United States Environmental Protection Agency Atmospheric Research and Exposure Assessment Laboratory Research Triangle Park, NC 27711 Research and Development EPA/600/SR-93/101 September 1993 vyEPA Project Summary Field Test of Generic Method for Halogenated Hydrocarbons J.F. McGaughey, J.T. Bursey, R.G. Merrill, Jr. Validation of a method for a particu- lar analyte or group of analytes means that the performance of the sampling and analytical methodology for these analytes has been established and dem- onstrated through field tests at the type of source category of interest: that is, the precision and bias of the method have been established experimentally. In examination of the available method validation data for organic compounds listed in Title III of the Clean Air Act Amendments (CAAA) of 1990, the lack of overall method validation data is readily apparent. In some cases, ana- lytical methods have been validated for a number of analytes, but there is no validation information for the sampling methodology. Full validation for sam- pling and analytical methods, for both field and laboratory operations, is avail- able for fewer than 10 % of the analytes listed in Title III of the CAAA at any source category. Field validation may be performed by side-by-side compari- son of a candidate method to a vali- dated method to establish comparable performance for the same analytes in the same matrix (same source cat- egory). Another procedure for valida- tion of a method is to perform spiking operations in the field so that the pre- cision and bias of the method can be demonstrated from sample collection through analysis. Both dynamic and static procedures for the validation of a method are permitted in EPA's Vali- dation Protocol in Method 301. This Project Summary was developed by EPA's Atmospheric Research and Exposure Assessment Laboratory, Re- search Triangle Park, NC, to announce key findings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction The United States Environmental Pro- tection Agency (EPA), under the authority of Title III of the Clean Air Act Amend- ments (CAAA) of 1990, requires the iden- tification and/or validation of sampling and analytical methods for the halogenated volatile and semivolatile organic com- pounds which are listed (Table 1 and Table 2). The candidate methods for testing the volatile organic compounds are VOST (SW-846 Sampling Method 0030 and SW- 846 Analytical Methods 5040 or 5041), and for testing the semivolatile organic compounds, SemiVOST (SW-846 Sam- pling Method 0010 and SW-846 Analytical Method 8270) is used. The VOST and SemiVOST methods were first evaluated in a laboratory environment, and dynamic spiking procedures were also developed and evaluated. The results of the labora- tory study were reported in an earlier docu- ment. After the laboratory evaluation, the next step was to attempt to validate the two candidate test methods at a coal-fired power plant that does not routinely emit high levels of these hazardous air pollut- ants (HAPs). The absence of high levels of the HAPs was determined by analyzing samples collected during a pretest sur- vey. A field test was planned to further verify the analyte spiking methodology in a non-laboratory environment and to as- sess the added effect of sampling a com- 1^ A) Printed on Recycled Paoer ------- bustion matrix (stack gas). Minimizing the source contribution of the HAPs in the sample matrix simplified the evaluation of the results for the effectiveness of the spiking procedures. A source with signifi- cant levels of all the HAPs shown in Tables 1 and 2 could not be located. Results and Discussion Validation of VOST and SemiVOST was accomplished by performing sampling and analysis following the EPA methods ex- cept for the use of a quadruple (QUAD) probe system required by EPA Method 301. Validation procedures for a method include protocols for determining and docu- menting the quality of data generated by that method. The bias (systematic error) and precision (reproducibility of measure- ment) are determined in a statistically valid manner. The procedures for validating a method for a given analyte or set of analytes require introducing known con- centrations of the analyte(s) into the sam- pling train or comparing the candidate method against a validated test method. The bias of the method can be evaluated by determining the recovery of the known quantity of analyte which has been spiked into the sampling train or by comparison of the results obtained by the candidate method to the results obtained by the vali- dated method. In order to determine the precision of the test method, multiple or collocated simultaneous samples are taken and analyzed. If dynamic spiking tech- niques are used, it is essential that the analyte be introduced into the sampling train as near to the end of the probe as possible, and that the analyte be intro- duced continuously for the duration of the sampling operation. Bias may result from analytical interfer- ences, errors in calibration, or inefficien- cies in the collection of the analyte. When the bias of the method is determined for a given analyte, a correction for the bias may be made. The EPA Method 301 al- lows for this correction within a range of 70 to 130%. Bias values outside this range may require the rejection of the candidate method. Precision is the variability in the data that is obtained from the entire measure- ment system (both sampling and analysis) as determined from the multiple or collo- cated sampling trains. Following the EPA Method 301 procedures, two paired sam- pling trains were used to determine the precision of the entire system. Use of QUAD trains with four collocated sam- pling probes allows operation of two spiked trains and two unspiked trains. EPA Method 301 requires that the precision not be greater than 50 % relative stan- dard deviation for the method to be valid. To determine bias and precision in the field, a total of 24 samples using qua- druple collocated sampling trains was col- lected. For quadruple trains, six complete sampling runs constitute the minimum Method 301 requirement. The halogenated compounds listed in the CAAA of 1990 for which method vali- dation is required and for which labora- tory testing has been performed are shown in Tables 1 and 2. Pesticides, polychlori- nated biphenyls, 2,3,7,8-tetrachlorodi- benzo-p-dioxin, and dibenzofurans were excluded from this study, since special- ized methods are available for these analytes Not all of the candidate analytes for the VOST and SemiVOST performed successfully in those methods. Four com- pounds could not be analyzed by the VOST of SemiVOST methods either in the laboratory or in the field: • Bis(chloromethyl) ether, chloromethyl methyl ether, and epichlorohydrin could not be analyzed by the VOST analytical method. Since these com- pounds are water-soluble and react with water, the failure of the VOST analytical methodology was antici- pated. • Chloroacetic acid could not be ana- lyzed in the SemiVOST analytical method because of its unstable and reactive nature. The laboratory evaluation included the following components: • Determination of chromatographic re- tention times for both volatile and semivolatile compounds using gas chromatography/mass spectrometry (GC/MS); • Determination of recoveries from sor- bents for both volatile and semivolatile compounds; • Determination of analytical method de- tection limits for both volatile and semivolatile halogenated organic com- pounds; and • Design, construction, and evaluation of dynamic spiking equipment and techniques for use in the field spiking of volatile and semivolatile haloge- nated organic compounds. The fied validation of the VOST and SemiVOST was accomplished by dynami- cally spiking the trains with the specific halogenated organic compounds while si- multaneously sampling emissions from a combustion source. During each QUAD sampling run, only two of the four sam- pling trains were dynamically spiked; the other two unspiked trains were used to establish the background level of any tar- get compounds in the stack gas. A sam- pling scheme to meet the requirements of method validation was designed statisti- cally to ensure the collection of appropri- ate numbers of samples for each method. Samples were analyzed according to SW- 846 Method 5041 and SW-846 Meth- od 8270, with statistical evaluation of data. Results are summarized in Tables 3 and 4. Based on the work performed in the laboratory and the field evaluation of the VOST and SemiVOST methods, the fol- lowing conclusions may be drawn from the results shown in Tables 3 and 4: • Using the criteria for acceptable per- formance of recovery between 50 and 150 %, with a percent standard de- viation of 50 or less, the VOST meth- odology performed successfully in a coal-fired boiler emission matrix at a nominal concentration of 12 ng/liter for the following compounds: cis-1,3- dichloropropene, trans-1,3-dichloro- propene, trichloroethene, methyl chlo- roform (1,1,1-trichloroethane), carbon tetrachloride, vinyl chloride, 1,1,2-tri- chloroethane, tetrachloroethene, chlo- robenzene, vinylidene chloride (1,1- dichloroethene), chloroform, methyl- ene chloride, ethylene dichloride (1,2- dichloroethane), ethylidene dichloride (1,1-dichloroethane), methyl iodide (iodomethane), propylene dichloride (1,2-dichloropropane), vinyl bromide, methyl bromide (bromomethane), and ethyl chloride (chloroethane). • Using the criteria for acceptable per- formance of recovery between 50 and 150 % with a percent relative stan- dard deviation of 50 or less, the SemiVOST methodology performed successfully in a coal-fired boiler emis- sions matrix at a nominal concentra- tion of 6 |ig/ft3 for the following com- pounds: hexachloroethane, benzyl chloride, hexachlorobutadiene, 1,1,2- trichloroethane, 2,4,5-trichlorophenol, chlorobenzene, dichloroethyl ether, benzotrichloride, bromoform, 1,2,4-tri- chlorobenzene, ethylene dibromide (1,2-dibromoethane), 1,1,2,2-tetra- chloroethane, 1,4-dichlorobenzene, 2- chloroacetophenone, tetrachloro- ethene, and trans-1,3-dichloro- propene. ------- The VOST methodology did not per- form acceptably .under the field con- ditions for methyl chloride (chloro- methane), chloroprene, ethylene di- bromide (1,2-dibromoethane), and al- lyl chloride (3-chloropropene). The SemiVOST methodology did not perform acceptably under the field conditions for 2,4,6-trichlorophenol, cis-1,3-dichloropropene, 1,2-dibromo- 3-chloropropane, hexachlorobenzene, pentachloronitrobenzene, pentachlo- rophenol, hexachlorocyclopentadiene, chlorobenzilate, epichlorohydrin, 3,3'- dichlorobenzidine, and bis(chloro- methyl) ether. Some compounds were tested in both methodologies because they exhib- ited volatility (boiling points) appropri- ate for inclusion in either method. The following compounds performed ac- ceptably in both VOST and Semi- VOST: tetrachloroethene, trans-1,3- dichloropropene, 1,1,2-trichloroethane, and chlorobenzene. Ethylene dibro- mide (1,2-dibromoethane) performed acceptably in the SemiVOST meth- odology, but did not meet recovery criteria for the VOST methodology. cis-1,3-Dichloropropene performed ac- ceptably using the VOST methodol- ogy but did not meet the criteria for successful performance in the SemiVOST methodology. Table 1. Halogenated Compounds for Which Laboratory Testing Has Determined the Applicability of the VOST Method. Compound Boiling point fC) Comments Allyl chloride bis(chloromethyl) ether Carbon tetrachloride Chlorobenzene Chloroform Chloromethyl methyl ether Chloroprene 1 , 3-Dichloropropylene Epichlorohydrin Ethyl chloride Ethylene dibromide Ethylene dichloride Ethylidene dichloride Methyl bromide Methyl chloride Methyl chloroform Methylene chloride Methyl iodide Propylene dichloride Tetrachloroethylene 1, 1,2-Trichloroethane Trichloroethylene Vinyl chloride Vinyl bromide Vinylidene chloride 44-46 106 ' 77 132' 60.5-61.5 55-57 59.4 1 05-106 2 115-177' 123 131-132 ' 83 57 43 -24.2 3 74-76 39.8-40 41-43 95-96 121 ' 110-115' 86.9 -13.43 164 30-32 Acceptable performance in laboratory Decomposes in water; cannot be analyzed Recovery too high in laboratory study Acceptable performance in laboratory Acceptable performance in laboratory Decomposes in water; cannot be analyzed Acceptable performance in laboratory Acceptable performance in laboratory Decomposes in water; cannot be analyzed Acceptable performance in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Recovery unacceptable high in laboratory Erratic and unacceptable n laboratory Recovery too high in laboratory study Recovery too high in laboratory study Acceptable performance in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Above the maximum VOST boiling point of 100°C; Included in the testing because compounds in the range of 100-132°C are frequently tested by the VOST method. Boiling temperature at 730 mm Hg. Below the common lower temperature limit of 30°C usually used for VOST. Boiling temperature at 750 mm Hg. Table 2. Halogenated Compounds for which Laboratory Testing has Determined the Applicability of the SemiVOST Method. Compound Boiling po Comments Benzotrichloride Benzyl chloride bis(Chloromethyl) ether4 Bromoform Chloroacetic acid Chlorobenzene4 2-Chloroacetophenone Chlorobenzilate 1,2-Dibromo-3-chloropropane 219-223 177-181 106 150-151 189 132 244-245 147 196 Acceptable performance in laboratory Acceptable performance in laboratory Unacceptably low recovery in laboratory Acceptable performance in laboratory Cannot be analyzed by SemiVOST method Acceptable performance in laboratory Acceptable performance in laboratory Unacceptably low recovery in laboratory Acceptable performance in laboratory ------- Table 2. Halogenated Compounds for which Laboratory Testing has Determined the Applicability of the SemiVOST Method (continued). Compound Boiling point (°C) Also tested in VOST methodology. Boiling temperature at 740 mm Hg. Boiling temperature at 730 mm Hg. Boiling temperature at 15 mm Hg. Table 3. Results of VOST Field Validation Comments 1 ,4-Dichlorobenzene 3,3'-Dichlorobenzidine Dichloroethyl ether 1 , 3-Dichloropropene Epichlorohydrin ' Ethylene dibromide ' Hexachlorobenzene Hexachlorobutadiene Hexachlorocyclopentadiene Hexachloroethane Pentachloronitrobenzene Pentachlorophenol 1, 1,2,2-Tetrachloroethane Tetrachloroethylene ' 7, 2, 4- Trichlorobenzene 1,1,2-Trichloroethane ' 2,4, 5- Trichlorophenol 2, 4, 6- Trichlorophenol 173 MP=165 6567" 105 106 3 115-117 131-132 323-326 210-220 239 186 328 3095 147 121 214 110-115 248 2 246 Acceptable performance in laboratory Erratic performance in laboratory Acceptable performance in laboratory Unacceptably low recovery in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Unacceptably low recovery in laboratory Acceptable performance in laboratory Erratic performance in laboratory Acceptable performance in laboratory Unacceptably low recovery in laboratory Unacceptably low recovery in laboratory Acceptable performance in laboratory Unacceptably low recovery in laboratory Acceptable performance in laboratory Acceptable performance in laboratory Erratic performance in laboratory Unacceptably low recovery in laboratory Compound Percent recovery Percent RSD Methyl chloride (chloromethane) Ethylidene dichloride (1, 1 -dichloroethane) Chlorobenzene Vinyl chloride Vinylidene chloride (1, 1-dichloroethylene) Chloroform Propylene dichloride (1,2-dichloropropane) Methyl bromide (bromomethane) Ethyl chloride (chloroethane) Methylene chloride Methyl chloroform (1, 1, 1-trichloroethane) Carbon tetrachloride Ethylene dichloride (1,2-dichloroethane) Trichloroethylene cis- 1, 3-Dichloropropene trans - 1 , 3-Dichloropropene 1, 1,2-Trichloroethane Tetrachloroethene Methyl iodide (iodomethane) Allyl chloride (3-chloropropene) Ethylene dichloride (1,2-dibromoethane) Chloroprene Vinyl bromide 937.0 75.7 88.2 110.4 88.0 81.8 67.2 53.7 50.3 77.7 109.6 106.7 76.6 125.5 136.8 134.9 98.0 97.7 72.8 29.9 34.9 40.1 60.7 53.8 13.7* 22. 02 27.32 31.32 14.82 9.6? 20.22 28. T2 27.1* 43. S2 47.2s 33.02 15.62 26. 02 38. 12 22. 12 21.92 37.6 19.5 31.6 22.4 34.32 1 Chloromethyl methyl ether, bis(chloromethyl) ether, and epichlorohydrin could not be analyzed by the VOST methodology. 2 Acceptable performance by the analyte in the VOST method, using acceptability criteria of 50-150% recovery, with Percent Relative Standard Deviation of 50 or less. ------- Table 4. Results of SemiVOST Field Validation Compound Percent recovery Percent RSD bis(Chloromethyl) ether Epichlorohydrin cis- 1, 3-Dichloropropene trans- 1 , 3-Dichloropropene 1, 1,2-Trichloroethane 1 ,2-Dibromoethane Tetrachloroethene Chlorobenzene Bromoform 1, 1,2,2-Tetrachloroethane Dichloroethyl ether 1 ,4-dichlorobenzene Benzyl chloride Hexachloroethane 1 , 2-Dibromo-3-chloropropane 1,2,4- Trichlorobenzene Hexachlorobutadiene Benzotrichloride 2- Chloroace tophenone Hexachlorocyclopentadiene 2,4, 6- Trichlorophenol 2,4, 5- Trichlorophenol Hexachlorobenzene Pentachlorophenol Pentachloronitrobenzene Chlorobenzilate 3, 3 '-Dichlorobenzidine 0.0 6.0 49.1 52.0 56.4 58.9 53.2 63.3 59.8 64.1 60.9 56.1 60.1 74.0 44.8 59.5 65.4 60.1 56.0 42.3 49.8 62.7 44.6 42.4 43.4 40.7 4.4 128 1 37.5 352s 37 T2 369* 372* 35 12 37 62 35. 32 34.7s 352s 36 S2 369s 360 35 T2 43. 12 36 S2 40 T2 61 8 470 432* 339 41 5 379 506 1649 Chloroacetic acid could not be analyzed by the SemiVOST methodology. Acceptable performance by the analyte in the SemiVOST method, using acceptability criteria of 50-150% recovery, with Percent Relative Standard Deviation of 50 or less. . GOVERNMENT PRINTING OFFICE: 1993 - 750-071/80076 ------- ------- ------- J.F. McGaughey, J.T. Bursey, and R.G. Merrill, Jr., are with Radian Corporation, Research Triangle Park, NC 27709. Merrill D. Jackson is the EPA Project Officer (see below). The complete report, entitled "Field Test of a Generic Method for Halogenated Hydrocarbons," (Order No. PB93-212181AS; Cost: $36.50, subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Atmospheric Research and Exposure Assessment Laboratory U.S. Environmental Protection Agency Research Triangle Park, NC 27711 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati, OH 45268 Official Business Penalty for Private Use $300 BULK RATE POSTAGE & FEES PAID EPA PERMIT NO. G-35 EPA/600/SR-93/101 ------- |