Method NCASI 99.01 (1999)

NCASI METHOD IM/CAN/WP-99.01

IMPINGER/CANISTER SOURCE SAMPLING METHOD FOR SELECTED HAPS AT WOOD PRODUCTS FACILITIES

NCASI SOUTHERN REGIONAL CENTER

JANUARY 1999

Srimanta

http://www.airtoxics.com/literature/methods/Method%20NCASI%2099.01%20(1999).pdf

i

Acknowledgements

This method was prepared by Dr. MaryAnn Gunshefski, Senior Research Scientist, Dr. David Word, Program Manager, Jim Stainfield, Research Associate, and Steve Cloutier, Research Associate, at the NCASI Southern Regional Center. Other assistance was provided by Terry Bousquet, Senior Research Scientist, with the NCASI West Coast Regional Center.

For more information about this method, contact:

Dr. David Word NCASI PO Box 141020 Gainesville, FL 32614 (352) 377-4708 ext. 241 FAX (352) 371-6557 email [email protected]

Dr. MaryAnn Gunshefski NCASI PO Box 141020 Gainesville, FL 32614 (352) 377-4708 ext. 244 FAX (352) 371-6557 email [email protected]

For more information about NCASI publications, contact: Publications Coordinator NCASI PO Box 13318 Research Triangle Park, NC 27709-3318 (919) 558-1987 National Council of the Paper Industry for Air and Stream Improvement, Inc. (NCASI). 1999. Methods Manual, Impinger/Canister Source Sampling Method for Selected HAPs at Wood Products Facilities, Research Triangle Park, N.C.: National Council of the Paper Industry for Air and Stream Improvement, Inc. 2000 by the National Council of the Paper Industry for Air and Stream Improvement, Inc. NCASI’s Mission To serve the forest products industry as a center of excellence for providing technical information and scientific research needed to achieve the industry’s environmental goals.

ii

Disclaimer The mention of trade names or commercial products does not constitute endorsement or recommendation for use.

IM/CAN/WP-99.01, Impinger/Canister Method for Selected HAPs at Wood Products Facilities

1 January 1999

NCASI METHOD IM/CAN/WP-99.01

IMPINGER/CANISTER SOURCE SAMPLING METHOD FOR SELECTED HAPS AT WOOD PRODUCTS FACILITIES

1.0 Introduction

1.1 This method is intended for the sampling of selected hazardous air pollutant (HAP) concentrations in stationary source emissions at wood products mills or panel plants. The analysis of the impinger contents is performed by gas chromatography/flame ionization detection (GC/FID), and a colorimetric method. The analysis of the canister contents is performed by gas chromatography/mass selective detection (GC/MSD) and gas chromatography/flame ionization detection (GC/FID). This method has been written to conform with the contents and format of EPA Air Methods.

2.0 Method Description

2.1 Principle, applicability, interferences, and stability

2.1.1 Principle - A sample of the source gas is drawn through three midget impingers, each containing chilled organic free water. A Teflon-head pump and a critical orifice are used to maintain the flow through the impingers of approximately 400 mL/min. A portion of the gas exiting the pump is drawn into an evacuated stainless steel canister for an analysis of the compounds not trapped in the aqueous impingers. The water from the impingers is analyzed by direct injection into a gas chromatograph equipped with a flame ionization detector (GC/FID). The formaldehyde concentration in the impinger solution is determined by the acetylacetone procedure. This procedure involves the reaction of acetylacetone with formaldehyde to produce a colored derivative which is measured by colorimetric analysis.

For analysis of the canister contents, a sample is drawn from the canister and is analyzed by cryogenic preconcentration followed by injection into a gas chromatograph equipped with a mass selective detector (GC/MSD). For the analysis of terpene concentrations collected in the canister, a second sample is drawn from the canister and is analyzed by injection into a gas chromatograph equipped with a flame ionization detector (GC/FID). In both analyses, the retention times of each of the compounds are compared with those of known standards containing the same compounds. Concentrations of the analytes are calculated from calibration curves obtained from analysis of standard solutions.

A diagram summarizing these analyses and the corresponding analytes is given in Figure 1. The three character designations given in this diagram for the individual analyses will be used throughout the method to distinguish them. EPA Methods


2 January 1999

1-4, or equivalent methods, must be performed in order to obtain mass emission rates. These methods are not described in this document.

2.1.2 Applicability - The method has been evaluated though the use of train spikes and run spikes performed during an extensive field sampling effort. This method was found to be applicable for the measurement of these selected HAPs found in emission vents at wood products facilities. This method is not applicable if the moisture content of the source gas is greater than approximately 60% (by volume).

2.1.3 Interferences - Compounds present in the source gas can coelute with the analytes of interest during the chromatographic analysis. These types of interferences can be reduced by appropriate choice of GC columns, chromatographic conditions, and detectors. Method interferences may also be caused by contaminants in solvents, reagents, glassware and other sample processing hardware.

2.1.4 Stability – A formal stability study has not been performed, but laboratory tests show that the impinger catch was stable for approximately 2 weeks if kept refrigerated, at which time acrolein begins to degrade. At room temperature, the acrolein in the impinger catch degrades in a matter of hours. The canister catch, in general, was stable for over 3 weeks.

2.1.5 Validation – This method is designed to be a self-validating method. This is accomplished through the use of spikes during the sampling events. It has not been evaluated using the United States Environmental Protection Agency (EPA) Method 301, Field Validation of Emission Concentrations from Stationary Sources (Appendix A to CFR 63).

2.2 Apparatus

2.2.1 Sampling apparatus - A diagram of the sampling train is shown in Figure 2.

2.2.1.1 Heated Sampling Probe - The sampling probe is constructed of 1/2 inch OD stainless steel tubing. For wood products sources, the probe is maintained at 250 ± 25°F. The probe inlet is placed near the center of the stack or duct.

2.2.1.2 Heated Filter Box - The heated probe is directly connected to a heated box containing a Teflon filter. The filter housing and connections are made of stainless steel. A thermocouple connected to or within the filter housing is used to record the filter temperature which should be maintained at 250 ± 25°F. An unheated Teflon line is used to convey the sample from the back of the heated filter box to the first impinger.


3 January 1999

2.2.1.3 Midget Impingers - Three midget impingers are connected in series to the end of the Teflon line exiting the heated filter box. The first impinger has a frit on the end of the stem to improve gas/liquid contact. The following two impingers have regular tapered stems. All impinger train connectors should be glass and/or Teflon.

2.2.1.4 Filter - A second Teflon filter can be used after the impingers to prevent any fiber, debris, or water from accidentally being drawn into the sample pump system.

2.2.1.5 Variable Area Flow Meter - A flow meter should be placed in line after the impingers for a flow check during sampling.

2.2.1.6 Flow Control Device - A 400 ± 50 mL/min critical orifice should be used for flow control.

2.2.1.7 Teflon Head Vacuum pump - The critical orifice is followed by a pump, with a Teflon head, capable of providing a vacuum of about 18 inches of Hg. (Pump capacity should be sufficient to obtain and maintain critical conditions at the orifice.)

2.2.1.8 Variable Area Flow Meter - A flow meter should be placed in line before the canister for a flow check during sampling.

2.2.1.9 Needle valve - A needle valve is placed before the canister to regulate the sample flow.

2.2.1.10 Canisters - 6 L SUMMA™ polished canister or 6 L SilcoSteel™ canister is used to collect a portion of the sample gas.

2.2.1.11 Thermometer - An accurate thermometer is used to measure the canister and ambient temperature.

2.2.1.12 Pressure Gauge - A pressure or vacuum gauge capable of indicating ± 0.1 in Hga (absolute) is placed after the impingers and before the canister. The gauge is used to indicate the canister pressure before and after the sample run as well as during the leak check procedure. The gauge can also be used to determine barometric pressure.

2.2.1.13 Sample storage bottles - Glass (i.e., 40 mL VOA vials) or polyethylene bottles can be used to store the impinger catch sample after stack sampling is complete.


4 January 1999

2.2.2 GC/FID analysis apparatus (impinger analysis) [AQU]

2.2.2.1 Laboratory glassware - Volumetric pipets, volumetric flasks, autosampler vials, syringes, and cuvettes necessary for standards preparation and analysis.

2.2.2.2 Gas chromatography system - Gas chromatography analytical system complete with a temperature-programmable gas chromatograph suitable for splitless injection and all required accessories including syringes, analytical columns and gases.

2.2.2.3 Column - 30 m x 0.32 mm x 0.25 µm bonded phase DB-WAX fused silica capillary column (J&W Scientific or equivalent), or 30 m x 0.53 mm x 3 µm bonded phase DB-624 fused silica capillary column (J&W Scientific or equivalent), or other column shown to be capable of separating the analytes of interest.

2.2.2.4 GC detector - Flame ionization detector with appropriate data system.

2.2.3 Formaldehyde analysis apparatus (impinger analysis) [FOR]

2.2.3.1 Spectrophotometer - A spectrophotometer capable of measuring absorbance at 412 nm.

2.2.4 Cryogenic preconcentration/GC/MSD analysis apparatus (canister analysis) [T14]


2.2.4.2 Cryogenic concentration system - A cryogenic preconcentrator is required to concentrate the sample and to introduce it to the GC/MSD system.


2.2.4.4 Column - 60 m x 0.32 mm x 0.25 µm bonded phase DB-624 fused silica capillary column (J&W Scientific or equivalent), or other column shown to be capable of separating the required analytes.

2.2.4.5 Mass selective detector – A mass selective detector capable of scanning from 29 to 300 amus every 2 seconds or less using 70


5 January 1999

volts electron energy in the electron impact ionization mode, and appropriate data system.

2.2.5 GC/FID analysis apparatus (canister analysis) [TER/THC]


2.2.5.2 Sample loop injection system - A system capable of extracting a sample from the canister and into a sample loop which can then inject the sample onto the GC/FID system.


2.2.5.4 Column - 30 m x 0.32 mm x 0.25 µm bonded phase DB-1 fused silica capillary column (J&W Scientific or equivalent), or other column shown to be capable of separating the terpenes of interest.

2.2.5.5 GC detector - Flame ionization detector with appropriate data system.

2.2.6 Combustion gas analysis [COx]

2.2.6.1 Bacharach gas analyzer.

2.3 Reagents

2.3.1 Water - Deionized water is to be used as the impinger collection liquid, and in the preparation of all standard and spike solutions.

2.3.2 Pure compounds - Reagent grade acetaldehyde, acrolein, propionaldehyde, methyl ethyl ketone, methyl isobutyl ketone, methanol, phenol, 37% formaldehyde solution (formalin), camphene, p-mentha-1,5-diene, 3-carene, cumene, p-cymene, limonene, α-pinene, β-pinene, and ethyl ether for preparation of standard and spike solutions.

2.3.3 GC/FID calibration primary stock solution (impinger analysis) [AQU] - Prepare stock solution by diluting an aliquot of the pure compounds in a 100 mL volumetric flask according to the following table.


6 January 1999

Compound

Amount to Add to 100 mL Volumetric Flask (µL)

acetaldehyde 128 acrolein 119 methanol 126

methyl ethyl ketone 124 methyl isobutyl ketone 125

propionaldehyde 124 phenol* 100 mg

*solid

2.3.4 GC/FID calibration and matrix spike solutions (impinger analysis) [AQU] - Prepare standard solutions by serial dilutions of the stock solution. The recommended calibration range is 0.5 to 1000 mg/L. Prepare matrix spike solutions by calculating the concentration of analytes desired, and diluting the primary stock solution.

2.3.5 GC/FID internal standard primary spiking solution (impinger analysis) [AQU] - For calibration standard analysis, prepare primary stock solution by adding 0.312 mL cyclohexanol and diluting to 100 mL with DI water in a 100 mL volumetric flask (3 mg/mL cyclohexanol). For impinger analysis, prepare stock solution by adding 3.12 mL cyclohexanol and diluting to 2 L with DI water in a 2 L volumetric flask (1.5 mg/mL cyclohexanol).

2.3.6 Acetylacetone reagent (impinger analysis) [FOR] - Prepare by dissolving 15.4 g of ammonium acetate in about 50 mL of DI water in a 100 mL volumetric flask. Add 0.20 mL of acetylacetone to this solution, along with 0.30 mL of glacial acetic acid. Mix thoroughly and dilute to 100 mL with DI water. Store reagent in a brown glass bottle in the refrigerator. Reagent is stable for at least two weeks.

2.3.7 Formaldehyde analysis primary stock solution (impinger analysis) [FOR] - Prepare stock solution by diluting 2.7 mL of formalin in 1000 mL volumetric flask with DI water. (1000 mg/L formaldehyde)

2.3.8 Formaldehyde analysis calibration standard solution (impinger analysis) [FOR] - Prepare standard solution by diluting 1.0 mL of primary stock solution in 100 mL volumetric flask with DI water. (10 mg/L formaldehyde)

2.3.9 Formaldehyde analysis calibration solutions (impinger analysis) [FOR] - A series of calibration standards are made from the standard solution by adding 0, 0.1, 0.2, 0.4, 1.0 and 1.5 mL of the standard solution to individual screw-capped vials. The volume in each vial is adjusted to 2.0 mL with DI water. This corresponds to 0, 0.5, 1, 2, 5, 7.5 mg/L calibration solutions. To each vial, 2.0 mL of the


7 January 1999

acetylacetone reagent is added and the procedure described in Section 2.4.4.3 is then followed.

2.3.10 GC/MSD calibration primary stock gas cylinder [T14 analytes] (canister analysis) [T14] - Obtain a cylinder containing the compounds of interest at a level of 1 ppmv. Refer to EPA Compendium Method TO-14 for possible compound list.

2.3.11 GC/MSD calibration and matrix spike gas canisters [T14 analytes] (canister analysis) [T14] - Prepare standard canisters by serial dilutions of the stock cylinder. The recommended calibration range is 50 to 500 ppbv.

2.3.12 GC/MSD calibration primary stock gas canister [aqueous analytes] (canister analysis) [T14] – Prepare a primary stock gas canister by first preparing a stock solution by diluting an aliquot of the pure compounds in a 100 mL volumetric flask according to the following table.

Compound


acetaldehyde 281 acetone 369 acrolein 334

methanol 202 methyl ethyl ketone (2-butanone) 448

methyl isobutyl ketone 628 propionaldehyde 360

phenol (solid) 439

Inject 10 µL of this stock solution into an evacuated canister along with 140 µL of water. Fill canister with N2 to 60 in Hga. This will result in a canister concentration of 1000 ppbv for these compounds.

2.3.13 GC/MSD calibration and matrix spike gas canisters [aqueous analytes] (canister analysis) [T14] - Prepare standard canisters by serial dilutions of the stock canister. The recommended calibration range is 50 to 500 ppbv.

2.3.14 GC/MSD internal standard cylinder (canister analysis) [T14] - Obtain a cylinder containing internal standard compounds for the GC/MSD analysis. Bromochloromethane, 1,-4-difluorobenzene, and d5-chlorobenzene are commonly used. Refer to EPA Compendium Method TO-14 for additional guidance.

2.3.15 GC/FID calibration primary stock gas canister (canister analysis) [TER] – Prepare a primary stock gas canister by first preparing a solution containing the analytes in ethyl ether using the following table:


8 January 1999

Compound


camphene 809 p-mentha-1,5-diene 810

3-carene 786 cumene 694

p-cymene 780 limonene 811 α-pinene 795 β-pinene 793

Inject 100 µL of this solution into a evacuated canister and fill to 60 in Hga. This will result in terpene concentrations of 100 ppmv.

2.3.16 GC/FID calibration canisters (canister analysis) [TER] – Prepare calibration canisters by serial dilutions of the stock canister. The recommended calibration range is 1 to 300 ppmv.

2.3.17 GC/FID calibration primary stock gas canister (canister analysis) [THC] - Obtain a cylinder containing propane at a level of 900 ppmv.

2.3.18 GC/FID calibration and matrix spike gas canisters (canister analysis) [THC] - Prepare standard canisters by serial dilutions of the stock cylinder. The recommended calibration range is 15 to 2700 ppmv as C (3 to 900 ppmv as propane).

2.4 Procedure

2.4.1 Sample Bottle Preparation - Determine the number of samples bottles required for the sampling trip. Weigh each bottle and record the pre-sampling weight on the bottle. To each bottle add 1 mL of the 1.5 mg/mL cyclohexanol internal standard stock solution (see section 2.3.5) and 75 mL DI H2O.

2.4.2 Sampling - A sample field data sheet is shown in Figure 3.

2.4.2.1 Measure and record ambient temperature and barometric pressure. Source gas flow rate is determined by EPA methods 1-4 or equivalent methods.

2.4.2.2 Preparation of collection train - The sampling train consists of: a heated probe, heated filter box, three midget impingers in series immersed in an ice bath, a critical orifice, a rotameter, a Teflon-head sample pump, and an evacuated canister with a needle valve flow controller, rotameter, and a pressure gauge. For each emission


9 January 1999

source tested the sample probe and filter housing should be cleaned with organic-free water and the filter replaced. The three impingers each contain approximately 25 mL of organic free water. For sources with very high amounts of moisture (>40%), a fourth dry impinger, used as the first train impinger, may be necessary as a water dropout. A clean evacuated canister is attached to the sample pump exhaust vent. This part of the system includes the vacuum/pressure gauge, rotameter, needle valve, and canister temperature indicator. The critical orifice should allow collection of about 400 mL/min of dry air. A sample collection time of one hour is used.

2.4.2.3 Leak and flow check procedure - The sample system must be checked for leaks prior to sampling. How the leak check is performed is dependent on the configuration of the train as designed by the manufacturer. In general, a leak test of the probe , impingers, and pump would be performed by drawing a vacuum on the system and testing for a change in pressure with an inline gauge. The canister sampling portion can be combined with the impinger section or treated separately. This would also require a vacuum or pressure gauge. The canister valve is kept closed until after any leak check is performed. The leak check procedure shall be conducted when all of the measurement system's components have reached their appropriate operating temperatures.

For a vacuum leak check, plug the sampling probe inlet tip and turn on the pump to draw a vacuum. When the vacuum reading is approximately 15 inches of Hg, isolate the test section with the on/off valve. Note the beginning and ending readings on the vacuum gauge over a two minute period. An acceptable leak rate must be less that 1.0 inch of Hg / 2 min. A leak may be indicated by a flow of bubbles in the impinger (leak ahead of the impingers), liquid being drawn into the stem of the impinger (leak in an impinger or behind the impingers), or a loss of vacuum. If a leak is present, tighten fittings, connections, and impingers and restart leak check procedure. Slowly and carefully remove the plug from the end of the probe to prevent the filter from dislodging from the backing plate or water from reversing through the impinger stems. After the system has been proved to be leak free or has an acceptable leak rate, the canister and gauge must be isolated and the vacuum pressure of the evacuated canister be checked by opening the canister valve. A pressure of less than 1.0 in Hga is required to assure that the canister can withdraw enough sample without diluting the sample unnecessarily or that any contamination has been introduced since the cleaning of the


10 January 1999

canister. After verifying that the canister has the correct vacuum pressure close the canister valve.

Next, check the flow rate at the probe inlet with a bubble flowmeter. The flow rate should be comparable to the flow rate of the critical orifice with the impingers off-line. Record five measurements of the flow rate and turn off the pump.

2.4.2.4 Sample collection - Insert the probe into the stack perpendicular to the flow and secure it. Start the pump, recording the time and the flow reading on the rotameter. One minute after starting the sample run open the canister valve and adjust the flow rate to the canister with the needle valve. This is done to insure that the canister is sampling stack gas and not clean air from the train system volume. At the end of the sample run turn off the pump and record the canister temperature and pressure, then close the canister valve. A normal sample run is 60 minutes. Record the stop time and remove the probe from the vent. Turn on the pump and recheck the sample flow rate at the probe inlet and turn off the pump. If the flow rate has changed significantly, redo sampling with fresh capture water. A slight variation (<10%) in flow can be averaged.

Disconnect the Teflon tubing at the back of the heated box. Rinse the line into the impingers by adding about 10 mL of deionized water into the tubing. Use the sample pump to "pull" the rinse water into the first impinger.

2.4.3 Sample Recovery - Transfer the contents of the impingers into appropriate labeled and pre-weighed sample storage bottle. The contents of the three impingers can be combined into one bottle. If a large amount of water was collected in the dropout impinger, 2 bottles can be used. Store sample bottles in a cooler with ice, or refrigerated at approximately 4oC until they can be stored in a laboratory refrigerator. Place cap on canister valve and ship to the laboratory.

2.4.4 Sample analysis

2.4.4.1 Preparation of impinger samples [AQU] - Remove bottles from refrigerator. Weigh the sample bottles and record weights on the bottle. Transcribe initial and final bottle weight to sample field data sheet. Bottles do not need to be at room temperature before weighing.

2.4.4.2 GC/FID impinger analysis [AQU] - Analysis is performed by direct aqueous injection into the GC/FID. Place an aliquot of the impinger catch in an autosampler vial and analyze. Representative


11 January 1999

conditions for the GC/FID analysis are given in Tables 1 and 2. Other chromatographic columns and conditions may be used if it has been established that the compounds are separated and quality control parameters are met. Some possible interfering compounds include ethanol, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide. Once the GC/FID system is optimized for analytical separation and sensitivity, the sample operating conditions must be used to analyze all samples, blanks, calibration standards and quality assurance samples. Note that constant injections of aqueous samples can cause water to buildup in the system. This will cause the retention times to shift, and the peaks to broaden. It is recommended that after approximately 50 injections a bakeout of the system be performed. This should consist of heating the injector to 250oC, the oven to over 2000C and the detector to 275oC for several hours.

2.4.4.3 Formaldehyde sample analysis [FOR] - Remove a 2.0 mL aliquot of the impinger sample and transfer to a screw-capped vial. Add 2.0 mL of the acetylacetone reagent and mix thoroughly. Place vial in a water bath at 60oC for 10 minutes. Allow vials to cool to room temperature. Transfer solution to cuvette and measure the absorbance at 412 nm. If the sample concentration is above the calibration curve, dilute original sample solution and repeat entire procedure. Do not dilute colored (derivatized) samples.

2.4.4.4 Preparation of canisters – Record pressure of canisters when returned to the lab. Add humidified nitrogen gas (N2) to each canister to increase the pressure in the canister to approximately 40 in Hga. Record final pressure.

2.4.4.5 GC/MS canister analysis [T14] – Analysis is performed by removing a sample from the canister and using cryogenic preconcentration to remove the moisture, air, and to concentrate the sample. This is followed by a gas chromatograph with a mass selective detector. Representative conditions for the concentration and GC/MSD analysis are given in Table 3.

2.4.4.6 GC/FID canister analysis [TER/THC] – Analysis is performed by using a gas sample loop injection port for introduction of the sample into the GC/FID. Representative conditions for the GC/FID analysis are given in Table 4.

2.4.4.7 Bacharach gas analysis [COx] – A sample of the canister contents is analyzed using the Bacharach gas analyzer for CO, O2 and CO2. Record readings.


12 January 1999

2.4.5 Quality Assurance/Quality Control - Each field sampling program or laboratory that uses this method is required to operate a formal quality assurance program. Laboratory or field performance is compared to established criteria to determine if the results of analyses meet the performance criteria of the method.

2.4.5.1 Field blank samples - A field blank sample of water must be prepared to assure that the water being used in the impingers is not contaminated. It is made in the field by filling a 40 mL VOA vial or polyethylene bottle with the same water being used to fill the impingers.

2.4.5.2 Field duplicate samples - Duplicate samples should be collected and are then analyzed as separate samples. One duplicate is collected per mill or per every ten sample runs conducted at a mill, whichever is more stringent. For the duplicate, dual impinger trains and pumps may be connected to a single probe and filter box. The average of the duplicate values are reported for the run value. Results of the duplicate sample analysis are reported with the sample results. There are no acceptance criteria for the analytical results of the field duplicates (see Figure 4).

2.4.5.3 Field train spike sample- A field train spike recovery run should be conducted for each mill tested. This spike recovery test should be conducted on the full sample train, that is the spike solution should be introduced into the tip of the sampling system (into the heated probe). The sample train is then operated outside or independent of the source(s) tested. The field spike solution should contain all compounds that are to be sampled for and reported. Sample flow rate and sample time should be identical or very close to the actual sample runs. Care must be taken to prevent introduction of any ambient organic contaminants during this procedure. If a single spike is used, the mass of each analyte introduced should be targeted to be ± 50% of the mass expected to be captured in an actual sample run. Alternatively, both "low" and "high" spike solutions can be used on two separate spike recovery runs to bracket the expected capture from the source. Field spike recovery results should be reported. A criterion for field spike recovery of 70% to 130% is used to determine the validity of the sampling effort. This type of spiking provides a check of the complete field sampling procedure, sample storage, and sample analysis.

2.4.5.4 Field run spike sample – A field run spike should be conducted for each mill tested. Duplicate sample trains are set up to sample the source, then the first impinger of one of these two trains is spiked. The two sample trains are then run as a typical source sample.


13 January 1999

Spike recovery is determined by subtracting the source concentration obtained from the non-spiked-train from the total-spike-plus-source concentration determined from the spiked train. Targets and criteria are as specified in the paragraph above (see Figure 4).

2.4.5.5 Laboratory blank sample - A laboratory blank sample should be analyzed with each batch of samples. A batch is considered no more than 20 samples of similar matrix type.

2.4.5.6 Laboratory duplicates - A replicate injection of one sample in the analytical batch should be performed. The results of the duplicate analysis should be within 10% of the mean of the original and duplicate sample analysis.

2.4.5.7 Laboratory matrix spike samples - A laboratory matrix spike sample may be prepared with each group of similar matrix type. Using the mean concentration determined by the replicate analyses, or the background level determined from a single measurement, determine the spiking level which will give one to four times the background. If the background sample does not have detectable levels of analytes, spike the sample at approximately five times the lowest calibration level of the instrument. Spike the sample with the determined amount of the calibration standard/matrix spike solution and proceed to analyze the sample in the normal manner. The results can be considered acceptable if the calculated spike recovery is 80 to 120%. In cases where multiple analytes are present, the analyte with the highest concentration should govern the acceptance criteria.

2.5 GC calibration

2.5.1 Internal standard calibration [AQU, T14]

2.5.1.1 For [AQU] analysis, place 10 µL of the internal standard solution into an autosampler vial. Fill the autosampler vial with a high level calibration standard. The internal standard concentration will be 15 mg/L. For [T14] analysis, inject a high level calibration standard along with the internal standards. Determine the retention time of the analytes relative to the internal standard. Each analyst should optimize the temperature program or instrument conditions, as necessary, to establish distinct separate peaks.

2.5.1.2 Calculate the relative response factor for the analytes (RRFM) using Equation 1. If the average of the relative response factor for the


14 January 1999

analytes is constant, i.e., exhibits a coefficient of variation less that 20%, the calibration is acceptable and the average RRFM can be used in all subsequent calculations; otherwise, the calibration curve solutions must be reanalyzed and reevaluated. It may be necessary to perform instrument maintenance prior to reanalysis. If reanalysis also fails to produce a linear curve, new calibration standards must be prepared and analyzed.

2.5.1.3 Analyze and calculate the percent recovery of a mid-range calibration standard, daily, prior to each sample set, using Equation 2 to verify the calibration. The percent recovery should be between 80-120%. If it is not, either prepare a new standard or perform instrument maintenance. If necessary, re-calibrate the instrument.

______________________________________________________________________________

Equation 1

M

IS

IS

MM C

CxAARRF =

AM = area of analyte peak

AIS = area of internal standard peak CM = concentration of analyte injected (mg/L) CIS = concentration of internal standard injected (mg/L) ______________________________________________________________________________ ______________________________________________________________________________

Equation 2

MIS

ISS

RRFxACxA(mg/L)Conc =

As = Area of the analyte peak in the sample CIS = Concentration of the internal standard (mg/L) AIS = Area of the internal standard peak RRFM = Relative response factor of analyte (Section 2.5)

______________________________________________________________________________

2.5.2 External standard calibration [TER, THC]

2.5.2.1 Inject a high level calibration standard and determine the retention time of each analyte. Each analyst should optimize the temperature program or instrument conditions, as necessary, to establish distinct separate peaks.


15 January 1999

2.5.2.2 Measure and plot the response of each analyte vs. concentration. If the correlation coefficient of the graph is greater than 0.99, the calibration is acceptable and the equation of the line can be used in all subsequent calculations; otherwise, the calibration curve solutions must be reanalyzed and reevaluated. It may be necessary to perform instrument maintenance prior to reanalysis. If reanalysis also fails to produce a linear curve, new calibration standards must be prepared and analyzed.

2.5.2.3 Analyze and calculate the concentration of a mid-range calibration standard, daily, prior to each sample set to verify the calibration. The percent recovery should be between 80 and 120%. If it is not, either prepare a new standard or perform instrument maintenance. If necessary, re-calibrate the instrument.

2.6 Analytical range and minimum calibration level

2.6.1 Demonstrate that the calibration curve is linear (relative response factors exhibit a coefficient of variation less than 20%, or correlation coefficient greater than 0.99) throughout the range of the calibration curve.

2.6.2 Demonstrate that the analytes are detectable at the minimum levels using the lowest level calibration curve standard.

2.7 Calculations

To determine the stack concentration of each analyte, three factors must be calculated: the mass of the analyte in the impinger, the mass of the analyte in the canister, and the total volume of gas sampled. The calculations to determine these factors are given in the following sections.

2.7.1 Determination of dry volume of gas sampled:

• Convert pre- and post-flow rates to STP (Eq. 3)

• Calculate water vapor flow rate at STP (Eq. 4)

• Calculate dry flow rate at STP (Eq. 5)

• Calculate dry volume sampled at STP (Eq. 6)


16 January 1999

Equation 3

Qi,f (STP) = initial or final flow rate at STP (L/min) Qi,f = initial or final measured flow rate (L/min) Pi.f = initial or final measured barometric pressure (in Hg) P(STP) = pressure at STP = 29.2 in Hg Ti,f = initial or final temperature (°R) T(STP) = temperature @STP = 68°F = 528°R

____________________________________________________________________________ ____________________________________________________________________________

Equation 4

Qwi, wf (STP) = initial or final flow rate of water vapor at STP (L/min) Pwi, wf = initial or final water vapor pressure (in Hg) [look up in H2O Vapor Table based on Temperature]

____________________________________________________________________________ ____________________________________________________________________________

Equation 5

___________________________________________________________________________

=

fi

STP

STP

fifiSTPfi T

TxPP

QQ,)(

,,)(,

=

f,i

STP

)STP(

wf,wi)STP(f,i)STP(wf,wi T

TxPP

QQ

( ) ( )L/min

2QQQQ

Q

QQQ

(STP)wf(STP)f(STP)wi(STP)i(STP)

(STP)wfwi,(STP)i,f(Dry)i,f(STP)

−+−=

−=


17 January 1999

Equation 6

pressureandetemperaturstandardatvolumesampledryTotal(L)V

(min)timesampletotalxQ(L)V

dry probe,

(STP)dryprobe,

=

=

minL

____________________________________________________________________________

2.7.2 Determination of mass collected in impingers (Eq. 7)

Equation 7

L0.100impingerinwaterofvolumeassumedV

)(10x(L)Vx(mg/L)labfromconc.reportedg)(mass

imp

3impimpingeranalyte

==

=µ

Since we are adding the internal standard before sampling, and are using an internal standard calibration curve for the [AQU] analysis, this volume is set at 0.100 L. For the calculation of the [FOR] mass, the actual volume collected in the impinger catch must be used.

__________________________________________________________________________

2.7.3 Determination of mass collected in canister:

• Calculate volume of wet sample collected in canister (Eq. 8 and 9)

• Calculate volume of H2O vapor collected in canister (Eq. 10)

• Calculate volume of dry sample collected in canister (Eq. 11)

• Calculate correction factor (required because only a portion of total sample drawn through probe is collected in the canister) (Eq. 12)

• Calculate total volume in canister after lab dilution (Eq. 13)

• Calculate mass collected in canister (Eq. 14)


18 January 1999

Equation 8

=

)(

)(,

STP

CANfi

(CAN) fi,

(STP)(STP)(CAN)f i, P

PTT

L6.0V

Vi,f (CAN) (STP) = initial or final volume of canister @STP (L) Ti,f (CAN) = initial or final temperature of canister (°R) Pi.f (CAN) = initial or final temperature of canister (in Hga)

____________________________________________________________________________

Equation 9

)STP()CAN(i)STP()CAN(f(STP))CAN(i-f VVV −=

Vf-i (CAN) (STP) = Volume of wet sample collected in canister @STP (L)

_____________________________________________________________________________

Equation 10

= °

°−°

)STP(

)SAT(F38

)F38(

)STP()STP()CAN(if(STP) F38@OH P

PTT

)L(V)L(V2

T38°F = It is assumed the temperature of the air sample leaving the 3rd impinger is 38°F = 498°R

P38°F (SAT) = vapor pressure of H2O @38°F = 0.2319 in Hga

_____________________________________________________________________________

Equation 11

)L(V)L(V)L(V )STP(F38@OH)STP()CAN(if(dry)(CAN) 2 °− −=

____________________________________________________________________________


19 January 1999

Equation 12

)L(V)L(V

CF(dry)(CAN)

(dry)probe=

CF = canister mass correction factor

____________________________________________________________________________

Equation 13

=

)STP(

)LAB(f

)LAB(f

)STP(

PP

TT

L0.6)L((STP) (LAB)fV

Vf (LAB) (STP) = final volume of canister in laboratory (L) Tf (LAB) = final temperature of canister in laboratory (°R) Pf (LAB) = final pressure of canister in laboratory (in Hga)

____________________________________________________________________________

Equation 14

( )( ) ( )( )3analyte(STP)(LAB)f(wet)canisteranalyte 10mw

L24.0mole1Vppbvmass −

=µ )L()g(

ppbv(wet) = measured conc. in lab mwanalyte = molecular weight of analyte (g/mole)

___________________________________________________________________________

2.7.4 Calculation of source concentration

• Calculate total mass of analyte collected in sample train (Eq. 15)

• Calculate total volume of analyte collected (Eq. 16)

• Calculate source concentration (Eq. 17)


20 January 1999

Equation 15

( )CFx)g(mass)g(mass)g(mass canisteranalyteimpingeranalytetotalanalyte µ+µ=µ

____________________________________________________________________________

Equation 16

( ) ( )

µ=

mole1L24.0

mw110)g(mass)L(volume 6-

totalanalytetotalanalyte

____________________________________________________________________________

Equation 17

6

(dry)probe

totalanalyte(dry) 10x

volumevolume

ppmv =

___________________________________________________________________________

2.8 Alternative procedures - Not applicable to this method.

2.9 References

Wight, Gregory D. 1994. Fundamentals of Air Sampling, Lewis Publishers, Boca Raton, FL.

EPA Compendium Method TO-14, “Determination of Volatile Organic Compounds (VOCs) in Ambient Air Using SUMMA® Passivated Canister Sampling and Gas Chromatographic Analysis,” EPA/600/4-89/017, June 1988.


21 January 1999

2.10 Tables and diagrams

Table 1. GC/FID Operating Conditions for Selected HAPs Analysis in Impingers – DB-624 Column [AQU]

Injection: Direct (Splitless) Injector Temperature: 170°C Injection Volume: 1 µL Injection Liner Size: 2 mm id (no packing) Syringe Rinse 10 rinses with VOC free DI water FID Detector Temperature: 275°C H2 Flow Rate: Approx. 50 mL/min Air Flow Rate: Approx. 500 mL/min Makeup Gas: Helium Makeup Gas Flow Rate: Approx. 25 mL/min Carrier Gas: Helium Carrier Gas Flow Rate: Constant pressure mode to give 6

mL/min at room temperature Column: J&W DB-624, 30 m x 0.53 mm id x

3 micron fused silica capillary column with 10 m deactivated fused silica guard column

Cryogenics: On Temperature Program °C: Initial: 0°C for 3 min Ramp 1: 5°C/min to 50°C for 0 minutes Ramp 2: 70°C/min to 105°C for 17 minutes Ramp 3: 70°C/min to 220°C for 3 minutes Retention Time Order: Acetaldehyde, Methanol, Acrolein,

Propionaldehyde, Methyl Ethyl Ketone, Methyl Isobutyl Ketone, Cyclohexanol, Phenol


22 January 1999

Table 2. GC/FID Operating Conditions for Selected HAPs Analysis in Impingers – DB-WAX Column [AQU]

Injection: Direct (Splitless) Injector Temperature: 170°C Injection Volume: 1 µL Injection Liner Size: 2 mm id (no packing) Syringe Rinse 10 rinses with VOC free DI water FID Detector Temperature: 275°C H2 Flow Rate: Approx. 50 mL/min Air Flow Rate: Approx. 500 mL/min Makeup Gas: Helium Makeup Gas Flow Rate: Approx. 25 mL/min Carrier Gas: Helium Carrier Gas Flow Rate: Constant pressure mode to give 3

mL/min at room temperature Column: J&W DB-WAX, 30 m x 0.32 mm id

x 1.4 micron fused silica capillary column with 10 m deactivated fused silica guard column

Cryogenics: On Temperature Program °C: Initial: 0°C for 3 min Ramp 1: 5°C/min to 50°C for 4 minutes Ramp 2: 70°C/min to 100°C for 10 minutes Ramp 3: 70°C/min to 200°C for 4 minutes Retention Time Order: Acetaldehyde, Propionaldehyde,

Acrolein, Methyl Ethyl Ketone, Methanol, Methyl Isobutyl Ketone, Cyclohexanol, Phenol


23 January 1999

Table 3. GC/MS Operating Conditions for Selected HAPs Analysis in Canisters [T14]

Cryogenic Preconcentrator Sample Volume for Calibration: 500 mL Module 1 Trap Temperature: -150oC Module 1 Desorb Temperature: 20oC Module 2 Trap Temperature: -10oC Module 2 Desorb Temperature: 180oC Module 3 Trap Temperature: -170oC Module 3 Inject Temperature: 100oC Transfer Line Temperature: 100oC

Gas Chromatograph/Mass Selective Detector Inlet Temperature: 180oC Carrier Gas: Helium Carrier Gas Flow Rate: Constant flow mode at 2.0 mL/min Column: J&W DB-624, 60 m x 0.25 mm id x

1.4 micron fused silica capillary column with 10 m deactivated fused silica guard column

Cryogenics: On Temperature Program °C: Initial: 20°C for 3 min Ramp 1: 3°C/min to 100°C for 3 minutes Ramp 2: 5°C/min to 140°C for 2 minutes Ramp 3: 7°C/min to 240°C for 0 minutes Total Run Time: 57 min Mass Range Scan: 29-250 amu


24 January 1999

Table 4. GC/FID Operating Conditions for Terpene/THC Analysis in Canisters – DB 624 Column [TER/THC]

Injection: Split Injector Temperature: 180°C Injection Volume: 2 mL – sample loop Split Ratio: 1.5:1 Split Flow: 4.8 mL/min Total Flow: 9.8 mL/min FID Detector Temperature: 250°C H2 Flow Rate: 40 mL/min Air Flow Rate: 450 mL/min Makeup Gas: Helium Makeup Gas Flow Rate: 45 mL/min Carrier Gas: Helium Carrier Gas Flow Rate: Ramped pressure mode. Initial

pressure 14.0 psi. Ramp 7 psi/min to 9.3. Initial flow 3.2 mL/min.

Column: J&W DB-624, 30 m x 0.32 mm id x 0.25 micron fused silica capillary column with 10 m deactivated fused silica guard column

Cryogenics: Off Temperature Program °C: Initial: 55°C for 16 min Ramp 1: 120°C/min to 240°C for 2 minutes Retention Time Order: Cumene, α-pinene, camphene, β-

pinene, p-mentha-1,5-diene, 3-carene, p-cymene, limonene


25 January 1999

Figure 1. Schematic of Sample Analyses and Analytes

[T14]GC/FID Analysis

Canister Analysis

Sampling Train

Propionaldehyde Methyl Ketone p-mentha-1.5-diene

Methyl Ketone

Methyl Ethyl Ketone Limonen

Methyl Ethyl Ketone Methano cis-1,2-dichloroethylene

Phenol Phenol Alpha-

T14 Compound

Propionaldehyde Beta-

Acetaldehyd Formaldehyd Acetaldehyd Camphen Calibrated with

CO

Acrolei Aceton 3- O2

Methano Acrolei p- CO2

[TER] GC/FID

for Terpenes

[FOR] Acetylacetone Procedure

[AQU] GC/FID Analysis

[THC] GC/FID Analysis for Total

Hydrocarbons

[COx]Bacharach Gas

Analyzer

Impinger Analysis


26 January 1999

Figure 2. Chilled Impinger/Canister Sampling Train for Use at Wood Products Mills to Measure Selected HAPs

Heated Probe (250 F)

Ice Water Bath

Heated Filter Box (250 F)

Filter Variable Area Flow Meter

Critical Orifice 400 mL/min

Teflon Head PumpVariable

Area Flow Meter

Needle Valve

6L Canister

Vent Gas


27 January 1999

Figure 3. Field Sampling Data Sheet

SAMPLER DATE: CANISTER ID# CAN CODE:

SAMPLING CODE: FIELD SPKIE Y N gas____mL aqueous_____mL

DESCRIPTION:

SECTION 1a SECTION 1b SECTION 2 SECTION 3 SECTION 4 SECTION 5

LEAK

CHECK

1

2

3

4

5

AVG

% DIFFERENCE % DIFFERENCE

°F in. Hga °F in. Hga

LEFT VAC. GA. VENT

TIME FLOW (mL/min) (in. Hga) TIME P (in Hga) FLOW (mL/min) TEMP °F FLOW (mL/min)

START

5

10

15

20

25

30

35

40

45

50

55

STOP

COMMENTS:

AMBIENT TEMPERATURE / PRESSURE

IMPINGER CANISTER

PRE-RUN POST-RUN

PRE-RUN POST-RUN PRE-RUN POST-RUN

FINAL

DIFFERENCE

PROBE SAMPLE FLOW RATES COMBINED TRAIN FLOW RATES

PRESSURE

INITIAL

TRAIN SPIKE

NCASI HAPS TRAIN FIELD DATA SHEET


28 January 1999

Figure 4. Various Apparatus of Sampling Trains

Heated Probe Filter

Box F

Pump/ Control

Box

Aqueous ImpingersSUMMA CanisterN

Run NormalRun 1

Heated Probe Filter

Box

F

Pump/ Control

Box

Aqueous ImpingersD

Run Duplicate

Run 2

F

Pump/ Control

Box

Aqueous ImpingersN

Run Normal

Heated Probe Filter

Box

F

Pump/ Control

Box

Spike Tee (for introduction of liquid spike solution)

SRun Spike

Run 3

F

Pump/ Control

Box

Aqueous ImpingersN

Run Normal

Previously spike SUMMA Canister

Method NCASI 99.01 (1999)

Documents