us epa - evaluation of total organic emissions analysis

EPA-600/R-04/144October 2004

Evaluation of TotalOrganic EmissionsAnalysis Methods

EPA-600/R-04/144October 2004

Evaluation of Total Organic EmissionsAnalysis Methods

By

Raymond G. MerrillEastern Research Group, Inc.

1600 Perimeter Park DriveMorrisville, NC 27560

Contract 68-D7-0001Purchase Order 2C-R212-NALX

Project Officer: Jeffrey V. Ryan National Risk Management Research Laboratory

Air Pollution Prevention and Control DivisionAir Pollution Technology Branch

U.S. Environmental Protection AgencyResearch Triangle Park, NC 27711

U.S. Environmental Protection AgencyOffice of Research and Development

Washingtion, DC 20460

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Abstract

The rationale and supporting experimental data for revising EPA’s 1996 Guidance for TotalOrganics are summarized in this document, which reports both the results of research and theinvestigation of improvements to the Total Organic Emissions (TOE) guidance used by EPAto measure recoverable organic material from stationary source emission samples in support ofthe Office of Solid Waste Risk Burn requirements. This document describes the purpose,experimental design, and results from several related investigations into the performance ofspecific techniques to determine TOE. Results include analysis of recoverable organic materialfrom three specific boiling point/vapor pressure classes: light hydrocarbons and volatileorganics, semivolatile organics, and nonvolatile organic compounds. Improved procedures foranalysis of volatile organics, semivolatile organics, and nonvolatile organic compounds aredescribed. The experimental approach used to address weaknesses in TOE analysis proceduresis discussed, and the effect of improvements to these measurement procedures is reported. Theexperimental results in this report support the sampling and analytical guidance necessary tocharacterize the full range of recoverable organic material encountered in source emissions.

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Foreword

The U.S. Environmental Protection Agency (EPA) is charged by Congress with protectingthe Nation’s land, air, and water resources. Under a mandate of national environmental laws,the Agency strives to formulate and implement actions leading to a compatible balancebetween human activities and the ability of natural systems to support and nurture life. To meetthis mandate, EPA’s research program is providing data and technical support for solvingenvironmental problems today and building a science knowledge base necessary to manageour ecological resources wisely, understand how pollutants affect our health, and prevent orreduce environmental risks in the future.

The National Risk Management Research Laboratory (NRMRL) is the Agency’s center forinvestigation of technological and management approaches for preventing and reducing risksfrom pollution that threaten human health and the environment. The focus of the Laboratory’sresearch program is on methods and their cost-effectiveness for prevention and control ofpollution to air, land, water, and subsurface resources; protection of water quality in publicwater systems; remediation of contaminated sites, sediments and ground water; preventionand control of indoor air pollution; and restoration of ecosystems. NRMRL collaborates withboth public and private sector partners to foster technologies that reduce the cost ofcompliance and to anticipate emerging problems. NRMRL’s research provides solutions toenvironmental problems by: developing and promoting technologies that protect and improvethe environment; advancing scientific and engineering information to support regulatory andpolicy decisions; and providing the technical support and information transfer to ensureimplementation of environmental regulations and strategies at the national, state, andcommunity levels.

This publication has been produced as part of the Laboratory’s strategic long-term researchplan. It is published and made available by EPA’s Office of Research and Development toassist the user community and to link researchers with their clients.

Sally Gutierrez, Acting DirectorNational Risk Management Research Laboratory

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EPA Review Notice

This report has been peer and administratively reviewed by the U.S. Environmental ProtectionAgency and approved for publication. Mention of trade names or commercial products does notconstitute endorsement or recommendation for use.

This document is available to the public through the National Technical Information Service,Springfield, Virginia 22161.

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Contents

Section PageAbstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iiList of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viList of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viAcronyms and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiAcknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Conclusions and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Methods and Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Total Volatile Organic Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Analysis Recommendations and QC Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 5Sample Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

XAD-2 Cleaning Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Method 0010 Sample Recovery and Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Total Chromatographable Organics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Nonvolatile (GRAV) Organics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4 Experimental Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Measurement of Volatile Organic Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Evaluation Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13FGC Calibration Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Instrument Detection Limit Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Procedures to Evaluate XAD-2 Preparation and Blanking . . . . . . . . . . . . . . . . . . . . . 16Procedures for Evaluating the Artifacts and Interferences with GRAV Analysis . . . . 17

Fine Particulate Filtration Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Filter Extract Inorganic Interference Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . 18Probe Wash Inorganic Interference Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5 Quality Control Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21QC for Volatile Organic Analysis by FGC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21XAD-2 QA/QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21QC for Total Chromatographable Organics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22QC Requirements for GRAV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

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List of Figures

Figure Page1 Stationary Source Emissions Sampling and Analysis Techniques. . . . . . . . . . . . . . . . . 22 Schematic of Solid Sorbent Extractor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Modified Method 3452 Sample Preparation Scheme for Method 0010

Components Analyzed for TCO and GRAV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Packed Column FGC Calibration Chromatogram. . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

List of Tables

Table Page1 Field GC Analysis Recommendations and QC Requirements . . . . . . . . . . . . . . . . . . . 52 Calibration Standard Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 FGC Chromatographic Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Calibration Response Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 FGC Detection Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 XAD-2 Blank Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 XAD-2 GRAV Blanks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 Inorganic Salts Mixture Used for GRAV Interferents Analysis . . . . . . . . . . . . . . . . . 189 Filtration Simulation, Glass Wool versus Cellulose Filtration. . . . . . . . . . . . . . . . . . . 1810 Filter Extraction Simulation, Methylene Chloride Extracts. . . . . . . . . . . . . . . . . . . . . 1911 Probe Rinse Simulation, Methanol/Methylene Chloride Extracts . . . . . . . . . . . . . . . . 1912 Field GC Analysis QC Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2113 QC Guidelines for XAD-2 Resin Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2214 QC Requirements for Total Chromatographable Organics . . . . . . . . . . . . . . . . . . . . . 2215 QC Requirements for GRAV Analysis of Volatile Compounds . . . . . . . . . . . . . . . . . 23

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Acronyms and Abbreviations

Term DefinitionAEERL EPA’s former Air and Energy Engineering Research LaboratoryBP boiling pointC7 n-heptane (straight chain hydrocarbon, saturated, 7 carbon atoms)C10 n-decaneC12 n-dodecaneC14 n-tetradecaneC17 n-heptadecane (straight chain hydrocarbon, saturated, 17 carbon atoms)CH4 methaneDSCM dry standard cubic meterEPA U.S. Environmental Protection AgencyFGC field gas chromatographyFID flame ionization detectorGC gas chromatograph or gas chromatographyGMW gram molecular weightGRAV gravimetric massIDL instrument detection limitLevel 1 AEERL Procedures Manual: Level 1 Environmental AssessmentMDL minimum detection limitMS mass spectrometryNERL EPA’s National Exposure Research Laboratorynonvolatile compound class generally defined by boiling point above 300 °CORD EPA’s Office of Research and Developmentppmv parts per million by volumeOSW EPA’s Office of Solid WasteQC quality controlRCRA Resource Conservation and Recovery ActROP recommended operating procedureRTP Research Triangle ParkSCOT surface coated open tubular chromatographic columnSVOCs semivolatile organic compoundsTCO total chromatographable organic compoundsTedlar trade name for sampling bag material used in direct collection of air samplesTOE total organic emissions (combination of FGC, TCO, and GRAV mass)VOCs volatile organic compounds

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Acknowledgments

This document was prepared for the U.S. Environmental Protection Agency’s Office ofResearch and Development, NRMRL/APPCD/Air Pollution Technology Branch, located inResearch Triangle Park, NC. Technical contributions from Jeffrey Ryan at EPA and fromDr. Joan Bursey and Mr. Robert Martz of Eastern Research Group are gratefully acknowledged.

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Section 1Introduction

The EPA’s Office of Solid Waste (OSW) has devel-oped guidance1 for conducting stack emissions testsin association with requirements for the permitting ofhazardous waste combustion facilities. The guidancefor conducting a risk burn requires a comprehensivecharacterization of organic and inorganic emissions,including the determination of total organic emissions(TOE). Stand alone guidance for determining TOEwas previously released in 1996.2 The TOE determi-nation represents a gross measurement of the totalvolatile, semivolatile, and nonvolatile organic com-pounds emitted. The TOE are used to derive anorganic mass balance to qualify the completeness anduncertainty of the associated risk assessment.

Peer and public reviews of OSW’s Risk Burn Guid-ance for Hazardous Waste Combustion Facilitieswere critical of the TOE methodology, particularlywith respect to the total chromatographable organiccompound (TCO) and gravimetric mass (GRAV)measurement procedures used to characterize thesemivolatile and nonvolatile organic fractions respec-tively. Significant concern was raised regarding thepotential for high bias in the GRAV determinationdue to the presence of inorganic compounds in theTOE sample. Combined with the GRAV method’slack of measurement sensitivity relative to the non-volatile, organic analyte-specific measurementmethods, the GRAV portion may dominate theoverall TOE measurement, resulting in a poor quanti-tative characterization of the identified compounds.

As a result of these comments and concerns, a seriesof experiments were conducted to investigate identi-fied measurement issues and achieve proceduralimprovements in order to ultimately revise and

update the TOE methodology. This document de-scribes the purpose, experimental design and resultsfrom several related investigations into the perfor-mance of specific techniques to determine TOE.

The procedures described in this report measure andreport TOE mass. These procedures are performed topermit comparison of the portion of organic emis-sions that have been characterized by “target analytespecific” methods to the total organic emissions fromsource sampling.

TOE procedures allow the total volatile and extract-able organic mass from stationary source emissionsto be quantified. The total recoverable organic massreported as TOE is the result of combining data fromthree fractions of organic compounds: volatile or-ganic compounds (VOCs), TCO for semivolatileorganic compounds, and GRAV measurements fornonvolatile organic material. These three fractionsare defined as follows:

C VOCs include organic compounds with boil-ing points less than 100 °C. These compoundsare measured by two analytical techniques.Gas samples collected by EPA SW-846Method 00403 or equivalent are analyzedusing a field gas chromatography (FGC).Volatile organic materials captured in thecondensate of the EPA SW-846 Method 0040train are analyzed using purge and trap gaschromatography/flame ionization detection(GC/FID);

C Semivolatile organic compounds (SVOCs)include organic material with boiling pointsbetween 100 and 300 °C. SVOCs are mea-sured by TCO analysis performed by an

Evaluation of Total Organic

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Figure 1. Stationary Source Emissions Sampling andAnalysis Techniques.

analytical laboratory using GC/FID andsample extract(s) from an EPA SW-846Method 00104 sampling train; and

C Nonvolatile organic compounds (GRAV)with boiling point greater than 300 °C aremeasured as the residual mass of sampleextract(s) from a Method 0010 sampling train.

The combination of two sampling and four analyticaltechniques gives the investigator the gross mass of allrecoverable organic material. The total organicemissions are the sum of VOCs, TCO, and GRAV.A summary of these three techniques is shown inFigure 1.

Emissions Analysis Methods

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Section 2Conclusions and Recommendations

ConclusionsResults of the research performed on synthetic andauthentic environmental samples focused on issuesranging from the availability of calibration standardsfor field GC analysis to determining the cause forinorganic interference with the nonvolatile organicanalysis.

Volatile organic compounds (BP<100 °C) present insamples collected in Tedlar bags according to theprocedures in EPA SW-846 Method 00403 requireanalysis in the field by GC/FID (FGC). The recoveryof gaseous standard material containing methane,ethane, propane, n-butane, n-pentane, n-hexane, andn-heptane was confirmed. Polymer-based packedcolumns such as Alltech Haysep Q 80/100 mesh andsurface coated open tubular (SCOT) gas chromatog-raphy columns such as J&W GS-Q or equivalentwere found to provide adequate resolution andsensitivity for this analysis. The minimum detectionlimit (MDL) of FGC is limited by the amount ofsample that can be introduced through the sampleloop. The MDL that can be achieved by FGC is in therange of 0.6 ppm (1500 :g/m3). For stationary sourcesamples with volatile organic material present at orbelow 1 ppm, the FGC method is not sensitiveenough to provide a reliable basis for volatile TOEunless samples are concentrated using alternativetechniques. Where FGC shows results less than1 ppm, independent laboratory analysis of the bagsamples for methane should be performed followedby cryogenic preconcentration and analysis of C2 - C7organic compounds. For volatile compounds col-lected in bags, uniform FID response for all com-pound classes is assumed in this methodology.

Determination of SVOC mass in samples collected by

EPA SW-846 Method 00104 requires extraction andconcentration of the various train components asdescribed in EPA SW-846 Method 35425 and subse-quent analysis by GC/FID. Field samples collected inthis way require additional preparation to removepolar volatile solvents (methanol or acetone), inor-ganic interferents, and water prior to concentration.Experimental results demonstrate that the performingthe separatory funnel extraction of the XAD-2 andparticulate filter Soxhlet extracts followed by 0.45:m filtering was adequate to remove the field recov-ery solvents, inorganic interferents, and water. Theseparatory funnel extraction of the Soxhlet extractsrepresents a minor operational modification to theMethod 3542 sample preparation approach but offerssignificant improvement in analytical results. Experi-mental results also showed that XAD-2 porouspolymer resin used to collect SVOCs can be cleanedwith an extraction procedure using water, methylenechloride, and methanol.

Nonvolatile organic material analysis is also per-formed for the Method 0010 train components. Thesame sample extract used to determine SVOCs isused to determine nonvolatile organic materials.Evaporation of a known volume of the Method 0010organic extract has resulted in variable and artificiallyhigh results because of improper sample preparationand inorganic interferents retained during samplepreparation. The experimental results from GRAVanalysis of synthetic and authentic combustionparticulate sample extracts showed that the separatoryfunnel extraction of the XAD-2 and particulate filterSoxhlet extracts followed by 0.45 :m filtering wasadequate to remove more than 90% of the potentialinorganic interferences to gravimetric determinationof nonvolatile organic material in Method 0010


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samples. Methanol solvent wash and methylenechloride extraction of solid particulate from munici-pal waste combustion fly ash and a cement kiln dustshowed the presence of dissolved inorganic materials.The separatory funnel extraction of these Soxhletextracts followed by 0.45 :m filtering was adequateto reduce the level of inorganic interference belowdetection limit for the GRAV measurement. As aresult, the modifications to Method 3542 to includethe separatory funnel extraction of the XAD-2 andparticulate filter Soxhlet extracts followed by 0.45:m filtering specifically for TCO and GRAV analysiswill be included in the revised TOE guidance. Addi-tional experimental results indicated the need forprecautions to monitor and minimize airborne dustdepositing in GRAV samples. GRAV mass of partic-ulate extracts was so low in the two cases studied thatdeposition of room air dust could make a significantcontribution to the total mass of GRAV samples.GRAV analysis samples must be covered usingprocedures described in the method so that airbornedust is minimized as an interference. Finally, GRAVanalysis results indicated a need to perform analysisin duplicate and report the average result to achievethe required accuracy.

RecommendationsFGC procedures should be modified to requirecalibration with a gaseous hydrocarbon standardcontaining methane, ethane, n-propane, n-butane, n-pentane, n-hexane, and n-heptane. Concentrations ofindividual hydrocarbons and the total hydrocarbonbalance should be calculated in units of :g/m3. Totalvolatile organic material measured from Method0040 bag samples at concentrations less than 1500:g/m3 are likely to be below detection limits, andsamples should be concentrated for accurate compari-son to speciated volatile compound analysis of thesame stationary source emissions.

Packed column analysis should be performed with aminimum of 1 mL gaseous injection. SCOT columnanalysis should be performed at an injection volumethat provides the optimum peak shape without split-

ting the methane elution profile (peak).

XAD-2 must be cleaned within 2 weeks of use orreevaluated for blank content requirements for TCOand GRAV. Preparation of XAD-2 requires cleaningto the minimum standards reported here whichincludes washing with water, extraction with metha-nol, and extraction with methylene chloride, de-scribed elsewhere in this report.

For TCO and GRAV analysis, Method 0010 samplesmust follow the modified Method 3542 preparationprocedures. Method 3542 does not remove all of thepotential inorganic interference in methylene chlorideextracts of the mixture of inorganic salts studied inthis evaluation. Following soxhelt extraction, theXAD-2 and particulate filter methylene chlorideextracts should be extracted at least twice withadequate volumes of both high and low pH waterfollowed by 0.45 :m filtering to ensure completeremoval of potential inorganic interferences in sourcesamples. Either glass wool or cellulose fiber filtersmay be used in the final drying step prior to concen-tration of the extract.

The entire analysis window for TCO is established byinjecting n-heptane (C7) and n-heptadecane (C17) asthe retention time reference peaks between which theTCO integration will occur. The retention timewindow for TCO is established during calibration.The TCO range is defined by all peaks falling after C7(n-heptane) and before C17 (n-heptadecane). Integra-tion of the detector response must begin after the C7returns to within 10% of baseline, and terminatewhen the beginning (front) of C17 is more than 10%of baseline.

GRAV analysis must be performed on a balance of atleast 5 place accuracy (10 :g detection limit). GRAVanalysis must be performed in duplicate and reportedas the average of the two measurements. Samplesmust be protected from deposition of room air dust toachieve the quality control (QC) limits shown in thisreport.


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Section 3Methods and Materials

Total Volatile Organic EmissionsCompounds with boiling points below 100 °C aresampled into Tedlar bags using EPA SW-846 Meth-od 0040 sampling procedures and analyzed in thefield by GC/FID. The GC/FID recommended operat-ing procedure (ROP) for this method is found inGuidance for Total Organics.2 The range of applica-ble compounds for total VOC determination includesmethane, with a boiling point of -160 °C, to n-hep-tane, with a boiling point of 98 °C. The nominalreporting range for the methodology extends to 100°C. Methane, ethane, and propane can be separatedand reported individually. The FGC results arereported as a total.

Analysis Recommendations and QC Require-mentsCalibration standards can be ordered at severalconcentrations or prepared by dilution of a certified

stock standard in Tedlar bags or pressurizedcylinders.A dilution of a certified C1 S C7 standardgas mixture should also be prepared as a daily qualitycontrol calibration check sample. This QC sampleshould be prepared at a concentration approximatelyin the middle of the calibration range and should beanalyzed at least once per day during stationarysource field sampling. QC requirements for field GCanalysis of volatile compounds are shown in Table 1.

A custom certified calibration gas standard pur-chased commercially that contained methane, ethane,n-propane, n-butane, n-pentane, n-hexane, and n-heptane at approximately 100 ppm each in nitrogenwas used for all work on FGC work reported here.The concentration of each hydrocarbon and of thetotal mixture was calculated in micrograms per cubicmeter as described later in this section. The stockstandard contained compounds shown in Table 2.

Table 1. Field GC Analysis Recommendations and QC Requirements.

Analysis RecommendationsInstrumental Parameter Recommended Value

Injection Temperature AmbientDetector Temperature 220 °CInitial Column Temperature 100 °CColumn Oven Temperature Program 100 °C to 190 °C at 15 °C/minFinal Column Oven Hold Parameters Hold at 190 °C for 12 minPacked Chromatographic Column Capable of C1 S C7Normal Hydrocarbon Separation

HaysepQ 80/100 mesh, 2 m by 3.18 mm by 2.16 mmID stainless steel (or equivalent) (Alltech)

SCOT Chromatographic Column Capable of C1 S C7 Nor-mal Hydrocarbon Separation.

GS-Q, 30M by 0.53 mm ID fused silica J&W Scientific(or equivalent)

continued


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Table 1. (concluded)

QC RequirementsQuality Indicator Performance Requirements

Peak Resolution R = 1.252

Calibration Materials Certified gas cylinder(s) containing methane, ethane,propane, butane, pentane, hexane, and heptane

Calibration Curve • Three concentrations that bracket the sample analy-sis range.

• Correlation coefficient of 0.995 or greater• Single calibration measurements should agree

within 20% of the average calibration curve or amean response factor.

Sensitivity 5 :g/dry standard cubic meter (DSCM)Precision ±15% relative standard deviation on replicate analysis.Bias ±10% relative standard deviation on daily QC analyses.

Fresh QC check samples are prepared if analysis failsQC check requirements. If subsequent analysis resultsalso fail QC requirements, instrument is recalibrated.

Completeness 100% of the aliquots are reanalyzed if analysis calibra-tion check results do not meet quality specifications.

Retention Time ±5% relative standard deviation from mean retentiontime for each calibration compound.

Table 2. Calibration Standard Specifications.

Compound Concentration (ppm) Concentration (:g/m3)Methane 103 67,700Ethane 105 129,000n-Propane 104 188,000n-Butane 105 250,000n-Pentane 101 299,000n-Hexane 101 357,000n-Heptane 101 415,000Total 720 1,706,000


7

C CGMW

g m ppmµ 3 24 4141000= ×

.

The concentration of each hydrocarbon in parts permillion was converted to micrograms per cubic meterusing

(1)

where:= concentration of each hydrocarbonC

g mµ 3

expressed in micrograms per cubicmeter;

Cppm = concentration of each hydrocarbonexpressed in parts per million;

GMW = gram molecular weight of each hydro-carbon.

The following steps were applied to each componentof the multi-component standard:

1. Determine the concentration of each compo-nent of the standard in parts per million.

2. Using the equation above, convert the con-centration of each component to microgramsper cubic meter.

3. Sum the concentrations of each of the compo-nents in micrograms per cubic meter to obtaina total concentration, which can then berelated to the sum of the chromatographicpeak areas at each concentration level.

To determine total mass of the hydrocarbons for thecalibration curve, the concentrations of each of thehydrocarbons (in micrograms per cubic meter) aresummed, and total concentration (sum of the concen-tration of each component of the standard) is plottedvs. area counts. Calibration values for individualhydrocarbons and the sum of the entire group weredetermined using linear regression and averageresponse calculations.

A Varian Model 3400 gas chromatograph equippedwith a HaysepQ 80/100 mesh, packed chromato-graphic column measuring 2 m by 3.18 mm by 2.16mm ID stainless steel and a FID was configured toperform VOC analysis.

Gas was introduced into the injection port of the gaschromatograph using a 1 mL stainless steel gassampling loop. A SCOT column coated with PorapakQS was also evaluated for FGC analysis. An exampleof column(s), conditions, and QC requirements isshown in Table 1. The chromatographic column(s)used in the field GC must be capable of resolving theC1 S C7 hydrocarbons at baseline level. A multipointcalibration consisting of at least three points (ana-lyzed in triplicate) at different concentrations wasprepared.

Sample AnalysisAfter calibration of the field GC, sample analysisbegins when the sample container (the Tedlar bag) isconnected to the sampling valve and the sample gasis drawn through the valve and into the GC sampleloop or a gas-tight syringe. The sample is injectedinto the chromatograph. The temperature programand integrator/data system data acquisition are startedsimultaneously with the injection of the sample.Chromatograms and integrator/data system output arecollected.

The sample is analyzed twice (i.e., duplicate injec-tions) and integrated from a retention time of zero tothe end of the C7 peak. The total concentration inmicrograms per cubic meter is calculated from thesummed integrated area of the standard peaks fromzero through the end of C7 to yield the value for thegaseous portion of the TOE analysis for each injec-tion.

The simple arithmetic mean of the duplicate injec-tions is reported as the bag portion of the FGCresults.

XAD-2 Cleaning MethodsXAD-2 is a macroreticulate porous polymer madefrom styrene (vinylbenzene) and divinylbenzene. Theemulsion block copolymerization process used toform cross-links in the resin gives the resin a porestructure and chemical stability ideally suited forsampling and recovery of SVOCs from the Method0010 sampling train. The polymer synthesis processalso exposes the raw resin to high concentrations of


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naphthalene, styrene (vinylbenzene), divinylbenzeneand low molecular weight byproducts of these re-agents and the polymerization reaction. If these com-ponents are not removed during XAD-2 cleaning,they will be extracted as part of the sample prepara-tion procedures and will provide a positive bias to theTCO results. It is essential that XAD-2 be clean andfree from contaminants that could contribute apositive bias to the TCO and GRAV determination.

Preparation of XAD-2 within 2 weeks of sampling orexperimental work provides sufficient time for thecleaning and drying process and avoids extendedstorage, which may result in contamination andelevated levels of extractable material in blanks. Thecleaning method described below has proven to be acost-effective and high quality procedure for prepar-ing XAD-2.

The procedure for cleaning XAD-2 is derived fromthe Procedures Manual: Level 1 EnvironmentalAssessment (Second Edition)6 developed by the U.S.EPA. The original methodology has been improvedto provide a reproducible method for preparingsorbent material sufficiently clean for low levelorganic compound capture and analysis. The com-plete cleaning cycle requires approximately 5 work-ing days to finish. Typical background or blank totalorganic concentrations (TCO) from XAD-2 preparedby this procedure are on the order of 1 :g per gram ofsorbent medium. Typical GRAV background aftercleaning by this procedure is on the order of 6 :g pergram of sorbent medium. The cleaning procedureused to obtain these results includes the followingsteps:

• Resin is obtained from the manufacturer,supplier or recycled from prior use. Resincleaned by a secondary vendor should betreated like recycled resin. Recycled andrecleaned resin usually contains less organiccontamination and is preferred over rawmaterial straight from the manufacturer.Naphthalene is the most common contami-nant in sorbent that has not been properlycleaned.

• The resin is soaked and washed several times

with deionized water if new from the manu-facturer. Resin “fines” float to the surface ofthe water wash and are removed by skimmingthe surface with a fine screen or dipping thefines out with a glass beaker before the nextcleaning step.

• The water-washed or recycled resin is loadeddirectly into the extractor for solvent clean-ing. The entire cleaning procedure is done“wet” with final drying taking place only atthe end of the process.

• Distillation type extractors, each capable ofholding 900 g of resin, are typically used toextract the resin with sequential extractions ofmethanol, methylene chloride, and methylenechloride again. An extraction apparatus fol-lowing the design in Appendix B of the Pro-cedures Manual: Level 1 EnvironmentalAssessment (Second Edition)6 and shown inFigure 2 is efficient and effective for XAD-2cleaning. Solvent sufficient to completely fillthe extraction chamber and at least 30% ofthe solvent reservoir is required for the ex-traction. Fresh solvent is used for each step ofthe extraction. Solvent is drained betweensteps, and the extractor is pre-rinsed with thesolvent to be used in the next step.

• After the final extraction, the methylenechloride is drained and the extractor body isremoved to a hood where the resin is dried.Drying is accomplished by a gentle stream ofnitrogen. The nitrogen is delivered from thegas output of a liquid nitrogen tank through aheat exchanger to the sorbent to removemethylene chloride residue from the finalextraction step. Residual methylene chlorideis reduced to 1000 :g/g of resin.

• The dried resin is transferred to a clean, dryglass jar with a Teflon or equivalent linedscrew cap lid. For blank QC purposes, aportion of the dried sorbent equal to a typicalfield sample (usually 40 g) is extracted, pre-pared and analyzed by the method used forfield samples.

• If the analysis of the clean XAD-2 meetsmethod acceptance criteria, it is labeled with


9

Figure 2. Schematic of Solid Sorbent Extractor.

a laboratory identification number and storedat room temperature in a clean, solvent-freecabinet for use in sampling. The clean resin isstable and can be stored for 2 to 3 weeks.Longer storage times are possible if the mate-rial is refrigerated, but a blank sample mustbe checked before material stored for longerthan 3 weeks is used for field sampling.

Method 0010 Sample Recovery andPreparationStationary source samples for application of thisanalysis method are taken by SW- 846 Method 00104

and prepared by SW-846 Method 35425 (as modifiedfor TCO and GRAV analysis). A flow chart forpreparation of SW-846 Method 0010 samples usingmodified SW-846 Method 3542 is shown in Figure 3.The Method 0010 sampling train generates threesample fractions from various train components thatmust be carefully recovered and prepared to ensureresults that meet the quality requirements for TCOand GRAV analysis. Solvents used to rinse samplingtrain glassware may dissolve inorganic material and

water. The inorganic material is carried through thesample preparation process with the water and polarsolvents and remains in the concentrated extractsunless steps are taken to remove the water and polarsolvents. The interferents must be removed during thesample extraction and preparation steps before theorganic extract is concentrated for final analysis.Several minor modifications were made to Method3542 to ensure that water soluble (polar) solvents andinorganic material are removed from the samplesprior to TOE analysis. At the end of the preparationprocedures, extracts may be combined and concen-trated to a final volume of 5 mL, producing oneextract per Method 0010 sampling train for the TOEanalysis. Alternatively, each of the three sampleextracts may be analyzed for TOE separately.

Total Chromatographable OrganicsTCO analysis is used to measure the total organicmass of compounds boiling between 100 and 300 °C.The TCO Method is described in detail in Guidancefor Total Organic.2 The TCO procedure consists ofanalysis of the combined concentrated probe wash,


10

Figure 3. Modified Method 3452 Sample Preparation Scheme for Method 0010Components Analyzed for TCO and GRAV.


11

filter, XAD-2, and impinger extracts from the threemajor components of the sampling train. The analysisis generally performed in the laboratory after extrac-tion, compositing, filtration, and concentration of theextracts of the individual components of theMethod 0010 sampling train.

Capillary chromatography is used to obtain the bestpossible resolution of chromatographic peaks. Forstationary source emission gas samples, an aliquot ofthe Method 0010 methylene chloride extract isinjected onto a capillary GC column with an FIDdetector, and the peak areas are summed over theretention time window that encompasses the TCOboiling point range. The entire analysis window isestablished by injecting n-heptane and n-heptadecaneas the retention time reference peaks between whichthe TCO integration will occur. The retention timewindow for TCO is established during calibration.The TCO range is defined by all peaks falling after C7and before C17. Integration of the detector responsebegins after the C7 peak returns to within 10% ofbaseline and terminates when the beginning (front) ofthe C17 peak is more than 10% of baseline.

The TCO calibration standard curve is generated withhydrocarbon standards that fall within the TCOrange, specifically n-decane (C10), n-dodecane (C12),and n-tetradecane (C14). Calibration is performedusing a solution of standards prepared from neatliquid standards of the individual hydrocarbons inmethylene chloride. The quantitative calibrationstandards should be prepared to cover the concentra-tion range expected in the source samples. A multi-point calibration of at least three points (in triplicate)is generated in units of micrograms per milliliter. Thecalibration curve for TCO is calculated using linearregression statistics. The total detector response forthe TCO range reported as one number is used in thelinear regression calculation. The C7 and C17 detectorresponse is not included for the calibration pointdetermination. After calibration has been performed,a daily QC check sample is run to verify that the GCis performing correctly. The QC check sampleconsists of a standard in the middle of the workingrange of the GC calibration standards.

Nonvolatile (GRAV) OrganicsThe third component of the total organics measure-ment process is called gravimetric mass (GRAV).The GRAV method has also been described in detailin Guidance for Total Organics.2 Extractable organicmaterials with nominal boiling points of 300 °C andhigher are determined by this procedure. Samplesextracted from sampling media using methylenechloride and dried to constant weight are determinedquantitatively by this procedure. GRAV analysismeasures organic compounds with vapor pressuresless than or equal to n-heptadecane (C17). The rangeof organics is defined by boiling point, in this casegreater than 300 °C.

For stationary source emission gas samples, theGRAV procedure is carried out on an aliquot of thesame Method 0010 methylene chloride extract usedfor TCO determinations. GRAV analysis is per-formed using samples prepared using the modifiedSW-846 Method 3542 procedures to remove bothinorganic interferents and water from the samplingtrain recovery process. The analysis is generallyperformed in the laboratory after extraction, composi-ting, filtering, and concentrating the extracts of theindividual components of the Method 0010 samplingtrain.

The GRAV method quantifies organic material witha boiling point greater than 300 °C. A carefullymeasured aliquot of the Method 0010 methylenechloride extract is placed in a cleaned, dry, pre-weighed aluminum weighing pan. The solvent isallowed to evaporate in a fume hood at room temper-ature. Exposure to dust and contaminants is mini-mized by covering the samples with an aluminumtent or placing them under some form of clean cover.The GRAV samples are then dried completely toconstant weight in a room temperature desiccator.The residue in the pan is weighed accurately, and themass is recorded as the GRAV value. For this proce-dure, a portion of the pooled extracts from theMethod 0010 sampling train used for TCO are alsoused for GRAV. A volume of 1 mL of the pooledextract is used for each of the GRAV determinations.Duplicate GRAV analyses are performed, and the


12

results are averaged.

GRAV organics with BP greater than 300 °C aremeasured on an analytical balance capable of weigh-ing accurately to ±0.005 mg (5 :g). The GRAVvalue, in micrograms, is converted to units of

micrograms per sample by multiplying the averagepan results for the sample by the ratio of total extractvolume to GRAV aliquot volume. Final GRAVresults are reported in micrograms per cubic meter bydividing micrograms per sample by the Method 0010sample volume (expressed as cubic meters).


13

Section 4Experimental Procedures

Measurement of Volatile Organic Emis-sions The Volatile Organic Emissions portion of the TotalOrganic Emissions measurement is determined in twoparts:

C First, a field GC analysis of the gaseousportion of the Method 00403 sample is con-ducted using sample collected in a Tedlarbag. The range of organic material identifiedby field GC is defined by the boiling pointrange less than 100 °C. The procedure isnormally performed in the field to minimizesample (compound) loss due to storage andshipping.

C Second, the aqueous portion of the sample(condensate from the Method 0040 samplingtrain) is analyzed in the laboratory usingpurge and trap GC with a FID. This aqueousportion, which is actually the condensate fromMethod 0040 sample, is normally transferredto a vial with no headspace for shipment tothe laboratory.

Field GC analysis is limited by a detection limit of1 S 10 parts per million by volume (ppmv), equiva-lent to 2000 S 20,000 :g/m3. Identification of meth-ane, ethane, and propane is possible although specificcompound identification is not required for the TOEdetermination. These compounds may be present insignificant quantities in stack samples, and correctidentification and quantification will more accuratelycharacterize the organic emissions.

Once both portions have been quantified, they areadded together to yield the volatile organic emissionscontribution to the TOE.

Evaluation ExperimentsA series of laboratory experiments was completed todetermine the quality parameters and detection limitsfor the FGC method. The goal of the FGC evaluationexperiments was to confirm that calibration standardsthat include n-heptane could be prepared and ana-lyzed using the FGC analytical procedure. A secondgoal of the FGC evaluation was determination ofdetection limits for samples collected in Tedlar bags.Previous FGC experiments were performed with n-hexane as the latest-eluting compound in the calibra-tion gas. Prior to these evaluation experiments, thevolatile organic material in the boiling point rangebetween n-hexane and n-heptane was erroneously notincluded in the FGC results. (Note that the TCOdetermination begins after elution of the C7 peak,whereas the FGC determination includes the C7peak).

The experimental work included evaluation of acommercially prepared standard containing normalhydrocarbons from methane to n-heptane and adetection limit study for the method.

Experiments were performed to:C Confirm that n-heptane could be included in

the calibration mixture;C Determine the response factor for individual

calibration compounds and the average re-sponse factor for the C1 S C7 calibrationmixture; and

C Evaluate both a polymer based packed gaschromatographic column and a SCOT columnfor FGC analysis.

FGC Calibration PerformanceThe stock standard was diluted into reusable 1.5-L


14

high pressure aluminum cylinders. The concentra-tions of all hydrocarbons in calibration standardswere 74,500 :g/m3 (31 ppm); 117,000 :g/m3 (51ppm); 337,000 :g/m3 (148 ppm); 845,000 :g/m3

(371 ppm); and 1,706,000 :g/m3 (720 ppm). TheFGC was calibrated by injecting each of these cali-bration samples into the gas chromatograph threetimes. A linear regression was performed on theresulting peak area versus concentration data. Cali-bration response factors in units of area per concen-

tration were determined from the linear regressionstatistics of the calibration sample analysis results.Gas chromatographic conditions used to generatecalibration response factors and detection limits areshown in Table 3. Response factors for individualhydrocarbons and the total VOC response factor areshown in Table 4. An example packed columnchromatogram showing peak shape, resolution, andretention times is presented in Figure 4.

Table 3. FGC Chromatographic Conditions.

FGC Instrument Parameter Instrument Set PointInjector Temperature AmbientInitial Column Temperature 100 °CColumn Oven Temperature Program 100 °C to 190 °C at 15 °C/minFinal Column Oven Hold Parameters Hold at 190 °C for 12 minColumn Carrier Gas Flow Approximately 30 mL/minFID Detector Temperature 220 °C

Table 4. Calibration Response Factors.

Compound Response FactoraLinear Regression

Correlation Coefficient (r2)Methane 5.0575 0.9987Ethane 5.611 0.99995Propane 5.6159 0.99995n-Butane 5.7466 0.99996n-Pentane 5.6923 0.99993n-Hexane 5.749 0.99993n-Heptane 5.6889 0.99998Average 5.6783 0.99957a Varian GC/FID Model 3400


15

Figure 4. Packed Column FGC Calibration Chromatogram.

Other choices of polymer-based column packing maygive satisfactory results but should be evaluatedbefore use. Most polymer-based columns capable ofseparating methane, ethane, and propane suffer frombreakdown and bleed at the temperatures needed toelute n-heptane.

Instrument Detection Limit StudyThe lowest calibration standard concentration (i.e.,74,500 :g/m3, or 31 ppm) was used to determine anapproximate instrument detection limit for thismethod under the operating conditions described inTable 3. The detection limit for individual com-pounds C1 through C7 was calculated using theapproach in EPA 40 CFR 136, Appendix B. Resultsof the instrument detection limit (IDL) for individualcomponents and for the sum of the compounds in thecalibration standard are shown in Table 5. Theapproximate instrument detection limit was deter-mined for each of the calibration components and forthe sum of the components because the detectionlimit will vary depending on the composition of thesample. The lowest calibration point was not within2 to 5 times the estimated detection limit as specified

by 40 CFR Part 136, Appendix B. Precision for fixedloop injections was very high resulting in a minimumdetection limit range (on a per compound basis) of100 to 200 :g/m3. FGC instrument detection limitscan be as high as 1400 :g/m3 (0.6 ppm) for the sumof the calibration standard components due to thechromatographic data system imprecision integratingthe broad peaks for C6 and C7 hydrocarbons.

Table 5. FGC Detection Limits.

CompoundIDL

(:g/m3)Std.

DeviationMethane 106 33.8Ethane 106 33.9n-Propane 167 53.4n-Butane 219 69.8n-Pentane 270 86.1n-Hexane 460 147n-Heptane 1112 353Total 1440 459


16

Procedures to Evaluate XAD-2 Prepa-ration and BlankingPrior to sampling, the sampling train and samplingmedia must be prepared, cleaned and blanked. Al-though some forms of “precleaned” resin are com-mercially available, all XAD-2 used for TCO andGRAV analysis must be analyzed before use toensure the extractable background of semivolatile andnonvolatile organic materials meets the appropriatequality requirements. Many unexpectedly high TCOand GRAV field sample results originate from poorpreparation and cleaning of sampling train or XAD-2sampling media. The experimental procedures pro-vided in this section demonstrate that XAD-2 can becleaned to meet quality control requirements for TCOand GRAV analysis.

Experiments were performed to evaluate the ability toclean XAD-2 to acceptable levels for use as a solidsorbent for TOE measurements and to establish thequality control requirements for properly cleanedXAD-2 sampling media. The cleaning requirements,including acceptable blank levels for TCO andGRAV determination, are included in this section.Untreated XAD-2 is available from the manufacturer,Supelco, Inc.; precleaned XAD-2 is available fromvarious commercial vendors. All XAD-2 used forTCO and GRAV analysis, recleaned just prior to useor not, must be checked for TCO and GRAV blanklevels. The quality control check for XAD-2 cleanli-ness requires extracting a portion of the sorbentapproximately equal to the quantity that will be usedto collect samples (typically 20 to 40 g). If TCO andGRAV blank levels do not meet the method qualitycontrol requirements, the XAD-2 should be re-cleaned. XAD-2 should be prepared within 2 weeksof the sampling episode and can be stored at roomtemperature in a clean glass bottle closed by a Teflonlined cap. Refrigerated storage is acceptable and mayretard increases in blank contamination.

In the experimental work described here, TCOanalysis was performed on portions of XAD-2sorbent media cleaned according to the proceduresdescribed in Section 3. XAD-2 sorbent was thenchecked for residual TCO and GRAV. Two lots of

approximately 1000 g of XAD-2 were cleaned. Onelot of XAD-2 was untreated (raw) resin directly fromthe manufacturer. A second lot was prepared usingrecycled XAD-2 that had been cleaned and stored dryin a clean glass jar with Teflon lined screw cap forover 6 months. Each lot of XAD-2 was extracted anddried as it would be for a source sampling episode.

Two (2) 40-g portions of XAD-2 from each lot wereextracted with pesticide grade methylene chloride ina Soxhlet extractor to determine the residual TCOand GRAV in the cleaned resin. TCO and GRAVwere determined for both lots of XAD-2. Blankaliquots were concentrated using a 3-ball Snydercolumn. Final concentrates were never taken below3.0 mL. Final sample volume used for TCO andGRAV analysis was 5 mL. The TCO and GRAVanalysis results from these two lots of XAD-2 areshown in Table 6.

Table 6. XAD-2 Blank Results.

LotDescriptionTCO (:g/g)

GRAV (:g/g)

New XAD-2 0.975 5.94New XAD-2 (Duplicate) NAa 5.62Used XAD-2 0.985 6.56Used XAD-2 (Duplicate) NA NAaNA = not available.

A second issue associated with residual organicmaterial in clean XAD-2 involves the effect ofpreparing XAD-2 extracts using EPA SW-846Method 35425 separatory funnel extraction proce-dures. The question investigated was whether prepar-ing methylene chloride extracts using Method 3542increases, decreases, or has no effect on the back-ground organic material in the clean resin. Therefore,two sets of XAD-2 blank extracts were prepared. Thefirst set was extracted with methylene chloride anddried by filtration through anhydrous sodium sulfate.The second set of extracts was processed throughSW-846 Method 3542 separatory funnel extractionprocedures. The results of these experiments areshown in Table 7. The practical detection limit forGRAV is 6.6 :g/gram XAD-2 based on a balance


17

Table 7. XAD-2 GRAV Blanks.

Sample Description mg/mLa mg GRAV/40 g XAD-2

:g GRAV/gm XAD-2

Average :g GRAV/gm XAD-2

Recycled XAD, Rep 1 without Method 3542 preparation 0.090 0.45 11.6.6

Recycled XAD, Rep 2 without Method 3542 preparation 0.015 0.08 2.0New XAD, Rep1 without Method 3542 preparation 0.025 0.12 3.0

5.9New XAD, Rep2 without Method 3542 preparation 0.070 0.35 8.8Recycled XAD, after Method 3542 Preparation Rep 1 0.045 0.22 5.5

2.4Recycled XAD, after Method 3542 Preparation, Rep 2 0.005 0.02 0.5Recycled XAD, after Method 3542 Preparation, Rep 3 0.010 0.05 1.2New XAD, after Method 3542 Preparation, Rep 1 0.015 0.08 2.0

2.7New XAD, after Method 3542 Preparation, Rep 2 0.025 0.12 3.0New XAD, after Method 3542 Preparation, Rep 3 0.025 0.12 3.0a milligrams GRAV per milliliter extract. Extracts were taken to a final volume of 5 mL; 1-mL aliquot used to perform GRAV determination.

sensitivity of 10 :g. Results in Table 7 have beenreported using 0.01 mg as the lower limit of weightfor a 10: balance. Using Method 3542 provides anadded step that reduces the blank GRAV componentof the XAD-2 sorbent material and is more represen-tative of the blank contribution to SW-846 Method0010 samples prepared using SW-846 Method 3542.

Procedures for Evaluating the Artifactsand Interferences with GRAV AnalysisArtifacts and interferences in GRAV measurementshave been reported by several investigators,7 produc-tion of GRAV artifacts from inorganic carryoverduring sample preparation is one of the most com-monly reported concerns. Common interferentsinclude

C Fine particles, which may be collected duringsampling of stationary source emissions ormay be due to XAD-2 fragments;

C Methanol, collected during sampling or aresidual of the solvents used in the field torinse the sampling train components;

C Water, used in the sampling train or collectedduring sampling because of the moisturecontent of the stationary source; and

C Inorganic salts collected during sampling.

These materials must be removed from sampleextracts prior to sample concentration and TCO andGRAV analysis. Improper filtering of the sampleextracts can result in GRAV analyses biased high.Inadequate removal of methanol and/or water resultsin loss of TCO material. Inadequate removal ofmethanol and/or water also causes a positive bias inGRAV results due to carryover of inorganic salts.Inorganic salts can also be extracted from filtersamples by methylene chloride. Inorganic salts mustbe removed from the sampling train extracts prior toconcentration to avoid a positive bias in GRAV.

Methanol and water must also be removed from theorganic extracts of the Method 0010 samples prior toany concentration step so that the only solvent pres-ent during evaporative concentration is methylenechloride (BP 49 °C). The presence of water and/ormethanol in the final extract will result in a higherboiling solvent during the sample concentration step.This higher boiling mixture will cause a loss ofsemivolatile organic material in the TCO boilingpoint range.


18

Experiments were designed to investigate these issuesas well as to determine if modifications to EPA SW-846 Method 3542 would mitigate the commonly re-ported interferences to the TCO and GRAV analyses.

Authentic fly ash samples from a municipal wasteincinerator and from a cement kiln were used torepresent a typical field sample. Environmental flyash and cement kiln dust were extracted both individ-ually and in a 50:50 mixture. Mixtures of 10 inor-ganic salts as shown in Table 8 were also prepared byweighing equal portions of each salt into a highdensity linear polyethylene container and mixingtogether thoroughly. Experimental work was per-formed using recovery solvents specified in EPASW-846 Method 0010 and extraction solvents speci-fied in EPA Method 3542. The solid fly ash andsynthetic inorganic mixture were extracted separatelywith several solvents typical of source sample recov-ery to determine whether inorganic interferenceoccurred in standard sample preparation proceduresand whether separatory funnel extraction followed by0.45 :m filtering mitigated those interferences.

Table 8. Inorganic Salts Mixture Used for GRAVInterferents Analysis.

Aluminum ChlorideCalcium ChlorideCalcium Chloride DihydrateCalcium Sulfate HemihydrateCalcium Sulfate DihydrateFerric ChlorideIron(II) Sulfate HeptahydrateLead (II) ChloridePotassium ChloridePotassium SulfateSodium NitrateZinc ChlorideZinc Sulfate

Fine Particulate Filtration EvaluationCement kiln dust was extracted with methylenechloride for 16 hours in a Soxhlet extractor. Two

procedures were performed on the sample extract.First, the sample was filtered through 1 g of anhy-drous sodium sulfate supported by a glass wool plugas specified in EPA Method 3542. The resultingliquid filtrate was concentrated to 5 mL and analyzedfor nonvolatile mass using the GRAV technique. Ina second procedure the glass wool plug was replacedby a cellulose filter that was folded and placed intothe glass filtration funnel. One gram of anhydroussodium sulfate was added to the filter paper in thefunnel, and the sample extract was filtered throughthis apparatus. The results of glass wool plug versuscellulose filter filtration, shown in Table 9, indicatethere is no difference between the two approaches toremove fine particulate from methylene chlorideparticulate extracts.

Table 9. Filtration Simulation, Glass Wool versusCellulose Filtration.

SampleDescriptiona

Glass Wool :g/gram par-

ticulate

CelluloseFilter

:g/gram par-ticulate

Sample 1 120 120Sample 2 185 210a Cement kiln dust methylene chloride extract

Filter Extract Inorganic Interference Evalua-tionMethylene chloride was used to extract particulatematerial and a mixture of inorganic salts to testwhether samples prepared using SW-846 Method0010 contained materials that interfere with theGRAV methodology. Potential interferents includethe presence of dissolved solids or fine particulates.The purpose of extracting real and synthetic particu-late material was to determine whether inorganic saltscould be extracted with methylene chloride andproduce an interference or artifact in the GRAVanalysis procedure.

The inorganic salt mixture was extracted in a Soxhletextractor using 100% methylene chloride for 16hours. The mixture of inorganic salts was extracted in


19

duplicate. Methylene chloride extraction was fol-lowed by drying with anhydrous sodium sulfate,filtration through cellulose filter media, and KudernaDanish concentration to 5 mL. Replicate GRAVanalysis was performed on each 5-mL extract. Theresults of these analyses are shown in Table 10,where GRAV results as high as 1900 :g/gram of saltmixture are observed. A separate set of extracts of theinorganic salt mixture was also prepared. Water wasadded to this second set of methylene chloride ex-tracts and extracted using the separatory funnelliquid/liquid extraction procedures described in SW-846 Method 3542. These extracts were preparedfollowing Method 3542, dried by filtration throughanhydrous sodium sulfate, filtered using a 0.45 :mTeflon syringe filter, and concentrated to 5 mL.Treatment of these samples using the EPA Method3542 separatory funnel liquid/liquid extraction and0.45 :m filtering resulted in a significant decrease ofthe inorganic interferences. The results of the saltmixture extraction and Method 3542 preparation areshown in Table 10. Results from the extraction of thesalt mixture show that interference with the GRAVanalysis is possible if inorganic salts are present insource emission samples and that separatory funnelliquid/liquid extraction and 0.45 :m filtering removesmost of the dissolved inorganic interference.

Table 10. Filter Extraction Simulation, MethyleneChloride Extracts.

Sample Description

GRAV inExtract

:g/gm solid

GRAV in Ex-tract after

Method-3542Cleanup

Salts Mixture 1962 309Salts Soxhlet Duplicate 1650 368Cement Kiln Dust 110 175Cement Kiln Dust,Duplicate

215 220

Municipal Waste FlyAsh (Extract 1)

190 200

A similar treatment of fly ash and cement kiln dust(Table 10) indicates that organic GRAV material is

present on the real fly ash and is not affected by theseparatory funnel liquid/liquid extraction and 0.45:m filtering cleanup.

Probe Wash Inorganic Interference Evalua-tionTo evaluate the potential inorganic interference fromMethod 0010 probe washes, the mixture of inorganicsalts was added to a solution of methylene chloridesaturated with methanol. The mixture contained 20%methanol in methylene chloride. Five (5) grams ofsalt mixture were added to the methanol/methylenechloride solvent, thoroughly mixed and allowed tostand for 30 minutes. The same treatment was per-formed on a mixture of cement kiln dust (2.5 g) andmunicipal waste combustor fly ash (2.5 g).

Soluble salts and organic material were recovered byfiltering the supernatant liquid from these extracts.GRAV analysis was performed on the soluble frac-tion. The results are shown in Table 11. Sampleswere further processed using SW-846 Method 3542separatory funnel liquid/liquid extraction and 0.45:m filtering. The results of the GRAV analysis of theMethod 3542 preparations are also shown in Table11. The GRAV results from methanol/methylenechloride extracts of cement kiln dust and municipalwaste combustor fly ash were approximately 50 timeshigher in mass than the comparable methylenechloride sample extracts. Greater than 90% of thepotential interference was removed by processing thesamples with the separatory funnel liquid/liquidextraction and 0.45 :m filtering.

Table 11. Probe Rinse Simulation, Meth-anol/Methylene Chloride Extracts.

Sample Description

GRAV inExtract

:g/gm solid

GRAV in Ex-tract after

Method 3542Cleanup

Mixed Salts 584,400 201650/50 Mixed MWCAsh/Cement Kiln Dust

10,900 100


20


21

Section 5Quality Control Procedures

QC results for TOE measurements are summarized inthis section.

QC for Volatile Organic Analysis byFGCQC for FGC analysis is performed during calibrationand daily QC check sample analysis. QA/QC require-ments for FGC method evaluation are shown in Table12.

XAD-2 QA/QCAnalytical interferences or contaminants appear inthe resin after storage. These contaminants may causethe cleaned resin to fail the QC requirements for themethod used in sample analysis. Contaminantsoriginate from both external contamination or oxida-tion and from internal “bleeding” of entrained chemi-cals from very small or inaccessible pores in theresin. Subsequent recleaning and reuse reduces the

internal contributions to blank during storage. Conse-quently, cleaned XAD-2 has a usable shelf life of 1month after cleaning unless the sorbent is refriger-ated.

Contaminant levels may also increase if XAD-2 isexposed to high concentrations of oxidizing agentssuch as ozone or oxides of nitrogen during sampling.In an oxidizing environment, oxidation or decomposi-tion products of XAD-2 such as naphthalene, benzoicacid, benzaldehyde, aromatic esters, carboxylic acids,and aldehydes will be observed. Sufficiently highlevels of NOX (mole percent levels) can cause de-struction of the resin itself.

Cleaned XAD-2 resin was checked for blank contam-ination by extracting a quantity of resin equivalent tothe amount to be used during sampling (typically40 g). The resin was prepared and analyzed using the

Table 12. Field GC Analysis QC Requirements.

Quality Indicator RequirementsPeak Resolution (R) R = 1.252.Calibration Materials Certified gas cylinder(s) containing methane, ethane, propane, butane,

pentane, hexane, and heptane.Calibration Curve Three concentrations that bracket the sample analysis range.

Correlation coefficient of 0.995.Single calibration measurements should agree within 20% of the averagecalibration curve or a mean response factor.

Sensitivity 1500 µg/dry standard cubic meter (DSCM).Precision ±15% relative standard deviation on replicate analysis.Bias ±10% relative standard deviation on daily QC analyses. Fresh QC check

samples are prepared if analysis fails QC check requirements. If subsequentanalysis results also fail QC requirements, instrument is recalibrated.


22

Table 14. QC Requirements for Total Chromatographable Organics.

Quality Indicator RequirementsCompound Resolution separation (" ) = 1.25.Calibration Curve Three concentrations that bracket the sample analysis range.

Correlation coefficient of 0.995.No single calibration point deviation more than 20% from the averagecalibration curve.

Sensitivity 5 :g/mL in solution.Precision ±15% relative standard deviation on replicate analysis.Bias ±10% relative standard deviation on daily QC analyses. Fresh QC check

samples are prepared if analysis fails QC check requirements. If subsequentanalysis results also fail QC requirements, instrument is recalibrated.

Completeness 100% of the aliquots are reanalyzed if analysis calibration check results do notmeet quality specifications.

Retention Time ±5% relative standard deviation from the mean retention time for eachcompound.

same volumes of solvent and preparation proceduresthat are used for field samples following the proce-dures in EPA SW-846 Method 3542 for Method 0010samples. Extracts were analyzed for TCO and GRAVand must meet the QC criteria in Table 13 in order forthe XAD-2 to be acceptable for sampling. If theextracted resin fails to meet the acceptance criteria,the resin should be recleaned by sequential Soxhletextractions (once each) with methanol and methylenechloride. A sample of resin failing after a recleaningshould be discarded, and no further attempts made toclean that batch.

Table 13. QC Guidelines for XAD-2 ResinPreparation.

Analysis

MaximumBlank (per

gram of Resin)

XAD-2(used in thisevaluation)

TCO 1 :g/g resin 0.98 :g/g resinGRAV 10 :g/g resin 5.9 to 6.4 :/g

QC for Total ChromatographableOrganicsQuality control for TCO analysis by GC/FID isperformed during calibration and daily QC check

sample analysis. QA/QC requirements and perfor-mance experienced during TCO method evaluationare shown in Table 14. All QA/QC for TCO analysisis performed external to field sample analysis.

QC Requirements for GRAVThe predominant interferences for GRAV are incom-plete cleaning of XAD-2, airborne dust depositedduring weighing procedures, and inadequate controlof environmental conditions in weighing facilities.Blank weighing pans without solvent or sample werecarried through the evaporation and drying process asa quality control check for each set of samples.Sample weights were not corrected for blank weigh-ing pan mass gain. Solvent blank samples consistingof concentrated reagent solvent should be analyzed induplicate for each batch of samples. GRAV resultswere not corrected for solvent blanks. Therefore, theGRAV results represent a worst case for possibleblank contamination.

The QC requirements for GRAV include calibrationof the analytical balance, use of Class A volumetricglassware, duplicate analysis of each sample, andweighing samples to constant weight ±10 :g. QCrequirements for GRAV analysis of volatile com-pounds are shown in Table 15. Performance targets


23

have been established from experimental laboratorydata.6

Inorganic salts and contamination of samples bymicrofragments of XAD-2 and other fine particulatematter can cause artifacts or interference in GRAVanalyses if the procedures described in this guidancedocument are not followed. The use of Method 3542with the additional procedures described in Section 4to prepare samples collected from Method 0010 airsamples reduces the contamination. Either filtrationwith prerinsed cellulose filter media (Whatman #1filter media or equivalent) and drying with sodiumsulfate or filtration through anhydrous sodium sulfatesupported by a glass wool plug followed by 0.45 µmfiltering is effective at removing fine particle artifactsthat interfere with GRAV analysis.

The following steps are crucial to quality control forGRAV analysis:

C Use high quality reagents for performingprocedures (extractions, rinses, etc.) “Ultra-

pure” reagents are recommended.C Assure that all glassware and field and labo-

ratory equipment have been cleaned thor-oughly with high quality reagents. Cover theweighing pan containing GRAV analysisaliquot for drying by building a tent withaluminum foil, shiny side out.

C Allow solvent in GRAV pans to evaporate todryness before placing GRAV pans in adesiccator for final drying to constant weight.

C Run control pans: dry pan blank (dust blank)and solvent blank. Blank weighing panswithout solvent or sample should be carriedthrough the evaporation and drying process asa quality control check for each set of sam-ples. Solvent blank samples consisting ofconcentrated reagent solvent should be ana-lyzed in duplicate for each batch of samples.Sample weights should be corrected for blankweighing pan mass gain using the dust blank.

C Check balance calibration prior to eachweighing.

Table 15. QC Requirements for GRAV Analysis of Volatile Compounds.

Quality Indicator RequirementsAnalytical Balance Sensitivity ± 0.01 mg (±10 :g).Analytical Balance Calibration Annually by NIST Traceable Standards.Analytical Balance Calibration Checks Daily during analysis periods using NIST Class S weights.Precision ±15% relative standard deviation on replicate analysis or ±15 µg,

whichever is greater.Bias ±5% relative standard deviation on daily QC check. If bias criteria

are failed, analytical balance is recalibrated.Completeness 100%; aliquots are reanalyzed if analysis calibration check results

do not meet quality specifications.Blank GRAV Pan <50 :gReagent Blank <60 :g

24

Section 6References

1. U.S. EPA, Risk Burn Guidance for Hazardous Waste Combustion Facilities, EPA530-R-01-001. Officeof Solid Waste, Washington, DC, July 2001.

2.3. U.S. EPA, Guidance for Total Organics, EPA600-R-96-036 (NTIS PB97-118533). National Exposure

Research Laboratory, Research Triangle Park, NC, November 1996.

4. U.S. EPA, SW-846 Method 0040, “Sampling of Principal Organic Hazardous Constituents fromCombustion Sources Using Tedlar® Bags”. http://www.epa.gov/epaoswer/hazwaste/test/pdfs/0040.pdf(Accessed October 2004)

5. U.S. EPA, SW-846 Method 0010, “Modified Method 5 Sampling Train”.http://www.epa.gov/epaoswer/hazwaste/test/pdfs/0010.pdf (Accessed October 2004)

6. U.S. EPA, SW-846 Method 3542, “Extraction of Semivolatile Analytes Collected Using Method 0010(Modified Method 5 Sampling Train)”.http://www.epa.gov/epaoswer/hazwaste/test/pdfs/3542.pdf (Accessed October 2004)

7. U.S. EPA, IERL-RTP Procedures Manual: Level 1 Environmental Assessment (Second Edition). EPA-600/7-78-201 (NTIS PB-293 795), October 1978.

8. Public comments on Guidance on Collection of Emissions Data to Support Site-Specific Risk Assessmentsat Hazardous Waste Combustion Facilities (EPA 530-D-98-002), as reported in the RCRA Docket (F-1998-GCEA-FFFFF).http://docket.epa.gov/edkpub/do/EDKStaffCollectionDetailView?objectId=0b0007d48001eee6 (AccessedOctober 2004)

http://www.epa.gov/epaoswer/hazwaste/test/pdfs/0040.pdf



http://docket.epa.gov/edkpub/do/EDKStaffCollectionDetailView?objectId=0b0007d48001eee6

Eastern Research Group, Inc.1600 Perimeter Park DriveMorrisville, NC 27560 68-D7-000, 2C-R212-NALX

TECHNICAL REPORT DATA(Please read Instructions on the reverse before completing)

1. REPORT NO. 2. 3. RECIPIENT'S ACCESSION NO.

EPA-600/R-04/1444. TITLE AND SUBTITLE 5. REPORT DATE

Evaluation of Total Organic Emissions Analysis Methods October 20046. PERFORMING ORGANIZATION CODE

7. AUTHORS 8. PERFORMING ORGANIZATION REPORT NO.

Raymond G. Merrill

9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT NO.

11. CONTRACT/GRANT NO.

12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED

U. S. EPA, Office of Research and DevelopmentAir Pollution Prevention and Control DivisionResearch Triangle Park, North Carolina 27711

Final, 06/00–09/0314. SPONSORING AGENCY CODE

EPA/600/1315. SUPPLEMENTARY NOTES

The EPA Project Officer is Jeffrey V. Ryan, Mail Drop E305-01, phone (919) 541-1437, [email protected]. ABSTRACT

The rationale and supporting experimental data for revising EPA’s 1996 Guidance for Total Organics aresummarized in this document, which reports both the results of research and the investigation ofimprovements to the Total Organic Emissions (TOE) guidance used by EPA to measure recoverableorganic material from stationary source emission samples in support of the Office of Solid Waste Risk Burnrequirements. This document describes the purpose, experimental design, and results from several relatedinvestigations into the performance of specific techniques to determine TOE. Results include analysis ofrecoverable organic material from three specific boiling point/vapor pressure classes: light hydrocarbonsand volatile organics, semivolatile organics, and nonvolatile organic compounds. Improved procedures foranalysis of volatile organics, semivolatile organics, and nonvolatile organic compounds are described. Theexperimental approach used to address weaknesses in TOE analysis procedures is discussed, and theeffect of improvements to these measurement procedures is reported. The experimental results in thisreport support the sampling and analytical guidance necessary to characterize the full range of recoverableorganic material encountered in source emissions.

17. KEY WORDS AND DOCUMENT ANALYSIS

a. DESCRIPTORS b. IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group

Air PollutionEmissionMeasurementExperimental DesignOrganic Compounds

Pollution ControlStationary Sources

13B14G

14B07C

18. DISTRIBUTION STATEMENT 19. SECURITY CLASS (This Report) 21. NO. OF PAGES

Release to Public Unclassified 3220. SECURITY CLASS (This Page) 22. PRICE

Unclassified EPA Form 2220-1 (Rev. 4-77 ) PREVIOUS EDITION IS OBSOLETE forms/admin/techrpt.frm 7/8/99 pad

us epa - evaluation of total organic emissions analysis

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