Treatment of 2,4,6-trinitrotoluene (TNT)-contaminated soil in the Joliet Army Ammunition Plant (JAAP) soil slurry bioreactor (SSBR) eliminated detectable TNT but left trace levels of residual monoamino and diamino metabolites under some reactor operating conditions. The reduction of solvent-extractable bacterial mutagenicity in the TNT-contaminated soil was substantial and was similar to that achieved by static pile composts at the Umatilla Army Depot Activity (UMDA) field demonstration. Aquatic toxicity to Ceriodaphnia dubia from TNT in the leachates of TNT-contaminated soil was eliminated in the leachates of JAAP SSBR product soil. The toxicity of soil product leachates to Ceriodaphnia dubia was reasonably predicted using the specific toxicities of the components detected, weighted by their leachate concentrations. In samples where TNT metabolites were observed in the soil product and its leachates, this method determined that the contribution to predicted toxicity values was dominated by trace amounts of the diamino-metabolites, which are very toxic to ceriodaphnia dubia. When the SSBR operating conditions reduced the concentrations of TNT metabolites in the product soils and their leachates to undetectable concentrations, the main contributors to predicted aquatic toxicity values appeared to be molasses residues, potassium, and bicarbonate. Potassium and bicarbonate are beneficial or benign to the environment, and molasses residues are substantially degraded in the environment. Exotoxins, pathogenic bacteria, inorganic particles, ammonia, and dissolved metals did not appear to be important to soil product toxicity.

Complex matrixes typically cannot be analyzed directly to obtain the selectivity and sensitivity required for most trace analysis applications. To circumvent this problem, solid-phase microextraction (SPME) techniques were used to preconcentrate analytes selectively prior to gas chromatographic/ion trap mass spectrometric analysis. This approach was applied to the trace analysis of explosives and their metabolites in seawater. The choice of SPME sorbent phase was shown to be important especially for the amino metabolites of trinitrotoluene (TNT) and RDX, which were extracted better on polar phases. Although equilibration times were quite lengthy, on the order of 30 min or greater, a sampling time of only 10 min was shown to be sufficient for achieving low part-per-billion (ppb) to part-per-trillion (ppt) detection limits for TNT and the amino metabolites in real seawater samples. While SPME was ideal for rapid screening of explosives in seawater samples, methods for improving the reproducibility and accuracy of quantification are still being investigated.

The half-life of di-isopropyl methylphosphonate (DIMP) in ground water at 10 degrees C was estimated to be 500 years with a 95% confidence interval of 447 to 559 years from measurements of the hydrolysis rates at four temperatures ranging between 70 and 98 degrees C. First-order kinetics were assumed, and the Arrhenius equation was used to extrapolate the hydrolysis rates to the normal temperature of ground water, 10 degrees C. The half-life calculated at this temperature for ASTM Type II water was estimated to be 684 years with a 95% confidence interval of 470 to 995 years, in agreement with a previously published study. The major hydrolysis products detected were isopropyl methylphosphonic acid and methylphosphonic acid. After heating samples for 43 days at 90 degrees C, the molar accounting of the remaining DIMP and its detected hydrolysis products was 15% of the starting material. Inorganic phosphate was not detected. The very slow rate of DIMP hydrolysis in ground water suggests that the unidentified products are not likely to accumulate to any significant extent.

A method is described for determining methylphosphonic acid, ethyl methylphosphonic acid and isopropyl methylphosphonic acid, which are hydrolysis products of the nerve agents VX (S-2-diisopropylaminoethyl O-ethyl methylphosphonothiolate) and GB (sarin, isopropylmethyl phosphonofluoridate). The analytes are extracted from 50 ml groundwater using a solid-phase extraction column packed with 500 mg of silica with a bonded quaternary amine phase, and are eluted and derivatized with methanolic trimethylphenylammonium hydroxide. Separation and quantitation are achieved using a capillary column gas chromatograph equipped with a flame photometric detector operated in its phosphorus-selective mode. Two independent statistically-unbiased procedures were employed to determine the detection limits, which ranged between 3 and 9 μg/l, for the three analytes.

Di-isopropyl methylphosphonate (DIMP) and dimethyl methylphosphonate (DMMP) are byproducts and surrogates for Sarin (GB) and VX; they are readily quantitated at {mu}g/L concentrations in groundwaters. Liter aqueous samples are fortified with triethylphosphate, then passed through a sandwich of 3 preconditioned extraction disks: glass fiber filter to remove particulates, C{sub 18}-based extraction disk to collect DIMP, and carbon-based extraction disk to collect DMMP. The two extraction disks are dried and extracted with MeOH. After the extract is fortified with with diethyl ethylphosphonate internal standard, it is analyzed using a gas chromatograph with a nitrogen- phosphorus detector. When the pump and treat criterion is used, detection limits for DMMP and DIMP are 2 {mu}g/L. Method recovery is 40-50%, based on synthetic groundwaters containing 0.2-50 {mu}g/L of each analyte. DIMP and DMMP are cleanly resolved.

Di-isopropyl methylphosphonate (DIMP) is a byproduct from the manufacture of the nerve agent Sarin. The persistence of DIMP in the ground water is an important question in evaluating the potential environmental impacts of DIMP contamination. The half-life of DIMP in ground water at 10 deg C was estimated to be 500 years with a 95% confidence interval of 447 to 559 years from measurements of the hydrolysis rates at temperatures between 70 to 98 deg C.Extrapolation of the kinetics to 10 deg C used the Arrhenius equation, and calculation of the half-life assumed first-order kinetics. Inorganic phosphate was not detected.

This method employs a ternary gradient generated from (1) a 90:10 water:methanol solution that is 0.015 M in potassium phosphate at pH 5.1; (2) methanol; and (3) acetonitrile to separate fifteen explosives, byproducts, and metabolites of 2,4,6-trinitrotoluene (TNT) on a C-18/anion exchange stationary phase. TNT, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), six reduction metabolites and three oxidation metabolites of TNT have been separated and quantitated in a single chromatographic run. Because of the anion exchange character of the stationary phase, the anionic TNT metabolite 2,4,6-trinitrobenzoic acid also may be separated and quantitated using this method. Quantitation limits generally lower than 1 ppm have been established by a systematic certification procedure. The performance of the mixed mode separation method combined with diode array ultraviolet absorbance detection has been demonstrated with samples derived from both biological (tissues and physiological fluids) and environmental (soil, composts, and leachates) sources.

Propellant nitroesters (diethyleneglycol dinitrate and nitroglycerin) and stabilizer (Akardite II. N-methyl-N,N'-diphenylurea) were determined ill combustible cartridge case (CCC) wall specimens from 120 mm M829 rounds which had been exposed to elevated temperatures in environmental chamber,,; or which were returned from deployment in Southwest Asia. The results suggest that the migration of these components from the propellant is uniform about the circumference of the adhesive joint between the CCC body and adapter but not longitudinally above and below the joint. The accumulation appears to be linear with time of exposure, with both nitroesters migrating at approximately the same rate with similar energies of activation. The conventional sampling and analysis method is compared with it new micro-sampling and analytical method which reduces solvent waste and extraction time, and considerably reduces damage to the rounds from removal of the analytical specimen.

A new solid-phase extraction procedure extracts N-nitrosodimethylamine (NDMA) at part-per-trillion (ng/L) concentrations from aqueous samples using a C18 (reversed-phase) membrane extraction disk layered over a recently introduced carbon-based extraction disk. The reversed-phase disk removes nonpolar water-insoluble neutrals and is set aside; the carbon-based disk is extracted with a small volume of dichloromethane. NDMA is quantified in the organic extract using a gas chromatograph equipped with both a short-path thermal desorber and a chemiluminescent nitrogen detector. The detection limit for the procedure, calculated using two statistically unbiased protocols, is 3 ng of NDMA/L; the analyte recovery is approximately 57%. A related procedure substitutes a standard automatic sampler for the short-path thermal desorber and is suitable for determining NDMA in heavily contaminated (> 300 ng of NDMA/L) aqueous samples. The detection limit for the procedure, calculated in the same manner as above, is 300 ng of NDMA/L, with an analyte recovery of approximately 64%. The detection limits and measured recovery values are comparable to those observed in earlier work, in which a conventional continuous overnight extraction with dichloromethane was used to remove NDMA from the aqueous samples. The newer procedures described herein offer a 50-fold savings in extraction time and a 100-fold reduction in dichloromethane consumed per sample while maintaining the wide range (3-4 orders of magnitude concentrations of NDMA) observed for the original procedures used in tandem. Authentic contaminated groundwaters are extracted using both the conventional and disk-based extraction procedures and analyzed; the observed NDMA concentrations are virtually identical over a target range spanning 100-10000 ng of NDMA/L.

From September 1989 through January of 1990, there was a major effort to sample and analyze the Active Liquid-Low Level Waste (LLLW) tanks at ORNL which include the Melton Valley Storage Tanks (MVST) and the Bethel Valley Evaporator Service Tanks (BVEST). The purpose of this report is to summarize additional analytical data collected from some of the active waste tanks from November 1993 through February 1996. The analytical data for this report was collected for several unrelated projects which had different data requirements. The overall analyte list was similar for these projects and the level of quality assurance was the same for all work reported. the new data includes isotopic ratios for uranium and plutonium and an evaluation of the denature ratios to address criticality concerns. Also, radionuclides not previously measured in these waste tanks, including 99Tc and 237Np, are provided in this report.

Aerated and nonaerated windrow composts of explosives-contaminated sediments at the Umatilla Army Depot Activity (UMDA, Hermiston, OR) were characterized chemically and toxicologically as a function of composting time. The concentrations of explosives in organic solvent extracts of the composts and in the aqueous leachates of the composts, the bacterial mutagenicity of organic solvent extracts from the composts, and the toxicity of aqueous leachates from the composts to Ceriodaphnia dubia all declined rapidly (<15 d) with composting. The nonaerated windrow method of composting was slightly more efficient than was the aerated windrow method for reducing explosives concentrations in the composts (TNT, 99.9%; RDX, >99.7%; HMX, 98.5%) and in their leachates (>99.6%, >98.8%, and >97.5%, respectively). Extractable mutagenicity declined 99.7 and 97.9%, respectively, for strains TA-98 and TA-100 (without S-9 metabolic activation) in the nonaerated compost. The two types (aerated and nonaerated) of windrow composts had about the same level of efficiency in lowering leachable toxicity (by 92% and 87%, based on reductions in C. dubia survival and fecundity, respectively). Thus, windrow composting appeared to be at least as effective as static-pile and mechanically stirred composting evaluated previously. Windrow composting also appeared to be somewhat more effective for HMX transformation.

The sampling and analysis of nine inactive liquid low-level waste (LLLW) tanks at the Oak Ridge National Laboratory (ORNL) are described-tanks W-17, W-18, WC-5, WC-6, WC-8, and WC-11 through WC-14. Samples of the waste tank liquids and sludges were analyzed to determine (1) the major chemical constituents, (2) the principal radionuclides, (3) metals listed on the US Environmental Protection Agency (EPA) Contract Laboratory Program Inorganic Target Analyte List, (4) organic compounds, and (5) some physical properties. The organic chemical characterization consisted of determinations of the EPA Contract Laboratory Program Target Compound List volatile and semivolatile compounds, pesticides, and polychlorinated biphenyis (PCBs). This report provides data (1) to meet requirements under the Federal Facility Agreement (FFA) for the Oak Ridge Reservation to characterize the contents of LLLW tanks which have been removed from service and (2) to support planning for the treatment and disposal of the wastes.

The carcinogen N-nitrosodimethylamine (NDMA) may be quantitated routinely at ultratrace (ng/L) levels in drinking water or contaminated groundwater. The aqueous sample is passed through a preconditioned Empore C18 filter disk to remove neutral nonpolar species and then extracted continuously overnight with highest purity dichloromethane. The latter is then concentrated to 1 mL, and a large aliquot (up to 200 microL) is loaded onto a dual-stage carbon sorbent trap, after which the solvent is removed with ultrapure helium. The concentrated residues are then injected onto a gas chromatographic column using a short-path thermal desorber. NDMA is selectively detected using a chemiluminescent nitrogen detector (CLND) operated in its nitrosamine-selective mode. The reporting limit for this procedure, evaluated using two independent statistically unbiased protocols, is 2 ng of NDMA/L. A related procedure, employing an automatic sampler instead of the short-path thermal desorber, provides convenient analysis of heavily contaminated samples and exhibits a reporting limit (same protocols cited previously) of 110 ng of NDMA/L. When the two methods are used together in a "two-tiered" protocol, NDMA concentrations spanning 4 orders of magnitude (ng/L to microgram/L levels) may be measured routinely. The low-level procedure employing only the short-path thermal desorber was applied successfully to three sources of drinking water, where NDMA concentrations ranged between 2 and 10 ng of NDMA/L. The two-tiered protocol was applied to a series of contaminated groundwaters whose NMDA concentrations ranged between approximately 10-7000 ng of NDMA/L. The results agreed with those obtained from an independent collaborating laboratory, which used a different analytical procedure.

Supercritical fluid extraction (SFE) experiments with composted explosives lagoon soil suggest that recoveries of explosives and metabolites depend more on solvent diffusivity and viscosity than on the solubility of the analytes in the supercritical fluid. Preliminary evidence suggests that SFE recoveries for octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX; a particularly difficult to extract explosive) can equal those for an 18 hr. ultrasonic extraction in acetonitrile. Much work is needed to confirm this observation, particularly to optimize the SFE conditions and improve the reproducibility of the extractions.

Soil contaminated with explosives was supplemented with carbon-14 labelled 2,4,6-trinitrotoluene (C-14-TNT) and was composted in a field static pile composting experiment. After 90 d of composting, the distribution of carbon-14 (C-14) activity in fractions from acetonitrile extraction (''free'' fraction, 1.2% of the initial C-14-activity) and filtration (''insoluble - particle'' fraction, 17.9%), alkaline hydrolysis (''insoluble hydrolyzable'' fraction, 56.8%), and combustion of the residue (''insoluble nonhydrolyzable'' fraction, 4.7%) showed that the bulk of the C-14-activity, and presumably transformed product(s) of the C-14-TNT, accumulated in a nonextractable, but hydrolyzable fraction. Repetitive aqueous leaching of the compost and also ultraviolet light irradiation followed by leaching suggest that the insoluble fraction of transformed TNT should not be released appreciably by the action of acid rain or sunlight.

The initial development is reported for a novel countercurrent filtration/dialysis and solid phase extractant system for the rapid isolation of low molecular weight target compounds from biological media. Except for piperazine (a highly water-soluble drug), recoveries of 50 - 85% were achieved for chemical warfare agent simulants and anthelmintic drugs extracted from meat, grain, or milk. The results suggest the potential for broad applications to complex samples such as environmental media and physiological specimens which traditionally require extensive fractionation prior to analysis.

There is a great need for a rapid and simple means of determining the moisture content in combustible cartridge case (ccc) munitions. Previous studies have demonstrated that accumulation of moisture in ccc rounds, such as the M829, leads to softening of the case wall and weakening of the adhesive joint. Moisture in the ccc can lead to incomplete combustion of the case upon firing the round. Currently, there are no facile methods for measuring the moisture content. A prototype portable meter for non-destructive and rapid estimation of moisture in ccc has been developed. The Munitions Case Moisture Meter Model ORNL-1 demonstrates the feasibility of developing an instrument based on the moisture dependence of dielectric properties, to measure moisture in ccc munitions in storage and in the field. These instruments are simple, inexpensive, lightweight, portable, low-power battery operated, and intrinsically safe. They provide nondestructive, noninvasive, and rapid measurements. Calibration data for the prototype are not available at this time. Therefore, calibration of the meter and the development of a scale reading directly moisture content in munitions rounds could not be completed. These data will be supplied by the US Army from its tests of the meter with actual munitions. However, experimental results on empty cccs in laboratory conditions demonstrate satisfactory performance of the instrument. Additional work is needed to bring the prototype to its optimum usefulness and accuracy for field measurements. This includes: Calibration of the meter scale with full-up munitions; Data and evaluation procedures to adjust the performance of the meter for different environmental conditions such as temperature and humidity; and Studies of the dielectric properties of moist ccc materials, as a function of frequency and temperature, are needed for adjustment of the meter for optimal performance.

Static-pile and mechanically stirred composts of explosives-contaminated soil at the Umatilla Army Depot Activity (UMDA, Umatilla, OR) in a field composting optimization study were characterized chemically and toxicologically. The concentrations of extractable explosives (e.g., 2,4,6-trinitrotoluene) in the composts and their aqueous leachates, the mutagenicity of organic solvent extracts from the composts, and the toxicity of compost aqueous leachates to Ceriodaphnia dubia all decreased considerably with 20 d of composting. After 44 d (mechanical composters) or 90 d (static piles) of composting, the toxicity, mutagenicity, and concentrations of extractable explosives decreased more than 90% in some cases. The composting efficiency was generally inversely proportional to the percentage (v/v) of contaminated soil. Composting in static piles was efficient up to about 20% (v/v) of contaminated soil; composting in the mechanically stirred composters was efficient up to about 25% soil. Mechanical composting was more efficient than composting in static piles. The main conclusion of this study is that composting can effectively remediate explosives-contaminated soil and sediment. However, low levels of explosives and metabolites, bacterial mutagenicity, and leachable toxicity to Ceriodaphnia may remain after composting. The sources of residual toxicity and mutagenicity and the ultimate fate of the explosives are unknown.

Studies were conducted to evaluate lipophilicity as a predictor of sorption for a mixture of organic compounds with high vapor pressures commonly present at hazardous waste sites. Sorption partition coefficients (K(p)) for the mixture of 16 volatile and semivolatile organic compounds were measured on a Captina silt loam (Typic Fragiudult) and a McLaurin sandy loam (Typic Paleudults) using a zero headspace extractor. The experimental K(p) was determined for acrylonitrile, furan, methyl ethyl ketone, tetrahydrofuran, benzene, toluene, p-xylene, chlorobenzene, chloroform, nitrobenzene, 1,2-dichlorobenzene, 1,2,3-trichloropropane, carbon tetrachloride, ethylene dibromide, 1,2,4,5-tetrachlorobenzene, and hexachlorobenzene on each of the two soils. The K(p) values were generally lower in the McLaurin sandy loam, which had a lower organic C content (0.66 +/- 0.04%) than the Captina silt loam (organic C content = 1.49 +/- 0.06%). Sorption was normalized to soil organic C content of the soil by converting K(p) for each compound and soil to K(oc). Weighted regression analyses of K(oc observed) for the compounds in the mixture on K(oc predicted) from the n-octanol/water partition coefficient (K(ow)) for individual compounds yielded a pooled, weighted regression of K(oc observed) = 1.084 + 0.457 K(oc predicted), n = 29, r = 0.88. Statistical analysis indicated that the slope of 0.457 +/- 0.046 (estimated standard error) was significantly less than 1.00, indicating that soil sorption of nonionic organic compounds differed from that predicted for the same individual compounds based on K(ow). The results indicate that predictive equations for sorption of individual organic compounds can be applied to mixtures of volatile and semivolatile organic compounds in soils when log K(ow) are in a range from approximately 1 to 3; however, outside this range a correction factor may be needed.

Thirty-eight inactive liquid low-level radioactive waste tanks are currently managed by the Environmental Restoration Program of Oak Ridge National Laboratory. The contents of these tanks are to be characterized in preparation for future corrective actions and remediation activities as part of compliance with the pending Federal Facility Agreement for the Oak Ridge Reservation. Twenty-nine of these tanks were sampled and analyzed in 1989. Three of the tanks (TH-2, WC-1, and WC-15) were not accessible from the surface and thus were not sampled until 1990. This report presents the sampling and analytical results of that campaign. All three tanks in this report had negligible regulatory organic compounds in the samples that were collected. There were no US Environmental Protection Agency (EPA) Target Compound List (TCL) constituents for volatile organics detected in any of the aqueous samples. The only semivolatile organics detected were 2-chlorophenol (52 {mu}g/L) in tank TH-2 and dichloroethane (14--15 {mu}g/L) and diethyl either (15--17 {mu}g/L) in tank WC-15. A thin oil layer was discovered floating on top of the aqueous contents in tank WC-15. The analysis of the oil layer detected no volatile organics and showed only one EPA TCL constituent, di-n-butylphthalate, at 1900 {mu}g/L. Low levels of Resource Conservation and Recovery Act (RCRA) metals were observed in the samples from tank TH-2, but only the mercury level exceeded the RCRA limit. Samples from tank WC-1 had elevated levels of the RCRA metals barium, chromium, and lead. There were also finely suspended particles in one of the samples from tank WC-1, which was filtered and analyzed separately. This solid fines have levels of transuranium elements {sup 238}Pu and {sup 241}Am high enough to classified as transuranic waste.