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HJ 833-2017: Soil and sediment. Determination of sulfide． Methylene blue spectrophotometric method
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Soil and sediment. Determination of sulfide． Methylene blue spectrophotometric method
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HJ 833-2017
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Basic data | Standard ID | HJ 833-2017 (HJ833-2017) | | Description (Translated English) | Soil and sediment. Determination of sulfide����Methylene blue spectrophotometric method | | Sector / Industry | Environmental Protection Industry Standard | | Classification of Chinese Standard | Z18 | | Classification of International Standard | 13.080 | | Word Count Estimation | 12,184 | | Date of Issue | 2017-07-18 | | Date of Implementation | 2017-09-01 | | Quoted Standard | GB 17378.3; GB 17378.5; HJ 613; HJ/T 166 | | Regulation (derived from) | MEP Announcement 2017 No. 31 | | Issuing agency(ies) | Ministry of Ecology and Environment | | Summary | This standard specifies the determination of sulfites in soils and sediments by methylene blue spectrophotometry. This standard applies to the determination of sulfide in sediments and soils. When the sample volume is 20g, the detection limit is 0.04 mg/kg and the lower limit of determination is 0.16 mg/kg. | HJ 833-2017: Soil and sediment. Determination of sulfide． Methylene blue spectrophotometric method
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(Soil and sediments - Determination of sulfide - Methylene blue spectrophotometric method)
National Environmental Protection Standard of the People 's Republic of China
Determination of soil and sediment sulfide
Methylene blue spectrophotometric method
Soil and sediment - Determination of sulfide -
Methylene blue spectrophotometric method
2017-07-18 released
2017-09-01 implementation
Ministry of Environmental Protection released
i 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
8 samples
9 Analysis steps
Calculation and representation of results
11 Precision and Accuracy 8
12 Quality assurance and quality control
13 Waste treatment 9
Appendix A (informative) Gas preparation method Preparation of sulfide standard stock solution
Foreword
For the implementation of the "People's Republic of China Environmental Protection Law" to protect the environment, protect human health, regulate soil and sediment sulfide
Determination method, the development of this standard.
This standard specifies the methylene blue spectrophotometric method for the determination of sulfides in soil and sediments.
This standard is the first release.
Appendix A to this standard is an informative appendix.
This standard is organized by the Environmental Monitoring Department of the Ministry of Environmental Protection, the Secretary for Science and Technology Standards.
The main drafting unit of this standard. Tianjin Environmental Monitoring Center.
The standard verification unit. Liaoning Province Environmental Monitoring Experimental Center, Inner Mongolia Environmental Monitoring Center Station, Fuzhou Environmental Monitoring Center Station, Lake
South China Environmental Monitoring Center Station, Tianjin Binhai New Area Environmental Protection Monitoring Station, Yangzhou City Environmental Monitoring Center Station.
The Environmental Protection Department of this standard approved on July 18,.2017.
This standard has been implemented since September 1,.2017.
This standard is explained by the Ministry of Environmental Protection.
Determination of soil and sediments Sulfide - Methylene blue spectrophotometric method
Warning. The sulfuric acid, hydrochloric acid, N, N-dimethyl-p-phenylenediamine hydrochloride used in the experiment are corrosive.
Wear protective equipment as required to avoid direct contact with these chemicals. The sample pretreatment process should be operated in a fume hood.
1 Scope of application
This standard specifies the methylene blue spectrophotometric method for the determination of sulfides in soil and sediments.
This standard applies to the determination of sulfides in soil and sediments.
When the sampling amount is 20 g, the detection limit is 0.04 mg/kg and the determination limit is 0.16 mg/kg.
2 normative reference documents
The contents of this standard refer to the following documents or their terms. For undated references, the valid version applies to this standard.
Specification for ocean monitoring - Part 3. Sample collection, storage and transport
Specification for marine monitoring - Part 5. Sediment analysis
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
Sulfide sulfide
Refers to soil and sediments in the acid-soluble sulfide.
4 Principle of the method
The sulfide in the soil and the sediment is acidified to form hydrogen sulfide gas, and the hydrogen sulfide is blown out by heating the blowing or distillation apparatus,
Sodium oxide solution absorption, the formation of sulfur ions in the presence of high iron ions in acidic solution with N, N-dimethyl-p-phenylenediamine reaction to produce methylene
Base blue, measured at 665 nm wavelength of its absorbance, sulfide content and absorbance value is proportional to.
5 interference and elimination
Under specified conditions, elemental sulfur does not interfere with the determination of sulfide. Determination of sulfide by sulfite, bisulfite and thiosulfate
No interference. Nitrite can react with methylene blue to make the determination result low, when the nitrite concentration (in N) is higher than 12.0 mg/kg
, This method does not apply.
26 reagents and materials
Unless otherwise stated, analytical analytical reagents conforming to national standards are used in the analysis, and the test water is freshly prepared distilled water or deionized water.
6.1 Sulfuric acid. ρ (H2SO4) = 1.84 g/ml.
6.2 hydrochloric acid. ρ (HCl) = 1.19 g/ml, excellent grade pure.
6.3 Sodium hydroxide (NaOH).
6.4 N, N-dimethyl-p-phenylenediamine hydrochloride [NH2C6H4N (CH3) 2 · 2HCl].
6.5 Ammonium sulfate [Fe (NH4) (SO4) 2 · 12H2O].
6.6 soluble starch [(C6H10O5) n].
6.7 Zinc acetate [Zn (CH3COO) 2 · 2H2O].
6.8 Iodine (I2).
6.9 Potassium iodide (KI).
6.10 Sodium thiosulfate (Na2S2O3.5H2O).
6.11 anhydrous sodium carbonate (Na2CO3).
6.12 Sodium sulfide (Na2S · 9H2O).
6.13 ascorbic acid (C6H8O6).
6.14 Ethylenediamine tetraacetic acid disodium (C10H14O8N2Na2 · 2H2O).
6.15 Potassium Dichromate (K2Cr2O7). Reference reagent.
Take appropriate amount of potassium dichromate in the weighing bottle, drying at 105 ℃ ± 1 ℃ 2 h, placed in the dryer cooling, spare.
6.16 Sulfuric acid solution. 1 5 (V/V).
Measure 20 ml of sulfuric acid (6.1) slowly into 100 ml of water, cooling.
6.17 hydrochloric acid solution. 1 1 (V/V).
Measure 250 ml of hydrochloric acid (6.2) slowly into 250 ml of water, cooling.
6.18 Antioxidant solution.
Weigh 2.0 g of ascorbic acid (6.13), 0.1 g of disodium ethylenediaminetetraacetate (6.14), 0.5 g of sodium hydroxide (6.3)
Water, shake and store in a brown reagent bottle. Pro is now available.
6.19 Sodium hydroxide solution. ρ (NaOH) = 10 g/L.
Weigh 10.0 g of sodium hydroxide (6.3) dissolved in 1000 ml of water, shake.
6.20 N, N-dimethyl-p-phenylenediamine solution. ρ [NH2C6H4N (CH3) 2 · 2HCl] = 2 g/L.
Weigh 2.0 g of N, N-dimethyl-p-phenylenediamine hydrochloride (6.4) in 700 ml of water, slowly add.200 ml of sulfuric acid (6.1), cold
But then diluted with water to 1000 ml, shake. The solution was stored in a sealed brown bottle at room temperature for three months.
6.21 ammonium ferric sulfate solution. ρ [Fe (NH4) (SO4) 2] = 100 g/L.
Weigh 25.0 g of ammonium ferric sulfate (6.5) in 100 ml of water, slowly add 5.0 ml of sulfuric acid (6.1), and then diluted with water to 250
ml, shake well. Solution such as the emergence of insoluble, should be used after filtration.
6.22 Starch solution. ρ [(C6H10O5) n] = 10 g/L.
3 Weigh 1.0 g of soluble starch (6.6), with a small amount of water into a paste, slowly pour 50 ml of boiling water, continue to boil to the solution to clarify,
Set to 100 ml, cooled and stored in the reagent bottle. Pro is now available.
6.23 Zinc acetate solution. ρ [Zn (CH3COO) 2] = 1 g/L
Weigh 1.20 g of zinc acetate (6.7), dissolve in a small amount of water and dilute to 1000 ml.
6.24 potassium dichromate standard solution. c (1/6K2Cr2O7) = 0.1000 mol/L.
Accurately weighed 4.9032 g potassium dichromate (6.15) dissolved in 100 ml of water, transferred to 1000 ml volumetric flask, diluted to the mark, shake.
Can save for one year.
6.25 iodine standard solution. c (1/2I2) ≈0.01 mol/L.
Accurately weighed 1.27 g of iodine (6.8) dissolved in 100 ml of water, then add 10.0 g of potassium iodide (6.9), dissolved and transferred to 1000 ml
Brown capacity bottle, diluted to the mark, shake. Pro is now available.
6.26 sodium thiosulfate standard solution. c (Na2S2O3) ≈ 0.1 mol/L.
Weigh 24.8 g sodium thiosulfate (6.10) in 100 ml of water, add 1.0 g of anhydrous sodium carbonate (6.11), dissolve and transfer to
1000 ml brown volumetric flask, diluted with water to the mark, shake. Stored in a brown glass reagent bottle, protected from light for 6 months. Pro is now available
Standard If the solution appears turbid, you have to filter and use after calibration. You can also purchase commercially available certified materials.
Calibration method. In a 250 ml iodine flask, add 1.0 g of potassium iodide (6.9), 50 ml of water and 10.00 ml of potassium dichromate
Solution (6.24), shaken until completely dissolved, then add 5.0 ml of sulfuric acid solution (6.16), immediately dense packing, in the dark place for 5 min.
After removal, with the sodium thiosulfate standard solution to be calibrated to the solution was pale yellow, add 1 ml of starch solution (6.22), continue titration
To blue just disappeared, record the amount of sodium thiosulfate standard solution. While 10.00 ml of water instead of potassium dichromate standard solution for empty
White titration. The concentration of sodium thiosulfate standard solution is calculated according to formula (1).
00.101000.0
) OSNa (
VV
c
(1)
Where.
c (Na2S2O3) - sodium thiosulfate standard solution concentration, mol/L;
0.1000 - Concentration of potassium dichromate standard solution, mol/L;
10.00 - potassium dichromate standard solution volume, ml;
V1 - titration of potassium dichromate standard solution consumption of sodium thiosulfate standard solution volume, ml;
V0 - titration blank solution consumes the volume of sodium thiosulfate standard solution, ml.
6.27 Sodium thiosulfate standard titration solution. c (Na2S2O3) ≈0.01 mol/L.
Accurately absorb 10.00 ml sodium thiosulfate standard solution (6.26) in 100 ml brown volumetric flask, dilute to the mark, shake. Pro
With the current allocation.
6.28 Sulfide standard stock solution. ρ (S2-) ≈100 mg/L.
Take a certain amount of sodium sulfide (6.12) in the Buchner funnel, rinse with water to remove surface impurities, with dry filter paper to absorb moisture, weighed 0.75
g in 100 ml of water dissolved, with medium-speed quantitative filter paper filter to 1000 ml brown volumetric flask, constant volume. Temporary use standard.
Calibration method. in 250 ml iodine bottle, followed by adding 10.0 ml of sodium hydroxide solution (6.19), 10.00 ml to be calibrated sulfide
4 standard stock solution, 20.00 ml iodine standard solution (6.25), diluted with water to about 60 ml, add 5.0 ml sulfuric acid solution (6.16), immediately
Cracked in the dark place for 5 min. After extraction, titration with sodium thiosulfate standard titration solution (6.27) titration to the solution was light yellow, add
1 ml of starch solution (6.22), continue to titrate to blue just disappeared, record the amount of sodium thiosulfate standard titration solution. At the same time with 10.00
ml of water instead of the standard sample of sulfide to be calibrated for blank test. The concentration of the sulfide standard stock solution is calculated according to equation (2).
00.10
100003.16) OSNa () (
) S (322012)
cVV (2)
Where.
ρ (S2 -) - sulfide standard stock solution concentration, mg/L;
V1 - titration sulfide standard stock solution consumption of sodium thiosulfate standard titration solution volume, ml;
V0 - Titration of blank solution consumption of sodium thiosulfate standard titration solution volume, ml;
c (Na2S2O3) - sodium thiosulfate standard titration solution concentration, mol/L;
16.03 - molar mass of sulfide (1/2S2-), g/mol;
10.00 - the amount of sulfide standard stock to be calibrated, ml.
Sulfide standard stock solution can also be purchased directly from a commercially available reference material or prepared using a gas generating device.
A.
6.29 Sulfide standard liquid. ρ (S2 -) = 10.00 mg/L.
Remove a certain amount of newly calibrated sulfide standard stock solution (6.28) to 2.0 ml of sodium hydroxide solution (6.19) and 80 ml of water
In a 100 ml brown volumetric flask and formulated with water to prepare a sulfur-based standard solution containing a sulfur ion concentration of 10.00 mg/L. Pro is now available
With
6.30 quartz sand. particle size 0.841 mm ~ 0.297 mm.
6.31 Nitrogen. Purity ≥99.99%.
6.32 Explosion-proof glass beads.
7 instruments and equipment
7.1 Spectrophotometer. 10 mm cuvette.
7.2 acidification - blowing - absorption device (Figure 1). the connection pipe are used silicone tube.
7.3 acidification - distillation - absorption device (Figure 2).
7.4 Analysis of balance. 0.01 g and 0.1 mg.
7.5 Sampling Bottle..200 ml brown with a riveted glass bottle.
7.6 Absorbent tube. 100 ml with plug color tube.
7.7 General laboratory equipment and equipment commonly used.
51 - water bath; 2 - reaction bottle; 3 - add acid split funnel; 4 - absorption tube.
Figure 1 Sulfide acidification - blowing - absorption device
1 - heating device; 2 - distillation bottle; 3 - condenser; 4 - absorption tube.
Figure 2 Sulfide acidification - distillation - absorption device
8 samples
8.1 Collection and storage of samples
According to the relevant provisions of HJ/T 166 collection of soil samples, in accordance with the relevant provisions of GB 17378.3 collection of sediment samples.
The collected sample shall be filled with the container and sealed in a brown stopper glass bottle (7.5) for 24 h. Also 4 ℃
Frozen storage, within 3 d determination. Or by adding sodium hydroxide solution (6.19) for immobilization, soil samples should be so that the sample surface of all infiltration, Shen
The sample should ensure that the upper part of the sample is formed with alkaline water seal and measured within 4 days.
8.2 Determination of dry matter content and moisture content of samples
At the same time as the sample was measured, the dry matter content of the soil samples was measured according to the relevant regulations of HJ 613, and the correlation was made according to GB 17378.5
Specifies the moisture content of the sediment sample.
8.3 Preparation of sample
8.3.1 Preparation of blowing sample
Weigh 20 g sample (if the sulfide concentration is high, may take less sample), accurate to 0.01 g, transferred to 500 ml reaction bottle, add
Into 100 ml of water, then add 5.0 ml of antioxidant solution (6.18), gently shake. Measure the amount of 10.0 ml of sodium hydroxide solution (6.19)
6100 ml with plug colorimetric tube (7.6) as the absorption liquid, the lower end of the air pipe into the absorption liquid surface to ensure that the absorption is complete. Connect the acid
(6.3), the nitrogen flow rate was adjusted to 300 ml/min, and the temperature of the water bath was raised to 100 ° C,
Pass nitrogen for 5 min to remove oxygen from the reaction system. Close the separatory funnel piston, add 20 ml of hydrochloric acid solution (6.17) to the separatory funnel,
Open the piston to slow the acid into the reaction bottle, the reaction bottle into the water bath, to maintain the nitrogen flow rate of 300 ml/min. After 30 min, stop
Heating, adjust the nitrogen flow to 600 ml/min air 5 min after the closure of nitrogen. Rinse the airway with a small amount of water, into the absorption liquid, to be tested.
8.3.2 Preparation of distilled samples
Weigh 20 g samples (if the sulfide concentration is high, may take less appropriate sample), accurate to 0.01 g, transferred to 500 ml distillation bottle, add
Into 100 ml of water, then add 5.0 ml of antioxidant solution (6.18), gently shake, and add a few pieces of explosion-proof glass beads (6.32). Measure the amount of 10.0
ml Sodium hydroxide solution (6.19) in 100 ml of plug colorimetric tube (7.6) as the absorption liquid, the lower end of the distillate conduit is inserted into the absorption liquid
Under the surface to ensure full absorption. Add 20 ml of hydrochloric acid solution (6.17) to the distillation flask and immediately tighten the stopper, open the condensate, open
The heating device was distilled at a rate of 2 ml/min to 4 ml/min. When the solution in the colorimetric tube reaches about 60 ml, the distillation is stopped.
Rinse the distillate tubing with a small amount of water and incorporate it into the absorption solution.
Note. During the preparation of the sample, the airtightness of the blowing or distilling device should be maintained to avoid leakage. If a leak occurs, the sample is discarded and resampled.
8.4 Preparation of blank samples
The quartz sample (6.30) was used instead of the actual sample and a blank sample was prepared according to 8.3.
9 Analysis steps
9.1 Standard curve drawing
Take 6 100 ml with plug colorimetric tube (7.6), add 10.0 ml sodium hydroxide solution (6.19), respectively, take 0.00,0.50,1.00,
3.00, 5.00 and 7.00 ml of Sulfide Standard Use (6.29) into each color tube, add water to about 60 ml, slowly along the color tube wall
10.0 ml of N, N-dimethyl-p-phenylenediamine solution (6.20), immediately after the plug and slowly reversed once, open a small mouth along the wall by adding 1.0 ml of ammonium ferric sulfate
Solution (6.21), immediately the plug and shake well. Placed 10 min, diluted with water to the mark, shake. Use a 10 mm cuvette to
Water for reference, and absorbance at 665 nm. With the sulfide content (μg) as the abscissa, with the corresponding blank after the absorbance
Value for the ordinate to draw the standard curve.
Note. N, N-dimethyl-p-phenylenediamine solution and ammonium ferric sulfate solution should be slowly along the wall of the colorimetric tube, and then quickly mix the dust to avoid vulcanization
Hydrogen escape loss.
9.2 Determination of the sample
9.2.1 Determination of blowing sample
Remove the colorimetric tube, add water to about 60 ml, according to 9.1 determination of sample absorbance.
9.2.2 Determination of distilled samples
Remove the colorimetric tube and measure the absorbance of the sample according to 9.1.
79.3 Determination of blank samples
The measurement of the blank sample (8.4) was carried out according to 9.2.
10 results are calculated and expressed
10.1 Results calculation
10.1.1 Calculation of soil samples
Soil sulfide content 1 (mg/kg) Calculated according to formula (3).
dmwmb
aAA
- 01 (3)
Where.
1 - content of sulfide in soil, mg/kg;
A - the absorbance of the sample;
A0 - absorbance of blank sample;
a - the intercept of the standard curve;
b - the slope of the standard curve;
m - the quality of the soil sample, g;
dmw - dry matter content of soil samples,%.
10.1.2 Calculated results of sediment samples
Sediment Sulfide content 2 (mg/kg) Calculated according to formula (4).
)1(
2 wmb
aAA
- (4)
Where.
2 - content of sulfide in sediments, mg/kg;
A - the absorbance of the sample;
A0 - absorbance of blank sample;
a - the intercept of the standard curve;
b - the slope of the standard curve;
m - the mass of the sample to be weighed, g;
w - moisture content of sediment samples,%.
10.2 Results
When the result is less than 1.00 mg/kg, the result is retained to two digits after the decimal point; when the result is greater than or equal to 1.00 mg/kg,
8 result retains three significant digits.
11 precision and accuracy
11.1 precision
In the case of blowing pretreatment, six laboratories had a sulfide content of 0.50 mg/kg, 1.50 mg/kg, 3.00 mg/kg and 12.0 mg/kg
The relative standard deviations in the laboratory were. 2.2% ~ 13%, 3.4% ~ 9.2%, 3.6% ~
9.7%, 2.6% ~ 12%, respectively. The relative standard deviations were 15%, 14%, 7.2% and 2.8%, respectively. The repeatability limits were 0.11
mg/kg, 0.21 mg/kg, 0.48 mg/kg, 2.2 mg/kg, respectively. The reproducibility limits were 0.21 mg/kg, 0.47 mg/kg, 0.68 mg /
8.6 mg/kg.
In the laboratory pretreatment, six laboratories had a sulfide content of 0.50 mg/kg, 1.50 mg/kg, 3.00 mg/kg and 12.0 mg/kg
The relative standard deviations in the laboratory were 6.0% ~ 11%, 3.7% ~ 12%, 2.5% ~ 7.8% respectively,
1.3% ~ 6.8%. The relative standard deviations were 5.9%, 12%, 6.6% and 8.7% respectively. The repeatability limits were 0.10 mg/kg,
0.25 mg/kg, 0.38 mg/kg, 1.3 mg/kg; reproducibility limits were 0.12 mg/kg, 0.45 mg/kg, 0.58 mg/kg, 2.8 mg/kg, respectively
11.2 Accuracy
Using six pre-treatment, six laboratories were tested for four actual soil or sediment samples with a spiked concentration of 0.50
mg/kg ~ 6.00 mg/kg, the recoveries were. 70.6% ~ 94.8%, 75.9% ~ 94.8%, 75.4% ~ 101%, 73.4% ~ 92.0%
The recoveries were. (84.6 ± 17.2)%, (84.8 ± 15.0)%, (86.9 ± 21.2)% and (83.2 ± 14.4)%, respectively.
Using the pre-treatment by distillation, six laboratories were tested for four actual soil or sediment samples with a spiked concentration of 0.50
mg/kg ~ 6.00 mg/kg, the recoveries were 67.5% ~ 92.3%, 65.0% ~ 94.2%, 71.9% ~ 112% and 84.5% ~ 103% respectively.
The recoveries were. (78.2 ± 17.8)%, (78.3 ± 22.0)%, (85.2 ± 29.2)% and (89.4 ± 13.6)%, respectively.
12 quality assurance and quality control
12.1 blank test
Each batch of samples should be at least one laboratory blank, the determination of the results should be lower than the method detection limit.
12.2 Determination of standard curve
The correlation coefficient of the standard curve regression equation should be greater than or equal to 0.999.
12.3 parallel sample determination
Each batch of samples should be 10% parallel to the two-sided determination of less than 10 samples, the parallel sample of not less than one. Parallel parallel test
The relative deviation of the fruit should be within 30%.
Determination of the recoveries of spiked samples
Each batch of samples should be 10% of the spike recovery rate, less than 10 samples, the standard sample of not less than 1. Actual sample spikes
9 recovery rate should be between 60% to 110%.
13 Waste treatment
The waste generated during the course of the experiment should be stored in a suitable sealed container and commissioned by a qualified unit for disposal.
Harmful to people and the environment.
Appendix A
(Informative)
Preparation of sulfide standard stock solution by gas generation method
According to Figure A.1 connection device, from the bottle 1 into the nitrogen (6.31), blowing 5 min, 0.25 g sodium sulfide (6.12) into the bottle 1,
Rapidly capping, adjust the flow rate of nitrogen, at a rate of 2 bubbles per second nitrogen for about 5 min, the solution in the bottle 3 was slightly cloudy (generating sulfur
Zinc-based colloidal solution), the ventilation was stopped and the solution was filtered into a 250 ml brown reagent bottle with medium-speed quantitative filter paper and calibrated for use.
The zinc sulfide colloidal solution stored in the cold dark can be stable for 3 ~ 7 d.
1 - hydrogen sulfide generator, built-in hydrochloric acid solution (6.17) 10 ml; 2 - gas cylinders, built-in water.200 ml;
3 - zinc sulfide colloidal solution generator, built-in zinc acetate solution (6.23).200 ml.
Figure A.1 Sulfide standard stock solution preparation unit
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