HG/T 2935-2006 English PDF (HGT2935-2006)
HG/T 2935-2006 English PDF (HGT2935-2006)
HG/T 2935-2006: Feed grade ferrous sulfate
CHEMICAL INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
Filing No.: 18218-2006
Replacing HG 2935-2000
Feed grade ferrous sulfate
ISSUED ON: JULY 26, 2006
IMPLEMENTED ON: MARCH 01, 2007
Issued by: National Development and Reform Commission of PRC
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Categories ... 5
4 Requirements ... 5
5 Test method ... 5
6 Inspection rules ... 16
7 Signs, labels ... 16
8 Packaging, transportation, storage ... 16
Feed grade ferrous sulfate
This standard specifies the requirements, test methods, inspection rules, signs, labels, packaging, transportation, storage of feed grade ferrous sulfate.
This standard applies to monohydrate or heptahydrate feed grade ferrous sulfate. This product is used as iron supplement, in feed processing.
Molecular formula: FeSO4 • nH2O, n = 1 or n = 7
Relative molecular mass: 169.92 (n = 1), 278.01 (n = 7) (according to the international relative atomic mass in 2001)
2 Normative references
The provisions in following documents become the provisions of this Standard through reference in this Standard. For the dated references, the subsequent amendments (excluding corrections) or revisions do not apply to this Standard; however, parties who reach an agreement based on this Standard are encouraged to study if the latest versions of these documents are applicable. For undated references, the latest edition of the referenced document applies.
GB/T 1250 Rules for expression and judgement of limiting values
GB/T 6003.1-1997 Test sieves of metal wire cloth
GB/T 6678 General principles for sampling chemical products
GB/T 6682-1992 Water for laboratory use - Specifications (eqv ISO 3696:1987) GB 10648 Feed label
GB/T 13079-1999 Determination of total arsenic in feeds
GB/T 13080-2004 Determination of lead in feeds - Method using atomic absorption spectrometry
HG/T 3696.1 Inorganic chemical products - Preparations of standard volumetric solutions for chemical analysis
HG/T 3696.2 Inorganic chemical products - Preparations of standard solutions for are required in the test, shall be prepared according to the provisions of HG/T 3696.1, HG/T 3696.2, HG/T 3696.3.
5.3 Identification test
184.108.40.206 Potassium ferricyanide solution: 100 g/L.
220.127.116.11 Barium chloride solution: 50 g/L.
5.3.2 Identification method
18.104.22.168 Identification of sulfate ion
Take a little specimen. Add water to dissolve it. Add barium chloride solution dropwise to form a white precipitate. This precipitate is insoluble in hydrochloric acid and nitric acid.
22.214.171.124 Identification of ferrous ions
Take a little specimen. Add water to dissolve it. Add potassium ferricyanide solution dropwise to form a dark blue precipitate.
5.4 Determination of ferrous sulfate content and iron content
5.4.1 Method summary
After the specimen is dissolved, add sulfur-phosphorus mixed acid. Use sodium diphenylamine sulfonate as indicator. Use potassium dichromate standard titration solution for titration to determine the content of ferrous sulfate and iron. 5.4.2 Reagents
126.96.36.199 Thion-phosphorus mixed acid: Add 150 mL of sulfuric acid and 150 mL of phosphoric acid to 700 mL water. Mix well.
188.8.131.52 Potassium dichromate standard titration solution: c (1/6K2Cr2O7) ≈ 0.05 mol/L.
184.108.40.206 Sodium diphenylamine sulfonate indicator solution: 5 g/L.
5.4.3 Analytical procedures
Weigh about 0.2 g of specimen (accurate to 0.0002 g). Place it in a 250 mL conical flask. Add 30 mL of water to dissolve it. Add 10 mL of sulfur-phosphorus mixed acid, 2 drops of sodium diphenylamine sulfonate indicator solution. Immediately use potassium dichromate standard titration solution to titrate, until the solution turns purple, which is solution, which is consumed by titrating the blank solution, in milliliters (mL); c - The exact value of the concentration of potassium dichromate standard titration solution, in moles per liter (mol/L);
m - The value of sample mass, in grams (g);
M - The molar mass value M (FeSO4 • 7H2O) = 278.0 [or measured by iron (Fe), its molar mass value M (Fe) = 55.84], when ferrous sulfate heptahydrate product is measured by ferrous sulfate heptahydrate (FeSO4 • 7H2O), in gram per mole (g/mol). Take the arithmetic mean value of parallel determination results as measurement result; the absolute difference of two parallel determination results is not more than 0.3% for ferrous sulfate; it is not more than 0.1% for the iron content.
5.5 Determination of arsenic content
5.5.1 Silver diethyldithiocarbamate - spectrophotometric method (arbitration method)
220.127.116.11 Method summary
In acidic medium, arsenic is reduced by zinc to generate arsine gas, then it is introduced into silver diethyldithiocarbamate [Ag(DDTC)] solution for absorption, so as to form yellow or brownish red silver sol. The color depth is directly proportional to the content of arsenic. It is subject to colorimetric determination by a spectrophotometer. 18.104.22.168 Reagents and materials
22.214.171.124.1 Silver diethyldithiocarbamate (Ag-DDTC)-triethylamine-chloroform solution: 2.5 g/L.
126.96.36.199.2 Arsenic standard solution: 1 mL solution contains 50 μg of arsenic (As). Use a pipette to pipette 5.00 mL of arsenic standard solution, which is prepared according to HG/T 3696.2. Place it in a 100 mL volumetric flask. Dilute to the mark. Shake well.
188.8.131.52.3 Arsenic standard solution: 1 mL of solution contains 1 μg of arsenic (As). Use a pipette to pipette 2.00 mL of arsenic standard solution (184.108.40.206.2), into a 100 mL volumetric flask. Add 1 mL of hydrochloric acid. Dilute to the mark. Shake well. Prepare it before use.
220.127.116.11.4 Sulfuric acid solution: 1 + 4.
18.104.22.168.5 Tartaric acid solution: 200 g/L.
22.214.171.124.6 Lead acetate absorbent cotton.
126.96.36.199.7 Potassium iodide solution: 150 g/L.
188.8.131.52.8 Stannous chloride hydrochloric acid solution: Dissolve 40 g of stannous chloride (SnCl2 • 2H2O) in 50 mL of hydrochloric acid solution (1 + 1). Use water to dilute it to 100 mL.
184.108.40.206.9 Arsenic-free zinc particles: Particle size (3.0 ± 0.2) mm.
220.127.116.11 Instruments and equipment
Same as Chapter 4 of GB/T 13079-1999.
18.104.22.168 Analytical procedures
22.214.171.124.1 Specimen solution: Weigh about 3 g of specimen, accurate to 0.01 g. Place it in a 150 mL beaker. Add 10 mL of sulfuric acid solution. Heat it. Slightly boil it for 2 min. After cooling, completely transfer to the arsenic bottle. Add 25 mL of tartaric acid solution. Shake well. Add water to 40 mL.
126.96.36.199.2 Drawing of working curve: Accurately pipette 0.00 mL, 1.00 mL, 2.00 mL, 4.00 mL, 6.00 mL, 8.00 mL, 10.00 mL of arsenic standard solution, in seven arsenic generating bottles, respectively. Add 10 mL of sulfuric acid solution each. Add water to dilute it to 40 mL. Shake well. Measure the absorbance, after operating according to 188.8.131.52.3, to find the regression equation. Draw a standard curve, using the absorbance as the ordinate and the mass of arsenic (μg) as the abscissa.
184.108.40.206.3 Reduction reaction and colorimetric determination: Add 2 mL of potassium iodide solution to the specimen solution and working curve solution, respectively. Shake well. Then add 2 mL of stannous chloride hydrochloric acid solution. Shake well. Let it stand for 15 min.
Accurately pipette 5.00 mL of Ag-DDTC-triethylamine-chloroform solution, into a dry absorption bottle. Connect the generation absorption device (airtight, the catheter is plugged with fluffy lead acetate cotton) (see device Figure 1). Quickly add 4 g of arsenic-free zinc pellets, from the side tube of the generator bottle. Let it react for 45 minutes (when the room temperature is lower than 15 °C, the reaction is extended to 1 h). Gently shake the generating bottle twice, during the reaction. After the reaction, remove the absorbing bottle, use chloroform to dilute it to 5 mL. Shake well. Immediately measure using a 1 cm absorption cell. Take the original absorption solution as a reference to measure the absorbance at 520 nm. Find out the arsenic content in the specimen solution, from the working curve.
220.127.116.11 Method summary
In an acidic medium, use zinc to reduce arsenic to generate arsine gas. Use lead acetate cotton to absorb a small amount of hydrogen sulfide, which is produced after the reaction. The escaped arsine gas reacts with mercury bromide (test paper) to generate yellow-brown As2Hg3. According to depth of color, determine the arsenic content in the sample.
18.104.22.168 Reagents and materials
Mercury bromide test paper.
Other reagents and materials are the same as 22.214.171.124.
126.96.36.199 Instruments and equipment
188.8.131.52 Analytical procedures
184.108.40.206.1 Specimen solution: Weigh (3.00 ± 0.01) g of specimen. Place it in a 150 mL beaker. Add 10 mL of sulfuric acid solution. Heat it. Slightly boil for 2 min. After cooling, transfer it completely to the jar of the arsenic fixer. Add 25 mL of tartaric acid solution. Shake well. Add water to 40 mL.
220.127.116.11.2 Standard comparison solution: Accurately pipette 6.00 mL of arsenic standard solution, into the jar of the arsenic fixer. Add 10 mL of sulfuric acid solution. Add water to dilute it to 40 mL. Shake well.
18.104.22.168.3 Reduction reaction and colorimetric determination: Add 2 mL of potassium iodide solution to the specimen solution and the standard comparison solution, respectively. Shake well. Then add 2 mL of stannous chloride hydrochloric acid solution. Shake well. Let it stand for 15 minutes.
Press the mercuric bromide test paper, between the glass caps at the upper end of the glass tube. Use a rubber band or other methods to fix the upper end of the glass cap and the glass tube (see Figure 2). Quickly add 4 g of arsenic-free zinc pellets to the jar of the arsenic fixer. Plug the rubber stopper of the arsenic fixer. Let it react for 45 minutes (when the room temperature is lower than 15 °C, the reaction is extended to 1 h). During the reaction, gently shake the generation bottle twice. After the reaction, remove the glass cap. Take out the mercuric bromide test paper. Immediately carry out the comparison. The yellow color of the mercury bromide test paper of the sample shall not be deeper than that of the standard solution.
After the specimen is treated, use ether to extract the interfering substances in the sample. Add sulfide to the water phase to react the lead in the specimen, so as to form a brown precipitate. Compare it with the standard comparison solution to determine whether the lead content is within the limit.
22.214.171.124 Reagents and solutions
b) Hydroxylamine hydrochloride.
d) Aqua regia: 70 mL hydrochloric acid + 30 mL nitric acid.
e) Hydrochloric acid solution: 1 + 1.
f) Acetic acid solution: 1 + 19.
g) Sodium sulfide-glycerol solution.
Preparation: Weigh 5 g of sodium sulfide. Put it in a 100 mL beaker. Add a mixture of 30 mL of glycerol and 10 mL of water. Dissolve it. Transfer it into a brown bottle. Store it in an airtight place, away from light. The validity period is three months. h) Lead standard solution: 0.01 mg of lead (Pb) per milliliter of solution. Pipette 1.00 mL of lead standard solution, which is prepared according to the requirements of HG/T 3696.2. Place it in a 100 mL volumetric flask. Use water to dilute it to the mark. Shake well.
i) Phenolphthalein indicator solution: 10 g/L.
126.96.36.199 Analytical procedures
Weigh (0.50 ± 0.01) g of the specimen. Place it in a porcelain evaporating dish. Add 3 mL of aqua regia. Evaporate it to dryness, on a boiling water bath. Add 5 mL of hydrochloric acid solution to dissolve the residue. Transfer it into a 150 mL separatory funnel. Use 5 mL of hydrochloric acid solution each time to wash the ceramic evaporating dish twice. Combine the washings into the separatory funnel. Use diethyl ether to extract three times, using 40 mL of acetyl each time. Then add 20 mL of diethyl ether. Shake for 1 min. After standing for layering, transfer the aqueous layer into a 50 mL colorimetric tube. Add 0.05 g of hydroxylamine hydrochloride. Dissolve it. After heating on a boiling water bath for 10 min, add 1 drop of phenolphthalein indicator solution. Add ammonia water dropwise, until the solution turns red. After cooling, add hydrochloric acid solution dropwise, until the solution is almost colorless. Add 2 mL of acetic acid solution. Use water to dilute it to about 50 mL. Add 2 drops of sodium sulfide-glycerol solution dropwise. Use water to dilute it to the mark. Shake well. Leave 6 Inspection rules
6.1 All items specified in this standard are exit-factory inspection items, which shall be inspected batch by batch.
6.2 The feed grade ferrous sulfate, which is produced continuously or by the same shift of the manufacturer, using the same materials, under basically same production conditions, forms a batch. Each batch of product shall not exceed 40 t. 6.3 Determine the number of sampling units, according to the provisions of GB/T 6678. When sampling, insert the sampler vertically into 3/4 of the packaging bag, for sampling. After mixing the collected samples, divide them into quarters to no less than 200 g. Contain it into two clean, dry glass bottles with ground stoppers. Seal tightly. Paste a label on the bottle, indicating the name of the manufacturer, product name, batch number, sampling date, the name of the sampler. One bottle is used for inspection, whilst the other bottle is stored for future reference. The storage time is determined by the manufacturer, according to actual needs.
6.4 Feed grade ferrous sulfate shall be inspected by the quality supervision and inspection department of the manufacturer, in accordance with the provisions of this standard. The manufacturer shall ensure that all products that leave the factory meet the requirements of this standard.
6.5 If any index of the inspection result does not meet the requirements of this standard, it shall be re-inspected, by re-sampling from twice the amount of packaging bags. Even if only one index of the re-inspection result does not meet the requirements of this standard, the entire batch of products is not qualified.
7 Signs, labels
7.1 There shall be firm and clear signs, on the packaging. The content includes manufacturer name, manufacturer address, product name, trademark, "feed grade" words, net weight, batch number or production date, production permit number, the number of this standard.
7.2 Each batch of exit-factory product shall have signs, the contents of which are in accordance with the requirements of GB 10648.
8 Packaging, transportation, storage
8.1 Feed-grade ferrous sulfate is packed in double layers, wherein the inner packaging is plastic film bag AND the outer packaging is plastic woven bag. The inner bag is tied by rope or heat-sealed; the outer bag is sealed by bag-sewing machine. The net content of each bag is 25 kg or 50 kg. Where the user has special requirement, it shall be