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HJ 910-2017: Ambient air -- Determination of gaseous mercury -- Gold amalgamation collection and analysis by cold vapor atomic absorption spectrophotometry
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Ambient air -- Determination of gaseous mercury -- Gold amalgamation collection and analysis by cold vapor atomic absorption spectrophotometry
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Basic data | Standard ID | HJ 910-2017 (HJ910-2017) | | Description (Translated English) | Ambient air -- Determination of gaseous mercury -- Gold amalgamation collection and analysis by cold vapor atomic absorption spectrophotometry | | Sector / Industry | Environmental Protection Industry Standard | | Classification of Chinese Standard | Z15 | | Word Count Estimation | 17,162 | | Date of Issue | 2017-12-29 | | Date of Implementation | 2018-04-01 | | Regulation (derived from) | Ministry of Environmental Protection Bulletin 2017 No. 86 | | Issuing agency(ies) | Ministry of Ecology and Environment | HJ 910-2017: Ambient air -- Determination of gaseous mercury -- Gold amalgamation collection and analysis by cold vapor atomic absorption spectrophotometry
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People's Republic of China national environmental protection standards
Ambient air - Determination of gaseous mercury - Gold
amalgamation collection and analysis by cold vapor atomic absorption
2017-12-29 Posted
2018-04-01 implementation
Directory
Foreword .ii
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
7 samples .6
8 Analysis Step 7
9 Results Calculation and Presentation 8
10 Precision and accuracy .9
11 Quality Assurance and Quality Control .9
12 Waste treatment .11
13 Precautions ..11
Appendix A (Normative) Preparation of enriched tubes and schematic 12
Appendix B (Informative) Preparation of iodine activated carbon 13
Foreword
In order to implement the Law of the People's Republic of China on Environmental Protection and the Law of the People's Republic of China on Prevention and Control of Atmospheric Pollution,
Habitat, to protect human health, regulate the determination of gaseous mercury in the ambient air, the development of this standard.
This standard specifies the determination of gaseous mercury in the air atmosphere gold film enrichment/cold atomic absorption spectrophotometry.
This standard Appendix A normative appendix, Appendix B is an informative annex.
This standard is released for the first time.
This standard by the Environmental Protection Department of Environmental Monitoring Division and Science and Technology Standards Division to develop.
This standard was drafted. Beijing Environmental Protection Monitoring Center.
This standard verification unit. Shanghai Jiading District Environmental Monitoring Station, Songjiang District, Shanghai Environmental Monitoring Station, Dongcheng District, Beijing
Environmental Protection Monitoring Station, Beijing Kangju Environmental Monitoring Station, Changping District, Beijing Environmental Protection Monitoring Station and Beijing Environmental Protection
Monitoring Center.
This standard MEP approved on December 29,.2017.
This standard since April 1,.2018 come into operation.
This standard is interpreted by the MEP.
Ambient air - Determination of gaseous mercury - Gold enrichment/cold atomic absorption
Spectrophotometry
Warning. Mercury and its compounds used in the experiment are toxic. All sample pretreatments should be done in a fume hood. During operation
Wear protective equipment as required to prevent inhalation of airways and skin and clothing.
1 scope of application
This standard specifies the determination of gaseous mercury in the air atmosphere gold film enrichment/cold atomic absorption spectrophotometry.
This standard applies to the determination of gaseous mercury in the ambient air.
When the sampling volume is 60 L (60 min, standard state), the detection limit of the method is 2 ng/m3 and the lower limit of determination is 8 ng/m3.
When the sampling volume is 1440 L (24 h, standard state), the detection limit of this method is 0.1 ng/m3 and the lower limit of determination is 0.4 ng/m3.
2 Normative references
This standard references the following documents or the terms. For undated references, the effective version applies to this book
standard.
HJ 194 Manual Air Quality Monitoring Technical Specifications
3 method principle
The mercury in the ambient air is collected by the gold film microparticle mercury enrichment tube to generate gold amalgam on the gold film surface. Will be sampled
The enrichment tube is heated and analyzed at 600 ° C or above, and the mercury is quantitatively released. When the carrier gas enters the mercury analyzer, it is re-enriched and
Analytical, at 253.7 nm, determined by cold atomic absorption spectrophotometry.
4 Interference and elimination
Acid and alkali gases and water vapor directly into the cold atomic absorption cell will affect the determination of mercury results. At cold atomic absorption pass
Gas pipeline in series with a buffer filled with gas washing buffer bottle and a water buffer bottle (empty bottle), which can effectively eliminate dry
Disturb
5 Reagents and materials
Unless otherwise stated, analytical grade reagents that meet national standards are used. Experimental water for the newly prepared resistivity
Deionized water greater than or equal to 18 ΜΩ · cm.
5.1 anhydrous calcium chloride (CaCl2). excellent grade pure.
5.2 Potassium dichromate (K2Cr2O7). excellent grade pure.
5.3 Mercuric chloride (HgCl2). excellent grade pure.
Before use, dry it at 105 ℃ for 2 h and place it in a silica gel dryer.
5.4 Stannous chloride (SnCl2 · 2H2O). excellent grade pure.
5.5 Sodium hydroxide (NaOH). excellent grade pure.
5.6 potassium dihydrogen phosphate (KH2PO4). excellent grade pure.
Before use, dry it at 105 ℃ for 2 h and place it in a silica gel dryer.
5.7 Disodium hydrogen phosphate (Na2HPO4). excellent grade pure.
Before use, dry it at 105 ℃ for 2 h and place it in a silica gel dryer.
5.8 Hydrochloric acid (HCl). ρ = 1.19 g/ml, excellent grade pure.
5.9 sulfuric acid (H2SO4). ρ = 1.84 g/ml, excellent grade pure.
5.10 Nitric acid (HNO3). ρ = 1.42 g/ml, excellent grade pure.
5.11 stannous chloride solution. ρ (SnCl2 · 2H2O) = 0.25 g/ml.
Weigh 25.0 g of stannous chloride (5.4) in a 150 ml dry beaker, add 25 ml of hydrochloric acid (5.8) and heat until all dissolved
After solution, dilute to 100 ml with experimental water. Nitrogen (5.22) was purged with a blower (6.6) at 1.0 L/min for 15 min
Above to remove mercury. Pro use now with.
5.12 Sodium hydroxide solution. ρ (NaOH) = 0.30 g/ml.
Weigh 30.0 g of sodium hydroxide (5.5) in a 150 ml dry beaker and dilute to 100 ml with a small amount of experimental water.
Store in polyethylene bottle.
5.13 phosphate buffer solution. pH≈6.8.
Were accurately weighed 3.4 g of potassium dihydrogen phosphate (5.6) and 3.5 g of disodium hydrogen phosphate (5.7), in a 250 ml beaker
The experimental water dissolved, transferred to a 1000 ml volumetric flask to volume. Commercially available phosphate buffered solutions may also be used.
5.14 buffer.
Prepared with phosphate buffer solution (5.13) and the experimental water volume ratio of 1.1.
5.15 sulfuric acid solution. 1 49.
Prepared with sulfuric acid (5.9) and experimental water at a volume ratio of 1.49.
5.16 Fixative. ρ (K2Cr2O7) = 0.5 g/L.
Weigh 0.5 g of potassium dichromate (5.2) was dissolved in 950 ml experimental water, then add 50 ml of nitric acid (5.10) at 4 ℃
The following refrigerated can be stored for 3 months.
5.17 Mercury standard stock solution. ρ (Hg) = 100 μg/ml.
Weigh 0.1354 g mercuric chloride (5.3), dissolved in a small amount of fixed solution (5.16), into a 1000 ml volumetric flask,
Then dilute with fixative (5.16) to the mark. Store below 4 ℃ for 1 year. Commercial standard solutions can also be used.
5.18 Mercury standard intermediate solution ρ. ρ (Hg) = 10.0 μg/ml.
Pipette 10.0 ml standard stock solution of mercury (5.17) in a 100 ml volumetric flask and dilute to the mark with a fixative (5.16).
Cold storage at 4 ℃ can be stored for 6 months.
5.19 Mercury standard intermediate solution II. ρ (Hg) = 1.00 μg/ml.
Pipette 1.00 ml standard stock solution of mercury (5.17) in a 100 ml volumetric flask and dilute to the mark with a fixative (5.16).
Cold storage at 4 ℃ can be stored for 3 months.
5.20 mercury standard solution Ⅰ. ρ (Hg) = 0.10 μg/ml.
Pipette 1.00 ml Mercury standard intermediate I (5.18) in a 100 ml volumetric flask and dilute with sulfuric acid (5.15) to
Marking. Pro use now with.
5.21 mercury standard solution Ⅱ. ρ (Hg) = 0.01 μg/ml.
Pipette 1.00 ml of mercury standard intermediate solution II (5.19) in a 100 ml volumetric flask and dilute with sulfuric acid solution (5.15) to
Marking. Pro use now with.
5.22 Nitrogen. Purity ≥99.99%.
6 instruments and equipment
6.1 rich tube
Contains gold particles can be enriched mercury particles. The preparation method and schematic diagram of the rich tube is shown in Appendix A. The tube absorbs saturated mercury
The amount is 1 μg. Can also be purchased directly from the sale of gold particles mercury enrichment tube.
Note 1. Due to the different specifications of thermal analyzers used in different instruments, the specifications of the enriched tubes prepared or purchased should be matched with the instruments.
Note 2. Before sampling, the tube is heated in a muffle furnace (6.5) at 750 ℃ for 3 h. The blank value of the tube should be lower than the detection limit (about 0.15 ng).
After cooling, the ends of the rich tube are plugged tightly with polyethylene or PTFE, placed in a polyethylene self-sealing bag or a special plugged glass tube for preservation,
1 month use.
6.2 gaseous mercury sampling system
6.2.1 consists of an air sampler (6.2.2), a sampling system connection tube (6.2.3), an enrichment tube (6.1), a membrane holder (6.2.4) and
Quartz fiber filter (6.2.5) composition, a schematic view of Figure 1.
1-air sampler; 2-sampling system connecting pipe; 3-rich tube; 4-membrane holder; 5- quartz fiber membrane.
Figure 1 gaseous mercury sampling system composition diagram
6.2.2 Air Sampler. It should have the function of automatically accumulating the sample volume, the flow range of 0.1 ~ 1.5 L/min, flow control
The error is ± 2.5%. Flow calibration should be performed before sampling.
6.2.3 Sampling System Connection pipe. Polyethylene or Teflon pipe, and the sampling system interface or connector supporting.
6.2.4 membrane support. polyethylene or PTFE material, diameter 25 mm, and quartz fiber filter (6.2.5) supporting the use of.
6.2.5 Quartz fiber membrane. pore size 0.45 μm, diameter 25 mm. Used to filter out airborne particles when sampling.
Note. quartz fiber filter before use must first muffle furnace (6.5) heated at 500 ℃ for 1 h to remove the mercury, the treated quartz fiber
The filter is wrapped in tin foil and stored in a silica gel dryer for use within 1 month.
6.3 Thermal analysis - cold atomic absorption mercury measurement system
6.3.1 consists of air purification tube (6.3.2), thermal analyzer (6.3.3) and cold atomic absorption mercury analyzer (6.3.4), indicating
See Figure 2. Has the function of regulating and controlling the temperature of the thermal analyzer, the temperature control error is ± 1 ℃; with constant
(0 ~ 1000 ng) and trace (0 ~ 20 ng) two test modes.
1-air purifying pipe; 2-thermal resolver; 3-gas washing buffer bottle; 4-water buffer bottle;
5- Built-in enrichment thermal analyzer; 6-Atomic atomic absorption cell; 7-Mercury detector; 8- Suction pump;
9-flow controller, 10-flow meter, 11 mercury exhaust filter, 12 workstations.
Figure 2 Thermal analysis - cold atomic absorption mercury measurement system
6.3.2 Air Purification Tubes. Blank (6.1) for Thermal Analysis - Cold Atomic Absorption Mercury System Line Inlet Empty
Gas purification.
6.3.3 Thermal resolver. can be heated to above 600 ℃, the working curve into the preparation of standard enrichment tube preparation, blank
Product and sample were measured when the blank and sample collection tube filled with rich tubes.
6.3.4 cold atomic absorption mercury analyzer. from the buffer containing 20 mm high buffer (5.14) gas buffer buffer, in addition to water buffer bottle
(Empty bottle), built-in enrichment thermal analyzer with a blank (6.1), cold atomic absorption cell, mercury detector,
Pump, flow controller, flow meter, mercury exhaust filter and workstation.
6.4 Mercury enrichment system
6.4.1 by the air purification tube (6.4.2), enrichment system connecting pipe (6.4.3), mercury vapor generation bottle (6.4.4), acid gas absorption
Bottles (6.4.5), U-type drying tubes (6.4.6), enrichment tubes (6.1), mercury tail gas filters (6.4.7), adjustable flow meters (6.4.8)
And suction pump (6.4.9). Schematic diagram shown in Figure 3.
1-air purifying pipe; 2-rich system connecting pipe; 3-mercury vapor generating bottle; 4-acid gas absorption bottle;
5-U-type drying tube 6-rich tube 7-mercury exhaust filter 8 adjustable flow meter 9 suction pump.
Figure 3 Mercury enrichment system
6.4.2 Air Purification Tubes. Blank (6.1) for the purge of the air at the inlet of the mercury-enriched system piping.
6.4.3 Enrichment system Connecting pipe. Polyethylene or Teflon pipe, which is matched with the enrichment system interface or connecting end.
6.4.4 Mercury Vaporizer Bottles. 25 ml glass vials, ground-tapped stoppers with perforated porous blowheads. Or other and enrichment
System to match the reaction device.
6.4.5 Acid gas absorption bottle. 25 ml glass turning bottle, with a bottle-shaped porous blowing head grinding mouth stopper. Built-in 10 ml of hydrogen and oxygen
The sodium solution (5.12) is used for the absorption of sour gas in the enrichment system for mercury.
6.4.6 U-shaped drying tube. U-shaped plugged glass with a tube outer diameter of 1.3 cm, a branch tube outer diameter of 0.5 cm and a height of 10 cm
Tube, built-in anhydrous calcium chloride (5.1), the ends of the packing stuffed with quartz cotton. Can also be purchased directly commercially available anhydrous calcium chloride drying tube.
6.4.7 Mercury tail gas filter. iodine-containing activated carbon tube, purchased directly or with their own active iodine activated carbon filled tube. Iodine live
For the preparation of carbon, see Appendix B.
6.4.8 adjustable flow meter. flow range of 0.1 ~ 1.0 L/min, flow control error of ± 2.5%.
6.4.9 Suction pump. Diaphragm pump, load flow ≥1.0 L/min, flow range of use 0.1 ~ 1.0 L/min.
6.5 muffle furnace. can be heated to above 800 ℃.
6.6 Air blower. Small flow control consisting of rotameter, pressure reducing valve, pressure gauge, constant flow valve, pipe and fittings
Controller, the flow range of 0.1 ~ 1.0 L/min adjustable, flow control error of ± 2.5%.
6.7 glassware. use the A-class glassware in line with national standards.
6.8 General laboratory equipment commonly used.
7 samples
7.1 Sampling system tightness inspection
Connect a sampling tube of the same size (6.1) to the gaseous mercury sampling system (6.2), open the sampler,
Blocking the intake side, if the sampler flow to zero, then the air tightness is good.
7.2 sample collection
Refer to HJ 194 for sampling of gaseous pollutants for sampling. Remove sampling system air tightness check (7.1)
, Connect the other rich tube (6.1) to the gaseous mercury sampling system (6.2), leaving the rich tube at
In the vertical position, with the air intake facing up, sample at 1.0 L/min for 60 or 24 h and keep the flow constant. Record mining
Sample location, time, environmental conditions, sampling start flow, sampling end flow and sampling tube number and other information.
Note. During the sampler assembly and collection process, the sampler should wear powder-free gloves and located in the downwind of the sample to avoid
Pollution caused by objects and breathing. Avoid finger contamination with pipe ends during operation.
7.3 Sample preservation
After sampling, remove the sample collection tube, plug the ends of the sample collection tube with a polyethylene or Teflon plug,
Placed in polyethylene ziplock bag or special plugged glass tube, transported to the laboratory, measured within 1 month.
7.4 full program blank sample
Take one of the same collection tubes (6.1) as the sample collection site to the sampling site and synchronize with the sample collection (7.2)
Step connected to the sampling system, immediately removed, according to the sample (7.3) the same procedure for the entire program blank samples sealed, transported and stored until the machine measured.
7.5 Reagents Blank samples
According to 8.2.1 standard series of preparation steps to prepare a blank solution, and the solution into the mercury vapor bottle, take and sample
A collection of the same batch of a rich tube (6.1), with reference to 8.2.2 standard preparation steps of the preparation of rich sample blank tube sample enrichment tube,
The ends of the rich tube are plugged tightly with polyethylene or PTFE, and are put into a polyethylene self-sealing bag or a special plugged glass tube to be preserved until the machine is measured.
8 Analysis steps
8.1 Thermal analysis - Cold atomic absorption mercury measurement system reference conditions
Determination of wavelength, 253.7 nm; test mode, according to the concentration of mercury in the ambient air range, corresponding to select a constant or trace
Test mode; thermal analyzer resolution temperature, above 600 ℃, analytical time, 2 min, transfer time, 40 s; built-in enrichment
Thermal preconcentrator enrichment Preheat temperature, 160 ℃, analytical temperature, 600 ℃ or more, analysis time, 1 min (trace) or 2 min
(Constant); Suction flow, 0.5 L/min.
The actual test should refer to the instrument description, set the best analysis and measurement conditions.
8.2 working curve
8.2.1 Standard series of preparation
8.2.1.1 Preparation of high concentration standard series of work
The constant test, take six 25 ml mercury vapor bottle, prepared according to Table 1 high concentrations of working standard series. According to actual
Mercury concentrations in international samples Adjust the concentration range of the working standard series.
Table 1 high concentrations of mercury standard series
Bottle number 0 1 2 3 4 5
Mercury standard solution Ⅰ (5.20)/ml 0 0.05 0.10 0.50 1.00 2.00
Sulfuric acid solution (5.15)/ml 5.00 4.95 4.90 4.50 4.00 3.00
Mercury content/ng 0 5.00 10.0 50.0 100.200
8.2.1.2 Preparation of low concentration standard series of work
Trace test, take six 25 ml mercury vapor bottles, according to Table 2 preparation of low concentrations of working standard series.
Table 2 low concentration mercury standard series
Bottle number 0 1 2 3 4 5
Mercury standard use solution Ⅱ (5.21)/ml 0 0.05 0.10 0.50 1.00 2.00
Sulfuric acid solution (5.15)/ml 5.00 4.95 4.90 4.50 4.00 3.00
Mercury content/ng 0 0.50 1.00 5.00 10.0 20.0
8.2.2 Preparation of standard enrichment tubes
8.2.2.1 Enrichment system leak detection
A mercury vapor generator bottle (6.4.4), a vacant quartz tube (instead of an enrichment tube), are connected in series to the mercury enrichment system (6.4)
Open and adjust the enrichment flow rate to 0.8 L/min, block the intake end, if the flow rate to zero, it shows good air tightness.
8.2.2.2 Enrichment system Mercury removal
Remove the vial of mercury vapor with a blow bottle stopper, along the wall to the bottle by adding 5 ml of sulfuric acid solution (5.15) and 0.5 ml
The stannous chloride solution (5.11) is then immediately capped and evacuated for 5 min to remove possible mercury in the system.
8.2.2.3 Enrichment
In turn, the standard series of mercury vapor generators and concentrators (6.1) with different concentrations of mercury in 8.2.1 are connected in series to mercury enrichment
In system (6.4), open and adjust the enrichment flow to 0.8 L/min, remove the vial of mercury vapor with the blowing head,
Add 0.5 ml of stannous chloride solution (5.11) along the tube wall to the vial and immediately close the vial and concentrate for 3 min. Follow
Remove the prepared standard enrichment tube, the ends of the rich tube stuffed with polyethylene or PTFE plug, filled polyethylene bag or
Special stopper glass tube to save, to be measured on the machine.
8.2.3 Determination of standard enrichment tubes
The 8.2.2.3 prepared standard enrichment tube installed in order to thermal analysis - cold atomic absorption mercury system (6.3) and connected
Good pipeline. In accordance with the best instrument set conditions, run the thermal analysis program, the mercury vapor into the cold atomic absorption cell to carry out
Test, record the instrument's response value (low concentration standard series record peak height, high concentration standard series record peak area).
8.2.4 establishment of working curve
The standard series of mercury content (ng) as the abscissa, with its corresponding response to the vertical axis, the establishment of the working curve.
8.3 Sample Determination
8.3.1 Determination of sample collection tube
The sample after the rich pipe connected to the thermal analysis - cold atomic absorption mercury system (6.3), according to the standard with the rich
Determination (8.2.3) The same instrument conditions and procedures for the determination of the sample.
8.3.2 Determination of blank rich tubes
Reagent blank sample enrichment tube and full sample blank sample enrichment tube prepared in the same batch with the sample collection are respectively connected to the heat
Analytical - cold atomic absorption mercury measurement system (6.3), according to the same sample and sample enrichment tube (8.3.1) the same instrument conditions and instrumentation
As a step, the reagent blank sample and the whole program blank sample determination.
9 results calculated and expressed
9.1 Calculation Results
The mass concentration of gaseous mercury in ambient air is calculated according to equation (1)
W - mercury content measured in the sample collection tube, ng;
Vn - sampling volume at standard state (273.15 K, 101.325 kPa), L.
9.2 results indicated
When the sampling volume is 60 L (60 min, standard state) and the measurement result is less than 100 ng/m3, it is retained to the whole digit;
When the measurement result is 100 ng/m3 or more, 3 significant digits are reserved.
When the sampling volume is 1440 L (24 h, standard state) and the measurement result is less than 10.0 ng/m3, 1
Bit; When the result is greater than or equal to 10.0 ng/m3, 3 significant digits are reserved.
10 precision and accuracy
10.1 Precision
Six laboratories respectively prepared the standard enrichment of three concentration levels of 10.0 ng, 50.0 ng and 90.0 ng
Tubes (6 for each concentration) were determined. the relative standard deviations in the laboratory were 0.93% ~ 6.8%, respectively,
1.1% ~ 3.1% and 0.47% ~ 2.4% respectively. The relative standard deviations of the two laboratories were 6.7%, 2.8% and 1.4% respectively. The repeatability limit
Do not 1.2 ng, 2.7 ng and 3.6 ng, reproducibility limits were 2.2 ng, 4.7 ng and 4.9 ng.
Laboratory concentration of two standard concentration of 0.5 ng and 1.0 ng of mercury prepared standard enrichment tubes (each concentration level
Each 6) were measured, the relative standard deviations in the laboratory were 7.9% and 7.8%.
The concentration of ambient air samples at the two concentration levels actually collected (24 h) was measured in the laboratory (each concentration
The level of the parallel acquisition of six), get the average mercury content of 1.6 ng/m3 and 12.4 ng/m3, the laboratory phase
The standard deviations were 11% and 9.5% respectively.
10.2 Accuracy
Six laboratories tested two different concentrations of mercury standard sample solutions (11.4 ± 1.1) μg/L and (20.4 ± 1.6) μg/L
The standard sample enrichment tubes with the mercury contents of 11.4 ng and 20.4 ng were separately prepared by the gold membrane enrichment method
6), and their mercury content were determined, the relative errors were -7.0% -9.3%, -6.4% -5.0%; the relative error was
The final values were -0.07% ± 13% and -0.24% ± 8.6%, respectively.
11 Quality Assurance and Quality Control
11.1 Sampling Flow
The relative deviation of the flow at the beginning and the end of the sampling should be within 10%.
11.2 Calibration
Correlation coefficient of the working curve should be greater than or equal to 0.995, otherwise re-establish the working curve.
Before each analysis should prepare a curve of the middle point of the standard enrichment tube validation curve, such as the determination of concentration deviation greater than
10%, you need to re-establish the working curve.
11.3 Blank
At least one reagent blank should be prepared and analyzed after each working curve is established. Blank value should be below the detection limit (about
0.15 ng). Otherwise, the cause should be identified and the working curve should be re-established if necessary. Only after the reagents have passed the blank can the samples be analyzed.
At least one full program blank should be collected and analyzed for each batch of samples. Blank value should be less than 2 times the detection limit (about 0.3 ng)
Otherwise it should be re-sampled for analysis.
11.4 parallel sample determination
Each batch of samples should be collected at least a parallel sample, the relative deviation should be less than 20%.
11.5 standard sample determination
Gold membrane enrichment method using commercially available certified standard sample solution of a certain amount of mercury through the mercury enrichment system (6.4) rich
Set to enrichment tube (6.1), which is pre...
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