|
US$469.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email.
HJ 648-2013: Water quality. Determination of nitroaromatics by gas chromatography
Status: Valid
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| HJ 648-2013 | English | 469 |
Add to Cart
|
3 days [Need to translate]
|
Water quality. Determination of nitroaromatics by gas chromatography
| Valid |
HJ 648-2013
|
Standard similar to HJ 648-2013 HJ 511 HJ 945.3 HJ 943 Basic data | Standard ID | HJ 648-2013 (HJ648-2013) | | Description (Translated English) | Water quality. Determination of nitroaromatics by gas chromatography | | Sector / Industry | Environmental Protection Industry Standard | | Word Count Estimation | 18,165 | | Older Standard (superseded by this standard) | GB/T 13194-1991 | | Quoted Standard | GB 17378; HJ/T 164; HJ/T 91 | | Regulation (derived from) | Department of Environmental Protection Notice No. 33 of 2013 | | Issuing agency(ies) | Ministry of Ecology and Environment | | Summary | This standard specifies: water 15 kinds of nitrobenzene compounds liquid-liquid extraction/solid phase extraction gas chromatographic method. 15 kinds of nitrobenzene compounds include nitrobenzene, right Nitro Toluene nitro toluene, o nitro toluene, p ni | HJ 648-2013: Water quality. Determination of nitroaromatics by gas chromatography---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.
Water quality.Determination of nitroaromatics by gas chromatography
National Environmental Protection Standard of the People's Republic
Replace GB 13194-91
Determination of nitrobenzene compounds in water
Extraction/solid phase extraction-gas chromatography
Published on.2013-06-03
2013-09-01 Implementation
Ministry of Environmental Protection released
Content
Foreword..I
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..4
9 result calculation and representation..5
10 Precision and Accuracy..6
11 Quality Assurance and Quality Control 7
12 Waste treatment 7
13 Notes. 7
Appendix A (Normative Appendix) Method Detection Limit and Lower Measurement Limit.8
Appendix B (informative) Method Precision and Accuracy..9
Foreword
To protect the environment and protect the human body 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 Water Pollution Prevention and Control
This standard is established for the determination of healthy, standardized nitrobenzene compounds in water.
This standard specifies the liquid-liquid extraction and solidification of nitrobenzene compounds in surface water, groundwater, industrial wastewater, domestic sewage and seawater.
Phase extraction gas chromatography.
This standard is for the determination of water nitrobenzene, nitrotoluene, nitrochlorobenzene, dinitrotoluene by gas chromatography (GB 13194-91)
Revision.
This standard was first published in.1991. The original drafting unit was the Wuhan Environmental Monitoring Center Station. This is the first revision. This revision
The main content is.
-- Amend the standard name to "Determination of water-nitrobenzene compounds by liquid-liquid extraction/solid phase extraction - gas chromatography".
-- Increased the type of measurement of nitrobenzene compounds.
-- Expanded the scope of application of the method and increased the determination of domestic sewage and seawater.
-- Added sample preparation methods for solid phase extraction.
-- The analytical column was changed from packed column to capillary column, and the chromatographic conditions were changed accordingly.
- Liquid-liquid extraction solvent changed from benzene to toluene.
-- Modified the quantitative method for nitrobenzene compounds.
-- Modified the method detection limit.
-- Added quality assurance and quality control provisions.
Gas chromatographic method for the determination of nitrobenzene, nitrotoluene, nitrochlorobenzene and dinitrotoluene from the date of implementation of this standard
(GB 13194-91) abolished.
Appendix A of this standard is a normative appendix, and Appendix B is an informative appendix.
This standard was formulated by the Science and Technology Standards Department of the Ministry of Environmental Protection.
This standard was drafted. Tianjin Environmental Monitoring Center, Environmental Standards Institute of the Ministry of Environmental Protection.
This standard is verified by the National Key Laboratory of Environmental Pollution Control, Environmental Monitoring Center of Shenyang, and Environmental Protection of the Ministry of Agriculture.
Environmental Protection Monitoring Institute, Tianjin Tanggu District Environmental Protection Monitoring Station, Tianjin Dongli District Environmental Protection Monitoring Station and Tianjin Dagang District Environmental Protection
Monitoring station.
This standard was approved by the Ministry of Environmental Protection on June 3,.2013.
This standard has been implemented since September 1,.2013.
This standard is explained by the Ministry of Environmental Protection.
Water quality - Determination of nitrobenzene compounds - Liquid-liquid extraction/solid phase extraction - Gas chromatography
1 Scope of application
This standard specifies liquid-liquid extraction and solid phase extraction gas chromatography for the determination of 15 nitrobenzene compounds in water. 15 nitrobenzenes
The compounds include nitrobenzene, p-nitrotoluene, m-nitrotoluene, o-nitrotoluene, p-nitrochlorobenzene, m-nitrochlorobenzene, o-nitrochloride.
Benzene, p-dinitrobenzene, m-dinitrobenzene, o-dinitrobenzene, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 3,4-dinitrotoluene, 2,4-
Dinitrochlorobenzene, 2,4,6-trinitrotoluene.
This standard applies to the determination of nitrobenzene compounds in surface water, groundwater, industrial wastewater, domestic sewage and seawater.
The sampling amount of liquid-liquid extraction method is.200ml, the detection limit of the method is 0.017μg/L~0.22μg/L; when the sampling amount of solid phase extraction is 1.0L,
The detection limit of the method was 0.0032μg/L~0.048μg/L. See Appendix A for details.
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 17378 Ocean Monitoring Code
HJ/T 164 Technical Specifications for Groundwater Environmental Monitoring
HJ/T 91 Surface Water and Wastewater Monitoring Technical Specifications
3 Principle of the method
Liquid-liquid extraction. The nitrobenzene compound in the water is extracted with a certain amount of toluene, and the extract is subjected to dehydration, purification, and chromatographic analysis.
Solid phase extraction. adsorption of nitrobenzene compounds in water by solid phase extraction column or extraction disk, elution with n-hexane/acetone, eluent
After dehydration and constant volume, chromatographic analysis was carried out.
The extract is injected into a gas chromatograph, and the target compound is separated by a quartz capillary column and determined by an electron capture detector.
Qualitative, external standard method quantitative.
4 interference and elimination
4.1 Organic compounds such as organochlorine pesticides (hexachlorocyclohexane, DDT), halogenated hydrocarbons, chlorobenzene, etc., which may coexist in the water sample, are on the electron capture detector.
Although there is a response, there is no significant interference with the method in the method due to the difference in retention time.
4.2 Other substances in the water that may be co-existing with halogen or nitrogen in the electron capture detector may interfere with the determination, and the polarity is poor.
If the two larger capillary columns are separated and measured separately, the qualitative error can be greatly reduced.
4.3 For samples with complex background interference, qualitative determination can also be carried out using gas chromatography mass spectrometry.
5 reagents and materials
Analytical purification reagents that meet national standards are used for analysis, unless otherwise stated. The test water is freshly prepared deionized water or steamed.
Distilled water.
5.1 n-Hexane (C6H14). Chromatographically pure.
5.2 Acetone (C3H6O). chromatographically pure.
5.3 Methanol (CH4O). Chromatographically pure.
5.4 Toluene (C7H8). chromatographically pure.
5.5 anhydrous sodium sulfate (Na2SO4). baked in an oven at 450 ° C for 4 h, placed in a desiccator cooled to room temperature, filled into a bottle, dried
Saved in the device.
5.6 Hydrochloric acid (HCl). ρ (HCl) = 1.19 g/ml.
5.7 Sodium hydroxide (NaOH).
5.8 Nitrobenzene compound standard substance. the purity is not less than 98%.
Including nitrobenzene, p-nitrotoluene, m-nitrotoluene, o-nitrotoluene, p-nitrochlorobenzene, m-nitrochlorobenzene, o-nitrochlorobenzene,
p-Dinitrobenzene, m-dinitrobenzene, o-dinitrobenzene, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 3,4-dinitrotoluene, 2, 4-two
Nitrochlorobenzene, 2,4,6-trinitrotoluene standard material.
5.9 nitrobenzene standard stock solution. ρ =10.0mg/ml.
Accurately weigh 250mg of each nitrobenzene compound standard (5.8), accurate to 0.1 mg, and put 25.0ml brown capacity
In the bottle, use a small amount of toluene (5.4) to help dissolve, add n-hexane (5.1) to the mark, as a standard stock solution of nitrobenzene, at 4 ° C
Save for one year. Commercially available certified standard solutions are also available.
5.10 nitrobenzene standard use liquid. nitrobenzene and nitrotoluene ρ =.200mg/L; nitrochlorobenzene, dinitrotoluene, dinitrochlorobenzene and
Trinitrotoluene ρ = 20.0 mg/L.
Accurately transfer.200 μl each of nitrobenzene and nitrotoluene standard stock solution (5.9), nitrochlorobenzene, dinitrotoluene, dinitrochlorobenzene
And 20.0 μl of the standard stock solution of trinitrotoluene (5.9), in a 10.0 ml brown volumetric flask, make up to volume with n-hexane, mix and mix
The standard use solution can be stored for half a year at 4 °C.
5.11 Solid phase extraction column elution solution. 3 1 (V/V) n-hexane/acetone mixed solution.
5.12 Hydrochloric acid solution. 1 1 (V/V).
5.13 Sodium hydroxide solution. c (NaOH) = 0.1 mol/L.
4 g of sodium hydroxide (5.7) was dissolved in a small amount of water and diluted to 1000 ml.
5.14 Solid phase extraction adsorbent. 60~80 mesh, the matrix material is polystyrene-divinylbenzene spherical polymer copolymer. For example. HLB or
GDX502. In the Soxhlet extractor, acetone, n-hexane and methanol were successively extracted for 6 hours, then dried in an oven at 100 ° C, and transferred to
Cool to room temperature in a desiccator and store in a screw-capped glass vial with a ground glass stopper or a lined Teflon pad.
5.15 Silica-magnesium type adsorbent. for chromatography, 60~80 mesh, purchase 677 °C activated product, stored in a glass stopper with a ground or with a lined poly 4
Fluorine vinyl mat in a screw cap glass bottle container.
Activation of the silica-magnesium type adsorbent. the silicon-magnesium-type adsorbent is placed in a large porcelain crucible and spread out, and the upper part of the porcelain crucible is covered with aluminum foil, and the crucible is placed.
Into the oven, dried at 130 ° C for 16 h, then placed in a desiccator in a desiccator cooled to room temperature, sealed glass
Waiting for use in the bottle.
5.16 Carrier gas. nitrogen, the purity is not less than 99.999%.
6 Instruments and equipment
6.1 Gas chromatograph with temperature programmed function and electron capture detector (ECD).
6.2 Solid phase extraction unit.
6.3 Soxhlet extractor.
6.4 Muffle furnace.
6.5 oven.
6.6 Dryer.
6.7 Precision balance. The sensitivity is 0.1mg.
6.8 Column 1. fused silica capillary cross-linked 100% dimethyl with a column length of 60 m, an inner diameter of 0.32 mm and a film thickness of 1.0 μm
Polysiloxane columns (such as HP-1) and columns with similar properties.
Column 2. fused silica capillary cross-linked 14% cyanopropyl group with a column length of 30 m, an inner diameter of 0.25 mm and a film thickness of 0.25 μm
Benzene and 86% dimethylpolysiloxane columns (such as DB-1701) and columns with similar properties.
6.9 Solid phase extraction column. A solid phase extraction column packed with solid phase extraction adsorbent (5.14) (500mg~1000mg). Or use the same class
Commercial solid phase extraction column for type packing.
Pretreatment of the solid phase extraction column. The solid phase extraction column is placed on the needle seat of the solid phase extraction device, and the extraction column is pre-washed with 5 ml of n-hexane.
5 ml of methanol was added, and after the methanol was completely passed through the extraction column, 5 ml of water was added to leave the bed in a wet and activated state.
6.10 Drying column. 2 g of anhydrous sulfur is packed into the drying column (column length about.200 mm, inner diameter 6~10 mm) with sieve plate or glass wool at the bottom.
Sodium (5.5). The column should be rinsed with 10 ml of toluene or n-hexane before use to purify the dried column.
6.11 Silica-magnesium purification column. 60mm (column length) × 15mm (internal warp) glass or polyethylene column, with a thick hole glass sand core at the bottom.
Packing of the purification column. 1000mg activated silicon-magnesium type adsorbent (5.15) is placed in a 50ml beaker, and an appropriate amount of n-hexane is added.
Acetone (5.11), a silica-magnesium type adsorbent was prepared as a suspension. The suspension is then poured into a purification column and the purification column is tapped to fill the adsorbent.
(Commercial purification columns of the same type of packing can also be used).
6.12 Vial. 1L brown with ground stopper glass bottle.
6.13 Microinjectors. 100 μl, 50 μl and 10 μl.
6.14 separatory funnel. 0.1L, 0.5L, 1L or 2L.
6.15 Receiver. 10ml or 20ml with a graduated scale.
6.16 Common instruments used in general laboratories.
7 samples
7.1 Sample collection and preservation
Collection and storage of water samples in accordance with the relevant provisions of GB 17378, HJ/T 164 and HJ/T 91.
7.2 Preparation of samples
7.2.1 Liquid-liquid extraction
7.2.1.1 Extraction
Shake the water sample, accurately measure.200ml water sample, place it in the separatory funnel, add 10.0ml toluene (5.4), and shake for 3~5min.
After standing for 5-10 min, the two phases were layered, the aqueous phase was discarded, and the extract was dried over anhydrous sodium sulfate (6.10), and the extract was collected and purified.
Note 1. When emulsification occurs during the extraction process, it can be broken down by salting out, stirring, centrifuging, freezing or filtering with glass wool.
7.2.1.2 Purification
Groundwater, seawater and extracts of surface water, industrial wastewater and domestic sewage with low background interference can be directly injected into the gas phase without purification.
The chromatograph was analyzed.
Activate the purification column (6.11) with 10 ml of toluene and discard it. When about 1 ml of toluene is left on the column, transfer the extract to the purification column.
Wash the container containing the extract with a small amount of toluene, add it to the column, and rinse the column with 5 ml of toluene at a rate of 2 ml/min.
The effluent is in the receiving tube. Make up to 20 ml with toluene and prepare for chromatographic analysis.
7.2.2 Solid phase extraction
7.2.2.1 Adjustment of water samples
Before the analysis of the water sample, adjust the pH value of the water sample to about 7 with hydrochloric acid solution (5.12) or sodium hydroxide solution (5.13).
Methanol (5.3) was added to the water sample to make the methanol concentration 5 ‰ and mix.
7.2.2.2 Enrichment of water samples
According to the concentration of water sample and the degree of interference, accurately measure the appropriate amount of water sample (10ml~1000ml) in the sample bottle, and open the vacuum of the solid phase extraction device.
System, the water sample is continuously passed through the activated extraction column (6.9), and the flow rate is maintained at 5~10ml/min for water sample enrichment.
Always keep at least 1cm high water sample on the column bed, the loading speed should be stable, not too fast or too slow, and try to avoid air ventilation
Pass the column bed. After all the samples have passed through the extraction column, rinse the inner wall of the sample bottle with 10 ml of water, continue vacuum suction for 10 min or use high purity nitrogen.
Blow and dry the extraction column. If the sample is extracted using an automated solid phase extraction apparatus, the extraction is performed according to the operating procedures of the respective instruments.
7.2.2.3 Sample elution and concentration
After washing the sample bottle with 10 ml of n-hexane/acetone (5.11), the sample was eluted at a rate of 2 ml/min. The eluate was passed through a dry column (6.10).
Set in the receiving tube, set to 10.0ml, for chromatographic analysis.
Note 2. If the water sample contains a higher concentration of suspended solids, the water sample should be filtered first, and the filter membrane is extracted with 5 ml of n-hexane/acetone. The extract is passed through a column of anhydrous sodium sulfate (6.10).
After dehydration, it was combined with the solid phase extraction eluate for analysis.
Note 3. If the extract cannot be chromatographed in time, it should be stored at 4 °C in the dark and analyzed within 40 days.
7.3 Preparation of blank samples
Take 10~1000ml of experimental water instead of water sample, and prepare blank sample according to the same extraction and purification steps as sample preparation (7.2).
8 Analysis steps
8.1 Chromatographic Analysis Reference Conditions
8.1.1 Column 1 Chromatographic Reference Conditions
Column temperature. 60 ° C for 1 min, 10 ° C/min to.200 ° C, for 1 min, 15 ° C/min to 250 ° C,
Hold for 5 min; gasification chamber temperature. 250 ° C; detector temperature. 300 ° C; carrier gas flow rate. 1.0 ml/min; makeup gas flow. 60 ml/min;
Injection method. split/splitless injection; injection volume. 1.0 μL.
8.1.2 Column 2 Chromatographic Reference Conditions
Column temperature. 50 ° C for 2 min, 12 ° C/min to.200 ° C, for 1 min, 15 ° C/min to 270 ° C,
Hold for 5 min; gasification chamber temperature. 250 ° C; detector temperature. 300 ° C; carrier gas flow rate. 1.0 ml/min; makeup gas flow. 60 ml/min;
Injection method. split/splitless injection; injection volume. 1.0 μL.
8.2 Calibration
Initial calibration. use nitrobenzene standard solution (5.10) diluted with toluene (5.4) or solid phase extraction column elution solution (5.11)
The nitrobenzene and nitrotoluene are 50, 100,.200, 500, and 1000 μg/L, respectively; the other nitrobenzenes are 5, 10, 20, and 50, respectively.
100μg/L standard series, respectively, take 1.0μl of the standard series solution into the gas chromatograph inlet, according to the concentration and chromatogram of each component
The peak area (or peak height) is plotted as a standard curve.
8.3 Determination
Use a micro syringe or autosampler to take 1.0 μl of the sample (7.2) into the gas chromatograph, in the same chromatographic conditions as the standard curve.
The measurement was carried out. Record the retention time and peak area (or peak height) of the chromatographic peak.
8.4 Standard chromatogram
A standard chromatogram of the nitrobenzene compound on column 12, see Figure 1.
Figure 1 Spectra of nitrobenzene compounds on column 1
1-nitrobenzene; 2-o-nitrotoluene; 3-m-nitrotoluene; 4-p-nitrotoluene; 5-m-nitrochlorobenzene; 6-p-nitrochlorobenzene; 7- O-nitrochloride
Benzene; 8-p-dinitrobenzene; 9-m-dinitrobenzene; 10-2,6-dinitrotoluene; 11-o-dinitrobenzene; 12-2,4-dinitrotoluene ;13-2,4-
Dinitrochlorobenzene; 14-3,4-dinitrotoluene; 15-2,4,6-trinitrotoluene.
A standard chromatogram of the nitrobenzene compound on column 2, see Figure 2.
Figure 2 Spectra of nitrobenzene compounds on column 2
1-nitrobenzene; 2-o-nitrotoluene; 3-m-nitrotoluene; 4-p-nitrotoluene; 5-m-nitrochlorobenzene; 6-p-nitrochlorobenzene; 7- O-nitrochloride
Benzene; 8-p-dinitrobenzene; 9-m-dinitrobenzene; 10-2,6-dinitrotoluene; 11-o-dinitrobenzene; 12-2,4-dinitrotoluene ;13-2,4-
Dinitrochlorobenzene; 14-3,4-dinitrotoluene; 15-2,4,6-trinitrotoluene
9 Calculation and representation of results
9.1 Quantitative results
The content of the target compound in the sample, iρ (μg/L), is calculated according to formula (1).
Iρ = V
Where. iρ - the content of a certain nitrobenzene compound in the sample, μg/L;
ρ - the concentration value calculated from the standard curve, μg/L;
iV - the volumetric volume of the extract, ml;
V -- water sample volume, ml.
9.2 Results representation
When the sample content is less than 1μg/L, the nitrobenzene and nitrotoluene results remain to the second place after the decimal point, nitrochlorobenzene, dinitrobenzene
The results of trinitrotoluene were retained to the second decimal place; when the sample content was greater than or equal to 1 μg/L, the result retained three significant figures.
10 Precision and accuracy
10.1 Precision
10.1.1 Liquid-liquid extraction
Three laboratory standards for three concentrations of nitrobenzene compounds were determined in six laboratories. Among them, nitrobenzene and nitrotoluene are low, medium,
High spiked concentrations were 2.50μg/L, 10.0μg/L and 50.0μg/L; low, medium and high levels of nitrochlorobenzene, dinitrobenzene and trinitrotoluene
The spiked concentrations were 0.250 μg/L, 1.00 μg/L, and 5.00 μg/L, respectively.
The relative standard deviations in the laboratory corresponding to the three spiked concentrations were. 2.9%~4.2%, 1.7%~2.5%, 1.9%~3.8%; laboratory
The relative standard deviations were. 1.9% to 7.1%, 1.4% to 4.9%, and 1.2% to 4.6%.
The repeatability limits r for the three spiked concentrations are. nitrobenzene and nitrotoluene 0.31μg/L~0.35μg/L, respectively.
0.82μg/L~0.99μg/L, 3.4μg/L~4.6μg/L; nitrochlorobenzene, dinitrobenzene and trinitrotoluene 0.027μg/L~0.14μg/L,
0.075 μg/L ~ 0.11 μg/L, 0.31 μg/L ~ 0.45 μg/L. Reproducibility limits R are. nitrobenzene and nitrotoluene 0.34μg/L ~ 0.42μg/L,
0.87μg/L~1.16μg/L, 3.5μg/L~4.7μg/L; nitrochlorobenzene, dinitrobenzene and trinitrotoluene 0.031μg/L~0.14μg/L,
0.079 μg/L ~ 0.16 μg/L, 0.043 μg/L ~ 0.70 μg/L.
10.1.2 Solid phase extraction
Three laboratory standards for three concentrations of nitrobenzene compounds were determined in six laboratories. Among them, nitrobenzene and nitrotoluene are low, medium,
The high spiked concentrations were 0.500μg/L, 2.00μg/L and 10.0μg/L, respectively; low, medium, and nitrochlorobenzene, dinitrobenzene and trinitrotoluene
The high spike concentrations were 0.050 μg/L, 0.200 μg/L, and 1.00 μg/L, respectively.
The relative standard deviations in the laboratory corresponding to the three spiked concentrations were. 1.7%~4.0%, 1.4%~2.6%, 1.8%~3.3%; laboratory
The relative standard deviations were. 1.8% to 5.3%, 1.8% to 6.6%, and 1.3% to 3.5%.
The repeatability limits r for the three spiked concentrations are. nitrobenzene and nitrotoluene 0.056μg/L~0.066μg/L,
0.18μg/L~0.21μg/L, 0.66μg/L~0.72μg/L; nitrochlorobenzene, dinitrobenzene and trinitrotoluene 0.0056μg/L~0.0066μg/L,
0.017μg/L~0.021μg/L, 0.061μg/L~0.084μg/L. Reproducibility limits R are. nitrobenzene and nitrotoluene
0.063μg/L~0.074μg/L, 0.21μg/L~0.26μg/L, 1.0μg/L~1.3μg/L; nitrochlorobenzene, dinitrobenzene and trinitrotoluene
0.0060 μg/L ~ 0.0085 μg/L, 0.022 μg/L ~ 0.038 μg/L, 0.080 μg/L ~ 0.11 μg/L.
10.2 Accuracy
10.2.1 Liquid-liquid extraction
Six laboratories analyzed actual samples (including industrial wastewater, surface water and domestic sewage) and actual samples.
The concentration of the spiked water samples was 10.0 μg/L for nitrobenzene and nitrotoluene, 1.00 μg/L for nitrochlorobenzene, dinitrobenzene and trinitrotoluene.
The recoveries of spiked standards were. 83.9%~102% of wastewater; 83.2%~103% of surface water; 82.9%~102% of sewage.
The final recoveries of the spiked recovery are. Industrial wastewater (91.5±11.8)%~(94.7±10.5)%, surface water
(91.9±13.6)%~(95.4±11.5)%, domestic sewage (92.2±12.4)% ~ (92.2±12.4)%.
10.2.2 Solid phase extraction
Six laboratories analyzed and tested actual samples (including groundwater, surface water and seawater) and actual samples.
The concentration of spiked water samples was. nitrobenzene and nitrotoluene 2.00 μg/L, nitrochlorobenzene, dinitrobenzene and trinitrotoluene 0.200 μg/L.
The recoveries of spiked standards were. groundwater 84.0%~103%; surface water 83.5%~104%; seawater 83.5%~101%.
The final values of the spiked recovery were. groundwater (92.3±13.8)% ~ (95.0±13.8)%, surface water (92.4±13.9)%~(95.8
±15.9)%, seawater (92.3±14.0)% ~ (95.1±11.8)%.
See Appendix B for the specific results.
11 Quality Assurance and Quality Control
11.1 Retention time
A retention time window of t ± 3 s should be established prior to sample analysis. t is the average value of the retention time of each concentration standard substance at the initial calibration, s is
The standard deviation of the retention time of each reference material at the initial calibration. When the sample is analyzed, the target compound retention time should be within the retention time window.
11.2 The correlation coefficient of the standard curve should be ≥0.995, otherwise the standard curve should be redrawn.
11.3 Intermediate concentration test
The intermediate concentration test should be carried out during sample analysis. The relative deviation between the side value of the intermediate concentration and the curve should be less than 20%. Otherwise, it should be established.
New standard curve.
11.4 Blank test
Each batch of samples (10 to 20 samples as a batch) should be at least one full program blank and laboratory blank, the concentration of the target compound
Sho...
|