HJ 646-2013Ambient air and stationary source emissions. Determination of gas and particle-phase polycyclic aromatic hydrocarbons with gas chromatography/mass spectrometry (English PDF)

3.1 Full program blank whole program blank

The sealed storage cylinder and the glass fiber filter/cylinder are brought to the sampling site, and are exposed to the sampling site without sampling.

After sampling, the sample is shipped back to the laboratory, processed and measured in the same operating steps as the sample, for inspection from sample collection to analysis.

Whether the whole process is polluted.

3.2 Shipping Blank Trip Blank

The sealed sample cylinder and the glass fiber filter/cylinder are brought to the sampling site, and the sample is not opened during sampling, and the sample is returned to the experiment after sampling.

The chamber is processed and measured in the same operating steps as the sample to check whether the sample transport process is contaminated.

3.3 Internal standards

Compounds not contained in the sample are added to known amounts prior to sample analysis for quantitative analysis of the target compound.

3.4 Surrogate standards

A substance that is not contained in the sample but has similar physicochemical properties to the target compound to be tested. Usually added before sample extraction or sampling in, the recovery rate can be used to evaluate the effect of the sample preparation or sampling process on the analytical results.

3.5 Sampling efficiency sampling efficiency

Refers to the ability of the sampler to capture and retain polycyclic aromatic hydrocarbons. Add a certain amount of polycyclic aromatic hydrocarbons to the sampling filter, the same as the sample the operating conditions are pumped air to determine the retention capacity of the sample medium for polycyclic aromatic hydrocarbons.

3.6 Dynamic sampling efficiency

Add a certain amount of polycyclic aromatic hydrocarbons to the surface of the sampling adsorption column, pump air according to the same operating conditions as the sample, and determine the number of sampling media.

Retention capacity of cyclic aromatic hydrocarbons.

6.5 Anhydrous sodium sulfate (Na2SO4)

Bake at 450 ° C for 2 h in a muffle furnace before use, cool, and store in a ground glass bottle.

6.6 Decafluorotriphenylphosphine (DFPTT). 5mg/L (dichloromethane solvent), can be purchased directly from commercially available certified standard solutions, or with high concentration standards Quasi-solution preparation.

6.7 Alternatives

6.7.1 Alternative 1

2-fluorobiphenyl and p-terphenyl-d14 (P-Terphenyl-d14), purity. 99% or more. Can also use it He is an analog or deuterated polycyclic aromatic hydrocarbon. Commercially available certified standard solutions can be purchased directly.

6.7.1.1 Substitute 1 Stock solution. rho =.2000 µg/ml.

Weigh about 0.1g of difluorobiphenyl and p-terphenyl-d14 (6.7.1), accurate to 0.1mg, in a 50ml volumetric flask, with a small amount After dissolving in dichloromethane, dilute to the mark with n-hexane.

6.7.1.2 Alternative 1 Use solution. rho = 40 µg/ml.

Take 0.50 ml of the replacement 1 stock solution (6.7.1.1) in a 25 ml volumetric flask and dilute to the mark with n-hexane.

6.7.2 Alternative 2

Fluoranthene-D10, benzo(a)pyrene-D12, purity. 99% or more. Other deuterated polycyclic aromatic hydrocarbons can also be used. Can be purchased directly for sale Certified standard solution.

6.7.2.1 Substitute 2 Stock solution. rho =.2000 µg/ml.

Weigh fluoranthene-D10, benzo(a)pyrene-D12 (6.7.2), about 0.1g, accurate to 0.1mg, in a 50ml volumetric flask, use less After the amount of dichloromethane was dissolved, it was diluted to the mark with n-hexane.

6.7.2.2 Substitute 2 Use solution. rho = 40 µg/ml.

Take 0.50 ml of the replacement 2 stock solution (6.7.2.1) in a 25 ml volumetric flask and dilute to the mark with n-hexane.

6.8 Internal standard solution

6.8.1 Internal standard stock solution. rho=2000µg/ml.

Directly purchase commercially available certified standard solutions containing naphthalene-d8, 苊-d10, phenanthrene-d10, -d12, and 苝-d12.

6.8.2 Internal standard use solution. rho=400µg/ml.

The analytical internal standard stock solution (6.8.1) was diluted with n-hexane to 400 mg/L for use.

6.9 Standard solution

6.9.1 Standard stock solution of polycyclic aromatic hydrocarbons. rho=2000µg/ml.

Direct purchase of commercially available certified standard solutions, including naphthalene, terpenes, anthracene,, phenanthrene, anthracene, fluoranthene, anthracene, benzo (a) pyrene, Benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene,dibenzo(a,h)pyrene, benzo(ghi),茚(1,2,3-cd ) , below 4 ° C, sealed, protected from light, or refer to the manufacturer's recommended storage conditions.

6.9.2 Polycyclic aromatic hydrocarbon standard intermediate solution, rho=200mg/L.

Transfer the polycyclic aromatic hydrocarbon standard stock solution (6.9.1) and the substitute 1 stock solution (6.7.1.1) 1.00ml to a 10ml volumetric flask.

Dilute to the mark with n-hexane and mix.

6.9.3 Polycyclic aromatic hydrocarbon standard use solution, rho=20mg/L.

Take 1.00 ml of polycyclic aromatic hydrocarbon standard intermediate solution (6.9.2), dilute with n-hexane into a 10 ml volumetric flask, and mix.

Note 1. All the solutions (6.7, 6.8, 6.9) are transferred to the screw glass bottle with the Teflon gasket on the top cover, sealed and protected from light, and cooled below 4 °C.

Tibetan.

Note 2. If necessary, substitute 2 should be included.

6.10 Sample extract. 1 9 (V/V) diethyl ether/n-hexane mixed solution.

6.11 Eluent

6.11.1 Eluent 1. 2 3 (V/V) dichloromethane/n-hexane mixed solution.

6.11.2 Eluent 2. 1 1 (V/V) dichloromethane/n-hexane mixed solution.

6.12 Column chromatography silica gel. reagent grade, 100-200 mesh, pore size 30 Ao or 60 Ao. Before use, it is baked and activated in a shallow dish at 130 °C.

16h, take it out and put it in a desiccator for cooling, then put it into a glass bottle for use. If necessary, dilute with dichloromethane before activation.

6.13 Silica solid phase column or fluroric silica solid phase column. 1000mg/6ml, can also choose suitable capacity of commercial silica gel according to impurity content or a Florisil solid phase column.

6.14 Ultra-fine glass fiber filter or quartz fiber filter

Select the filter of the corresponding specification according to the sampling flow rate. The retention efficiency of the filter on 0.3µm standard particles is not less than 99% at the gas flow rate.

When the degree is 0.45m/s, the resistance of a single filter is not more than 3.5 KPa. At this air flow rate, the air purified by the high-efficiency filter is extracted for 5 hours.

The weight loss per square centimeter is not more than 0.012 mg. Heat in a Mafu furnace at 400 ° C for more than 5 h before use, cool, wrapped in aluminum foil, Stored in the filter cartridge to ensure that the filter is not stained before and after sampling, and is flat and unfolded before sampling.

6.15 Glass fiber filter cartridge (quartz filter cartridge)

The cut-off efficiency of 0.5µm standard particles is not less than 99.9%, and it is heated at 600 ° C for 6 hours or more in a muffle furnace before use, and is cooled.

Sealed to ensure that the filter cartridge is free of creases. If necessary, the mixture was refluxed with acetone and dichloromethane, and the solvent was evaporated and sealed for use.

6.16 XAD-2 resin (styrene-divinylbenzene polymer).

After refluxing for 16 hours with dichloromethane (6.1) before use, the dichloromethane was replaced and reflux extraction was continued for 16 hours.

/N-hexane extract (6.10) is refluxed for 16 hours, then placed in a fume hood to dry the solvent (can also be dried at 50 ° C vacuum) Dry 8h). Store in a clean wide-mouth glass bottle and store in a sealed container.

6.17 Polyurethane Foam (PUF)

Polyether type, density 22 ~ 25 mg/cm3, cutting length 10mm ~ 20mm cylindrical (diameter according to the glass sampling tube gauge Grid OK). Wash with distilled water before the first use, drain the water, wash it three times with acetone (6.4), put it into the Soxhlet extractor, and then it was extracted with acetone (6.4) for 16 h, and extracted with diethyl ether/n-hexane (6.10) for 16 h, and replaced with diethyl ether/n-hexane for 2 to 3 times.

The liquid was taken (6.10) and refluxed for 16 h each time. Then take out, dry the solvent or blow dry with nitrogen (can also be dried at 50 ° C vacuum) Dry 8h). Wrap it in aluminum foil and store in a suitable container. If necessary, the PUF is returned to its original form with acetone and the solvent is evaporated.

Commercially available pretreated PUFs can also be purchased.

It can also be extracted by other methods such as rapid solvent extraction (ASE) and automatic Soxhlet extraction.

Note 3. After purification, the amount of PUF, XAD-2 resin and filter/tube blank is less than 50ng for naphthalene and phenanthrene, and other polycyclic aromatic hydrocarbons are less than 10ng.

6.18 Nitrogen. purity >= 99.999%.

6.19 Glass wool

Dip with dichloromethane before use, and then store the solvent after removing the solvent.

7.1.3 Helium. purity >=99.999%

7.2 Ambient air sampling equipment

The sampling device consists of a sampling head, a sampling pump and a flow meter.

7.2.1 Sampling pump. It has automatic accumulative flow, automatic timing, and power-off re-start function. Large flow sampler load under normal sampling conditions it can reach more than 225L/min, and the medium flow sampler load can reach more than 100L/min. Ability to pump ambient air to the glass the fiber filter (6.14) and the adsorbent material in the adsorption sleeve behind it can collect at least 144m3 during continuous 24h.

Air sample.

7.2.2 Sampling head

The sampling head consists of a filter cartridge and a sorbent sleeve, as shown in Figure 1. The sampling head is equipped with different cutters to collect TSP, PM10 or PM2.5 particulate matter.

The filter cartridge consists of a filter holder, a filter, and a stainless steel screen. The filter holder is made of a metal material and can pass through A stainless steel mesh support frame holds the glass fiber/quartz filter.

The outer sleeve of the sorbent sleeve is made of PTFE or stainless steel, and the inside is equipped with a glass sampling cylinder. The bottom of the glass sampling cylinder is made of glass.

Supported by glass screen or stainless steel screen, the upper and lower layers of the glass sampling cylinder are PUF (6.17) with a thickness of at least 1cm, and the height is in the middle.

It is about 5cm of XAD-2 macroporous resin (6.16). The glass sampling cylinder is sealed between the filter holder and the suction pump. Adsorption during sampling the air inlet of the sleeve is connected with the filter holder, and the air outlet is connected with the end of the air pump. After sampling, the glass sampling cylinder can also be placed directly into Soxhlet Extracted from the extractor. Before and after sampling, the sampling cylinder is wrapped in aluminum foil and placed in a storage box to ensure the glass sampling cylinder and its inside.

The adsorbent is not contaminated before and after sampling.

Figure 1 Schematic diagram of the sampling head

7.2.3 Flowmeter

The flow rate can be set to not less than 100 L/min, and the sampling flow rate is calibrated with a standard flow meter before sampling.

7.3 Fixed source exhaust sampling equipment

When collecting polycyclic aromatic hydrocarbons in gas phase and particulates at the same time, the instrument recommended in HJ/T 365 can be selected, which consists of sampling tube and filtration.

The cylinder (or membrane), gas phase adsorption unit, condensing unit, flow metering and control device are shown in Figure 2.

HJ/T 48-compliant soot samplers can be used when collecting only polycyclic aromatic hydrocarbons in fixed source exhaust particulates.

Figure 2 Schematic diagram of the exhaust gas sampling device

1-flue; 2-thermocouple or thermal resistance thermometer; 3-piddle; 4-sampling tube; 5-filter cartridge (or membrane); 6-gas phase adsorption with condensing unit Unit; 7-micro pressure sensor; 8-pressure sensor; 9-temperature sensor; 10-flow sensor; 11-flow regulator; 12-sampling pump;

Microprocessing system; 14-micro printer or interface; 15-display

7.3.1 Cartridge (or filter) bracket. The filter cartridge (or filter) bracket is made of borosilicate glass or quartz glass and is sized to be used with the filter cartridge (or the filter membranes should be matched to facilitate the pick-and-place of the filter cartridge (or filter membrane) and the interface is well sealed.

7.3.2 Vapor adsorption unit with condensing unit. The condensing unit is used to separate and store the condensed water in the exhaust gas and store the condensed water capacity.

The volume of the device should be no less than 1L. The gas phase adsorption unit is an adsorption column, and the adsorption column generally has an inner diameter of 30 mm to 50 mm and a length of 70 mm.

200mm, can be loaded with 20g ~ 40g XAD-2 and PUF.

7.3.3 Flow metering and control device. A device for indicating and controlling the sampling flow. It can monitor dynamic pressure, static pressure, pre-meter temperature, Pre-meter pressure, flow and other parameters. The flow meter should have an accumulative flow meter that automatically performs temperature and pressure correction. The sample flow rate is before sampling.

Calibration should be done using a standard flow meter.

7.3.4 Sampling pump. The pump's no-load suction flow rate should be no less than 6L/min. When the sampling system load resistance is 20kPa, the flow rate should not be low.

At 30L/min.

7.4 Soxhlet extractor. 500 ml, 1000 ml, 2000 ml. Other equivalent extraction devices can also be used.

7.5 Constant temperature water bath. The temperature accuracy is controlled at ±5 °C.

7.6 Rotary evaporation device, equivalent equipment such as KD concentrator and organic sample concentrator can also be used.

7.7 Solid phase extraction purification device.

7.8 Glass column. glass column with a length of 350mm and an inner diameter of 20mm and a PTFE piston at the bottom.

7.9 Microinjectors. 10 µl, 50 µl, 100 µl, 250 µl.

7.10 Airtight syringe. 500µl, 1000µl.

7.11 Volumetric flask. Class A, 5ml, 10ml, 25ml, 50ml.

7.12 Other instruments and equipment commonly used in laboratories.

8.1 Sample Collection

Polycyclic aromatic hydrocarbons above the five rings are mainly found in particulate matter, which can be collected by glass fiber (quartz) membrane/filter; two-ring and three-ring Cycloaromatic hydrocarbons are mainly present in the gas phase and can pass through glass fiber (quartz) membranes/filter cartridges. XAD-2 resin and polyurethane foam (PUF) are available.

Collection; tetracyclic polycyclic aromatic hydrocarbons exist at the same time, and must be simultaneously treated with glass fiber (quartz) membrane/cylinder, resin and polyurethane foam.

Set samples.

8.1.1 Collection of ambient air and unorganized exhaust gas samples

Before the sampling on site, the flow rate of the sampler should be corrected. Install the filter clamp and the adsorbent sleeve in turn, and connect to the sampler.

Sampling the flow and starting sampling. After sampling, open the filter clip on the sampling head, gently remove the filter with tweezers, and sample the face.

Fold, take the sampling cylinder from the sorbent sleeve, wrap it with the folded-fold filter with aluminum foil, and put it in the original box to seal. After sampling Perform flow correction.

8.1.2 Sample collection of fixed source exhaust

Install the filter cartridge (6.15) and the vapor phase adsorption unit (7.3.2) with the condensing device, connect the instrument, and the sampling tube is made up of the sampling hole.

Insert the flue, place the sampling nozzle on the measuring point, face the airflow, start the sampling pump, adjust the suction speed of the sampling nozzle and the airflow velocity at the measuring point.

Equal (the relative error is controlled within 10%), make the necessary adjustment for the constant velocity sampling flow every 60 minutes, if the filter resistance increases to none the method maintains constant-speed sampling, and the sampling is continued after replacing the new filter cartridge. After reaching the required sample volume, quickly withdraw the sampling tube and stop sampling at the same time.

Pump, record parameters such as start and end time or sample volume.

When collecting only the particulate matter of the fixed source exhaust, the method for measuring the particulate matter in the exhaust gas of the fixed pollution source and the sampling method of the gaseous pollutant (GB/T 16157) for sampling.

8.2 Preservation of samples

After sample collection, it should be stored in the dark at 4 °C or less, and extracted within 7 days; or stored below -15 °C, and extracted within 30 days.

8.3 Preparation of samples

8.3.1 Sample extraction

Place the filter or filter cartridge and glass sampling tube directly in the Soxhlet extractor (if the resin and PUF in the glass sampling cylinder are transferred to the cable) in the extractor, rinse the glass sampling cylinder with a certain amount of ether/n-hexane extract (6.10), and transfer the rinse solution to the extractor).

Add 100 µl of substitute 1 to the solution (6.7.1.2), add appropriate amount of ether/n-hexane extract (6.10), and reflux a lot per...