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HJ 901-2017 English PDF

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HJ 901-2017: Ambient air. Determination of organochlorine pesticides. Gas chromatography
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Standard ID	Contents [version]	USD	STEP2	[PDF] delivered in	Standard Title (Description)	Status	PDF
HJ 901-2017	English	399	Add to Cart	4 days [Need to translate]	Ambient air. Determination of organochlorine pesticides. Gas chromatography	Valid	HJ 901-2017

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Basic data

Standard ID	HJ 901-2017 (HJ901-2017)
Description (Translated English)	Ambient air. Determination of organochlorine pesticides. Gas chromatography
Sector / Industry	Environmental Protection Industry Standard
Classification of Chinese Standard	Z15
Classification of International Standard	13.040.20
Word Count Estimation	17,110
Date of Issue	2017-12-14
Date of Implementation	2018-03-01
Quoted Standard	HJ 194; HJ 691
Regulation (derived from)	Ministry of Environmental Protection Bulletin 2017 No. 71
Issuing agency(ies)	Ministry of Ecology and Environment
Summary	This standard specifies gas chromatography for the determination of organochlorine pesticides in the ambient air. This standard applies to ambient air gas and particulate matter hexachlorobenzene, alpha-hexanol, gamma-hexa-, beta- hexamethylene, delta- hexamethylene, heptachlor, aldrin, epoxy heptachlor-B , Gamma-chlordane, alpha-chlordane, endosulfan I, 4, 4""-DDE, dieldrin, endrin, 4, 4""-DDD, 2, 4""-DDT, endosulfan Determination of 23 Organochlorine Pesticides of 2, 4, 4""-DDT, Enderaldehyde, Endosulfan Sulfate, Methoxy DDT, Ditrisone, and Mirex. See Appendix B for details. When the sampling volume is 350 m^(3) (standard state) and the volume of concentrated constant volume is 1.0 ml, the detection limit of 23 organochlorine pesticides determined by this method is 0.02~

HJ 901-2017: Ambient air. Determination of organochlorine pesticides. Gas chromatography

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(Ambient air - Determination of organochlorine pesticides - Gas chromatography) People's Republic of China national environmental protection standards Ambient air - Determination of organochlorine pesticides Gas chromatography Ambient air-Determination of organochlorine pesticides -Gas chromatography 2017-12-14 Published 2018-03-01 implementation Ministry of Environmental Protection released i directory Preface ... 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 ... 3 7 samples ... 4 8 Analysis step ... 6 9 Calculation and Expression of Results ... 8 10 Precision and accuracy ...8 11 Quality Assurance and Quality Control ...9 12 Waste Treatment ... 9 Appendix A (Normative) Detection limit and lower limit of the method ... 10 Appendix B (Informative) Compound List ... 11 Appendix C (informative) method of precision and accuracy ... 12 i 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 organochlorine pesticides in the ambient air, the development of this standard. This standard specifies the determination of organochlorine pesticides in ambient air by gas chromatography. Appendix A of this standard is a normative appendix, Appendix B and Appendix C are informative appendices. 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. Shenyang Environmental Monitoring Center Station. This standard verification unit. Jiangsu Province Environmental Monitoring Center, Henan Province Environmental Monitoring Center, Liaoning Province, environmental monitoring experiments Heart, Dalian Environmental Monitoring Center, Anshan Environmental Monitoring Center Station and Shenyang Environmental Protection Bureau Tiexi Branch Environmental Monitoring Station. This standard MEP approved on December 14,.2017. This standard since March 1,.2018 into effect. This standard is interpreted by the MEP.

1 Ambient air Determination of organochlorine pesticides by gas chromatography

Warning. The solvents and reagents used in this method are toxic. The experimental procedure should be carried out in a fume hood. Wear protective equipment as required and avoid contact with skin and clothing.

1 scope of application

This standard specifies the determination of organochlorine pesticides in ambient air by gas chromatography. This standard applies to ambient air and particulate matter hexachlorobenzene, α-BHC, γ-BHC, β-BHC, δ-VI Hexachlorocyclohexane, Aldrin, Epichlorohydrin B, γ-Chlordane, α-Chlordane, Endosulfan I, 4,4'-DDE, Dieldrin, Endrin, 4,4'-DDD, 2,4'-DDT, endosulfan II, 4,4'-DDT, isodilal, endosulfan sulfate, methoxy DDT, Moxa total of 23 kinds of organochlorine pesticides determination. See Appendix B for details. When the sampling volume is 350 m3 (standard state) and the volume of concentrated volume is 1.0 ml, this method measures 23 organic The detection limit of chlorine pesticides was 0.02 ng/m3 ~ 0.06 ng/m3, and the lower limit of determination was 0.08 ng/m3 ~ 0.24 ng/m3. See Appendix A for details.

2 Normative references

This standard references the following documents in the terms. For undated references, the effective version applies This standard. HJ 194 Manual Air Quality Monitoring Technical Specifications HJ 691 Environmental airborne semi-volatile organic compounds sampling techniques

3 method principle

A large flow sampler is used to collect the organochlorine pesticides in the ambient air and particulate matter into the filter and polyurethane foam (PUF), extracted with ether-n-hexane mixed solvent, the extract was concentrated, purified, gas chromatographic separation, electron Capture detector detection, according to the retention time qualitative, internal standard method or external standard method.

4 Interference and elimination

Other organic matter in the sample may interfere with the determination, choose to use sulfuric acid, magnesium silicate column and other purification methods to remove interference, However, the purification of sulfuric acid can cause the decomposition of some organochlorine pesticides, as detailed in 7.3.3.

5 Reagents and materials

Unless otherwise specified, analytical grade analytical reagents used in accordance with national standards were used. Experimental water is freshly prepared Pure water. 5.1 acetone (C3H6O). pesticide grade. 5.2 n-hexane (C6H14). pesticide residues. 5.3 ether (C4H10O). Chromatography. 5.4 Dichloromethane (CH2Cl2). pesticide grade. 25.5 Anhydrous sodium sulfate (Na2SO4). Bake in a muffle furnace at 400 ° C for 4 h before use, cool, Sealed and saved 5.6 Sodium chloride (NaCl). Bake in a muffle furnace at 400 ° C for 4 h before use, then cool and seal in a ground-glass jar Save. 5.7 sulfuric acid (H2SO4). ρ = 1.84 g/cm3, excellent grade pure. 5.8 ether - n-hexane mixed solvent. 1 9, Pro use now. 5.9 acetone - n-hexane mixed solvent. 1 9, Pro use now with. 5.10 ether - n-hexane mixed solvent. 5 5, Pro use now. 5.11 ether - n-hexane mixed solvent. 6 94, Pro use now with. 5.12 ether - n-hexane mixed solvent. 15 85, Pro use now. 5.13 Sodium chloride solution. ρ = 50 g/L. Weigh 50.0 g of sodium chloride (5.6) in a beaker, dissolved in water and set the volume to 1000 ml, mix, Pro use now. 5.14 Endrin and 4,4'-DDT standard solution. ρ = 100 μg/L. Buy a commercially available standard solution directly and dilute with n-hexane (5.2). 5.15 Substitute stock solution. ρ = 500 μg/ml. Direct purchase of a certified commercial standard solution containing 2,4,5,6-tetrachloro-m-xylene (TCX) and decabllylene (DCBP) mixed Combined solution or single standard solution. Other suitable alternatives may also be used. 5.16 Substitute intermediate solution. ρ = 50.0 μg/ml. Pipette 1.00 ml of stock solution (5.15) in a 10 ml volumetric flask, dilute with n-hexane (5.2) and mix well. 5.17 Alternative solution. ρ = 1.00 μg/ml. Pipette 1.00 ml of intermediate stock solution (5.16) into a 50 ml volumetric flask and dilute with n-hexane (5.2) and mix well. 5.18 Internal standard stock solution. ρ = 1000 μg/ml. Direct purchase of a certified commercial standard solution containing 1-bromo-2-nitrobenzene (BNB). 5.19 Internal standard intermediate solution. ρ = 100 μg/ml. Pipette 1.00 ml internal standard stock solution (5.18) in a 10 ml volumetric flask with n-hexane (5.2), and mix well. 5.20 Internal standard solution. ρ = 10.0 μg/ml. Pipette 1.00 ml internal standard intermediate solution (5.19) in 10 ml volumetric flask, with n-hexane (5.2) volume, mix. 5.21 standard stock solution. ρ =.2000 μg/ml. Direct purchase of the market a certified standard solution, including α-BHC, γ-BHC, β-BHC, δ-BHC, heptachlor, Aldrin, epichlorohydrin B, gamma-chlordane, alpha-chlordane, endosulfan I, 4,4'-DDE, dieldrin, endrin, 4,4'-DDD, Endosulfan II, 4,4'-DDT, isoderaldehyde, endosulfan sulfate, methylated DDT and docetaxel, a total of 20 kinds of organochlorine pesticides mixed Combined solution, the concentration of.2000 μg/ml. Hexachlorobenzene, 2,4'-DDT, Mirex single standard solution, concentration.2000 μg/ml. Can also be equipped System of 23 kinds of organochlorine pesticide mixed solution. 4 ℃ the following sealed, or reference standard solution certificate preservation conditions. 5.22 standard intermediate solution. ρ = 40.0 μg/ml. Pipette 1.00 ml standard stock solution (5.21) in a 50 ml volumetric flask, make up with n-hexane, and mix well. 5.23 standard solution. ρ = 1.00 μg/ml. Pipette 250 μl standard intermediate solution (5.22) and.200 μl intermediate solution (5.16) in 10 ml volumetric flask, 3 with n-hexane (5.2) constant volume, mix well. Note. All solutions (5.14 ~ 5.23) are transferred to a screw-capped glass bottle with Teflon liner, refrigerated at 4 ° C, sealed from light save. 5.24 Magnesium silicate solid phase extraction column. 1000 mg/6ml, according to the content of impurities can choose the appropriate capacity of commercial solid phase extraction Take the column. 5.25 Magnesium silicate. 150 μm to 250 μm (100 mesh to 60 mesh), activated at 130 ° C for at least 18 h before use, After cooling in the desiccator, transfer to a glass bottle and seal. 5.26 Quartz/glass fiber filter. Select the appropriate size according to the sampling head. The retention efficiency of the filter on 0.3 μm standard particles Not less than 99%. Before use in the muffle furnace 400 ℃ heating 5 h above, after cooling, stored in the filter box, to ensure that the filter at Sampling before and after not contaminated, and in the sample before the flat state. 5.27 Polyurethane Foam (PUF). polyether type, with a density of 22 mg/cm3 ~ 25 mg/cm3, cut to grow 70 mm, straight Cylindrical diameter of 45 mm to 65 mm (length, diameter as determined by the specifications of the glass sampling cartridge). Use hot water before use Scald, and then repeatedly rub into warm water, drained, rinsed with acetone (5.1) three times and placed in a Soxhlet extractor (6.4) Followed by acetone (5.1), ether - n-hexane mixed solvent (5.8) refluxed 16 h, replaced 2 times to 3 times fresh ether - n-hexane mixed solvent (5.8) reflux extraction, removed after the nitrogen (5.28) flow drying (vacuum can also be used at room temperature Dry 2 h ~ 3 h). Place glass sampling cartridge (6.3.2) in a suitable container and seal it. 5.28 Nitrogen. Purity ≥99.999%. 5.29 glass wool. before use dichloromethane (5.4) reflux extraction 2 h ~ 4 h, dried and sealed.

6 instruments and equipment

6.1 Gas Chromatograph. with Split/Splitless Inlet, Temperature Programmable, Dual Electron Capture Detector is recommended. 6.2 Column. Quartz capillary column, 30 m (length) × 0.25 mm (ID) × 0.25 μm (film thickness), two The column has different polarities of the stationary phase. It is recommended that Column 1 has a 5% phenyl 95% dimethylpolysiloxane or other phase Column; column 2 stationary phase is 14% cyanopropylphenyl 86% dimethylpolysiloxane, or 35% phenyl 65% dimethyl Polysiloxanes, or other equivalent columns. 6.3 Sampling device 6.3.1 Large flow sampler. to meet the HJ 691 requirements, with automatic accumulation of sampling volume, automatically convert the standard sampling volume Function, and automatic timing, power and then restart the function and automatically compensate for voltage fluctuations, changes in resistance caused by the flow changes Features. In the presence of filters and sorbents, for large flow rates, the sampler load flow should be up to 250 L/min, the working point of the flow rate of 225 L/min; for large flow sampling, the sampler load flow should be able to achieve 900 L/min, working point flow is 800 L/min. 6.3.2 Sampling head. to meet the HJ 691 requirements, by the filter holder and the sampling sleeve sleeve of two parts, as shown in Figure 1. Sampling head The material selection of stainless steel or PTFE and other non-adsorption of organic materials. Filter clip includes filter ring, filter and filter Film stent. Sampling tube Sleeve equipped with a glass sampling cylinder, the bottom of the sampling cylinder supported by a stainless steel mesh, the adsorption cartridge The material is PUF (5.27). Sampling tube sealed with a silicone rubber seal between the filter holder and the suction pump. Soxhlet extractor. 500 ml or 1000 ml. Other performance extraction devices may also be used. 6.5 Glass Column. 350 mm long, 20 mm id, glass column with Teflon piston on the bottom. 46.6 Concentration device. rotary evaporator, nitrogen purifier or other performance-equivalent equipment. 6.7 solid phase extraction device. 6.8 separatory funnel. 60 ml. 6.9 General laboratory equipment commonly used. 1-gas flow inlet; 2-filter holder; 3- sampling sleeve Barrel; 4-gas outlet; 5-filter ring; 6- Silicone rubber ring; 7-filter; 8- stainless steel mesh; 9-filter holder; 10-glass sampling cartridge. Figure 1 sampling head schematic

7 samples

7.1 Sample Collection 7.1.1 Ambient air samples According to HJ 194 and HJ 691, sampling points should be laid for the determination of meteorological parameters and sample collection. In situ sampling followed by the installation of membrane clamps, sampling tube sleeve, connected to the sampler, adjusting the sampling flow, began sampling. Mining After the sample was taken off the filter, the sample dust inside the fold, remove the glass sampling tube, wrapped with aluminum foil, into the storage box in the close 5 save. 7.1.2 Site blank samples Will seal the preservation of the blank glass sampling cartridge and filter to the sampling site, installed in the sampling head without sampling, after Remove the cartridge and filter, store it in the same way as the sample, and ship it back to the lab with the sample. 7.2 Sample preservation Samples were stored at room temperature protected from light, extracted within 24 h; otherwise, they should be stored in the dark below 4 ℃ and extracted within 7 d. The sample extract is refrigerated at below 4 ° C and analyzed within 40 days. 7.3 Sample Preparation 7.3.1 Sample Extraction Filters and glass sampling cartridges were transferred to a Soxhlet extractor (6.4),.200 μL replacement fluid (5.17) was added to the PUF, Add 300 ml ~ 500 ml ether - n-hexane mixed solvent (5.8) reflux extraction 16 h or more, refluxed three times per hour ~ 4 Times. After the extraction is completed and cooled to room temperature, the bottom bottle is taken out, the extraction cup interface is washed, and the cleaning liquid is transferred to the bottom bottle together. Add nothing Sodium sulphate (5.5) to sodium sulphate granules are free-flowing and are allowed to dry for 30 min. Note. If using automatic Soxhlet extraction, with ether - n-hexane mixed solvent (5.8) reflux extraction of not less than 40 cycles. As long as you can achieve this Standard requirements of quality control, but also the use of other sample extraction methods. 7.3.2 Sample concentration The sample extract was transferred to a concentration apparatus, concentrated at below 45 ℃, the solvent was replaced by n-hexane, concentrated to 1 ml about. If using sulfuric acid purification (7.3.3.1), concentrated to about 10 ml. 7.3.3 Sample Purification 7.3.3.1 sulfuric acid purification Transfer the sample extract concentrate (7.3.2) to a 60 ml separatory funnel (6.8), add 5 ml sulfuric acid (5.7), light Gently shake and deflate, shaking 1 min, after standing layered layer of sulfuric acid removed. Repeat the above procedure until the sulfuric acid layer is colorless. The organic phase Add 5 ml of sodium chloride solution (5.13), mix well, leave the aqueous phase after standing and stratification, and add anhydrous sodium sulfate (5.5) dehydration, according to 7.3.2 concentrated to 1 ml or less, to be purified. If no further purification, set to 1.0 ml, if Quantitative method using internal standard, adding 10.0 μl of internal standard solution (5.20), transferred to the sample bottle for analysis. This purification method does not apply to dieldrin, endrin, endosulfan I, endosulfan II, endodialdehyde, endrin and methoxy DDT determination. 7.3.3.2 Magnesium silicate solid phase extraction column purification Take solid phase extraction column (5.24), followed by 10 ml of acetone (5.1), 10 ml of n-hexane (5.2) pre-leaching, discard the flow Liquid. Keep the liquid level just above the bed and transfer the sample extract concentrate (7.3.2) or sulfuric acid concentrate (7.3.3.1) to In the column, the effluent is received, the sample bottle is washed twice with 1 ml of n-hexane (5.2), the wash liquid is transferred to the SPE column, With 10 ml acetone - n-hexane mixed solvent (5.9) elution, control the flow rate of less than 2 ml/min, continue to receive the eluent. wash Dehydration 7.3.2 concentrated to 1.0 ml or less, if using an internal standard method, the volume to 1.0 ml, adding 10.0 μl internal standard With liquid (5.20), transferred to the vial to be analyzed. 67.3.3.3 Magnesium silicate column purification The bottom of the glass column (6.5) is filled with glass wool (5.29) and 20 g of magnesium silicate (5.25) is wet-filled with n-hexane (5.2) Exhaust air bubbles, add 1 cm ~ 2 cm anhydrous sodium sulfate (5.5) on the top. Pre-rinse with 60 ml n-hexane (5.2) and keep The liquid level is slightly above the bed, the extraction concentrate (7.3.2) is transferred to the column and the sample bottle is washed with 1 ml of n-hexane (5.2) 2 times, were transferred to the column, discard the effluent. The column was eluted with.200 ml ether-n-hexane mixed solvent (5.11) at a rate of 2 ml/min to 5 ml/min Receive effluent as a first-stage eluent. Continue with.200 ml ether - hexane mixed solvent (5.12) eluting the column, then Receive effluent as a second-stage eluate. The column was eluted with.200 ml of ether-n-hexane mixed solvent (5.10) to receive the flow Effluent as a third-level eluent. If not received grading, you can directly use.200 ml acetone - n-hexane mixed solvent (5.9) Eluting the column and receiving the eluate. Eluate according to 7.3.2 concentrated below 1.0 ml, volume to 1.0 ml, if used Quantitative standard, adding 10.0 μl of internal standard solution (5.20), transferred to the sample bottle to be analyzed. The first eluent contains all of the PCBs except for endosulfan, dieldrin, endrin and their degradation products, Other pesticides at this level; dieldrin, endosulfan I, endrin distributed in the first or second level, may also co-exist at two levels; Endosulfan II, endrin, endosulfan sulfate are mainly distributed in the third-stage eluate; the endodildehyde distribution in the second and third Grade eluent. Note. Due to the solid phase extraction column and column specifications, the amount of magnesium silicate, the amount of eluent may be different at all levels of the eluate of organic chlorine There are differences in the elution efficiency of pesticides, the laboratory before the use of conditions required to conduct experiments; as long as this standard can meet the quality control Requirements, but also the use of other sample purification methods. 7.4 Preparation of blank samples 7.4.1 Site blank On-site blank samples (7.1.2) In-situ blank samples were prepared according to the same procedure as Preparation of samples (7.3). 7.4.2 Laboratory blank The same batch of sampling cartridges and filters according to the preparation of the sample (7.3) the same procedure for the preparation of laboratory blank samples.

8 Analysis steps

8.1 Instrument reference conditions Use 6.2 in the two different polarity of the column, one for the analytical column, one for the verification column. Inlet. 250 ° C; splitless injection, split at 0.75 min, split ratio 60.1; injection volume. 2.0 μl; column Temperature. maintained at 50 ℃ for 1 min, heated to 180 ℃ at 25 ℃/min, maintained for 2 min, heated to 280 ℃ at 5 ℃/min, Hold for 5 min; Carrier gas. Nitrogen (5.28); Flow rate. 1.0 ml/min; Electron capture detector (ECD). 300 ° C. 8.2 Instrument Performance Check Before the standard curve is drawn, the instrument system is inspected and injected with 1.0 μl of endrin and 4,4'-DDT mixed standard solution (5.14), the degree of degradation of the compound is measured, and if the above compound is detected, in addition, Dieldrin and 4,4'-DDE, 4,4'-DDD, which indicates that endrin and 4,4'-DDT decomposition, if a single component of the degradation The amount of ≥ 20% or the sum of both the degradation of ≥ 30%, the inlet and column heads need to be maintained. System inspection qualified rear Can draw a standard curve. 78.3 drawing of the standard curve Pipette a certain amount of standard solution (5.23), diluted with n-hexane (5.2) Preparation of standard series, the standard series of concentrations according to Times were 20.0 μg/L, 50.0 μg/L, 100 μg/L,.200 μg/L, 300 μg/L. If using internal standard quantitative, each 1.0 ml Add 10.0 μl of internal standard solution (5.20) to the standard solution. According to the instrument reference conditions (8.1) analysis, record the target compound Retention time, peak area (or peak height) of substance, internal standard, substitute. The concentration of the target compound (or ratio of internal standard concentration) as the abscissa, the target compound peak area or peak height (or And internal standard peak area or peak height ratio) for the vertical axis, using the least squares method to draw the standard curve. Organochlorine pesticide standard chromatogram See Figure 2. 8.4 Determination of the sample The determination of the sample is carried out according to the same instrument reference conditions (8.1) as the standard curve, and the peak of the chromatogram is recorded Between and peak area (or peak height). 8.5 Blank test The blank sample (7.4) was measured according to the same instrument conditions as the sample. min10 15 20 25 30 Hz min10 15 20 25 30 Hz 1-BNB (internal standard); 2-TCX (substitute); 3-α-hexacosyl; 4-hexachlorobenzene; Sixty-six Hexachloro-9-aldrin; 10-Epoxyheptachlor B; 11-γ-Chlordane; 12-Endosulfan I; 13-α-Chlordane; 14-4,4'-DDE; 15- Dieldrin; 16-Endrin; 17-Endosulfan II; 18-4,4'-DDD; 19-2,4'-DDT; 22-4,4'-DDT; 23-endrin; 24-methoxy DDT; 25-mirex; 26-decachlorodiphenyl (surrogate). Note. The column chromatographic column fixative is 14% cyanopropyl phenyl 86% dimethylpolysiloxane, the column chromatographic column fixative is 5% phenyl 95% dimethyl Polysiloxane. Figure 2 Organochlorine pesticide standard chromatogram 89 Calculation and representation of results 9.1 Qualitative method Qualified according to retention time. When the target compound is detected on the analytical column, verify it with a verification column. If the test column is also detected, as the group Points were detected; if the column was not detected in the verification, as the component was not detected. Chromatographic conditions can be changed or verified using GC-MS if necessary. 9.2 Quantitative method According to the peak area (or peak height), the internal standard method or external standard method. When the internal standard sample is disturbed, the peak area (or Peak height) abnormal, you must use the external standard method. Quantitative Results Report Analyze column results. 9.3 Results Calculation The mass concentration of organochlorine pesticides in ambient air (ρ) is calculated according to equation (1). FV   (1) Where.  - mass concentration of target compound in ambient air, ng/m3; i - the mass concentration of the target compound in the sample obtained from the standard curve, μg/L; V - sample volume concentrated volume, ml; F - the dilution of the sample; Vs - Sampling volume at standard conditions (101.325 kPa, 273 K), m3. 9.4 results indicated When the concentration of organochlorine pesticides in ambient air is greater than or equal to 1.00 ng/m3, the result retains three significant digits; less than At 1.00 ng/m3, the result is retained until the second decimal place. 10 precision and accuracy 10.1 Precision Six laboratories repeated the spiked (n = 6) spiked samples at 50.0 ng, 100 ng and 300 ng (Corresponding to 0.14 ng/m3, 0.29 ng/m3 and 0.86 ng/m3), and the relative standard deviations in the laboratory ranged from 1.4% to 20% 2.4% -18% and 1.1% -19% respectively. The relative standard deviations of the laboratories were 3.7% ~ 11%, 2.9% ~ 12% and 1.5% ~ 10%; The repeatability limit was 0.02 ng/m3 ~ 0.05 ng/m3, 0.03 ng/m3 ~ 0.07 ng/m3 and 0.07 ng/m3 ~ 0.26 ng/m3; reproducibility limits were 0.02 ng/m3 ~ 0.06 ng/m3, 0.05 ng/m3 ~ 0.09 ng/m3 and 0.07 ng/m3 ~ 0.27 ng/m3. See Table C.1 for details. 10.2 Accuracy Repeated determination (n = 6) of the five laboratories were ambient air samples spiked recoveries, the standard addition of 100 ng and 300 ng (equivalent to 0.29 ng/m3 and 0.86 ng/m3) respectively. The spiked recoveries were 60.1% -106% and 55.1% -106%, respectively. The final values of spiked recoveries were 70.1% ± 17.0% -97.3% ± 18.2% and 70...

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