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HJ 745-2015: Soil. Determination of cyanide and total cyanide. Spectrometric method
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Soil. Determination of cyanide and total cyanide. Spectrometric method
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HJ 745-2015
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Basic data | Standard ID | HJ 745-2015 (HJ745-2015) | | Description (Translated English) | Soil. Determination of cyanide and total cyanide. Spectrometric method | | Sector / Industry | Environmental Protection Industry Standard | | Classification of Chinese Standard | Z18 | | Classification of International Standard | 13.080 | | Word Count Estimation | 13,159 | | Date of Issue | 2015-06-04 | | Date of Implementation | 2015-07-01 | | Quoted Standard | HJ 484; HJ 613; HJ/T 166 | | Regulation (derived from) | Ministry of Environment Announcement 2015 No.39 | | Issuing agency(ies) | Ministry of Ecology and Environment | | Summary | This standard specifies the determination of cyanide in soil and total cyanide by spectrophotometry. This standard applies to the determination of soil cyanide and total cyanide. When the sample amount is 10 g, isonicotinic - barbituric acid spectrophotometric detection limit of 0.01 mg/kg, detection limit of 0.04 mg/kg; isonicotinic acid - pyrazolone spectrophotometric detection limit was 0.04 mg/kg, detection limit of 0.16 mg/kg. | HJ 745-2015: Soil. Determination of cyanide and total cyanide. Spectrometric method---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Soil.Determination of cyanide and total cyanide.Spectrometric method
2015-06-04 released
2015-07-01 implementation
National Environmental Protection Standard of the People 's Republic of China
Determination of soil cyanide and total cyanide
Soil-Determination of cyanide and total cyanide-
Spectrometric method
Ministry of Environmental Protection
Directory
Preface ..ii
1 Scope of application
2 normative reference documents
3 terms and definitions
4 Principle of the method
5 interference and elimination
6 reagents and materials
7 instruments and equipment .3
8 samples .4
9 Analysis steps
Calculation and representation of results
11 Precision and Accuracy 6
12 Quality assurance and quality control
13 Waste treatment 7
Appendix A (informative) Preparation and calibration of standard solution of potassium ferricyanide 8
Foreword
To implement the "People's Republic of China Environmental Protection Law" to protect the environment, protect the safety and health of the human body, regulate soil cyanide and
Determination of total cyanide, the development of this standard.
This standard specifies the spectrophotometric method for the determination of cyanide and total cyanide in soil.
This standard is the first release.
Appendix A to this standard is an informative appendix.
This standard is organized by the Ministry of Environmental Protection Science and Technology Standards Division.
The main drafting unit of this standard. Shanghai Environmental Monitoring Center.
The standard verification unit. Jiangsu Province Environmental Monitoring Center, Nanjing Environmental Monitoring Center Station, Suzhou City Environmental Monitoring Center Station, on
Pudong New Area Environmental Monitoring Station, Shanghai Putuo District Environmental Monitoring Station, Shanghai Textile Energy Conservation and Environmental Protection Center.
This standard is approved by the Ministry of Environmental Protection on June 4,.2015.
This standard has been implemented since July 1,.2015.
This standard is explained by the Ministry of Environmental Protection.
Determination of soil cyanide and total cyanide - Spectrophotometric method
Warning. Hydrocyanic acid and cyanide are highly toxic substances. In acidic solutions, highly toxic hydrocyanic acid gas (with pungent almonds)
Taste) will be volatile out. Therefore, the sample should not be acidified unless the experiment is carried out at a specific step. The entire experimental process should be ventilated
The laboratory personnel in the treatment of contaminated samples should be put on the appropriate gas masks.
1 Scope of application
This standard specifies the spectrophotometric method for the determination of cyanide and total cyanide in soil.
This standard is applicable to the determination of cyanide and total cyanide in soil.
When the sample amount is 10 g, the detection limit of isonicotinic acid-barbituric acid spectrophotometry is 0.01 mg/kg and the lower limit of determination is 0.04
Mg/kg; isonicotinic acid - pyrazolone spectrophotometric detection limit of 0.04 mg/kg, the determination of the lower limit of 0.16 mg/kg.
2 normative reference documents
The contents of this standard refer to the following documents or their terms. For those who do not specify a date, the valid version applies to this
standard.
Determination of water quality cyanide and its spectrophotometric method
Determination of Dry Matter and Moisture in Soil
Technical specification for soil environmental monitoring
3 terms and definitions
The following terms and definitions apply to this standard.
3.1
Cyanide cyanide
Refers to cyanide in the presence of zinc nitrate in the presence of zinc nitrate in the presence of zinc nitrate, including all simple cyanide
(Mostly alkali metal and alkaline earth metal cyanide) and zinc cyanide complex, does not include ferricyanide, ferrocyanide, copper cyanide complex,
Nickel cyanide complex and cobalt cyanide complex.
3.2
Total cyanide
Refers to cyanide in the presence of divalent tin and divalent copper in the presence of pH < 2 phosphoric acid, and the distillation can form cyanide
Department of simple cyanide (mostly alkali and alkaline earth metal cyanide, ammonium cyanide) and the vast majority of complex cyanide.
4 principle of the method
4.1 isonicotinic acid - barbituric acid spectrophotometric method
The cyanide ions in the sample react with chloramine T under weakly acidic conditions to form cyanogen chloride, then react with isonicotinic acid,
Into glutaraldehyde, and finally with barbituric acid reaction to produce purple blue compounds, the material at 600 nm wavelength at the maximum absorption.
4.2 isonicotinic acid - pyrazolone spectrophotometric method
The cyanide ions in the sample react with chloramine T under neutral conditions to form cyanogen chloride and then react with isonicotinic acid to form
Pentenaldehyde, and finally reacted with pyrazolone to form a blue dye, the material at 638 nm wavelength at the maximum absorption.
5 interference and elimination
When the sample particles can not be uniformly dispersed in water, but accumulate on the reagent-air surface or reagent-glass wall interface
, Will lead to reduced accuracy and precision, can be added before the distillation of 5 ml of ethanol to eliminate the impact.
Sulfide in the sample will interfere with the determination, the addition of copper sulfate during distillation can inhibit the interference of sulfide.
When the content of phenol in the sample is less than 500 mg/L, the determination of cyanide is not affected.
Grease interference can be added before the color of sodium dodecyl sulfate to be eliminated.
6 reagents and materials
Unless otherwise stated, analytical analytical reagents conforming to national standards are used in the analysis, and the test water is a freshly prepared distilled water or
Ion water.
6.1 tartaric acid solution. ρ (C4H6O6) = 150 g/L.
Weigh 15.0 g of tartaric acid dissolved in water, diluted to 100 ml, shake.
6.2 zinc nitrate solution. ρ [Zn (NO3) 2 · 6H2O] = 100 g/L.
Weigh 10.0 g of zinc nitrate dissolved in water, diluted to 100 ml, shake.
6.3 Phosphoric acid. ρ (H3PO4) = 1.69 g/ml.
6.4 Hydrochloric acid. ρ (HCl) = 1.19 g/ml.
6.5 hydrochloric acid solution. c (HCl) = 1 mol/L.
Measure 83 ml of hydrochloric acid (6.4) slowly into the water, let cool down to 1000 ml.
6.6 Stannous chloride solution. ρ (SnCl2 · 2H2O) = 50 g/L.
Weigh 5.0 g of stannous chloride dihydrate in 40 ml hydrochloric acid solution (6.5), diluted with water to 100 ml, with the current allocation.
6.7 copper sulfate solution. ρ (CuSO4 · 5H2O) =.200 g/L.
Weigh.200 g of copper sulfate pentahydrate dissolved in water, diluted to 1000 ml, shake.
6.8 Sodium hydroxide solution. ρ (NaOH) = 100 g/L.
Weigh 100 g of sodium hydroxide dissolved in water, diluted to 1000 ml, shake, stored in polyethylene containers.
6.9 Sodium hydroxide solution. ρ (NaOH) = 10 g/L.
Weigh 10.0 g of sodium hydroxide dissolved in water, diluted to 1000 ml, shake, stored in polyethylene containers.
6.10 Sodium hydroxide solution. ρ (NaOH) = 15 g/L.
Weigh 15.0 g of sodium hydroxide dissolved in water, diluted to 1000 ml, shake, stored in polyethylene containers.
6.11 Chloramine T solution. ρ (C7H7ClNNaO2S · 3H2O) = 10 g/L.
Weigh 1.0 g of chloramine T dissolved in water, diluted to 100 ml, shake, stored in brown bottles, with the current allocation.
6.12 potassium dihydrogen phosphate solution (pH = 4).
Weigh 136.1 g of anhydrous potassium dihydrogen phosphate (KH2PO4) in water, add 2.0 ml of glacial acetic acid (C2H4O2), dilute with water
Release to 1000 ml, shake well.
6.13 isonicotinic acid - barbituric acid color reagent.
Weigh 2.50 g of isonicotinic acid (C6H6NO2) and 1.25 g of barbituric acid (C4H4N2O3) in 100 ml of sodium hydroxide solution
(6.10), shake, when the temporary allocation is available.
6.14 Sodium hydroxide solution. ρ (NaOH) = 20 g/L.
Weigh 20.0 g of sodium hydroxide dissolved in water, diluted to 1000 ml, shake, stored in polyethylene containers.
6.15 Phosphate buffer solution (pH = 7).
Weigh 34.0 g of anhydrous potassium dihydrogen phosphate (KH2PO4) and 35.5 g of anhydrous disodium hydrogen phosphate (Na2HPO4) in water,
Release to 1000 ml, shake well.
6.16 isonicotinic acid - pyrazolone reagent.
6.16.1 isonicotinic acid solution.
Weigh 1.5 g of isonicotinic acid (C6H6NO2) in 25 ml sodium hydroxide solution (6.14), diluted with water to 100ml.
6.16.2 Pyrazolone solution.
Weigh 0.25 g of pyrazolone (3-methyl-1-phenyl-5-pyrazolone, C10H10ON2) was dissolved in 20 ml of N, N-dimethylformyl
Amine [HCON (CH3) 2].
6.16.3 isonicotinic acid-pyrazolone solution.
The mixture of pyrazolone solution (6.16.2) and isonicotinic acid solution (6.16.1) 1. 5 were mixed.
Note 1. isonicotinic acid dubbed solution after the show was pale yellow, so that the blank value increased, can be filtered. In the experiment to use colorless
N, N-dimethylformamide is preferred.
6.17 Potassium cyanide standard stock solution. ρ (KCN) = 50 μg/ml.
Purchase commercially available reference material. Such as self-preparation, can refer to HJ 484 implementation.
6.18 Potassium cyanide standard solution. ρ (KCN) = 0.500 μg/ml.
Absorb 10.00 ml of potassium cyanide standard solution (6.17) in 1000 ml brown volumetric flask, with sodium hydroxide solution (6.9) dilute
Release to the marking, shake, with the current allocation.
7 instruments and equipment
Unless otherwise stated, the use of the national standard A-class glass gauge is used for the analysis.
7.1 Analytical Balance. Accuracy, 0.01 g.
7.2 Spectrophotometer. with 10 mm cuvette.
7.3 constant temperature water bath device. temperature control accuracy ± 1 ℃.
7.4 Electric furnace. 600 W or 800 W, adjustable power.
7.5 All glass distiller. 500 ml, the instrument device shown in Figure 1.
7.6 Receiving bottle. 100 ml volumetric flask.
7.7 with a plug color tube. 25 ml.
7.8 Measuring tube. 250 ml.
7.9 General laboratory equipment and equipment commonly used.
1 - adjustable electric furnace 2 - distillation bottle 3 - condenser 4 - receiving bottle 5 - distillate conduit
Figure 1 All glass distiller
8 samples
8.1 Acquisition and storage
The sampling and sampling methods of the sampling points were carried out in accordance with HJ/T 166 and collected with a sealable polyethylene or glass vessel at 4 ° C
The samples were filled with containers and the samples were analyzed within 48 h of collection.
8.2 Sample Weighing
Weigh about 10 g dry weight of the sample on the weighed paper (accurate to 0.01 g), slightly wrapped into the distillation bottle. Also called sample
Dry matter was determined according to HJ 613.
Note 2. If the cyanide content of the sample is high, the sample may be weighed or measured after dilution of the absorbing liquid (sample A).
8.3 Preparation of cyanide samples
Referring to Figure 1, connect the distillation unit, open the condensate, add 10 ml sodium hydroxide solution (6.9) to the receiving flask (7.6)
As an absorbent. After adding the sample, add.200 ml of water, 3.0 ml of sodium hydroxide solution (6.8) and
10 ml of zinc nitrate solution (6.2), shake, quickly add 5.0 ml tartaric acid solution (6.1), immediately cover the plug. Open the electric furnace (7.4),
From the low gradually increased, distillate to 2 ml/min ~ 4 ml/min speed of heating distillation. When the sample is nearly 100 ml,
Stop the distillation, rinse the distillate with a small amount of water to remove the receiver bottle, water volume (V1), this is the sample A.
8.4 Preparation of total cyanide sample
Referring to Figure 1, connect the distillation unit, open the condensate, add 10 ml sodium hydroxide solution (6.9) to the receiving flask (7.6)
For the absorption of liquid. After adding the sample, add.200 ml of water, 3.0 ml of sodium hydroxide solution (6.8), 2.0
Ml of stannous chloride solution (6.6) and 10 ml of copper sulfate solution (6.7), shake well, add 10 ml of phosphoric acid (6.3), immediately
Capper Open the electric furnace (7.4), gradually increased from the low, distillate to 2 ml/min ~ 4 ml/min speed heating distillation. Then
Close the bottle sample nearly 100 ml, stop the distillation, with a small amount of water to rinse the distillate catheter after removal of the receiving bottle, water volume (V1)
This is sample A.
Note 3. As in the preparation of the sample, leakage of the distillation or absorption device leads to the volatilization of hydrogen cyanide, which will result in the analysis of cyanide
Health error and pollution of the laboratory environment, so in the distillation process must always check the vaporization of the distillation unit. Distillation
, The lower end of the distillate conduit must be inserted into the absorption liquid level, so that hydrogen cyanide absorption is complete.
8.5 blank sample preparation
In the distillation bottle (7.5), only.200 ml of water and 3.0 ml of sodium hydroxide solution (6.8) were added and operated in the same manner as in step 8.3 or 8.4 to give
Blank test sample B.
9 Analysis steps
9.1 Calibration curve drawing
9.1.1 isonicotinic acid-barbituric acid spectrophotometric method
Take 6 25 ml of plug colorimetric tube (7.7), respectively, by adding potassium cyanide standard solution (6.18) 0.00,0.10,0.50,
1.50, 4.00 and 10.00 ml, then add sodium hydroxide solution (6.9) to 10 ml. The cyanide content of the standard series is respectively
0.000.05,0.25,0.75,2.00,5.00 μg. Add 5.0 ml of potassium dihydrogen phosphate solution (6.12) to each tube, mix,
Quickly add 0.30 ml of chloramine T (6.11) solution, immediately cover plug, mix, place 1 min ~ 2 min. Add 6.0 ml to each tube
Isonicotinic acid - barbituric acid color reagent (6.13), diluted with water to the mark, shake, at 25 ℃ for 15 min (15 ℃ color 25 min;
30 ° C for 10 min). Spectrophotometer (7.2) at 600 nm wavelength, with 10 mm cuvette, with water as a reference, measured
Absorbance. The cyanide content (μg) is the abscissa, and the absorbance after deduction of the reagent blank is the ordinate.
line.
9.1.2 isonicotinic acid - pyrazolone spectrophotometric method
Take 6 25 ml of plug colorimetric tube (7.7), respectively, by adding potassium cyanide standard solution (6.18) 0.00,0.10,0.50,
1.50, 4.00 and 10.00 ml, then add sodium hydroxide solution (6.9) to 10 ml. The cyanide content of the standard series is respectively
Is 0.000.05,0.25,0.75,2.00,5.00 μg. Add 5.0 ml of phosphate buffer solution (6.15) to each tube and mix
And quickly add 0.20 ml of chloramine T (6.11) solution, immediately seize, mix, place 1 min ~ 2 min. Add to each tube
Into the 5.0ml isonicotinic acid-pyrazolone reagent (6.16), diluted with water to the mark, shake, in 25 ℃ ~ 35 ℃ water bath device (7.3)
In color for 40 min. Spectrophotometer (7.2) at 638 nm wavelength, with 10 mm cuvette, with water as a reference, measured suction
Luminosity. The cyanide content (μg) is the abscissa, and the calibration curve is drawn by taking the absorbance after the reagent blank as the ordinate.
Note 4. Hydrogen cyanide is volatile, so every step in 9.1.1 and 9.1.2 is handled quickly and the cap is tightened at all times.
9.2 Determination of sample
Extraction from Sample A 10.0 ml Sample A was operated in a 25 ml stopper color tube (7.7) according to 9.1.1 or 9.1.2.
9.3 blank test
Extraction from Sample B 10.0 ml Blank Sample B In a 25 ml stopper color tube (7.7), press 9.1.1 or 9.1.2
For.
10 results are calculated and expressed
10.1 Result calculation
Cyanide or total cyanide content of ω (mg/kg), calculated as cyanide (CN-) according to formula (1)
10) (
Vwmb
VaAA
Dm ×××
× - = ω
(1)
Where. ω - cyanide or total cyanide (105 ℃ dry weight) content, mg/kg;
A - absorbance of sample A;
BA - absorbance of blank sample B;
A - calibration curve intercept;
B - calibration curve slope;
1V - volume of sample A, ml;
2V - volume of sample A, ml;
M - the quality of the sample to be weighed, g;
Dmw - dry matter content in sample,%.
10.2 results are shown
When the determination result is less than 1 mg/kg, two decimal places are retained; when the result is greater than or equal to 1 mg/kg,
Effective figures.
11 precision and accuracy
11.1 precision
Six labs were used to determine the uniform samples with cyanide content of 0.17 mg/kg, 0.18 mg/kg, 1.48 mg/kg, and the laboratory
The relative standard deviations were 2.9 to 16%, 3.7 to 12% and 0.6 to 8.1%, respectively. The relative standard deviations were 9.0% and 22%
23%; repeatability limit 0.04 mg/kg, 0.04 mg/kg, 0.23 mg/kg; reproducibility limit 0.06 mg/kg, 0.12 mg/kg, 0.96
Mg/kg.
Six labs were used to determine the total sample with total cyanide content of 0.19 mg/kg, 0.41 mg/kg, 23.0 mg/kg.
The relative standard deviations were 1.2 ~ 20%, 3.5 ~ 12% and 1.2 ~ 9.5%, respectively. The relative standard deviations were 8.9% and 8.5%
13%; repeatability limit of 0.06 mg/kg, 0.09 mg/kg, 3.2 mg/kg; reproducibility limit of 0.07 mg/kg, 0.13 mg/kg, 9.0 mg/kg.
11.2 Accuracy
Six laboratory samples were prepared by adding spiked samples with a cyanide content of 0.17 mg/kg and 0.18 mg/kg.
3.0 ~ 4.0 μg, the recoveries were 72.1% ~ 95.8% and 71.8% ~ 94.8%, respectively. The final recoveries were 87.7% ± 16.6%
85.4% ± 18.8%.
6 laboratory samples of total cyanide content of 0.19 mg/kg, 0.41 mg/kg of uniform samples were measured by spiking, plus scalar
The recoveries were 72.8% ~ 118.7% and 83.0% ~ 112.1%, respectively. The final recoveries were 92.6% ± 29.8%
96.2% ± 21.4%.
6 laboratories of the total cyanide content of 25.7 mg/kg of the reference material were measured, the relative error of -26% to 8.2%, respectively,
Relative error final value. -10.3% ± 23.6%.
12 quality assurance and quality control
12.1 The cyanide and total cyanide content of the blank test should be less than the method detection limit.
12.2 each batch of samples should be 10% of the parallel sample analysis, the relative deviation of cyanide should be less than 25%, the relative deviation of total cyanide
Should be less than 15%. If the sample is not uniform, should meet the requirements of precision at least two parallel samples of the determination of parallel samples were
Value reported the results.
12.3 each batch of samples should do 10% of the standard sample analysis, cyanide and total cyanide spiked recovery should be controlled at 70% to 120%
between. Cyanide plus the standard use of cyanide standard solution, the total cyanide of the spikes can use potassium ferricyanide standard solution (preparation
With the calibration see Appendix A), after the spike of the sample with the sample to be tested simultaneously.
12.4 Regular use of certified reference materials for testing.
12.5 calibration curve regression equation of the correlation coefficient γ ≥ 0.99; each batch of samples should be done an intermediate checkpoint, the measured value and calibration
The relative deviation of the corresponding point concentration should not exceed 5%.
13 Waste treatment
The waste generated in the experiment should be collected collectively and marked clearly, such as "toxic waste (cyanide)", commissioned by qualified
Of the unit disposal.
Appendix A
(Informative)
Preparation and Calibration of Standard Solution of Potassium Ferricyanide
A.1 Reagents and materials
Unless otherwise stated, analytical analytical reagents conforming to national standards are used in the analysis, and the test water is a freshly prepared distilled water or
Ion water.
A.1.1 Potassium iodide (KI).
A.1.2 Hydrochloric acid solution. 1 1.
A.1.3 Starch solution. ρ = 0.01 g/ml.
Weigh 1.0 g of soluble starch, with a small amount of water into a paste, slowly pour 100 ml of boiling water, continue to boil to the solution to clarify the cold
But after storage in the reagent bottle, with the current allocation.
A.1.4 glacial acetic acid (C2H4O2).
A.1.5 zinc sulfate solution. ρ (ZnSO4) = 0.15 g/ml.
Weigh 15g zinc sulfate, diluted with just boiling water to 100 ml.
A.1.6 Standard solution for potassium dichromate. c (1/6K2Cr2O7) = 0.1000 mol/L.
Weigh the reference potassium dichromate 4.4030 g in water for 2 h drying at 105 ° C and transfer to 1000 ml volumetric flask.
Line, shake well.
A.1.7 sodium thiosulfate standard solution. c (Na2S2O3) = 0.1 mol/L.
Weigh 24.5 g of sodium thiosulfate pentahydrate (Na2S2O3.5H2O) and 0.2 g of anhydrous sodium carbonate (Na2CO3) in water
Moved to 1000 ml brown volumetric flask, constant volume to the marking, shake. To be used after calibration.
Sodium thiosulfate standard solution calibration.
(A.1.6) 15.00 ml In the iodine bottle, add 1 g of potassium iodide (A.1.1) and 50 ml of water, add
Into 5ml hydrochloric acid solution (A.1.2) 5 ml, dense plug. Set the dark place for 5 min, with the standard sodium thiosulfate standard solution to be calibrated
Titration to the solution was pale yellow, add 1 ml starch solution (A.1.3), continue to titrate to blue just disappeared, record the amount of standard solution,
While blank titration.
The concentration of sodium thiosulfate standard solution is calculated according to formula (A.1)
1000.0
) (
00.15
× - = VVc (A.1)
Where. 1V - titration of potassium dichromate standard solution sodium thiosulfate standard solution dosage, ml;
2V - titration of blank solution when the amount of sodium thiosulfate standard solution, ml;
0.1000 - Concentration of potassium dichromate standard solution, mol/L.
A.1.8 Sodium thiosulfate standard titration solution. c (Na2S2O3) = 0.01 mol/L.
Remove 10.00 ml of the above standard sodium thiosulfate standard solution (A.1.7) in a 100 ml brown volumetric flask,
Marking, shaking, with the current allocation.
A.2 preparation and calibration of potassium ferricyanide standard stock solution
A.2.1 potassium ...
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