Section 5: Procedures

• 5.1 Cleaning and Proofing
• 5.2 Sample Collection
• 5.3 Sample Recovery

Before the field tests, all train glassware, amber storage bottles, Teflon lid liners, probe brushes, glass wool, petri dishes and aluminum foil must be cleaned as described in Table 1. The cleaning procedures also apply to miscellaneous items such as graduated cylinders, plugs and caps, funnels and tweezers. Other cleaning procedures are recognized, but the components must be proofed according to the procedures detailed in Table 1 and pass the acceptance criteria.

Caution: Handle all Solvents in a Well-Ventilated Area

The effectiveness of the cleaning procedures is verified by proofing selected components and reagents. Proofing ensures that the glassware, reagents and recovery solvents are free of pollutants prior to sampling. All components coming into contact with the stack gas or recovery samples must be cleaned, but it is not necessary to proof all the cleaned components. The proofing samples are analyzed as specified in Section 6, using High Resolution Gas Chromatography/Low Resolution Mass Spectography. The components and reagents that require proofing are as follows:

Glassware cannot be re-used in the field with semi-volatile organic sampling. As a result, one complete set of pre-cleaned and proofed glassware must be allowed for each stack test. In addition, one complete set of glassware must also be allowed for the blank train. Assemble the complete sets of train glassware that will be needed and identify each set. Following the cleaning procedure described in Table 1, rinse each component from a train set three times each with hexane and acetone. Combine the rinses from each train into a pre-cleaned amber bottle with a pre-cleaned Teflon lid liner. Label the container. This sample constitutes the proof rinse for that train set. Repeat the above procedure for the other train sets and the blank train. Submit the proof rinses (one bottle per train) to the analytical lab for analysis.

Following the cleaning procedure, select three or four bottles from each box (48 bottles). Rinse these bottles three times each with hexane and acetone. Combine rinsings from each bottle in a pre-cleaned amber bottle with a pre-cleaned Teflon lid liner. Label the container and submit the proof rinse to the analytical laboratory. One proof rinse shall be submitted for each box of bottles.

A 30 g aliquot of each cleaned batch is taken and analyzed. This procedure is described in greater detail in the analytical method specified in Section 6.

Submit a sample of each solvent in a pre-cleaned amber bottle with a pre-cleaned Teflon lid liner. Label each container, including the batch or lot number. Take an aliquot of each solvent to form a combined hexane/acetone proof rinse. Submit the combined rinse to the analytical lab for analysis.

Submit a sample of each reagent in a pre-cleaned amber bottle with a pre-cleaned Teflon lid liner. Label each container and include the batch or lot number. Take an aliquot of each reagent to form a combined glycol/HPLC water proof rinse. Submit the combined rinse to the analytical lab for analysis.

Select the sampling site and the minimum number of traverse points according to procedures described in Method A of Environment Canada Report EPS 1-AP-74-1, "Reference Method of Source Testing: Measurement of Emissions of Particulates from Stationary Sources" (as amended). Without previous knowledge of the stack variables, a preliminary test should be conducted to obtain the following data:

• velocity profile across the stack (Method B)
  
• stack temperature and pressure (Method B)
  
• stack gas molecular weight (Method C)
  
• stack gas moisture content (Method D)

Use the information to select the largest nozzle possible for isokinetic sampling. The recommended minimum nozzle size is 4.76 mm (3/16 inch) inside diameter. A nozzle size should be selected such that 3 to 4 m³ (105.9 - 141.3 ft³) of dry standard sample gas will be collected over an approximate four-hour sampling period.

Select a suitable probe length that will permit access to all the sampling points.

Select a total sampling time so that the sampling time per traverse point is equal to or greater than five minutes.

Prepare the sampling train in a clean area to minimize contamination. Install the selected nozzle on the probe. Mark the probe to denote the location of each sampling point. Before preparing and assembling the train glassware, the components should be rinsed once each with hexane and acetone. Discard the rinses.

Carefully wrap the filter support with 25 mm (1-inch) Teflon tape along the circumference to provide a leak-free seal between both halves of the filter holder. Using a pair of tweezers, remove the filter from its petri dish, inspect for flaws and place on the perforated Teflon filter support. It is recommended that the filter assembly be "leak-checked" at 381 mm Hg (15 inches Hg) prior to assembly at the sampling site.

Add approximately 100 mL of ethylene glycol to the first impinger and about 200-300 g of silica gel to the third impinger. Weigh the condenser, XAD-2 trap, condensate trap and the three impingers to the nearest 0.5 g. Record each weight on the Moisture Analysis Data Sheet (Figure 2).

During the assembly of the train, the joints must be sealed by wrapping the ball joints with 13-mm (0.5-inch) Teflon tape. Do not use vacuum grease to seal the joints. The configuration of the glassware will determine to what extent the train can be assembled in the field lab. From train assembly to extraction of the stack sample, the open glassware joints must be sealed with pre-cleaned glass plugs or caps or aluminum foil at all times.

At the sampling site, set up the train as shown in Figure 1. Connect all temperature sensors and pitot lines. Adjust the filter compartment and probe heating systems to maintain a temperature of 120 ± 14°C (248 ± 25°F). Connect the cooling system. Do not add the water or ice until the pre-test leak check is completed.

Once the filter compartment and probe have reached the necessary temperatures, conduct a leak check on the sampling train. This is done by plugging the nozzle inlet and pulling a vacuum of 381 mm Hg (15 inches Hg). A leakage rate of less than 0.57 l/min (0.02 ft³/min) or four percent of the estimated average sampling rate, whichever is less, is acceptable. Unacceptable leakage rates must be corrected. Record the leakage rate and the vacuum on the Organics Sampling Data Sheet (Figure 3). Place water and crushed ice in the impinger bath and turn on the coolant recirculating pump for the condenser coil and XAD-2 tube. During testing, the temperature of the XAD-2 must not exceed 20°C (68°F) for effective removal of the semi-volatile organic species. At all other times the XAD-2 must not be exposed to temperatures above 50°C (122°F) to avoid thermal degradation.

Verify the heating and cooling systems and check that the probe and pitot tube are properly aligned. Level and zero the manometer. Clean the access port to avoid extraneous pick up of deposited material. To begin sampling, point the nozzle directly into the gas stream at the first traverse point. Block off the opening between the probe assembly and the access ports. With a nomograph or a programmable calculator, determine the orifice setting for isokinetic sampling. Record the initial dry gas meter reading. Immediately start the vacuum pump and adjust the sampling flow rate to isokinetic conditions. Sample for at least five minutes at each traverse point, the sampling time being the same for every point. Traverse the stack cross section and maintain isokinetic sampling (±10%) throughout the test. Record instrumentation readings on the Organics Sampling Data Sheet (Figure 3) every five minutes, or at regular intervals that are consistent with the sampling duration established for each point, whichever is less. To simplify recording in the field, values may be entered in units for which the sampling equipment is designed. These values may then be converted (if necessary) to the metric units specified in the equations where they are used. Readings must also be taken before and after a "leak-check" and when sampling is halted. Record all sampling interruptions.

During sampling, verify the heating and cooling systems. The temperature of the filter enclosure and probe must be 120 ± 14°C (248 ± 25°F). The XAD-2 temperature must be below 20°C. Verify the alignment of the probe and pitot tube to the gas stream. Check the level and zero of the manometer and adjust if necessary. Verify that the condensate volume is increasing as the run progresses. If the sampling system vacuum becomes so high that it is difficult to maintain isokinetic sampling the filter holder and/or sorbent tube must be replaced. If this occurs, a "leak-check" must be conducted before and after the replacement of the above components.

When it is necessary to halt sampling temporarily either to dismantle the sampling train during port change-over or to change a train component, turn off the pump and immediately withdraw the probe from the stack. Conduct a mandatory "leak-check" on the sampling train by plugging the nozzle and pulling a vacuum equal to or greater than the maximum value observed during sampling. Record the actual leakage rate. If the leakage rate exceeds 0.57 l/min (0.02 ft³/min) or four percent of the sampling flowrate, whichever is less, consult Environment Canada regarding the validity of the test. If the leakage rate is acceptable, proceed with dismantling the sampling train or changing the train component. Before continuing the test, conduct a "leak-check" on the assembled train by following the pre-test "leak-check" procedures used during sampling train preparation.

When the test is completed, conduct a mandatory post-test check on the sampling train by plugging the nozzle and pulling a vacuum equal to or greater than the maximum value observed during sampling. Record the actual leakage rate which must be less than either 0.57 l/min (0.02 ft³/min) or four percent of the sampling flow rate during the test, whichever is less. If the leakage rates are acceptable, proceed with the recovery of the samples.

When the test is finished, disconnect the probe and set it aside to cool. Seal both ends and take care not to lose any material in the probe. Disconnect the filter (and cyclone, if used) and seal both ends with pre-cleaned glass plugs or caps, or aluminum foil. Disconnect the XAD-2 and condenser. Seal both ends. Seal the ends of the impinger train. When transporting the sampling train components to the on-site lab, take care to minimize the possibility of sample loss or contamination. Samples must be recovered in a clean area.

One blank train must be submitted for every group of three sample trains. The blank train is handled in the same manner as the loaded train except that no stack gases are drawn through the train. However, a volume of ambient air equal to that drawn during the pre- and post-traverse "leak-checks" must be drawn through the blank train. Hence, on the day that the blank train will be submitted, it is necessary to record all volumes drawn into the sampling train during all "leak-checks". It is not necessary to heat the filter components of the blank train during sampling or to conduct "leak-checks" on the blank train. The sample recovery procedures for the loaded trains are also applicable to the blank train.

Wipe exterior surfaces of the nozzle and probe to remove excess particulate matter. Quantitatively recover the particulate matter and condensibles from the nozzle, probe, cyclone (if used), by-pass connector (if cyclone is not used) and the front-half of the filter holder by washing (with brush) these components with hexane and acetone. Wash and brush each component three times with hexane and acetone. Finally, rinse each component three times each with hexane and acetone. Store all rinses in a wide mouth amber glass bottle (pre-cleaned, with a pre-cleaned Teflon lid liner). Mark the liquid level on the outside of the bottle and label the container. Place the labelled container in a sealed clear plastic bag.

Note: The extension rod (stainless steel or Teflon) of the probe brush used to wash the probe liner shall be wiped with the recovery solvents prior to sample recovery.

Carefully remove the exposed filter from the filter holder and place on precleaned aluminum foil with exposed side up. Carefully transfer any loose particulate matter or filter fibres adhering to the support of the filter holder with a dry nylon bristle brush or sharp blade. Fold the filter in half and crimp the foil to close the edges. Place in a pre-cleaned glass petri dish. Label the petri dish and seal with 25-mm (one inch) wide Teflon tape around the circumference. The petri dish may also be sealed with aluminum foil.

Drain all the cooling water from the condenser and wipe the outside of the condenser to remove excess water. Weigh the condenser and record the weight on the Moisture Analysis Data Sheet. Soak each of these components five minutes each with hexane and acetone. Rinse each component three times each with hexane and acetone. Store the soak and rinses in a wide-mouth amber bottle (pre-cleaned, with a pre-cleaned Teflon lid liner). Mark the liquid level on the outside of the bottle and label the container. Place the labelled container in a sealed clear plastic bag.

Remove the aluminum foil on the tube and drain all the cooling water. Wipe the outside of the tube to remove excess moisture. Weigh the XAD-2 tube and record the weight on the Moisture Analysis Data Sheet. Seal both ends of the XAD-2 tube with pre-cleaned glass caps or plugs. Wrap the whole tube with aluminum foil and label the container.

Wipe the outside of these components to remove excess moisture. Weigh each component and record the weights on the Moisture Analysis Data Sheet. Empty each container into a pre-cleaned amber glass bottle with a pre-cleaned Teflon lid liner. Rinse each component three times each with HPLC water into the same container. Mark the liquid level on the outside of the bottle and label the container. Place the labelled container in a sealed clear plastic bag.

Wipe the excess moisture from the outside of these impingers and weigh each impinger. Record each weight on the Moisture Analysis Data Sheet.

Rinse each component including connectors three times each with hexane and acetone into a pre-cleaned glass amber bottle with a pre-cleaned Teflon lid liner. Mark the liquid level on the outside of the bottle and label the container. Place the labelled container in a sealed clear plastic bag. The sample recovery procedures for the front- and back-half components are illustrated in Figure 4.

Following the recovery of the train components, all samples must be kept cool (approximately 4°C). They may be stored in a refrigerator or on ice in an insulated chest during field storage and transport to the analytical laboratory.

Before transporting the insulated chest, it is critical to ensure that the containers are well-packed to minimize sample loss. Many materials are available to protect the glass container against shock. Extra care should be taken when packing the samples.