : preparation of biochemical test solution and biochemical synthesis. The quality index focuses on bioactive impurities. Can replace indicator, can be used for organic synthesis.
4, biological staining agent (BS) : preparation of microbial specimen staining solution. The quality index focuses on bioactive impurities. Can replace indicator, can be used for organic synthesis.
5, spectral pure (SP) : used for spectral analysis. They are suitable for spectrophotometer standard, atomic absorption spectrum standard and atomic emission spectrum standard.
6, electronic pure (MOS) : suitable for the production of electronic products, the content of electrical impurities is very low.
7, equivalent reagent (3N, 4N, 5N) : the main component content is 99.9%, 99.99%, 99.999% or more.
8, electrophoretic reagents: quality indicators pay attention to the control of electrical impurity content.
Chemical reagent grade classification
1, the first grade is excellent grade pure, also known as the guarantee reagent (symbol G.R.), our products with green label as a sign, this reagent purity is very high, suitable for precision analysis, can also be used as a reference material. 99.8%
2. The second grade is analytical pure, also known as analytical reagents (symbol A.R.), our products use red labels as a sign, the purity is slightly worse than the first grade, suitable for most analysis, such as the preparation of titrations, for identification and impurity inspection. 99.7%
3. The third grade is chemical pure, (symbol C.P.), our products use blue label as a sign, the purity is more different than the second grade, suitable for daily production analysis of industrial and mining. 99.5% or higher
4. The fourth grade is the experimental reagent (symbol L.R.), the impurity content is high, the purity is low, and the auxiliary reagent is commonly used in the analysis work (such as generating or absorbing gas, preparing lotion, etc.).
5. Reference reagent Its purity is equivalent to or higher than the guarantee reagent, usually dedicated to the reference material for capacity analysis. Weighing a certain amount of reference reagent diluted to a certain volume, generally can be directly obtained titrant, without calibration, if the reference product marked with the actual content, should be corrected when calculating.
6. Spectroscopic pure reagent (symbol S.P.) impurities can not be detected by spectroscopic analysis or the impurity content is below a certain limit, this reagent is mainly used in spectral analysis.
7. Chromatographic pure reagents are used for chromatographic analysis.
8. Biological reagents are used in some biological experiments.
9. Ultra-pure reagent is also known as high purity reagent. 99.99% or higher
Circuit processing technology, metal impurity content is less than 1ppb, through 0.05 micron aperture filter filtration, control 0.2 micron particles, filling in 100 purification environment to meet the SEMI C8 standard.
UP level: Applicable to 1 micron integrated circuit and TFT-LCD manufacturing process, the metal impurity content is less than 10ppb, filtered through 0.2 micron aperture filter, control 0.5 micron particles, filling in 100 purification environment, to meet the SEMI C7 standard
EL grade: The metal impurity content is less than 100ppb, the control of 1 micron particle size particles, to meet the SEMI C1 C2 standard, suitable for small and medium-sized integrated circuits and electronic components processing technology
The application of ultra-clean and high-purity chemical reagents in the electronics industry is mainly in chip integrated circuit manufacturing, semiconductor integrated circuit, TFT-LCD and related electronic device manufacturing process. First, it is used for wet cleaning of chip substrate before gluing; The second is used for etching and final degluing of the chip in the photolithography process.
At present, there are more than 10 kinds of most commonly used, which are mainly divided into four categories: one is acid, including sulfuric acid, hydrofluoric acid, nitric acid, hydrochloric acid, phosphoric acid, acetic acid, etc.; The second is alkali, mainly ammonium hydroxide; The third is solvent, which is divided into alcohols, ketones, esters, alkanes and so on; Four are other varieties, such as hydrogen peroxide, ammonium fluoride aqueous solution and so on.
Analytical purity (AR, red label) : high principal component content, high purity, low interference impurities, suitable for industrial analysis and chemical experiments. This is the grade most commonly used in laboratories. 99.7%
EL grade: The metal impurity content is less than 100ppb, the control of 1 micron particle size particles, to meet the SEMI C1 C2 standard, suitable for small and medium-sized integrated circuits and electronic components processing technology.
