HG/T 2631-1994 Chemical reagent cobalt sulfate heptahydrate (cobalt sulfate)
Some standard content:
Chemical Industry Standard of the People's Republic of China
Chemical Reagents
Cobalt Sulfate Heptahydrate (Cobalt Sulfate)
This reagent is a red crystal with a brownish yellow color and is easily soluble in water. Molecular formula: CoSO4·7H,O
Relative molecular mass: 281.10 (according to the 1989 international relative atomic mass). Subject content and scope of application
HG/T 2631—94
This standard specifies the technical requirements, test methods, inspection rules, packaging and marking of the chemical reagent cobalt sulfate heptahydrate (cobalt sulfate). This standard applies to the inspection of the chemical reagent cobalt sulfate heptahydrate (cobalt sulfate). 2 Reference standards
GB/T 601
GB/T 602
GB/T603
GB/T609
GB/T 619
GB/T 6682
GB/T 9723
GB/T 9738
Chemical reagents
Chemical reagents
Chemical reagents
Chemical reagents
Chemical reagents
Chemical reagents
Chemical reagents
Preparation of standard solutions for titration analysis (volumetric analysis)Preparation of standard solutions for determination of impurities
Preparation of preparations and products used in test methodsGeneral method for determination of total nitrogen
Sampling and acceptance rules
Specifications and test methods for water used in analytical laboratoriesChemical reagentsGeneral rules for flame atomic absorption spectrometryChemical reagentsGeneral method for determination of water-insoluble matterHG/T 3—119
3 Technical requirements
Packaging and marking
Chemical reagents
Cobalt sulfate heptahydrate [CCoSO7H.O] Content, %3.1
Analytically pure
Chemically pure
Maximum impurity content
Water-insoluble matter, %
Chlorofluoride (CI), %
Total nitrogen (N), %
Sodium (Na), %
Analytically pure
Approved by the Ministry of Chemical Industry of the People's Republic of China on April 13, 1994 832
≥98.5.
Chemical pure
1995-01-01 implementation
Calcium (Ca).%
Manganese (Mn),%
Iron (Fe),%
Nickel (Ni),%
Copper (Cu),%
Zinc (Zn),%
Test method
HG/T263194
Analytical pure
Chemical pure
Unless otherwise specified, the standard titration solution, impurity standard solution, preparation and product in this test method shall be prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603. The experimental water shall meet the third-grade water specifications in GB/T6682. 4.1 Determination of cobalt sulfate heptahydrate [CoSO4·7H2O] content Weigh 0.4g sample (accurate to 0.0001g). Dissolve in 100 mL of water, add 2 g of hydroxylamine chloride and 15 mL of aqueous ammonia, heat to 80 °C, add 0.05 g of methylthymol blue indicator, and titrate with a standard titration solution of disodium ethylenediaminetetraacetic acid [c(EDTA)=0.05 mol/L] until the solution changes from blue to reddish purple. The content is calculated as follows:
X=y·cX0.2811×100
Wherein: X is the mass percentage of cobalt sulfate heptahydrate, %; V
the volume of disodium ethylenediaminetetraacetic acid standard titration solution consumed by the sample, mL; C
0. 281 1-
the actual concentration of disodium ethylenediaminetetraacetic acid standard titration solution, mol/L; the mass of the sample·;
the mass of cobalt sulfate heptahydrate equivalent to 1.00mL disodium ethylenediaminetetraacetic acid standard titration solution (c(EDTA)=1.000mol/L), expressed in grams.
4.2 Determination of impurities
The sample must be weighed accurately to 0.01g.
4.2.1 Water-insoluble matter
Weigh 20g of sample, dissolve in 200mL of boiling water, cool to room temperature, filter with a No. 4 glass filter that has been constant weight at 105±2℃, wash the filter residue with hot water until the washing liquid is colorless, dry in an electric oven at 105±2℃ to constant weight, and calculate the result according to the provisions of Chapter 7 of GB/T9738. 4.2.2 Chloride
4.2.2.1 Preparation of cobalt sulfate heptahydrate solution without chloride Weigh 2g of sample, dissolve in appropriate amount of water, add 8mL of nitric acid solution (25%) and 4mL of silver nitrate solution (17g/L), dilute to 100ml; shake well, let stand for 12~18h, and filter.
4.2.2.2 Determination method
Weigh 0.5g sample, dissolve in 25mL water, add 2mL nitric acid solution (25%) and 1mL silver nitrate solution (17g/L), shake well, and place for 10 minutes. The turbidity of the solution shall not be greater than the standard. The standard is to take 25mL of chloride-free cobalt sulfate heptahydrate solution and impurity standard solution containing the following amount of chloride: 833
Analytical pure
Chemical pure
HG/T 2631--94
Diluted to 28ml, placed with the same volume of sample solution for 10 minutes and then turbidity compared. 4.2.3 Total nitrogen
0. 010mg Cl;
0. 025mg Cl.
Weigh 1g sample, dissolve in water, and dilute to 100mL. Take 5mL, dilute to 140mL, and measure according to the provisions of GB/T609. The yellow color of the solution shall not be darker than the standard.
The standard is to take the impurity standard solution containing the following amounts of nitrogen: analytically pure, chemically pure
dilute to 140mL, and treat it in the same way as the sample solution of the same volume. 4.2.4 Sodium
Measure according to the provisions of GB/T9723, where: 4.2.4.1 Instrument conditions
Light source: sodium hollow cathode lamp;
Wavelength: 589.0nm;
Flame: acetylene-air.
4.2.4.2 Determination method
0.025mgN.
Weigh 1g of sample, dissolve in water, add 5mL of hydrochloric acid solution (10%), and dilute to 100mL. Take 10mL (4mL for chemically pure), a total of four portions. Determine in accordance with the provisions of Article 6.2.2 of GB/T9723. 4.2.5 Calcium
Determine in accordance with the provisions of GB/T9723, where: 4.2.5.1 Instrument conditionsbzxZ.net
Light source: calcium hollow cathode lamp;
Wavelength: 422.7nm;
Flame: acetylene-air.
4.2.5.2 Determination method
Weigh 5g of sample, dissolve in water, add 2.5mL of hydrochloric acid solution (10%), and dilute to 100mL. Take 20mL (8mL for chemically pure), a total of four portions. Determine in accordance with the provisions of Article 6.2.2 of GB/T9723. 4.2.6 Manganese
Determine in accordance with the provisions of GB/T9723, where: 4.2.6.1 Instrument conditions
Light source: manganese hollow cathode lamp;
Wavelength: 279.5nm;
Flame: acetylene-air.
4.2.6.2 Determination method
Weigh 5g sample, dissolve in water, add 5mL hydrochloric acid solution (10%), dilute to 100mL. Take 10mL (2.5mL for chemically pure), a total of four portions. Determine in accordance with the provisions of Article 6.2.2 of GB/T9723. 4.2.7 Iron
Weigh 1g sample, dissolve in 10mL water, add 1mL hydrochloric acid solution (5%) and 2mL benzoylphenylhydroxylamine solution (20g/1.), and extract with 5mL chloroform. The yellow color of the organic layer shall not be darker than the standard. The standard is to take the impurity standard solution containing the following amount of iron: analytical pure
chemical pure
and treat it in the same way as the sample.
0.01mg Fe;
0. 05mg Fe.
According to the provisions of GB/T9723, among which: 4.2.8.1 Instrument conditions
Light source: nickel hollow cathode lamp;
Wavelength: 232.0nm;
Flame: acetylene-air.
4.2.8.2 Determination method
HG/T 2631--94
Weigh 5g sample, dissolve in water, add 5ml hydrochloric acid solution (10%), and dilute to 100ml. Take 10ml (1ml for chemically pure), a total of four portions. Determine according to the provisions of Article 6.2.2 of GB/T9723. 4.2.9 Copper
The test shall be carried out in accordance with the provisions of GB/T9723, where: 4.2.9.1 Instrument conditions
Light source: copper hollow cathode lamp;
Wavelength: 324.8nm;
Flame: acetylene-air.
4.2.9.2 Determination method
Weigh 10g sample, dissolve in water, add 2.5ml hydrochloric acid solution (10%), dilute to 100mL. Take 20mL (4ml for chemically pure), a total of four portions. Determine according to Article 6.2.2 of GB/T9723: 4.2.10 Zinc
Determine according to the provisions of GB/T9723, including: 4.2.10.1 Instrument conditions
Light source: zinc hollow cathode lamp;
Wavelength: 213.9nm;
Flame: acetylene-air.
4.2.10.2 Determination method
Weigh 2g sample, dissolve in water, add 5ml hydrochloric acid solution (10%), dilute to 100mL. Take 10mL (5mL for chemically pure), four portions in total. Determine according to the provisions of Article 6.2.2 of GB/T9723. 5 Inspection rules
Sampling and acceptance shall be carried out according to the provisions of GB/T619. 6 Packaging and marking
According to the provisions of HG/T3·-119, among which:
Inner packaging form G—2, Gz--2, G--3, Gz--3; outer packaging form W--1;
Packaging unit Class 3, Class 4.
Additional instructions:
HG/T 2631--94
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard is drafted by Beijing Chemical Factory. The main drafters of this standard are Wang Sunjiong, Han Baoying, and Chen Hua. From the date of implementation of this standard, the former standard HG3--914-76 "Chemical Reagent Cobalt Sulfate" of the Ministry of Chemical Industry of the People's Republic of China shall be invalid.
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