Some standard content:
HG2763—1996
This industry standard is formulated based on the product specifications of sodium monofluorophosphate of well-known foreign companies and the requirements of the domestic toothpaste industry. The technical indicators and parameters of this standard are equivalent to the product specifications of well-known foreign companies. In terms of analytical methods, the main content determination adopts the diffusion fluoride ion selective electrode instrument method, and the analysis of other items adopts the domestic general determination method. The analytical method is scientific, accurate and advanced. 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 the Tianjin Chemical Research Institute of the Ministry of Chemical Industry. The drafting units of this standard: Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Nuclear Industry Physical and Chemical Engineering Research Institute. The main drafters of this standard: Li Guangming, Lu Siwei, Sun Jingshan, Li Qixuan, Wen Qian. 589
Chemical Industry Standard of the People's Republic of China
Sodium Monofluorophosphate for Toothpaste Industry
HG 2763—1996
This standard specifies the requirements, test methods, inspection rules, as well as marking, packaging, transportation and storage of sodium monofluorophosphate for toothpaste industry. This standard applies to sodium monofluorophosphate for toothpaste industry, which is synthesized from sodium metaphosphate and sodium fluoride. This product is mainly used as an anti-caries and desensitizing additive for toothpaste, and is also used as a bactericide and preservative. Molecular formula: NazPO,F
Relative molecular mass: 143.95 (according to the 1991 international relative atomic mass) Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the following standards. GB191—1990 Pictorial signs for packaging, storage and transportation
GB/T601—1988 Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents GB/T 602--1988
GB/T 603—1988
Chemical reagents
Preparation of standard solutions for impurity determination (negISO6353-1:1982) Preparation of preparations and products used in chemical reagent test methods (negISO6353-1:1982) GB/T 610.1--1988
GB/T 6543--1986
GB/T 6678--1986
GB/T 6682-1992
GB/T 9735--1988
3 Requirements
Chemical reagents General method for determination of arsenic Arsenic spot method Corrugated paperboard
General rules for sampling of chemical products
Test methods for water specifications for analytical laboratories (egviS03696:1987) Chemical reagents
General method for determination of heavy metals
3.1 Appearance: This product is white crystals or white powder, visually free of impurities. 3.2 Sodium monofluorophosphate for toothpaste industry shall meet the requirements of Table 1. Table 1 Requirements
Sodium monofluorophosphate (as NazPO,F) content/%Bound fluorine (as F) content/%
Free fluorine (as F) content/%
Total fluorine (as F) content/%
Arsenic (As) content/%
Heavy metal (as Ph) content/%
pH value (20g/L solution)
Loss on drying/%
Approved by the Ministry of Chemical Industry of the People's Republic of China on January 24, 1996 590
Implementation on January 1, 1997
Test method
HG 2763—1996
The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and grade 3 water specified in GB/T6682. The standard titration solution, impurity standard solution, preparation and product required in the test shall be prepared in accordance with the provisions of GB/T601, G13/T602 and GB/T603 unless otherwise specified.
4.1 Sodium monofluorophosphate content
The content X of sodium monofluorophosphate (calculated as Na2PO,F) expressed as mass fraction is calculated according to formula (1): XI = 7.577X2
Where: X—the percentage of bound fluorine in the product (4.2); 7.577—the coefficient for converting the fluorine content in the product into the content of sodium monofluorophosphate. 4.2 Bound fluorine content
The content X2 of bound fluorine (calculated as F) expressed as mass fraction is calculated according to formula (2): X2 = X4 - X
Where: X,—the percentage of free fluorine in the product (4.3.5); X,———the percentage of total fluorine in the product (4.4.5). 4.3 Determination of free fluorine content
4.3.1 Method summary
(1)
The sample is placed in a weakly acidic medium, with a fluoride ion selective electrode as the measuring electrode and a saturated calomel electrode as the reference electrode to determine the fluoride ion concentration in the test solution.
4.3.2 Reagents and materials
4.3.2.1 Sodium nitrate solution: 30 g/L;
4.3.2.2 Nitric acid solution: 1+150;
4.3.2.3 Hexamethylenetetramine solution: 50 g/L;4.3.2.4 Fluorine standard solution: 1 mL of solution contains 1 mgF; Refining: In a plastic beaker, dissolve sodium fluoride with secondary water specified in GB/T6682 to make a saturated solution. Filter to remove insoluble matter, add anhydrous ethanol to the filtrate to precipitate sodium fluoride. The crystals obtained by filtration are washed with anhydrous ethanol, and the crystals are placed in an oven at 105-110°C and dried to constant weight.
Weigh 0.2210g of sodium fluoride (refined) (accurate to 0.0002g), dissolve it in a 100mL volumetric flask, dilute it to the mark with water, and shake it well. Store in a plastic bottle.
4.3.2.5 Fluorine standard solution: 1mL of solution contains 0.1mgF; use a pipette to transfer 10mL of fluorine standard solution (4.3.2.4), place it in a 100mL volumetric flask, dilute it to the mark with water, and shake it well. Store in a plastic bottle.
4.3.2.6 Fluorine standard solution: 1mL of solution contains 0.01mgF. Use a pipette to transfer 10mL of fluorine standard solution (4.3.2.5), place it in a 100mL volumetric flask, dilute it to the mark with water, and shake it well. Store in a plastic bottle.
4.3.3 Instruments and equipment
4.3.3.1 Digital ion meter: minimum scale value 0.001Px; 4.3.3.2 Fluoride ion selective electrode;
4.3.3.3 Calomel electrode;
4.3.3.4 Magnetic stirrer.
4.3.4 Analysis steps
4.3.4.1 Preparation of test solution
Weigh about 0.2g of sample (accurate to 0.0002g), place it in a 50mL volumetric flask, add 5mL of water to dissolve, use a pipette to add 591
HG 2763—1996
5mL sodium nitrate solution and 5mL hexamethylenetetramine solution, then add 5mL nitric acid solution, dilute to the scale with water, and shake well. 4.3.4.2 Preparation of fluorine standard solution for calibration Use a pipette to transfer 25 mL of fluorine standard solution (4.3.2.5) and fluorine standard solution (4.3.2.6) respectively, and place them in two 50 mL volumetric flasks. Use a pipette to add 5 mL of sodium nitrate solution and 5 mL of hexamethylenetetramine solution, and then add about 5 mL of nitric acid solution, adjust the pH of the solution to 5-6, and dilute to the scale. Transfer to two dry plastic bottles respectively. 4.3.4.3 Determination
Turn on the digital ion meter, connect the electrodes, set the "selector switch" to "PX-1", and adjust the instrument temperature to room temperature. According to the double standard insertion method, use the above-mentioned fluorine standard solution for calibration to calibrate the slope and position. Pour the test solution into a plastic beaker, balance it for 4 minutes under stirring, and then measure it. 4.3.5 Expression of analysis results
Free fluorine (F) content X expressed as mass fraction: calculated according to formula (3): Xs = anti log(-P,).V×0. 019m
Wherein: anti log(-Px)——antilogarithm of negative logarithm of fluoride ion concentration in test solution; V
volume of test solution, mL;
-mass of sample, g;
atomic weight of fluorine.
4.3.6 Allowable difference
The arithmetic mean of parallel determination results shall be taken as the determination result. The absolute difference of parallel determination results shall not exceed 0.1%. 4.4 Determination of total fluorine content
4.4.1 Summary of the method
The test solution is acidified with perchloric acid saturated with hexamethyldisiloxane to form hydrophobic trimethylfluorosilane, which diffuses and is absorbed by the alkaline solution. F ions are hydrolyzed in the absorption liquid. The fluoride ion selective electrode is used as the measuring electrode and the saturated calomel electrode is used as the reference electrode to determine the concentration of fluoride ions in the test solution.
4.4.2 Reagents and Materials
4.4.2.1 Sodium hydroxide solution: 4g/L;
4.4.2.2 Nitric acid solution: 1+150;
4.4.2.3 Saturated solution of hexamethyldisiloxane perchlorate; Pour 100mL (1+3.3) perchloric acid solution into a 175mL separatory funnel, add 50mL hexamethyldisiloxane, shake vigorously, and let it stand to separate. The lower layer is the saturated solution of hexamethyldisiloxane perchlorate. 4.4.2.4 Hexamethylenetetramine solution: 15g/L. 4.4.3 Instruments and equipment
4.4.3.1 Digital ion meter: minimum scale value 0.001Px; 4.4.3.2 Fluoride ion selective electrode;
4.4.3.3 Calomel electrode;
4.4.3.4 Magnetic stirrer;
4.4.3.5 Oscillator: 30 times/min, adjustable; 4.4.3.6 Diffusion box: made of polytetrafluoroethylene or polypropylene in a round shape (see Figure 1). a) Diffusion box cover: d110mm×20mm;
b) Diffusion box: d110mmX60mm;
c) Absorption cell: L×S×H=75mmX50mm×35mm. 592
4.4.4 Analysis steps
4.4.4.1 Preparation of test solution
HG 2763—1996
1—Diffusion box cover; 2Diffusion box; 3--Absorption cell Figure 1Diffusion box
Weigh about 0.2g of sample (accurate to 0.0002g), place it in a 250mL volumetric flask, and dilute it to the mark with water. Use a pipette to transfer 5mL of test solution and place it on the left side of the diffusion box (the diffusion plate should be placed at an angle of 30° and divided into three small chambers). Use a pipette to transfer 5ml of sodium hydroxide solution and place it in the middle chamber of the diffusion box. Take about 13ml of saturated hexamethyldisiloxane perchlorate solution and place it on the right side of the diffusion box. Apply Vaseline or vacuum grease to the interface of the diffusion box, cover it tightly with a lid, and seal it. Place the diffusion box on an oscillator and shake it for 2h (and then leave it for 24h).
4.4.4.2 Determination
Turn on the digital ion meter, connect the electrodes, set the "selector switch" to "PX-1", adjust the instrument temperature to room temperature, and use the fluorine standard solution (4.3.4.2) to calibrate the slope and position according to the double standard placement method. Open the diffusion box, add 5mL hexamethylenetetramine buffer and 5mL nitric acid solution to the middle chamber with a pipette, and adjust the solution pH to 5-6. After balancing for 4 minutes under stirring, perform the determination. 4.4.5 Expression of analysis results
The total fluorine (F) content X expressed as mass fraction is calculated according to formula (4):593
wherein: anti log(-P,)
HG 2763-1996
X = anti log(-P);VX0. 019
the antilog of the negative logarithm of the fluoride ion concentration in the test solution; the total volume of the liquid in the middle chamber of the diffusion box, ml.,Vr --
the volume of the test solution in the diffusion box, mL;V
4.4.6 Allowable difference
the total volume of the test solution, mL;
the mass of the sample, g;
the atomic weight of fluorine.
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.2%. 4.5 Determination of arsenic content
4.5.1 Method summary
See Chapter 3 of GB/T610.1.
4.5.2 Reagents and materials
4.5.2.1 Arsenic-free zinc particles;
4.5.2.2 Hydrochloric acid solution: 1+1;
4.5.2.3 Potassium iodide solution: 150g/L;
4.5.2.4 Stannous chloride solution: 400g/L; 4.5.2.5 Arsenic standard solution: 1mL contains 0.01mgAs. (4)
Use a pipette to transfer 10mL of the arsenic standard solution prepared according to GB/T602 into a 100mL volumetric flask, dilute with water to the mark and shake well. The solution is prepared before use.
4.5.2.6 Arsenic standard solution: 1mL contains 0.001mgAs. Use a pipette to transfer 10mL of arsenic standard solution (4.5.2.5), place it in a 100mL volumetric flask, dilute it to the mark with water, and shake it well. Prepare this solution before use.
4.5.2.7 Lead acetate cotton;Www.bzxZ.net
4.5.2.8 Mercuric bromide test paper.
4.5.3 Instruments and equipment
See Chapter 5 of GB/T610.1.
4.5.4 Analysis steps
Weigh about 1g of sample (accurate to 0.001g), place it in a 100mL beaker, add 50mL of water, and follow the steps in Chapter 6 of GB/T610.1 "Add 6mL of hydrochloric acid." The color of the mercuric bromide test paper shall not be darker than the standard. The standard is to use a pipette to transfer 3mL of arsenic standard solution (4.5.2.6) and treat it in the same way as the sample. 4.6 Determination of heavy metal content
4.6.1 Summary of the method
See Chapter 3 of GB/T9735.
4.6.2 Reagents and materials
4.6.2.1 Nitric acid solution: 1+1;
4.6.2.2 Ammonia solution: 2+3;
4.6.2.3 Glacial acetic acid solution: 1+2;
4.6.2.4 Saturated hydrogen sulfide water: prepare before use; 4.6.2.5 Lead standard solution: 1mL contains 0.01mgPb. Use a pipette to transfer 10mL of the lead standard solution prepared according to GB/T602, place it in a 100mL volumetric flask, dilute with water to the scale of 594
shake well. The solution is prepared before use.
4.6.3 Analysis steps
4.6.3.1 Preparation of test solution
HG 27631996
Weigh about 1g of sample (accurate to 0.001g), place in a 100ml beaker, add 10ml of water and 0.5mL of nitric acid solution, and adjust to pH~5 with ammonia water (check with precision test paper).
4.6.3.2 Determination
Transfer all the test solution to a 50ml colorimetric tube, add 0.5mL of acetic acid solution, add water to about 40mL, add 10mL of saturated hydrogen sulfide water, shake well, place in a dark place for 10 minutes, and compare with the lead standard colorimetric solution. The standard colorimetric solution is to take 5ml of lead standard solution with a pipette and treat it in the same way as the sample. 4.7 Determination of pH value
4.7.1 Summary of method
Immerse the glass electrode and the reference electrode in the test solution to form a primary cell, whose potential is related to the pH value of the solution. The pH value of the solution can be obtained by measuring the potential of the primary cell. 4.7.2 Instruments and equipment
4.7.2.1 Acidity meter: accuracy is 0.1 pH unit; 4.7.2.2 Glass electrode: must be soaked in water for more than 24 hours before use and stored in water; 4.7.2.3 Glycidyl electrode.
4.7.3 Analysis steps
Weigh about 2g of sample (accurate to 0.1g), place it in a 250ml beaker, add 100mL of water to dissolve it, and use a calibrated acidity meter to determine the pH value of the solution.
4.8 Determination of drying loss
4.8.1 Summary of the method
At a certain temperature, the drying loss is calculated by the reduction in the mass of the sample. 4.8.2 Analysis steps
Weigh 5g of the sample (accurate to 0.0002g) and place it in a weighing bottle that has been weighed to a constant weight. Place the weighing bottle in an oven at 105-110℃ and dry it to a constant weight.
4.8.3 Expression of analysis results
The drying loss X expressed as mass fraction is calculated according to formula (5): X, =m=ml ×100
Where: m—-mass of the sample after drying, g; m—-mass of the sample, g.
4.8.4 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.01%. 5 Inspection rules
5.1 All eight indicators specified in this standard are type inspection items, of which sodium monofluorophosphate, bound fluorine, free fluorine, total fluorine, and pH value are routine inspection items and should be inspected batch by batch. Under normal production conditions, type inspection should be carried out at least once every three months. 5.2 Sodium monofluorophosphate for toothpaste industry should be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products leaving the factory meets the requirements of this standard. Each batch of products leaving the factory should be accompanied by a quality certificate, which should include the manufacturer's name, address, product name, trademark, net weight, batch number or production date, shelf life, proof that the product quality complies with this standard, and the number of this standard. 5.3 The user has the right to inspect and accept the products received in accordance with the provisions of this standard. 5.4 Each batch of products shall not exceed 5t.
HG2763—1996
5.5 The number of sampling units shall be determined in accordance with the provisions of 6.6 of GB/T6678. Each box is a packaging unit, and one box has two bags. When sampling, insert the sample obliquely from the top of each selected packaging bag to 3/4 of the depth of the material layer, and take out no less than 50g of sample with a stainless steel sampler. After mixing the sample, reduce it to about 200g by quartering method, and immediately put it into two clean and dry polyethylene plastic bags and seal them; stick labels on the bags, indicating the manufacturer name, product name, batch number, sampling date and name of the sampler; one bag is used for inspection, and the other bag is kept for three months for reference. 5.6 If one of the indicators in the inspection results does not meet the requirements of this standard, re-sampling should be carried out from twice the amount of packaging for verification. If the verification results show that only one indicator does not meet the requirements of this standard, the entire batch of products will be unqualified. 6 Marking, packaging, transportation, purchase and storage
6.1 The packaging box of sodium monofluorophosphate for toothpaste industry should have firm and clear markings, including the manufacturer's name, address, product name, trademark, net weight, batch number or production date, shelf life and this standard number, as well as the "wet-afraid" mark in GB191. 6.2 Sodium monofluorophosphate for toothpaste industry is packaged in double corrugated boxes and plastic bags. The inner packaging is a plastic bag with a thickness of not less than 0.06mm. The outer packaging is a double corrugated box, and its performance and inspection methods should comply with the provisions of Class 2 products in GB/T6543. This product has two bags per box, and the net weight of each bag is 5kg, or the packaging specifications can be determined according to user requirements. 6.3 The inner packaging plastic bag of sodium monofluorophosphate for toothpaste industry is tightly sealed with a heat sealer, and the outer packaging box is tied with a plastic woven belt. 6.4 Sodium monofluorophosphate for toothpaste industry should be covered during transportation to prevent sun exposure, rain, and moisture, and must not be mixed with acidic substances. 6.5 Sodium monofluorophosphate for toothpaste industry should be stored in a cool, dry place, away from rain, moisture, sunlight, and heat; it should not be stored together with acidic substances.
6.6 Under the packaging, transportation, and storage conditions in accordance with this standard, the shelf life of this product is one year from the date of leaving the factory. 596
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