Some standard content:
1 Scope
Organic-inorganic compound fertilizer
GB18877-2002
This standard specifies the technical requirements, test methods, inspection rules, labeling, packaging, transportation and storage of organic-inorganic compound fertilizers. This standard applies to organic-inorganic compound fertilizers made from organic materials such as livestock and poultry manure, animal and plant residues, various decomposed urban domestic waste for field application (must meet the requirements of GB8172 Urban Domestic Waste Agricultural Control Standard) through fermentation treatment and addition of inorganic fertilizers.
Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any referenced document without a period, its latest version shall apply to this standard Chemical reagents/General method for determination of phosphorus (spot method) GB/T610.
GB/T1250
Method for expressing and determining limit values General rules for sampling of solid chemical products
GB/T6679
General method for determination of phosphorus content in chemical products GB/T7686
GB7959-1987 Hygienic standard for harmless treatment of feces Standard for control of urban domestic waste
GB8172
Solid chemical
GB8569
Determination of available phosphorus content in compound fertilizers
GB/T8573
GB/T8577
Determination of free water content in compound fertilizers Karl Fischer method Compound fertilizers (compound fertilizers) Material)
GB15063--2001
GB/T17767.1
Determination of total ammonia content in organic-inorganic compound fertilizersG13/T17767.3 Determination of total potassium content in organic-inorganic compound fertilizersGB18382-2001 Contents and requirements of fertilizer labelingHGT2843 Standard titration solution, standard solution, reagent solution and indicator solution used in chemical analysis of fertilizer products "Product Quality Arbitration Inspection and Product Quality Appraisal Management Measures" 3 Terms and definitions
Fertilizerfertilizer
Material whose main function is to provide plant nutrients3.2
Inorganic (mineral) fertilizerinorganie (mineral) fertilizerFertilizer marked with nutrients in the form of inorganic salts, made by extraction, physical and (or) chemical industrial methods. 3.3
4organicfertilizer
Organic fertilizer
Carbon-containing materials mainly derived from plants and (or) animals, applied to the soil to provide plant nutrition as its main function. GB18877-2002
Organic-inorganic compound fertilizerorganic-inorganiccompoundfertilizerCompound fertilizer containing a certain amount of organic fertilizer3.5
Total primarynutrient
The sum of total nitrogen, available phosphorus pentoxide and total potassium oxide, measured by mass fraction. 4
Appearance: Granular or strip product, free of mechanical impurities 41
Organic-inorganic compound fertilizers shall meet the requirements of Table 1 Table 1
Mass fraction of total nutrients N+P0+K0/%
Mass fraction of water (HO)/%
Mass fraction of organic matter/%
Particle size.00mm~4.75mm or 3.35mm~5.60mm/%pH p
Insect egg mortality/%
Escherichia coli value
Mass fraction of nitrogen-containing ions (CI-) =/%Mass fraction of arsenic and its compounds (as As)/%Mass fraction of copper and its compounds (as Cd)/%Mass fraction of lead and its compounds (as Pb)/% (Mass fraction of Cr>/%Mass fraction of its compounds (assuming Hg)/%The mass fraction of the single nutrient indicated shall not be less than 2.0%, and the absolute value of the negative deviation between the measured value and the indicated value of the single nutrient shall not be greater than 1.0%. If the mass fraction of oxygen ions in the product is greater than 3.0%, and the packaging container is marked with "*Contains oxygen", this item is not required. 5
Test method
The preparation of reagents, water and solutions used in this standard shall comply with the provisions of HG/T2843 when the specifications and preparation methods are not indicated. 5.1 Appearance
Visual determination.
5.2 Determination of total oxygen content
Perform in accordance with GB/T17767.1
5.3 Effective phosphorus pentoxide Determination of content
Perform according to the provisions of GB/T8573.
5.4 Determination of total potassium oxide content
Perform according to the provisions of GB/T17767.3, and cancel the step of adding formaldehyde solution in the test solution treatment in 6.1.2. 5.5 Determination of moisture content Karl Fischer method
Perform according to the provisions of GB/T8577.
5.6 Determination of organic matter content Potassium dichromate volumetric method 5.6.1 Principle
GB18877-2002
Use a certain amount of potassium dichromate-sulfuric acid solution to oxidize the organic carbon in the organic-inorganic compound fertilizer under heating conditions, and titrate the remaining potassium dichromate solution with ferrous sulfate (or ammonium ferrous sulfate) standard titration bath, and perform a blank test at the same time. Root According to the consumption of oxidant before and after oxidation, calculate the organic carbon content, and convert the organic carbon content into organic matter by multiplying the organic carbon content by the empirical constant 1.724. 5.6.2 Reagents and materials
5.6.2.1 Sulfuric acid.
5.6.2.2 Sulfuric acid solution: 1+1
5.6.2.3 Potassium dichromate-sulfuric acid solution: c(-KzCrO.)=0.4mol/L. Weigh 39.23g of potassium dichromate and dissolve it in 600mL~800mL of water, and dilute it to 1L with water. Transfer the solution into a 3L beaker. Take another 1L of sulfuric acid and slowly add it to the potassium dichromate solution, mix well, cool it, and store it in a reagent bottle for later use. 5.6.2.4 Ferrous sulfate (or iron sulfate) standard titration solution: c(FcY=0.25mol/L. Weigh 70g of ferrous sulfate (FeSO4:7HO) or 1100g of ammonium ferrous sulfate (NH4SO4-FeSO4:6HO). Dissolve in 900mL of water. Add 20ml of sulfuric acid and dilute to 1L with water (filter if necessary). Shake well and store in a brown bottle. This solution is easily oxidized by air, so it must be calibrated with potassium dichromate standard solution each time it is used. Add two clean aluminum sheets to the solution to keep the solution concentration stable for a long time. Calibration of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution: accurately pipette 25.0mL of potassium dichromate standard solution into a 250ml conical flask, add 50mL~60mL of water, 10mL of sulfuric acid solution and 3~5 drops of o-phenanthroline indicator, and titrate with ferrous sulfate (or ammonium ferrous sulfate) standard titration solution. The titrated solution turns from orange to bright green and finally to brick red as the end point. According to the consumption of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution, calculate its accurate concentration c according to formula 1): V
Wherein:
1-the concentration of potassium dichromate standard solution, in moles per liter (mol/L); V-the volume of potassium dichromate standard solution absorbed, in milliliters (mL); V-the volume of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution consumed in titration, in milliliters (ml.). 5.6.2.5 Potassium dichromate standard solution: c
K, Cr.O,) = 0.2500mol/L. Weigh 12.2577g of standard potassium dichromate dried at 120C for 4h, dissolve it with a small amount of water, then transfer it to a 11-volume flask, dilute it with water to the scale and mix it. 5.6.2.6 O-phenamide indicator. www.bzxz.net
5.6.2.7 Aluminum sheet (chemically pure).
5.6.3 Instruments
5.6.3.1 Common laboratory instruments:
5.6.3.2 Water bath.
5.6.4 Analysis steps
Weigh 0.1g~1.0g of the sample (accurate to 0.0001g) (containing no more than 20mg of organic carbon), put it in a 250ml conical flask, and accurately add 25.0ml of potassium dichromate-sulfuric acid solution.Add a small curved-neck slide to the mouth of the triangular flask, then put it into a boiling water bath at 100°C, keep it warm for 30 minutes (keep the water boiling), remove it, cool it down, rinse the triangular flask with water, the total volume of the solution in the flask should be controlled at 75mL~100mL, add 35 drops of o-phenantheline indicator, and titrate with ferrous sulfate (or ammonium ferrous sulfate) standard titration solution. The titrated solution changes from orange to bright green and finally to brick red, which is the titration end point. Perform a blank test at the same time. If the amount of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution used for titrating the sample is less than 1/3 of the amount of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution used for the blank test, the sample weight should be reduced and re-measured. Regarding nitrogen ion interference, the oxygen ion content (%) shall be determined according to the steps specified in 5.11 of this standard and then deducted from the organic carbon determination result.
5.6 Determination of organic matter content Potassium dichromate volumetric method 5.6.1 Principle
GB18877-2002
Use a certain amount of potassium dichromate-sulfuric acid solution to oxidize the organic carbon in the organic-inorganic compound fertilizer under heating conditions, and the remaining potassium dichromate solution is titrated with ferrous sulfate (or ammonium ferrous sulfate) standard titration solution. , and do a blank test at the same time. Calculate the organic carbon content based on the oxidant consumption before and after oxidation, and convert the organic carbon content by multiplying the organic carbon content by the empirical constant 1.724 to convert it into organic matter. 5.6.2 Reagents and materials
5.6.2.1 Sulfuric acid
5.6.2.2 Sulfuric acid solution: 1+1
5.6.2.3 Potassium dichromate-sulfuric acid solution: c (-K.Cr.O.) = 0.4 mol/L. Weigh 39.23g of potassium dichromate and dissolve it in 600mL~800mL of water, and dilute it to 1L with water. Transfer the solution to a 3L beaker, take another 1L of sulfuric acid and slowly add it to the potassium dichromate solution, mix well, cool it, and then add it to a reagent bottle for later use
5.6.2.4 Ferrous sulfate (or ammonium ferrous sulfate ) Standard titration solution: cFe) = 0.25moL/L Weigh 70g of ferrous sulfate FeSO:7HO (or 1100g of ammonium ferrous sulfate L(NH.)SO, -FeSO.·6H01. Dissolve in 900mL of water, add 20ml of sulfuric acid and dilute to 1L with water (filter if necessary), shake and store in a brown bottle. This solution is easily oxidized by air, so it must be calibrated with potassium dichromate standard drop solution each time it is used. Add two clean aluminum sheets to the solution to keep the solution liquid stable for a long time. Calibration of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution: Accurately pipette 25.0mL of potassium dichromate standard solution into a 250ml conical flask, add 50mL~60mL of water, 10mL of sulfuric acid solution and o-phenanthroline flavor Add 3 to 5 drops of indicator and use ferrous sulfate (or ammonium ferrous sulfate) standard titration solution to fully titrate. The end point is when the titrated solution changes from orange to bright green and finally to brick red. Calculate its exact concentration based on the consumption of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution according to formula (1): V
Where:
is the concentration of potassium dichromate standard solution, in moles per liter (mol/L); V is the volume of potassium dichromate standard solution absorbed, in milliliters (mL); V is the volume of ferrous sulfate (or ammonium ferrous sulfate) standard titration bath consumed in titration, in milliliters (ml). 5.6.2.5 Potassium dichromate standard solution: c
K, CrO,) = 0.2506 mol/L. Weigh 12.2577 g of standard potassium dichromate dried at 120°C for 4 hours, dissolve it in a small amount of water, transfer it to a 1L volumetric flask, dilute it to the mark with water, and mix well. 5.6.2.6 O-phenanthroline indicator.
5.6.2.7 Aluminum sheet (chemically pure).
5.6.3 Instruments
5.6.3.1 Common laboratory instruments:
5.6.3.2 Water bath.
5.6.4 Analysis steps
Weigh 0.1g~1.0g (accurate to 0.0001g) of the sample (containing no more than 20mg of organic carbon) and put it into a 250ml conical flask. Add 25.0mL of potassium dichromate-sulfuric acid solution accurately. Add a small bend to the mouth of the conical flask, and then put it into a boiling water bath at 100C, keep warm for 30min (keep the water boiling), remove it, cool it down, rinse the conical flask with water. The total volume of the solution in the flask should be controlled at 75mL~100mL, add 35 drops of o-phenanthroline indicator, and titrate with ferrous sulfate (or ammonium ferrous sulfate) standard titration solution. The titrated solution turns from orange to bright green and finally brick red, which is the titration end point. When performing a blank test at the same time, if the amount of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution used for the titration sample is less than 1/3 of the amount of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution used for the blank test, the sample amount should be reduced and re-measured. Regarding fluoride ion interference, the oxygen ion content (%) is determined according to the steps specified in 5.11 of this standard, and then deducted from the organic carbon determination result.
GB18877-2002
5.6.5 Expression of analysis results
Organic matter content 2 is expressed as mass fraction (%) and calculated according to formula (2): z[V-ex0.003×1.5×100×1.72412
Where:
V is the volume of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution consumed during blank test, in milliliters (mL): V is the volume of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution consumed during sample determination , in milliliters (mL) - the concentration of ferrous sulfate (or ammonium ferrous sulfate) standard titration solution, in moles per liter (mol/L): C2
The mass of carbon equivalent to 1.00mL of 1.000mol/L ferrous sulfate (or ammonium ferrous sulfate) standard titration solution, in grams (g):
Oxidation correction coefficient
The content of chloride ions in the sample, in mass fraction (%) 1/12 - The mass fraction of organic carbon equivalent to 1% chloride ions m
The mass of the sample, in grams (g): 1.724 - The empirical conversion coefficient between organic carbon and organic matter. The arithmetic mean of the parallel determination results is taken as the determination result. 5.6.6 Allowable difference/
The absolute difference of parallel determination results shall not be greater than 1.0%. The absolute difference of determination results of different laboratories shall not be greater than 15%. 5.7 Particle size determination by sieving method
According to the provisions of 5.6 of GB150.63-2001. 5.8 Determination of pH value by pH acidometer method
5.8.1 Principle
The sample is dissolved in water and measured by pH acidometer. 5.8.2 Reagents and solutions
5.8.2.1 Phthalate standard solution Liquid: cC.H.CO, HCO, K）-0.05mol/L5.8.2.2 Phosphate standard buffer solution (KH.PO.) = 0.025mol/L (Na.HPy = 0/025mol/L: 5.8.2.3 Borate standard buffer solution cNaB0） = 0.01mol/L5.83 Instruments
5.8.3.1 Common laboratory instruments:
5.8.3.2 PH acidity meter: sensitivity is 0.01pH unit. 5.8-4 Analysis steps
Weigh 10.00g of fresh sample into a 100ml beaker, add 50ml of water without carbon dioxide, stir for 1min and let stand for 30min?Measure with PH acidity meter. Before determination: Calibrate the acidometer with standard green solution 5.8.5 Expression of analysis results
The pH value of the sample is expressed as pH value, and the arithmetic mean of the parallel determination results is taken as the determination result 5.8.6 Permissible difference
The absolute difference of the parallel determination results shall not exceed 0.1 pH. 5.9 Determination of ant egg mortality
Carry out in accordance with the provisions of Appendix B of GB/T7959-1987. 5.10 Determination of coliform value
Carry out in accordance with the provisions of Appendix A of GB/T7959-1987. 5.11 Determination of chloride ion content
GB18877--2002
Carry out in accordance with the provisions of 5.7 of GB15063-2001. If the filtrate is colored, a certain amount of filtrate (containing about 25 mg of chloride ions) should be accurately drawn, 2 g to 3 g of activated carbon should be added, and the mixture should be fully stirred and filtered. The mixture should be washed 3 to 5 times, and about 5 ml of water should be used each time to collect all the filtrate in a 250 ml conical flask. The following determination is carried out according to 5.7.3 of GB15063--2001, "add 5 ml of nitric acid solution and 25.0 ml of silver nitrate solution".
5.12 Preparation of sample solutions for determination of arsenic, arsenic, lead, chromium and mercury 5.12.1 Reagents and materials
5.12.1.1 Hydrochloric acid:
5.12.1.2 Nitric acid
5.12.1.3 Hydrochloric acid solution: 1+5.
5.12.2 Apparatus
Usually, laboratories only use a heat exchanger and a hot plate with a power of 1.8 kW to 2.4 kW 5.12.3. Preparation of sample solution
Weigh 5g to 8g of sample (accurate to 0.00lg) and place in a 400mL tall beaker. Add 30ml of hydrochloric acid and 10ml of nitric acid. Cover with a cover and heat slowly on a hot plate (if the reaction is intense and foams are generated, remove from the hot plate and cool for a while). After the intense reaction is over, carefully remove the surface of the beaker and heat to evaporate the acid to nearly dryness to drive out all the nitric acid. Add 50ml of hydrochloric acid solution to the cold beaker and heat to dissolve. After cooling to room temperature, transfer to a 250ml volumetric flask, dilute to scale with water, mix well, filter, and discard the first few milliliters of filtrate for later use.
5.12.4 Preparation of blank solution
Except for not adding the test solution, the other steps are the same as the preparation of the sample solution. 5.13 Determination of arsenic content
5.13.1 Determination of arsenic content
Silver diethyldithiocarbamate spectrophotometry (parameter method) Principle
5. 13. 1. 1
In an acidic medium, pentavalent silver is reduced to arsenic hydrogen (AsH) by potassium iodide, stannous oxide and primary hydrogen. It is absorbed by a pyridine solution of silver diethyldithiocarbamate to generate red soluble colloidal silver. Its absorbance is measured at a wavelength of 540nm. The absorbance is proportional to the content of the silver.
5.13.1.2 Reagents and materials
5.13.1.21 Hydrochloric acid,
5.131.2.2 Ascorbic acid
5.13.1.2.3 Arsenic-free metallic zinc particles:
50g/L of potassium iodide solution
5.131.2.4 Box
5.13.1.2 5
Silver diethyldithiocarbamate (DDTC) pyridine solution: 5g/L. Dissolve 1.25g silver diethyldithiocarbamate in pyridine and dilute to 250ml with the same pyridine. Place in a brown volumetric flask and avoid exposure to light. It can remain stable for two weeks: 5.13.1.2.6 Stannous chloride-hydrochloric acid solution: Dissolve 40g stannous oxide CSnCl·2H,O1 in a mixture of 25ml water and 75ml hydrochloric acid
5.13.1.2.7 Lead acetate cotton: Dissolve 50mg lead acetate LPb(CHO)-3H0 in 250mL water. Use this solution to squeeze out the absorbent cotton and remove the excess solution. Store in a sealed container; 5.13.1.2.8 Standard solution: 0.1mg/mlL: 5.13.12.9 Standard solution: 0.0025mg/ml. Take 2.50ml. The standard solution (5.13.1.2.8) is placed in a 100 mL volumetric flask and diluted to the mark with water. Mix well. This solution contains 2.5% of argon per mL and is prepared for use. 5.13.13 Apparatus
5.13.1.3.1 All glass containers for arsenic determination must be washed with concentrated sulfuric acid-potassium dichromate solution, then cleaned with water, and dried for use; 5.13.1.3.2 Common laboratory instruments;
5.13.1.3.3 Specimen determination instrument: a 15-ball arsenic determination instrument according to GB/T7686, and the 15-ball absorption tube is replaced with a 10mL volumetric tube, as shown in Figure 1, or other arsenic determination instruments that have been proven by experiments to give the same results under the specified test conditions, 1-100mL conical flask for generating arsenic complex; 2-a connecting tube for collecting hydrogen sulfide; 3-a 10mL volumetric tube for absorbing hydrogen sulfide.
Figure 1 Arsenic determination instrument
513.1.3.4 Spectrophotometer: with an absorption cell with an optical path of 1cm. 5.13.1.4 Analysis steps
5.13.1.4.1 Since pyridine has a foul odor, the operation should be carried out in a fume hood. 5.13.1.4.2 Drawing of the working curve: As shown in Table 2, take the standard solution (5.13.1.2.9) and place it in 7 conical flasks (Figure 1 in the middle
Standard plated volume/ml
Corresponding content/μg
Standard liquid volume/ml
Corresponding content/pg
Add 10ml of hydrochloric acid and a certain amount of water to each conical flask, and the volume must be about 40mL. At this time, the acidity of the liquid is e (HCI) = 3mol/L. Then add 2.0ml of potassium iodide solution and 2.0mL of stannous chloride solution, mix well, and let it stand for 15min. Place a small amount of lead acetate cotton in the glass tube (Figure 1 in the middle 2) to absorb hydrogen sulfide and dioxide. Sulfur, etc. Pipette 5.0mlL silver diethyldithiocarbamate pyridine solution into a 10mL measuring cylinder, connect the instrument as shown in Figure 1, and keep the ground glass joint sealed during the reaction. Weigh 5 zinc particles into a conical flask, quickly connect the instrument, and allow the reaction to proceed for about 45 minutes. Remove the measuring cylinder and shake the solution thoroughly to produce purple-red colloidal silver. Use a 1cm absorption cell at a wavelength of 540nm, with a standard solution with a 0 content of arsenic as the reference solution, adjust the spectrophotometer absorbance to zero, and then measure the absorbance of each standard solution. The color-developing solution can be stable in the dark for 2h, and the measurement should be carried out during this period. Use the arsenic content () of the standard drop as the horizontal coordinate and the corresponding absorbance as the vertical coordinate to draw a working curve. GB18877-200 2
5.13.14.3 Determination. Pipette a certain amount of test solution (so that its arsenic content is less than 20g and its volume is less than 30mL) into a 100mL conical flask (1 in Figure 1), add 10ml hydrochloric acid; add water to make the volume about 40mL, and add 1g ascorbic acid. The following steps are carried out according to the operating steps specified in 5.13.1.4.2, starting from "then add 2.0mL iodine solution and 2.0mL stannous chloride solution, mix the spoon, and let it stand for 15min..-, until ".....determine the absorbance of the solution" to complete the determination. 5.13.1.4.4 Blank test: Use a blank drop solution, and the other steps are determined by the sample. 5.13.1.5 Expression of analytical results
Arsenic (As) content w is expressed in mass It is expressed as a fraction (%) and calculated according to formula (3): (-co) × 250 × 100
hungry VX10
The content of arsenic in the sample solution found by the working curve, in micrograms (ug): co-the content of arsenic in the blank solution found by the working curve, in micrograms (ug): 250-the total volume of the sample solution, in milliliters (ml):-the mass of the sample in grams (g):
Vs-the volume of the test solution taken during the determination, in milliliters (mL). The arithmetic mean of the parallel determination results is taken as the determination result. 5.13.1.6 Allowable error
The relative deviation of the parallel determination results shall meet the requirements of Table 3 Table 3
Mass fraction of arsenic
0. 000 1~0. 002 0
5.13.2 Determination of arsenic Arsenic spot method (Gutzeit method) 5.13.2.1 Principle
Allowable relative deviation
In an acidic medium, pentavalent arsenic is reduced to arsenic hydrogen (AH) by potassium iodide, stannous oxide and primary hydrogen, and then reacts with mercuric bromide test paper. The depth of the yellow spot generated is proportional to the concentration of the species. The yellow spot can be compared with a series of standard spots generated by the same operation at the same time to determine the content of the species in the sample.
5.13.2.2 Reagents and materials
5.13.2.2.1 Hydrochloric acid:
5.13.2.2.2 Metal-free zinc particles:
5.13.2.2.3 Potassium iodide solution: 150g/I-513.2.2.4 Stannous oxide-hydrochloric acid solution. Same as = 13.1.2.55.13.2.2.5 Lead acetate cotton: Same as 5.13.12.75.13. 2.2.6 Mercuric bromide test paper: Weigh 1.25g mercuric bromide and dissolve it in 25mL anhydrous ethanol. Soak the quantitative filter paper in the solution for 1 hour, take it out and dry it in a dark place, and store it in a sealed brown bottle: 5.13.2.2.7 Arsenic standard solution: 0.1mg/ml; 5.13.2.2.8 Arsenic standard solution: 0.0025mg/mL. Same as 5.13.1.2.9 5.13.2.3 Apparatus
5.1 3.2.3.1 All glass containers for testing must be washed with concentrated sulfuric acid-potassium dichromate solution, then cleaned with water, dried and ready for use: GB188772002
5.13.2.3.2 Common laboratory instruments:
5.13.2.3.3 Tablet: Tablet as specified in GB/T610.1, as shown in Figure 2, or other devices proven by experiments to give the same results under the specified test conditions. Arsenic determination device; 5.13.2.3.4 When using, clamp the mercuric bromide test paper between the upper end of the glass tube (4 in Figure 2) and the glass cap (5 in Figure 2), and fix it with rubber
Unit is mm
Guangri bottle
2 Glue cold:
3-glass tube
Wax tube mouth of glass tube:
5 Glass cap.
Figure 2 determination device
5.13.2.4 Analysis steps
Put a certain amount of test solution (so that the content of tantalum is 0.5-5g and the volume is less than 30mL) and a series of standard solutions (5.13.2.2.8) (0ml, 0.5mL, 1.0mL, 1.5ml, 2.0ml, the corresponding content of tantalum is 0μg, 1.25g, 2.50±g, 3.75μg, 5.00pg) in each wide-mouth bottle (1 in Figure 2), add 10mL hydrochloric acid and a certain amount of water to each wide-mouth bottle, and the volume must be about 40ml. At this time, the acidity of the solution is c(HCl)-3mol/L. Then add 2.0ml potassium iodide solution and 2.0ml stannous oxide solution, mix well, and put it in a hood for 15min.
Put a small amount of lead acetate cotton in the glass tube (32 in Figure 2) to absorb hydrogen sulfide, sulfur dioxide, etc. Fix the mercuric bromide test paper according to the instrument requirements of 5.13.2.3
Weigh 5 zinc particles into the wide-mouth bottle, quickly connect the instrument as shown in Figure 2, and let the reaction proceed in the dark for 1h1.5h. Remove the mercuric bromide test paper and compare the color of the mercuric bromide test paper of the test solution with the color scale of the arsenic standard solution series to determine the arsenic content in the test solution.
Blank test: Use a blank solution and the other steps are measured with the same sample. 5.1 3.2.5 Expression of analysis results
Arsenic content W. Expressed as mass fraction (%), calculated according to formula (4): (G-cm) × 250 × 100
Wherein:
Compared with the standard color scale, the arsenic content in the sample solution is obtained in micrograms (ug); Compared with the standard color scale, the arsenic content in the blank solution is obtained in micrograms (ag); 250 - the total volume of the sample solution, in milliliters (mL); m
The mass of the sample, in grams (g):
V--When measuring, the volume of the test solution is taken in milliliters (mL). The arithmetic mean of the parallel measurement results is taken as the measurement result. 5.13.2.6 Allowable error
The relative deviation of the parallel measurement results shall comply with the requirements of Table 3. 5.14 Determination of ferroxene content by atomic absorption spectrophotometry 5.14.1 Principle
CB18877-2002
The ferroxene in the sample solution is converted into atomic vapor by an atomizer, and the generated atomic vapor absorbs the characteristic light emitted from the hollow cathode lamp. The wavelength of light is 228.8nm, and the absorbance is proportional to the concentration of ground state atoms. 5.14.2 Reagents and materials
Hydrochloric acid solution: cCHCI) = 0.5mol/L:
Ion standard solution: 1mg/mL
Sodium standard solution: 0.01mg/mL Pipette 10.0mL of the standard solution (5.14.22) into a 1000ml volumetric flask. Dilute to the mark with hydrochloric acid solution and mix well;
Dissolve acetylene or inert gas (for graphite furnace method). Device
Usually laboratory instruments
Atomic absorption spectrophotometer has background correction device. Equipped with a pot hollow cathode lamp and air acetylene fast burner or graphite furnace analysis steps!
Working curve drawing: As shown in Table 4, take the standard solution (5.14.2.3) and place it in 6 100ml volumetric bottles, dilute to the mark with hydrochloric acid solution, and mix.
Aluminum standard solution volume/ml
-corresponding concentration/cpg/mL)
Saw standard solution volume/ml
Corresponding concentration/(g/ml)
Before determination, refer to the instrument manual according to the properties of the element to be measured to select the best working conditions. Then, at a wavelength of ?28.8nm, use air-acetone fast oxidation flame or graphite furnace, take the standard solution with 0 cadmium content as the reference solution, adjust the absorbance of the atomic absorption spectrophotometer to zero, and then determine the absorbance of each standard solution. Draw the working curve with the concentration of cadmium (/ml) of each standard solution as the horizontal axis and the corresponding absorbance as the vertical axis. 5.14.4.2 Determination: Place the sample solution without dilution or take a certain amount of sample solution according to the radium content into a 100mL volumetric flask and dilute it to the scale with hydrochloric acid solution, mix it evenly, and use it as the test solution for determination (radium concentration must be less than 0.8g/mL). Under the same conditions as the determination of the standard solution, measure the absorbance of the sample solution and find the corresponding concentration (μg/ml) on the working curve. 5.14.4.3 Blank test: Use a blank solution and the other steps are determined with the sample. 5.14.5 Expression of analysis results
GB 188772002
When the sample solution is directly measured without dilution, the (Cd) content ws, expressed as mass fraction (%), is calculated according to formula (5): 5.14.5.1
(cs - cos) × 250 × 100
Wherein:
The manganese concentration in the sample solution found by the working curve, in micrograms per milliliter (g/m):Cos
The concentration in the blank solution found by the working curve, in micrograms per milliliter (g/mL)Total volume of the sample solution, in milliliters (ml):250
The mass of the sample, in grams (g).
5.14.5.2 When a certain amount of sample solution is taken and diluted to 100mL for determination, the steel (Cd) content Us, expressed as mass fraction (%), is calculated according to formula (6):
(Co-Cg)×100
）X109
The concentration of cadmium in the sample solution found by the working curve, in micrograms per milliliter (μg/mL): Ce6
The concentration of aluminum in the blank solution found by the working curve, in micrograms per milliliter (/mL) 100 The total volume of the diluted sample solution, in milliliters (ml): : -- The mass of the sample, in grams (g): V, -- The volume of a certain amount of sample solution taken, in milliliters (ml): 250 -- The total volume of the sample solution, in milliliters (ml). The arithmetic mean of the parallel determination results is taken as the determination result. 5.14.6 Allowable difference
The relative deviation of parallel determination results shall conform to the requirements of Table 5: Table 5
Mass fraction of lead
0.0001~0.0020
≥0.0020
Atomic absorption spectrophotometry
515 Determination of lead content
5151 Principle
Allowable relative deviation
The lead in the sample solution is converted into atomic vapor by an atomizer. The produced atomic vapor absorbs the light of the characteristic wavelength of 283.3 nm emitted from the lead hollow cathode lamp. The absorbance is proportional to the concentration of the ground state lead atoms. 5.15.2 Reagents and materials
515.2.1 Hydrochloric acid solution: c(HCD)=0.5mol/L5.15.2.2 Lead standard solution: 1mg/mL
5.15.2.3 Lead standard solution: 0.1mg/ml. Pipette 10.0 ml of the lead standard solution (5.15.2.2) into a 100 mL volumetric flask, dilute to the mark with hydrochloric acid solution and mix well:
5.15.2.4 Dissolved acetylene or inert gas (for graphite furnace method) 515.3 Apparatus
5.15.3.1 Common laboratory instruments:
Atomic absorption spectrophotometer equipped with a lead hollow cathode lamp and an air-acetylene burner or a graphite furnace 5.15.4 Analysis steps
GB18877-2002
5.15.4.1 Drawing of the working curve: As shown in Table 6, pipette the lead standard solution (5.15.2.3) into five 100 mL volumetric flasks respectively, dilute to the mark with hydrochloric acid solution and mix well. Table 6
Volume of lead standard solution/ml
Corresponding lead concentration/(ug/mL)
Before determination, select the best working conditions according to the properties of the element to be determined and refer to the instrument manual. Then, at a wavelength of 283.3nm, use an air-acetylene oxidation flame or a graphite furnace, use a standard solution with a lead content of 0 as the reference solution to adjust the absorbance of the atomic absorption spectrophotometer to zero, and then determine the absorbance of each standard solution. Use the lead concentration (/mL) of each standard solution as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 5.15.4.2 Determination: Place the sample solution without dilution or take a certain amount of sample solution according to the lead content and place it in a 100mL volumetric flask, dilute it to the scale with hydrochloric acid solution, mix it. As the test solution for determination (the lead concentration must be less than 8.0g/mL), measure the absorbance of the sample solution under the same conditions as the standard solution for determination, and find the corresponding lead concentration (g/ml) on the working curve. 5.15.4.3 Blank test: Use blank solution and other steps shall be measured with the same sample. 5.15.5 Expression of analytical results
5.15.5.1 When the sample solution is directly measured without dilution, the total amount of lead (Pb) is expressed as mass fraction (%) and is calculated according to formula (7): (G = C) × 250 × 100
Where:
The lead concentration in the sample solution found by the working curve is in micrograms per milliliter (g/ml) The lead concentration in the blank solution found by the working curve is in micrograms per milliliter (uB/ml): 250 The total volume of the sample solution is in milliliters (mL): - The mass of the sample is in grams (g) 71
5.1 5.5.2 When a certain amount of sample solution is taken and diluted to 100mL for measurement, the lead (Pb) content is expressed as mass fraction (%) It is expressed as calculated according to formula (8):
Wherein:
(Ca-Co2X100
)×109
The concentration of lead in the sample solution found by the working curve, in micrograms per milliliter (g/mL): The concentration of lead in the blank solution found by the working curve, converted to micrograms per milliliter (ug/mL) 100 The total volume of the diluted sample solution, in milliliters (ml): mi-the mass of the sample, in grams (g): V-the volume of a certain amount of sample solution absorbed, in milliliters (mL) 250-the total volume of the sample solution, in milliliters (mL) The arithmetic mean of the parallel determination results is taken as the determination result. 5.15.6 Allowable error
The relative deviation of the parallel determination results shall meet the requirements of Table 7: --8)
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