HJ 540-2016_English: PDF (HJ540-2016)
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Stationary source emission - Determination of arsenic- Silver diethyldithiocarbamate spectrophotometric method
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HJ 540-2016
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| HJ 540-2009 | English | 359 |
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Ambient air and waste gas. Determination of arsenic. Silver diethyldithiocarbamate spectrophotometric method
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HJ 540-2009
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| Standard ID | HJ 540-2016 (HJ540-2016) | | Description (Translated English) | Stationary source emission - Determination of arsenic- Silver diethyldithiocarbamate spectrophotometric method | | Sector / Industry | Environmental Protection Industry Standard | | Classification of Chinese Standard | Z15 | | Classification of International Standard | 13.040.20 | | Word Count Estimation | 10,187 | | Date of Issue | 2016-07-26 | | Date of Implementation | 2016-10-01 | | Older Standard (superseded by this standard) | HJ 540-2009 | | Regulation (derived from) | Ministry of Environmental Protection Notice No.52 of 2016 | | Standard ID | HJ 540-2009 (HJ540-2009) | | Description (Translated English) | Ambient air and waste gas. Determination of arsenic. Silver diethyldithiocarbamate spectrophotometric method | | Sector / Industry | Environmental Protection Industry Standard | | Classification of Chinese Standard | Z15 | | Classification of International Standard | 13.040.20 | | Word Count Estimation | 9,967 | | Date of Issue | 2009-12-30 | | Date of Implementation | 2010-04-01 | | Quoted Standard | GB/T 15432; GB/T 16157; HJ/T 194; HJ/T 373; GB/T 6682 | | Drafting Organization | Beijing Municipal Environmental Monitoring Center | | Administrative Organization | Ministry of Environment Protection | | Regulation (derived from) | Department of Environmental Protection Notice No. 74 of 2009 | | Summary | This standard specifies the determination of air and exhaust gases to particulate matter exists in the form of arsenic and its compounds diethyl dithiocarbamate silver spectrophotometry. This standard applies to air and exhaust particulate matter exists in the form of the determination of arsenic and its compounds. |
HJ 540-2016
(Determination of arsenic in fixed sources - Silver diethyldithiocarbamate spectrophotometric method)
National Environmental Protection Standard of the People 's Republic of China
Replacing HJ 540-2009
Determination of arsenic in fixed source
Silver dimethyldithiocarbamate spectrophotometric method
Stationary source emission - Determination of arsenic-Silver
Diethyldithiocarbamate spectrophotometric method
2016-07-26 release
2016-10-01 implementation
Ministry of Environmental Protection released
Directory
Preface .ii
1 Scope of application
2 normative reference documents
3 Principle of the method
Interference and elimination
5 reagents and materials 2
6 instruments and equipment 3
7 Sample 3
8 Analysis steps
The results are calculated and expressed
10 Precision and Accuracy
Quality assurance and quality control
12 Waste treatment
Preface
In order to implement the Environmental Protection Law of the People's Republic of China and the Law of the People's Republic of China on the Prevention and Control of Atmospheric Pollution,
Environment, the protection of human health, regulate the fixed source of waste gas in the form of particulate matter and the determination of arsenic and its compounds,
Develop this standard.
This standard specifies the determination of fixed sources of waste gas in the form of particulate matter and its compounds of diethyldisulfide
Substituted carbamate spectrophotometric method.
This standard is for the determination of "ambient air and waste arsenic, silver diethyldithiocarbamate spectrophotometric (provisional)"
(HJ 540-2009).
This standard was first published in.2009, the original standard drafting unit for the Beijing Environmental Protection Monitoring Center. This is the first
The main contents of the amendment are as follows.
- According to the scope of application of the standard, the original standard name "Ambient air and arsenic determination of diethyldithioamino
Formic acid silver spectrophotometric method (tentative) "modified to" fixed source of waste gas arsenic determination of diethyldithiocarbamate silver
Spectrophotometry";
- the contents of the ambient air and so on have been removed from the original standard;
- Based on the experimental results, the detection limit was revised from 0.00 μg/m3 to 0.004 mg/m3 and the lower limit of determination was 3.5 μg/m3
Revised to 0.016 mg/m3;
- the collection of samples and the preparation of samples and other content has been revised;
- increased precision and accuracy and other content;
- improve the quality assurance and quality control content;
- Increased waste disposal.
Since the implementation of the standard date, the original standard "Determination of ambient air and arsenic arsenic diethyldithiocarbamate
Photometric method (provisional) "(HJ 540-2009) abolished.
This standard is organized by the Ministry of Environmental Protection Science and Technology Standards Division.
The drafting of this standard. Beijing Environmental Protection Monitoring Center, Beijing Xicheng District Environmental Protection Monitoring Station.
The standard verification unit. Yunnan Honghe State Environmental Monitoring Station, Beijing Changping District Environmental Protection Monitoring Station, Beijing Feng
Taiwan Environmental Protection Monitoring Station, Beijing Xicheng District Environmental Protection Monitoring Station, Beijing China measured North Detection Technology Co., Ltd.
The environmental protection department of this standard approved on July 26,.2016.
This standard has been implemented since October 1,.2016.
This standard is explained by the Ministry of Environmental Protection.
Determination of arsenic in fixed source
Silver dimethyldithiocarbamate spectrophotometric method
Warning. arsine is a highly toxic gas, before the test must check whether the arsine generator is connected to prevent leakage or reaction
The bottle was disintegrated. The reaction shall be carried out in a fume hood, and the operator shall wear protective equipment.
1 Scope of application
This standard specifies the determination of fixed sources of waste gas in the form of particulate matter arsenic and its compounds diethyldithio
Silver phthalate spectrophotometric method.
This standard is applicable to the determination of arsenic and its compounds in the form of particulate matter in fixed waste gas.
When the sampling volume is 0.4 m3 (standard state), the volume of the volume is 50.0 ml, the detection limit of this method is 0.004 mg/m3,
The lower limit of determination is 0.016 mg/m3 (both in As).
2 normative reference documents
The contents of this standard refer to the following documents or their terms. For undated references, the valid version is applicable
In this standard.
Determination of particulate matter and sampling method of gaseous pollutants in exhaust gas of fixed pollution sources GB/T 16157
HJ/T 373 fixed pollution source monitoring quality assurance and quality control technical specifications (Trial)
HJ/T 48 smoke and dust sampler technical conditions
HJ 77.2 Ambient air and exhaust dioxins Determination of isotope dilution High resolution gas chromatography - High resolution mass spectrometry
3 Principle of the method
Using quartz fiber filter cartridge to collect fixed sources of waste gas containing arsenic particles, nitric acid, sulfuric acid, hydrogen peroxide digestion after preparation
The solution of pentavalent arsenic in this solution was reduced to trivalent arsenic with potassium iodide (KI) and stannous chloride (SnCl2 · 2H2O)
Zinc particles and acid, resulting in new ecological hydrogen, the trivalent arsenic further reduced to gaseous arsine (AsH3), and dissolved in trichloromethyl
(CH5H10AgNS2) in the alkylene chloride (CHCl3) to form a magenta complex at 510 nm
Absorbance measured at the wavelength, within a certain range of its absorbance and arsenic content is proportional to.
4 interference and elimination
Mercury, manganese, copper, nickel, cobalt, lead and iron, 100 μg or less of cadmium and antimony below 50 μg, bismuth below 30 μg,
20 μg or less of chromium, 10 μg of the following selenium, no significant interference with the determination. When the content of antimony in the sample is greater than 50 μg, the interference
Arsenic determination, adding 3 ml of stannous chloride and 5 ml of potassium iodide solution, can inhibit 300 μg of antimony interference. Sulfide interference,
Can be removed with lead acetate cotton.
5 reagents and materials
Unless otherwise stated, analytical reagents conforming to national standards are used for analysis. The experimental water is a freshly prepared deionized water
Or distilled water.
5.1 Arsenic free zinc tablets. 10 mesh to 20 mesh.
Note 1. The rate of occurrence of arsine is affected by the size, surface state and dosage of the zinc particles, the reaction acidity and the temperature. Zinc tablets to 10 to 20
The purpose of the surface rough zinc particles to restore the high efficiency, the amount of 3 g ~ 5 g between the effect is better.
5.2 Potassium iodide (KI).
5.3 Stannous chloride (SnCl2 · 2H2O).
5.4 Lead acetate [Pb (CH3COO) 2].
5.5 Diethyldithiocarbamate (C5H10AgNS2).
5.6 Arsenic trioxide (As2O3). Reference reagent.
Before use, in 105 ℃ ~ 110 ℃ bake 2 h, stored in the dryer cooling, spare.
5.7 Sodium hydroxide (NaOH).
5.8 nitric acid. ρ (HNO3) = 1.42 g/ml, excellent grade pure.
5.9 sulfuric acid. ρ (H2SO4) = 1.84 g/ml, excellent grade pure.
5.10 hydrochloric acid. ρ (HCl) = 1.19 g/ml, excellent grade pure.
5.11 Trichloromethane (CHCl3).
5.12 Triethanolamine [(HOCH2CH2) 3N].
5.13 Hydrogen peroxide. ω (H2O2) = 30%, excellent grade pure.
5.14 sulfuric acid solution. 1 1.
Prepared with sulfuric acid (5.9).
5.15 Potassium iodide solution. ρ (KI) = 150 g/L
Weigh 15 g of potassium iodide (5.2), dissolved in water and diluted to 100 ml beaker.
5.16 Stannous chloride solution. ρ (SnCl2 · 2H2O) = 400 g/L.
Weigh 48 g of stannous chloride (5.3), add 50 ml of hydrochloric acid (5.10), dissolve it by heating, and then diluted with water to 100 ml
Beaker, ready for use.
5.17 lead acetate solution. ρ [Pb (CH3COO) 2] = 100 g/L.
Weigh 10 g of lead acetate (5.4), dissolve in water and dilute to 100 ml beaker.
5.18 Silver diethyldithiocarbamate Absorbate. ω (C5H10AgNS2) = 0.25%.
Weigh 1.25 g of silver diethyldithiocarbamate (5.5), add 100 ml of trichloromethane (5.11) and 4 ml of tri
Alcohol (5.12) was stirred and diluted to 500 ml with trichloromethane (5.11), shaken, left overnight, filtered with absorbent cotton
In the brown reagent bottle, in the 4 ℃ below the cold, dark can be stored for 3 months.
5.19 Sodium hydroxide solution. ω (NaOH) = 40%.
Weigh 40 g of sodium hydroxide (5.7), dissolve with water and dilute to 100 ml beaker.
5.20 arsenic standard stock solution. ρ (As) = 1.00 mg/ml.
Accurately weigh 0.0660 g (accurate to 0.0001 g) arsenic trioxide (5.6), add 10 ml of sodium hydroxide solution (5.19),
Dissolved in heat. The whole volume into the 100 ml volumetric flask, dilute the volume to the mark with water. Store in a brown reagent bottle at 4 ° C or lower
Refrigerated, sealed for 3 months. You can also purchase commercially available certified materials.
5.21 arsenic standard use of liquid. ρ (As) = 1.00 μg/ml.
Arsenic standard stock solution (5.20) placed in room temperature, diluted with water preparation, temporary with the allocation.
5.22 lead acetate
10 g of absorbent cotton immersed in 100 ml of lead acetate solution (5.17), 30 min after the removal, at room temperature to dry, dark
Preserved in the grinding glass bottles, the preservation period of 1 year.
5.23 quartz fiber filter cartridge
Should be pre-baked in the muffle furnace at 300 ℃ for 3 h, placed in a dryer to cool to room temperature. The arsenic in the digestion of the blank filter cartridge
The amount of not more than 1.3 μg. The particle size of particles with particle size greater than 0.3 μm is not less than 99.9%.
6 instruments and equipment
Unless otherwise stated, all Class A glass gauges conforming to national standards are used for analysis.
6.1 dust sampler. sampling flow range 5 L/min ~ 80 L/min, other performance and technical indicators in line with the provisions of HJ/T 48.
6.2 Visible Spectrophotometer. 10 mm cuvette.
6.3 adjustable thermoelectric plate. 40 ℃ ~.200 ℃.
6.4 polytetrafluoroethylene scissors.
6.5 arsine generation and absorption device. see Figure 1, airway and absorption tube before use in the application of anhydrous ethanol and experimental water followed
Cleaning, drying after use.
1-absorbent tube (inner diameter 8mm, 5ml); 4-acetate lead cotton filter
Figure 1 arsine generation and absorption device
6.6 Ultrasonic scrubber. ultrasonic frequency range of 30 KHz ~ 80 KHz.
6.7 Common laboratory equipment and equipment.
7 samples
7.1 Collection of samples
In accordance with the relevant provisions of GB/T 16157 implementation. Place the sampler with the quartz fiber filter cartridge into the sampling point in the exhaust cylinder
Constant speed sampling. Select the appropriate sampling time according to the concentration of arsenic, sample for 1 hour, or at 1 hour intervals
Collected three to four samples, while measuring temperature, pressure and other parameters. After sampling, carefully remove the cartridge, the seal inward
Folded, put back into the original filter box. Samples of particulate matter were collected using a soot sampler with a total sample volume of not less than 0.4 m3
(Standard state).
When the flue gas temperature is higher than 100 ℃, should take the cooling measures, so that the flue gas into the filter before the temperature is below 100 ℃, the specific side
The reference can be made to HJ 77.2.
7.2 Preservation of samples
The collected samples should be stored in a desiccator and completed within 7 days.
7.3 Preparation of samples
Use a polytetrafluoroethylene scissors (6.4) to cut the filter sample into flakes (do not shake off the dust), place it in a.200 ml Erlenmeyer flask,
Add 20 ml water infiltration. Adding 20 ml of nitric acid (5.8), 4 ml of sulfuric acid (5.9) and 2 drops to 3 drops of hydrogen peroxide (5.13)
Bottle into the glass funnel, heated in the hot plate (6.3) to the state of micro-boiling to maintain 2 h ~ 3 h, remove the funnel, with the appropriate amount of experiment
Rinse the funnel with water to the conical flask and continue heating in the slightly boiling state until the solution is near dry and allowed to cool. Add to the conical flask
25 ml of water (to be immersed in the sample), placed in the ultrasonic scrubber (6.6) for 5 min, remove the conical flask, with medium-speed quantitative filter
Paper filter; this step (plus 25 ml of water, ultrasound and filtration) repeated 5 times to 6 times. Combine the filtrate in a beaker and place it in electricity
Hot plate (6.3) to drain nitric acid until the solution remains about 4 ml. After cooling, add a small amount of experimental water to wash the beaker
Wall, the whole solution will be transferred to the arsenide bottle (6.5), add water to 50 ml, shake.
Note 2. nitric acid, sulfuric acid, hydrogen peroxide digestion of the sample, the organic matter must be completely decomposed, otherwise the results are low. The content of organic matter in the sample is higher than that in the sample
For a long time, should be added again hydrogen peroxide heating digestion to precipitate into gray, and the liquid level is calm, no longer produce nitrogen oxide brown smoke so far. Together
And then the filtrate must be evaporated to produce white smoke to drive nitric acid, otherwise the addition of zinc particles will produce brown gas, resulting in measurement failure, in case of
Resampling analysis.
7.4 Preparation of blank sample
7.4.1 Preparation of laboratory blanks
Take the same batch of filter cartridges and prepare a laboratory blank sample according to the same procedure as for sample preparation (7.3).
7.4.2 Preparation of full program blank samples
Each sampling at least take the same batch of blank filter cartridge two, to the sampling site as a whole program blank sample. Follow the sample with
Preparation of the procedure (7.3) The same procedure to prepare a full program blank sample.
8 Analysis steps
8.1 Calibration curve
8.1.1 Take 7 hydrogen arsenic vials, add 0.00 ml, 1.00 ml, 3.00 ml, 5.00 ml, 10.00 ml, 15.00 ml
And 25.00 ml of arsenic standard using liquid (5.21), add 7 ml of sulfuric acid solution (5.14), add water to 50 ml, then add 5 ml
Potassium iodide solution (5.15) and 3 ml stannous chloride solution (5.16), shake and let stand for 15 min. This standard series of arsenic content points
Do not be 0.00 μg, 1.00 μg, 3.00 μg, 5.00 μg, 10.0 μg, 15.0 μg, 25.0 μg.
8.1.2 Add 3 g to 4 g of arsenic-free zinc pellets (5.1) to solution (8.1.1) and immediately with argon with lead acetate (5.22)
The tube was connected to an absorption tube containing 5.0 ml of silver diethyldithiocarbamate absorption solution (5.18). After 1 h of reaction, the absorption was removed
Tube, along the airway wall by adding trichloromethane (5.11) and fixed to the absorption tube 5.0 ml scale, to be measured.
Note 3. High temperature in summer, too fast response, incomplete absorption, the results are low. If the room temperature is higher than 30 ℃, the bottle can be placed in the ice bath
cool down.
8.1.3 at the wavelength of 510 nm, with 10 mm cuvette to chloroform (5.11) as a reference, measured absorbance to arsenic
Content (μg) for the abscissa, absorbance value for the vertical axis, draw the calibration curve.
8.2 Determination of sample
Add 5 ml of potassium iodide solution (5.15) and 3 ml of stannous chloride solution (5.16) to the sample (7.3) and shake well. Stand still
After 15 min, the absorbance of the sample was measured according to the same procedure (8.1.2 to 8.1.3) as the plot of the calibration curve.
8.3 Determination of blank sample
The laboratory blank sample (7.4.1) and the whole program blank sample (7.4.2) were measured in the same manner as in the determination of the sample (8.2)
Of the absorbance.
9 Results calculation and representation
9.1 Results calculation
Calculate the concentration of arsenic in the particulate matter of the fixed source of pollution according to the formula (1), mg/m3.
0
Nd
AA a
As
B V 1000
(1)
Where the concentration of arsenic in the particulate matter of the fixed source (in As), mg/m3;
A - the absorbance of the sample;
0A - absorbance of laboratory blank samples;
A - the intercept of the calibration curve;
B - the slope of the calibration curve;
NdV - the sampling volume of the dry flue gas under the standard state (273 K, 101.325 kPa), m
3.
9.2 The result is shown
When the measured value is less than 0.1 mg/m3, the result is three after the decimal point; when the measured value is greater than or equal to 0.1 mg/m3,
The result retains three significant digits.
10 precision and accuracy
10.1 Precision
(5.00 μg/50 ml, 10.00 μg/50 ml and 15.00 μg/50 ml) in the three laboratories
A standard blank filter cartridge was loaded with 6 samples in parallel. The relative standard deviations in the laboratory were 2.8% ~ 4.6%
1.1% ~ 6.8% and 1.1% ~ 7.5% respectively. The relative standard deviations were 7.6%, 2.7% and 1.2%, respectively. The repeatability limits were
0.49 μg/50 ml, 1.3 μg/50 ml and 1.6 μg/50 ml, respectively. The reproducibility limits were 1.1 μg/50 ml, 1.4 μg/50 ml and 1.5 μg/50
Ml.
10.2 Accuracy
(5.00 μg/50 ml, 10.00 μg/50 ml and 15.00 μg/50 ml) in the three laboratories
A standard blank filter cartridge was loaded with 6 samples in parallel. The relative errors in the laboratory were -19.0% -0.4%
-5.1% ~ -1.0% and -2.9% ~ 0.3%; the relative error of the final value were -4.6% ± 14.5%, -1.4% ± 5.4%
-0.9% ± 2.4%.
11 quality assurance and quality control
11.1 Each batch of samples should be at least two laboratory blanks and two full program blanks, the determination of the results should be lower than the lower limit of determination.
Otherwise, look for the cause, re-sampling analysis.
11.2 The calibration curve shall be plotted for each analysis, and the correlation coefficient of the calibration curve should be greater than or equal to 0.999.
11.3 Other quality assurance and quality control shall comply with the requirements of HJ/T 373 and shall be avoided by finger touch during sampling and analysis
Filter to prevent contamination.
12 Waste treatment
The waste liquid produced in the experiment should be collected collectively in a covered container and labeled and labeled.
Line processing.
......
HJ 540-2009
Ambient air and waste gas.Determination of arsenic.Silver diethyldithiocarbamate spectrophotometric method
National Environmental Protection Standard of the People's Republic
Determination of ambient air and exhaust arsenic
Silver diethyldithiocarbamate spectrophotometry
(temporary)
Ambient air and waste gas-Determination of arsenic
-Silver diethyldithiocarbamate spectrophotometric method
Released.2009-12-30
2010-04-01 Implementation
Ministry of Environmental Protection released
Ministry of Environmental Protection
announcement
No. 74 of.2009
In order to implement the "Environmental Protection Law of the People's Republic of China", protect the environment, and protect human health, we now approve the lead gas of fixed pollution sources.
The four standards, such as the determination of flame atomic absorption spectrophotometry (tentative), are national environmental protection standards and are released.
The standard name and number are as follows.
I. Determination of lead in fixed pollution sources - Flame atomic absorption spectrophotometry (tentative) (HJ 538-2009);
2. Determination of lead in ambient air by graphite furnace atomic absorption spectrophotometry (tentative) (HJ 539-2009);
4. Determination of gaseous arsenic in the production of yellow phosphorus - Determination of silver diethyldithiocarbamate spectrophotometry (interim) (HJ 541-2009);
V. Determination of mercury in ambient air - Enrichment of sulfhydryl cotton - Cold atomic fluorescence spectrophotometry (interim) (HJ 542-2009);
6. Determination of mercury in fixed pollution sources - Cold atomic absorption spectrophotometry (provisional) (HJ 543-2009);
VII. Determination of Sulfuric Acid Fog of Fixed Pollution Sources by Ion Chromatography (Provisional) (HJ 544-2009);
VIII. Determination of gaseous total phosphorus in fixed pollution sources - Determination of quinolinol ketone capacity (provisional) (HJ 545-2009);
IX. Determination of Phosphorus Pentoxide in Ambient Air Ascorbic Acid Reduction - Molybdenum Blue Spectrophotometry (Provisional) (HJ 546-2009);
X. Determination of chlorine gas from fixed pollution sources, iodometric method (provisional) (HJ 547-2009);
XI. Determination of hydrogen chloride in fixed source pollution. Silver nitrate capacity method (provisional) (HJ 548-2009);
12. Determination of hydrogen chloride in ambient air and exhaust gas Ion chromatography (interim) (HJ 549-2009);
XIII. Determination of total cobalt in water quality 5-chloro-2-(pyridylazo)-1,3-diaminobenzene spectrophotometry (provisional) (HJ 550-2009);
14. Determination of Chlorine Dioxide in Water Quality Iodometric Method (Provisional) (HJ 551-2009).
The above standards have been implemented since April 1,.2010 and published by the China Environmental Science Press. The standard content can be found on the website of the Ministry of Environmental Protection.
Special announcement.
December 30,.2009
Content
Foreword..iv
1 Scope..1
2 Normative references..1
3 method principle..1
4 Interference and elimination.1
5 Reagents and materials.1
6 instruments and equipment.2
7 samples.3
8 Analysis steps..3
9 result calculation..3
10 Quality Assurance and Quality Control.4
11 Notes 4
Foreword
To protect the environment and protect people in order to implement the Environmental Protection Law of the People's Republic of China and the Law of the People's Republic of China on the Prevention and Control of Air Pollution
This standard is established for the health monitoring and regulation of arsenic and its compounds in air and exhaust gases.
This standard specifies the silver diethyldithiocarbamate spectrophotometric method for the determination of arsenic and its compounds in air and exhaust gases.
This standard was formulated by the Science and Technology Standards Department of the Ministry of Environmental Protection.
This standard was drafted. Beijing Environmental Protection Monitoring Center.
This standard was approved by the Ministry of Environmental Protection on December 30,.2009.
This standard has been implemented since April 1,.2010.
This standard is explained by the Ministry of Environmental Protection.
Iv
Determination of ambient air and exhaust arsenic
Silver diethyldithiocarbamate spectrophotometry (interim)
Warning. Arsine is a highly toxic gas. Before the experiment, it is necessary to check whether the hydrogen arsenide generator is connected to prevent air leakage or reverse.
The bottle should be broken. The reaction should be carried out in a fume hood.
1 Scope of application
This standard specifies the determination of silver and diethyldithiocarbamate in the presence of particulate matter in the air and exhaust gases.
Photometric method.
This standard applies to the determination of arsenic and its compounds in the form of particulate matter in air and exhaust gases.
When the method is to prepare a filter cartridge or filter into a 50 ml sample, the detection limit is 0.35 μg/50 ml (as As).
For organized exhaust emissions, the detection limit is 0.9 μg/m3 when the 400 L gas is collected, and the lower limit of determination is 3.5 μg/m3 (both
As count).
For air samples, the detection limit is 0.06 μg/m3 when the 6 m3 gas is collected, and the lower limit of determination is 0.24 μg/m3 (both in As).
2 Normative references
The contents of this standard refer to the terms in the following documents. For undated references, the valid version applies to this standard.
GB/T 15432 Determination of total suspended particulate matter in ambient air
GB/T 16157 Determination of particulate matter in fixed pollution source exhaust gas and sampling method of gaseous pollutants
HJ/T 194 Technical Specifications for Manual Air Quality Monitoring
HJ/T 373 Technical Specifications for Quality Assurance and Quality Control of Fixed Pollution Source Monitoring (Trial)
GB/T 6682 Analytical laboratory water specifications and test methods
3 Principle of the method
Collecting particulate matter in organized exhaust gas with a glass fiber filter cartridge or quartz filter cartridge, and collecting particulate matter in the air with a perchloroethylene filter
Samples, the collected samples were treated with mixed acid digestion.
In an acidic solution, potassium pentaoxide and stannous chloride (KI-SnCl2) are used to reduce pentavalent arsenic to trivalent arsenic, and zinc particles are added to the acid to produce
New ecological hydrogen, further reducing trivalent arsenic to gaseous arsine (AsH3), and diethyldisulfide dissolved in chloroform (CHCl3)
The action of silver urethane (Ag·DDC) produces a purple-red complex and the absorbance is measured at a wavelength of 510 nm.
4 interference and elimination
Hydrogen sulfide, hydrogen halide, and phosphine have similar color reaction with Ag·DDC, which produces positive interference with the determination of arsenic. When the sample is digested,
Sulfur and phosphorus have been oxidized and decomposed by nitric acid, no longer affecting. Hydrogen sulfide produced by a small amount of sulfide present in the reagent can be removed by lead acetate absorbent cotton.
锑 can be masked with KI-SnCl2 below 300 μg.
5 reagents and materials
Unless otherwise stated, analytically pure reagents that meet national standards were used for the analysis. Water, GB/T 6682, third grade.
5.1 Arsenic-free zinc particles. 10 to 20 mesh.
5.2 Nitric acid. ρ (HNO3) = 1.42 g/ml, excellent grade pure.
5.3 Sulfuric acid. ρ (H2SO4) = 1.84 g/ml, excellent grade pure.
5.4 Perchloric acid. ρ (HClO4) = 1.67 g/ml, excellent grade pure.
5.5 Hydrochloric acid. ρ (HCl) = 1.19 g/ml, excellent grade pure.
5.6 Sulfuric acid solution. 1 1.
5.7 Potassium iodide solution. ρ (KI) = 150 g/L.
Weigh 15 g of potassium iodide and dissolve in 100 ml of water.
5.8 Stannous chloride solution. ρ (SnCl2) = 400 g/L.
Weigh 48 g of stannous chloride (SnCl 2 · 2H 2 O), add 50 ml of hydrochloric acid (5.5), heat to dissolve, add water to 100 ml, add a few metals
Tin, kept in a brown bottle for later use.
5.9 Lead acetate solution. ρ[Pb(CH3COO)2]=100 g/L.
Weigh 10 g of lead acetate and dissolve in 100 ml of water.
5.10 Silver diethyldithiocarbamate (Ag·DDC) absorption liquid. w(Ag·DDC)=0.25%.
Weigh 1.25 g of silver diethyldithiocarbamate (Ag·DDC), add 100 ml of chloroform, 4 ml of triethanolamine, add four
Mix the carbon chloride to 500 ml, place it overnight, filter it into a brown bottle with absorbent cotton, and store it in the dark.
5.11 Arsenic standard stock solution. ρ (As) = 1.00 mg/ml.
Weigh 0.066 0 g of arsenic trioxide (reference reagent, dried at 105-110 ° C for 1 h), and dissolve with 10 ml of 40% NaOH solution.
solution. Transfer to a 100 ml volumetric flask and dilute to volume with deionized water. Store in brown bottles and store at low temperature. This solution per ml
Contains 1.00 mg of arsenic.
A standard solution for arsenic can also be used as a standard solution.
5.12 Arsenic standard use solution. ρ (As) = 1.00 μg/ml.
When used, the standard stock solution of arsenic (5.11) is diluted with water to a standard solution containing 1.00 μg of arsenic per ml.
5.13 lead acetate cotton
Immerse 10 g of cotton wool in 100 ml lead acetate solution (5.9), remove it after 30 min, dry at room temperature, and store in the dark.
6 Instruments and equipment
Unless otherwise stated, the analysis uses a Class A glass gauge that complies with national standards.
6.1 Soot sampler. The flow range is 5~50 L/min, and the accuracy is better than ±2%.
6.2 Medium flow particle sampler. The flow range is 80~130 L/min, and the accuracy is better than ±2%.
6.3 Visible spectrophotometer. with a 10 mm cuvette.
6.4 Glass fiber filter cartridge or quartz filter cartridge.
6.5 Perchloroethylene membrane. 0.45 μm.
6.6 Electric heating plate.
6.7 Arsenic hydrogen generation and absorption device. As shown in Figure 1, the connecting pipe and the absorption pipe should be washed and dried before use.
Φ8～9
Grinding mouth 5 ml
Φ8
Φ11
3 unit. mm
D20
1-conical flask; 2-air pipe; 3-absorbent pipe; 4-acetate lead cotton
Figure 1 Arsenic hydrogen generation and absorption device
7 samples
7.1 Sample collection
7.1.1 Organized emissions
The number of sampling points, sampling point setting and sampling method shall be implemented in accordance with the relevant provisions of Chapters 4 and 8 of GB/T 16157.
7.1.2 Air sample
The sampling method is carried out in accordance with the relevant provisions of GB/T 15432, using a medium flow particle sampler and a perchloroethylene filter to 100 L/min.
The flow is collected for 1 h. Record the sampling conditions in detail.
7.2 Preservation of samples
After the sample of the filter cartridge is collected, the seal is folded inward and placed vertically in the sample box for storage. The filter sample is folded into a clean paper bag or filtered after collection.
Store in a capsule.
7.3 Preparation of samples
7.3.1 Filter cartridge sample. Cut the sample of the filter cartridge obtained by 7.1.1 into a sheet (do not shake off the dust particles), put it in a 150 ml Erlenmeyer flask, add
7 ml sulfuric acid solution (5.6), 20 ml nitric acid (5.2), 4 ml perchloric acid (5.4), the bottle mouth is inserted into a funnel, heated on a hot plate, waiting to be played
After the reaction was stopped, the funnel was removed and heated to a thick perchloric acid white smoke. Remove and let cool, rinse the bottle with water, and then heat to thick white smoke.
In order to drive off the nitric acid. If the sample digestion is incomplete, add a small amount of nitric acid and continue heating until the sample becomes lighter. Cool, add a small amount of water, use
Filter the filter paper, wash the Erlenmeyer flask with water, filter the residue several times, combine the washing solution and the filtrate, and add water to 50 ml. Add 5 ml of potassium iodide solution
(5.7) and 3 ml of stannous chloride solution (5.8), shake and place for 15 min to reduce the pentad arsenic to trivalent arsenic.
7.3.2 Filter sample. According to the arsenic content, take the appropriate area filter sample (7.1.2), place it in a 100 ml Erlenmeyer flask, add 10 ml of nitric acid.
(5.2), placed overnight. Add 7 ml of sulfuric acid solution (5.6) and 2 ml of perchloric acid (5.4), insert the bottle into a funnel and heat on a hot plate.
After the violent reaction has ceased, the funnel is removed and heated to a thick perchloric acid white smoke. The subsequent digestion method is the same as the filter cartridge.
7.3.3 Blank sample of the whole procedure. take at least two blank cartridges of the same batch number or equal area filter, and transport and save at the same time as the sample, according to 7.3.1
Or 7.3.2 is prepared as a full procedure blank sample.
8 Analysis steps
8.1 Drawing of standard curves
8.1.1 Take 6 bottles of arsenic hydrogen and add arsenic standard solution (5.12) to make the solution contain 0.00, 1.00, 3.00, 5.00.
10.0, 15.0 μg arsenic, add 7 ml sulfuric acid solution (5.6), add water to 50 ml, add 5 ml potassium iodide solution (5.7), add 3 ml chloride
Tin solution (5.8), shake and place for 15 min.
8.1.2 Add 3 to 4 g of arsenic-free zinc (5.1) to the solution (7.3.1), immediately with a filter containing lead acetate (5.13) and
Connect the absorption tube of 5.0 ml Ag·DDC absorption solution (5.10). After reacting for 1 h, remove the absorption tube and add carbon tetrachloride to 5.0 ml.
Shake well and prepare for testing.
8.1.3 At a wavelength of 510 nm, use a 10 mm cuvette with carbon tetrachloride as a reference to determine the absorbance and subtract the blank from the arsenic content.
The absorbance is plotted against the standard curve.
8.2 Determination of sample solution
Transfer the sample solution (7.3) to the hydrogen arsenide generating bottle. Determine the sample solution by drawing the same standard curve as in steps 8.1.2 to 8.1.3.
The absorbance is calculated from the standard curve to determine the arsenic content in the sample solution.
The absorbance of the whole program blank sample solution (7.3.3) was determined in the same way, and the full program blank sample solution was calculated from the standard curve.
Middle arsenic content.
9 Calculation of results
9.1 Calculate the mass concentration of arsenic and its compounds in air and exhaust gas according to formula (1).
0 t
Nd a
(As)
Mm S
VS
ρ −= × (1)
Where. ρ (As) - mass concentration of arsenic and its compounds in air and exhaust gas (as As), mg/m3;
M--the arsenic content in the sample solution, μg;
M0--the average value of arsenic content in the blank filter cartridge or filter, μg;
Vnd--sample volume under standard state (101.325 kPa, 273 K), m3;
St--the total area of the sample filter, cm2;
Sa--Measurement membrane area taken in the measurement, cm2.
Note. For the filter cartridge sample, St=Sa, Vnd is the sampling volume (m3) of the dry gas under standard conditions.
9.2 The result is expressed as Equation (2) when expressed as As2O3.
twenty three
197.8(As O ) (As)
74.9
ρ ρ= × (2)
Where. ρ (As2O3)--mass concentration of arsenic and its compounds in air and exhaust gas (as As2O3), mg/m3.
10 Quality Assurance and Quality Control
Quality assurance and quality control measures are implemented in accordance with the relevant provisions of HJ/T 373 and HJ/T 194.
11 Precautions
11.1 AsH3 reacts with Ag·DDC to form red elemental colloidal silver, which promotes reduction when organic base and pyridine are present in chloroform.
And can increase the stability of red elemental colloidal silver in the solvent.
11.2 The rate of occurrence of arsine is greatly affected by the size, surface state and amount of zinc particles, reaction acidity and temperature. Zinc grain is 10~
20 mesh, the surface is rough, the effect is the same with 3~5 g. The acidity of sulfuric acid during the reaction is preferably 2.3 to 2.5 mol/L. Acidity is too high, anti
It should be too fast, the absorption is not complete; the acidity is too low, the reaction is too slow, the agitation of the bubbles in the reactor is not good, and the reaction may be incomplete. But warm
The degree is too high and the reaction is too fast, which may result in incomplete absorption of AsH3 and the result is low. If the room temperature is higher than 30 ° C, the bottle can be placed in cold water
Cool in the bath.
11.3 When the sample is digested with sulfuric acid-nitric acid-perchloric acid, the organic matter must be completely decomposed, otherwise the result is low. The content of organic matter in the sample is higher
For a long time, it should be repeatedly added with nitric acid to digest to a precipitate that turns grayish white, and the liquid level is calm, and brown NOx is no longer produced. After the digestion is complete
It is necessary to repeatedly evaporate to a thick white smoke to drive out the NOx, otherwise brown gas will be generated when the zinc particles are added in the next step, resulting in measurement failure.
In this case, you need to rework and redo.
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