Analysis of condensates from wood smoke. Components derived from

heavy fraction light fraction. Pb suspended in acetone bulk filter remaining. A. bulk filter remaining. 1.0 M MgCl, extrctn. 0.5 M NH40Ac extrctn. 4 M...
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Envkon. Scl. Technol. MQl,25, 1133-1137

Table IV. Analysis of Pb on Air Filter air filter size filter weight total P b acetone rinsing bulk filter remaining dried residue containing P b density separation of dried residue heavy fraction light fraction P b analysis by AAS heavy fraction light fraction P b suspended in acetone bulk filter remaining selective extraction A. bulk filter remaining 1.0 M MgCl, extrctn 0.5 M NH40Ac extrctn 4 M HNO, extrctn B. heavy fraction 1.0 M MgClz extrctn 0.5 M NH40Ac extrctn 4 M HNO, extrctn C. light fraction 1.0 M MgCl, extrctn 0.5 M NH40Ac extrctn 4 M HNO, extrctn FTIR analysis heavy fraction light fraction X-ray diffraction analysis heavy fraction light fraction

8 in. X 10 in. 2.6 g 2.3% 60 mg 2.4 g 155 mg 72.3 mg 77.7 mg

dicated only PbS0,. No indication of PbS04 in the IR spectrum may be due to the low concentration in the sample. By summing the selective extraction results of each fraction, the original filter would have had the lead present as 41.2% PbSO,, 10.1% PbO, and 48.8% PbS. Selective extraction with density separation can be used to determine the lead in air particles near a smelter. The next phase would be to expand the number of the lead species, determine the species from the various sources around a lead smelter, and correlate that to the lead species on the air filter.

Literature Cited

36.9 mg 4.7 mg 0.6 mg 15.6 mg

(1) Emmerich, W. E.; Lund, L. J.; Page, A. L.; Chang, A. C. J . Enuiron. Qual. 1982, 11, 178-181. (2) Chang, A. C.; Page, A. L.; Warneke, J. E.; Grgurevic, E. J . Enuiron. Qual. 1984, 13, 33-37. (3) McLaren, R. G.; Crawford, P. V. J . Soil Sci. 1973,24,172. (4) Stover, R. C.; Sommers, L, E.; Silviera, D. J. J.-Water Pollut. Control Fed. 1976,48, 2165-2175. ( 5 ) Reference deleted in proof. (6) Lake, D. L.;Kirk, P. W. W.; Lester, J. N. J . Enuiron. Qual. 1984, 13, 175. (7) Tessier, A.; Campbell, P. G. C.; Bisson, M. Anal. Chem. 1979,51, 844-850. (8) Calmano, W.; Forstner, U. Sci. Total Enuiron. 1983, 28, 17-90. (9) Guy, R. D.; Chakrabarti, C. L.; McBain, D. C. Water Res. 1978,12, 21-24. (10) Kheboian, C.; Bauer, C. F. Anal. Chem. 1987,59,1417-1423. (11) Tipping, E.; Hetherington, N. B.; Hilton, J.; Thompson, D. W.; Bowles, E.; Hamilton-Taylor, J. Anal. Chem. 1985,57, 1944. (12) Joint Committee on Powder Diffraction Standards, Inorganic Index to the Powder Diffraction File, 1970. (13) O'Connor, T. P.; Kester, D. R. Geochim. Cosmochim. Acta 1975, 39, 1531.

36 % 33% 31% 37 % 1.3% 61% 84 % 0% 16% PbS04, 6.9 mg PbS04 and PbO, no indication PbS04 and PbS, indicated PbSOa, indicated

fraction was 23% PbSO,, 30% PbS and less than 1% PbO. The FTIR found 14% PbSO, and the X-ray diffraction indicated PbS0, and PbS present. The selective extraction of the light fraction gave 7% PbS0, and 1% PbS, the FTIR did not show PbS04, and the X-ray diffraction in-

Received for review February 15, 1990. Revised manuscript received December 20, 1990. Accepted January 23, 1991.

Analysis of Condensates from Wood Smoke: Components Derived from Polysaccharides and Lignins Leslie A. Edye and Geoffrey N. Richards" Wood Chemistry Laboratory, University of Montana, Missoula, Montana 598 12

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A feasibility study has been carried out of the analysis of total condensate (at -50 "C)of smoke from smoldering combustion of wood. All of the phenol and furan components in the aqueous condensate were extracted into methylene chloride and the extract was analyzed by GC/MS. The same homologues of guaiacol and syringol derived from lignin were detected as have been described in earlier studies, but in addition, a series of furan derivatives were found. The latter are believed to arise from pyrolysis of polysaccharides. The carboxylic acids in the condensates were analyzed by titration and subsequent GC MS. Acetic acid was the dominant volatile acid found, wit a trace of propanoic, but no significant formic acid.

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Introduction Smoke from wildland fires is of concern because of the potential adverse health effects that may occur to wildland 0013-936X/9110925-1133$02.50/0

firefighters and to other people exposed to the smoke. The consumption of biomass by open burning is known to produce products of incomplete combustion-some of which are known carcinogens and others of which may be classified as strong irritants ( I ) . For example, during the major wildfire episode in the Greater Yellowstone National Park Area of 1988, approximately 1 2 000 medical visits were made by wildland firefighters for respiratory problems (I). The purpose of this work is to develop procedures aimed at giving an overview of the major volatile products of combustion of forest materials. We have initially concentrated on products from smoldering rather than flaming combustion because the former type of smoke is believed to present major health hazards during "mop-up" operations following range or forest fires. Many of the components of smoke are difficult to measure under field conditions, but their release may be proportional to other compounds that can be measured under field conditions.

0 1991 Amerlcan Chemlcal Soclety

Envlron. Scl. Technol., Vol. 25, No. 6,

1991

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If a relation can be established, then it will be much easier to diagnose the substances contained in some classes of wood smoke in the field. This study thus forms part of a program to investigate components of smoke likely to be generated in forest and range fires. Our aim has been to develop an analytical approach that can subsequently be applied to the major gaseous and aerosol emissions from controlled biomass fires in the laboratory (2). Because the emissions from smoldering combustion of wood contain aerosols, but relatively little particulate material, the volatiles have been condensed a t -50 "C without prior filtration and GC/MS analyses conducted on the condensates and on extracts of the condensates. The most recent reports relevant to our analytical methods have originated from the University of North Dakota (3,4 ) and relate to analysis of extracts of soot and of vapor from wood stoves. These reports describe the GC/MS identification of a wide range of homologues of guaiacol and syringol derived from lignin and show that the former series is dominant, especially in emissions from burning softwood. We have confirmed these findings and have also identified a range of furan derivatives, derived from pyrolysis of polysaccharides, in the smoke condensates. The carboxylic acid components of the condensates have also been separately investigated. Experimental Section Smoke Collection. Samples of ponderosa pine (Pinus ponderosa) and cottonwood (Populus trichocarpa) were ground to pass a 2-mm sieve, firmly packed into a ceramic dish (10.5-cm diameter, 1-cm depth), and heated under a radiant heating coil (5 cm above wood surface) inside an inverted glass funnel (32-cm diameter). The lip of the funnel was 0.5 cm above the bench to allow air intake and the neck was connected via a downward sloping Teflon TFE tube (0.9-cm i.d.) to two glass traps in series immersed in a bath at -50 "C. Smoke was drawn through the traps by a water aspirator pump a t 1.66 L/min. Typically, smoldering combustion of a 20-g wood sample took 30-40 min for almost complete conversion to ash, and during this time any occasional flaming was extinguished by temporarily reducing the current to the radiant heating coil. The final products of combustion were a mixture of char and ash remaining in the dish (