Some standard content:
National Standard of the People's Republic of China
Sulfuric acid
Copper sulfate
Theme content and scope of application
Copper
GB 437---- 93||tt| |Replaces GB43780
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of copper sulfate. This standard applies to copper sulfate containing 5 crystal waters. Active ingredient: copper sulfate
Molecular formula: CuS0,·5H,0)
Relative molecular mass: 249.68 (1989 international relative atomic mass) reference standard
2
GB 601
GB1604
Preparation of standard solutions for chemical reagent titration analysis (volume analysis) Pesticide acceptance rules
GR 1605
GB3796
3 Product classification bzxZ.net
Sampling methods for commercial pesticides
General rules for pesticide packaging
are divided into copper sulfate for agricultural use and non-agricultural use. 4 Technical requirements
4.1 Appearance: blue or blue-green crystal (if it appears as green-white powder, it is still valid), no visible foreign impurities. 4.2 Copper sulfate should meet the following index requirements: Refers to
item
copper sulfate (CuS)·5H0) content
acidity (measured by HSO,)
water-insoluble matter
5 test methods
Superior product
98.0
0.1
0. 2
Agricultural use
Qualified product| |tt||96.0
0.2
0.2
label
non-agricultural use
qualified product
94.0
0 . 2
0. 4
Unless otherwise specified, the reagents used in this test are all analytically pure reagents, and the water used is grade three water in GB6682. 5.1 Determination of copper sulfate content
5.1.1 Method summary
Approved by the State Bureau of Technical Supervision on 1993-12-30 16
Quasily approved
%| | tt | , using starch as the index carrier, titrate the precipitated iodine with sodium thiosulfate standard solution. From the consumed volume of sodium thiosulfate standard solution, calculate the copper sulfate content in the sample. The ionic reaction equation is as follows:
2Cu2 + +41\=--2Cu1+I2
2S,02- +I2 -$,0--→21
5.1.2 Reagents and solution
5.1.2.1 Potassium iodide (GB1272);
5.1.2.2 Nitric acid (B626):
5.1.2.3 Sodium fluoride (GB1264): saturated solution; 5.1.2.4 Ice Acetic acid (GB676): acetic acid solution, 36% (V/V); 5.1.2.5 Sodium carbonate (GB639): saturated solution; 5.1.2.6 Starch (HGB3095): 5g/L solution; 5.1.2.7 Sodium thiosulfate (GB637 ) Standard titration solution: c (Na2S, O3) = 0.2mol/L. Refer to Article 4.6 of GB601. 5.1.3 Operation steps
Weigh about 2g of the sample (accurate to 0.0001g) into a 250mL Erlenmeyer flask, add 100mL water to dissolve, add 3 drops of concentrated nitric acid, boil, cool, and add saturated sodium carbonate solution dropwise , until trace precipitation appears, then add 4 ml of acetic acid solution to make the solution slightly acidic. Add 10 ml of saturated sodium fluoride solution, 5 g of potassium iodide, and titrate with sodium thiosulfate standard titration solution until the solution turns pale yellow, add 3 ml of starch Solution, continue titrating until the blue color disappears, which is the end point. 5. 1.4 Calculation
The mass percentage content X of copper sulfate in the sample is calculated according to formula (1): C+V ||m
武：
The actual concentration of sodium thiosulfate standard titration solution, mol/LV, the volume of sodium thiosulfate standard titration solution consumed during titration, mLmr
try The mass of the sample, g;
(1)
0.2497---5, expressed in grams, which is equivalent to 1.00mL sodium thiosulfate standard titration solution Ec (Na2S20,) = 1.000mol/L Water copper sulfate mass.
5.1.5 Allowable difference
The absolute difference between two parallel measurement results should not be greater than 0.6%. 5.2 Determination of acidity
5.2.1 Reagents and solutions
5.2.1.1 Distilled water: newly boiled, pH value 6~8; 5.2.1.2 Potassium hydrogen tartrate (HGB3307): saturated potassium hydrogen tartrate Solution; 5.2.1.3
Sodium hydroxide standard titration solution: c (NaOH) 0.02mol/L. 5.2.2 Instruments
pH meter (with electromagnetic stirrer attached);
5.2.2.1
5.2.2.2
glass electrode;
5.2. 2.31
Saturated calomel electrode.
5.2.2.4 Burette: 10mL. With 0.05mL graduation. 5.2.3 Analysis steps
5.2.3.1 Calibration of pH meter
After the instrument is powered on, it should be stable for at least 15 minutes. Then, adjust the pointer to zero, and then put the electrode into the standard buffer solution [ The pH value of potassium oxide in saturated wine is pH=3.56 (25C) + pH=3.55 (30C). Adjust the pointer of the instrument to 17 of the standard buffer solution at this temperature
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GB 437 -- 93
pH value reading position. When the reading of the standard buffer solution remains unchanged, the instrument can be used. 5.2.3.2 Determination
Weigh about 2g of the sample (accurate to 0.001g), place it in a 100ml beaker, add 50ml of distilled water, dissolve the sample under electromagnetic stirring, and use sodium hydroxide standard titration solution by hand Titrate until the pH meter pointer reaches 4.00, which is the end point. 5.2.3.3 Calculation
The acidity X of copper sulfate, [% (m/m) is calculated according to formula (2): C: V Medium: '-
-The actual concentration of the sodium hydroxide standard titration solution, mol/L; the volume of the sodium hydroxide standard titration solution consumed when titrating the sample, mL; the mass of the ㎡ sample.g; | | tt |
5.3 Determination of water-insoluble matter content
Weigh 10g sample (accurate to 0.01g) and place it in a 200mL beaker, add 100mL distilled water and 2 drops of concentrated sulfuric acid, heat to dissolve, and keep warm Filter with a G4 filter crucible that has constant weight, and wash the filter residue with 20 mL of hot distilled water each time (a total of 5 washes). Place the G4 filter crucible containing the filter residue and bake it in an oven at 105~110°C until it reaches constant weight. 5.3.1 Calculate
the water-insoluble matter content X of copper sulfate. Calculate according to formula (3): m= m2 × 100
||m2—mass of filter crucible, g
—mass of sample, g. || tt | Less than 250.
6.2 Acceptance rules: Acceptance shall be carried out in accordance with GB1604 standards. 6.3 Copper sulfate shall not exceed the output per shift. 7 Marking, packaging, storage and transportation
7.1 Packaging of copper sulfate and markings should comply with the relevant regulations in GB3796. 7.2 The inner packaging of copper sulfate can be plastic bags, moisture-proof paper. The outer packaging can be divided into 25kg and 50kg net weights according to the user. Other packaging is required. 7.3. Indicate on the bag (box): manufacturer name, product name, grade, batch number, production date, net weight, trademark, pesticide registration number and this standard number
7.4. Strictly prevent moisture and sunlight during storage and transportation, and do not mix with food, seeds, and feed. 7.5 Guarantee period: Under the specified packaging and storage conditions, the guarantee period of copper sulfate is two years from the production date. Within two years, the quality of copper sulfate should still meet the requirements of this standard. | |tt | Technical focus. This standard was drafted by Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry and Shenyang Pesticide Factory. The main drafters of this standard are Chen Jianli, Ji Yuqing, Li Chongyang, Xu Wei and Yan Kun. The superior products of this standard refer to the World Health Organization standard WHOSMT/1.R1 (65) "Copper Sulfate Technical Material". bzso
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