to deliver quantities in the 2.0- to 10.0-L range. Recommendations for dilution procedures for
specific on-site methods are presented in Table 6.
RECOMMENDATIONS
1. Current on-site methods for TNT and RDX in soil rely on a short (one- to three-minute) extrac-
tion of soil with either acetone or methanol, prior to determination. Kinetic extraction studies on
highly contaminated soils indicate that extraction of TNT and RDX is incomplete when a three-
minute extraction period is used with either acetone or methanol. In general, however, a concentra-
tion of at least 70% of that attained after an 18-hour extraction is achieved after three minutes of
manual extraction. To account for this incomplete extraction, concentrations determined using this
short extraction and on-site analysis, at or above 7%, should be considered potentially reactive. We
also recommend that protocols that now specify a one- or two-minute extraction period be changed
to require a minimum of three minutes of shaking with the extracting solvent. When it is necessary
to pinpoint concentrations, a kinetic extraction study as detailed in this report can be carried out on
the sample.
2. Current on-site methods for TNT and RDX in soil were developed for detecting low (g/g)
concentrations. For this reason, extracts from highly contaminated soils must be diluted by as much
as 1 to 10,000 in order to obtain concentrations in the linear range of the tests. These dilutions can be
made using a one-step procedure utilizing glass microliter syringes. The resulting precision and
accuracy is adequate for this application.
LITERATURE CITED
Avolio, J., R. DeBono, and P. Radwanski (1995) Ion mobility spectrometry (IMS) field screening
methods and analysis of explosives in contaminated soils. In Proceedings of an International Sympo-
sium, Field Screening Methods for Hazardous Wastes and Toxic Chemicals. Las Vegas, Nevada, 2224 Feb-
ruary 1995, p. 1037.
Erickson, E.D., D.J. Knight, D.J. Burdick, and S.R. Greni (1984) Indicator tubes for the detection of
explosives. Naval Weapons Center, China Lake, California, Report NWC TP 6569.
Heller, C.A., S.R. Greni, and E.D. Erickson (1982) Field detection of 2,4,6-trinitrotoluene in water by
ion-exchange resins. Analytical Chemistry, 54: 286289.
Hutter, L., G. Teaney, and J.W . Stave (1993) A novel field screening system for TNT using EIA. In
Field Screening Methods for Hazardous Wastes and Toxic Chemicals, Proceedings of the 1993 U.S. EPA/
A&WMA International Symposium, vol. 1, p. 472.
Jenkins, T.F. (1990) Development of a simplified field method for the determination of TNT in soil.
USA Cold Regions Research and Engineering Laboratory Special Report 90-38.
Jenkins, T.F. and M.E. Walsh (1991) Field screening method for 2,4-dinitrotoluene in soil. USA Cold
Regions Research and Engineering Laboratory Special Report 91-17.
Jenkins, T.F. and S.M. Golden (1993) Development of an improved confirmation separation suitable
for use with SW846 Method 8330. USA Cold Regions Research and Engineering Laboratory Special
Report 93-14.
Jenkins, T.F., M.E. Walsh, P.W . Schumacher, P.H. Miyares, C.F. Bauer, and C.L. Grant (1989) Liquid
chromatographic method for determination of extractable nitroaromatic and nitramine residues in
soil. Journal of AOAC, 72: 890899.
Jenkins, T.F., C.L. Grant, G.S. Brar, P.G. Thorne, T.A. Ranney, and P.W. Schumacher (1996) Assess-
ment of sampling error associated with the collection and analysis of soil samples at explosives-
contaminated sites. USA Cold Regions Research and Engineering Laboratory Special Report 96-15.
Keuchel, C., L. Weil, and R. Niessner (1992a) Enzyme-linked immunoassay for the determination of
2,4,6-trinitrotoluene and related nitroaromatic compounds. Analytical Sciences, 8: 912.
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