Duplicate Method 8330 results by commercial
laboratory analysis were much less precise (RSD
= 19.2%) than those from the colorimetric and
acetone HPLC methods. Apparently any addi-
tional homogenization of samples by the com-
mercial laboratory was inadequate to overcome
the effect of using a much smaller sample size (2
g) for Method 8330. The correlation coefficient for
on-site colorimetric and Method 8330 results was
only 0.945 and the slope of the zero intercept
regression relationship was 0.813. Some decrease
in the correlation coefficient might be expected
due to the relatively large random error associ-
ated with the Method 8330 results. However, the
major reason for the poorer correlation coefficient
for this relationship is that the two sets of analy-
ses were done on different subsamples of soil,
unlike the on-site colorimetric and acetone HPLC
results, which were obtained from the same ac-
etone extract. This is an important observation
since validation of results from on-site methods is
invariably conducted with different subsamples
of soil (splits), and differences observed may be
due to actual differences in the analyte content in
the subsamples analyzed rather than differences
due to the analytical methods.

Mean concentrations for the seven discrete
samples analyzed by the on-site colorimetric
method ranged from 16 mg/kg to 324 mg/kg.
Analysis of variance (ANOVA) indicated that
there was a significant difference among samples
at the 95% level for all three methods of analysis
with F ratios of 257, 478, and 27.1, respectively,
for the on-site colorimetric, acetone HPLC and
Method 8330 (Table 3). The results from ANOVA
were used to partition the error from these three
sets of data into analytical error (S, ) and sam-
pling error (Sg) associated with short-range spa-
tial heterogeneity (Table 3). RSDs due to sam-
pling were much higher than those due to analysis
and were in quite good agreement for the three
sets of data (sampling RSDs ranged from 68.2% to
77.9%). For the on-site colorimetric data, sampling
error was over 11 times the error due to analysis.
These findings are in excellent agreement with
those obtained in our earlier study where the con-
taminants present were TNT, DNT or ammonium
picrate. In that study, four sampling locations
yielded data from the seven discrete samples that
were sufficiently homogeneous to allow partition
of variances into sampling and analytical error,
and the Ss/S, ratio ranged from about 6 to over
22. This similarity is not surprising since HMX,
like TNT, 2,4-DNT and picrate, is a solid at envi-

13

ronmental conditions and was deposited on site
as particles.

Table 3 also includes statistical analyses for the
composite sample. The mean values from the
analysis of the composite are within 10% of the
mean values for the seven discrete samples that
make up the composite for each method. The RSDs
for the on-site colorimetric and acetone HPLC
were 7.3% and 2.8%, respectively. These findings
reinforce our earlier conclusion that preparing a
homogeneous and representative composite for a
set of discrete samples is feasible and does not
require sophisticated equipment or exceptional
effort or time when 20-g subsamples are used for
analysis. The ability to prepare adequate compos-
ites for on-site analysis documented here, and
elsewhere (Jenkins et al. 1996), is particularly im-
portant. Providing adequate characterization of
the mean concentration for even a small geo-
graphical area using discrete samples would re-
quire large numbers of samples and analyses, gen-
erally beyond the financial resources available for
a specific investigation. However, the use of com-
posites and on-site analysis can effectively deal
with this problem.

The much higher RSD for the commercial
Method 8330 results (47.1%) agrees with similar
results for the discrete samples and is likely due
in large part to the 2-g subsample size, which is
inadequate to moderate the remaining heteroge-
neity within the bulk sample. The practice of
scooping a subsample from the top of a sample
bottle, common in many laboratories, may have
exaggerated the heterogeneity problem. Because
segregation of particles can occur due to vibra-
tion during shipping and storage (even for previ-
ously homogenized samples), careful subsampling
requires rehomogenization of the entire sample
prior to subsampling.

Results for characterization
of grid-sized areas for HMX

In the next phase of the study, the site was
divided into sixteen 6- x 6-m square grids be-
tween target tanks C and D, and extending in
front and beyond the target tanks as shown in
Figure 10. Each grid was then divided into 3- x
3-m quadrants that were labeled subgrids A-D;
letter designations were assigned in a clockwise
fashion starting with the upper left quadrant. In-
dividual analyses for surface soil samples obtained
in each subgrid and for grid composites are pre-
sented in Appendix A. A diagram showing an
overview of the HMX concentrations obtained



2:Am-ONT and 4-Am-DNT Concentration (ug/g)

GRID] Subgria Field [Analytical] Lab] Acetone | Acetone
NUMBER Sampling] Rep. | 8330 | HPLC | HPLC
Rep. AcN | 4-Am-DNT |2-Am-DNT
0B rN 2 36 Ea TST
b 49
mean= | _5.3
8 a 22 O73 O87
b 26
mean= | _2.4
c 2 TS 056 o50
b 13
mean= | _1.3
D a 09 045 043
b 09
mean= | 0.9
Comp. a 24 0.84 080
b 25 0.95 0.88
mean= | 25 0.89 0.84
Weans -
‘ABCD -@ 25 13 0.89
ABCD -b 24
ABCD 25
[Depth Samples
BRto4") a 27 1.20 1.09
b 24
mean=
B (4 t06") at 63 3.69 3.34
b 57
mean=
*Presence of amino-DNTs in acetone extract confirmed by GO-ECD.
Other Nitroaromatics Concentration (1.9/6)
GRID] Subgrid__] Field Analytical] Lab] Acetone | Lab
NUMBER Sampling] Rep. |8330AcN| HPLC [8330 AcN
Rep. TNB and DNB
Ds x a os a
b <0.3
mean=
B 2 3 a oF
b <0.3 <0.3
mean=
c 2 03 a <8
b <0.3 <0.3
mean=
D 2 3 a Os
b <03 38
mean=
Comp. a Os a 03
b <03 | trace | <03
mean=
Depth Samples
B(2to4") <03 a 18
<03 1"
64
B (410 6") at <0.3 a 03
b <03 03
mean= 03

*4.1 gig tetryl reported for Lab Method 8330 AcN.
Presence of DNTs in acetone extract confirmed by GC-ECD.

34



DATA FOR GRID C10
Results from Method 8330

TANK] GRID | FIELD] LAB. | [HMX} | [RDX]| [TNT] | [2+ 4 Am DNT] | [TNB + DNB]

NUMBER | dupl. | dup! | ppm | ppm | ppm ppm ppm
c 70 ry a 7 [<0 | os o5 Os
c 10 A b 13, | <1.0 | <03 04 <0.3
c 10 8 a 33 | <t.0 | <03 08 <0.3
c 10 B b 44 | <t0| 03 08 <0.3
c 10 c a 1 | <t.0 | <03 <0.3 <0.3
c 10 c b 24 | <1.0 | <03 <0.3 <0.3
c 10 io} a 13 | <1.0 | <03 <0.3 <0.3
c 10 D b 23 | <1.0 | <03 <0.3 <0.3
c 10 |Comp. a 12 | <1.0 | <03 <0.3 <0.3
c 10 |Comp. cy 14 | <1.0 | <03 03 <0.3

BEAN
c 70 A [meaniab] 15 | <1.0 [03 05 03
c 10 8 |meantab.| 39 | <1.0 |<o.3 08 <0.3
c 10 c |meantab.}| 2 | <1.0 | <0.3 <0.3 <0.3
c 10 BD |meantab.| 1.8 | <1.0 | <0.3 <0.3 <0.3
c 10 |Comp.Jmeantab.| 13 | <1.0 | <0.3 <03 <03
DATA FOR GRID C9

Results from Method 8330

TANK] GRID ]FIELD] LAB. | (HMX]][RDX]| [INT] [2+4AmDNT] | [TNB+ DNB}

NUMBER | dupl. | dup. | ppm | ppm | ppm ppm. ppm
c o ry a <10 | <10 | <0, <3 03
c 9 A b <1.0 | <1.0 | <03 23 <0.3
c 9 B a 38 | <10 | <03 <0.3 <0.3
c 9 B > 37 | <1.0 | <03 <03 <0.3
c 9 c a 14 | <t.0 | <3 <03 <0.3
c 9 c b 17 | <t.0 | <0.3 <0.3 <0.3
c 9 io) a 15 | <1.0 | <03 <0.3 <0.3
c 9 i} b 13 | <1.0 | <03 <0.3 <0.3
c 9 | Comp. a 3.6 | <1.0 | <03 <0.3 <0.3
c 9 |Comp. b 4 | <1.0 | <03 <0.3 <0.3

MEAN

c 9 A |meantab.] <1.0 | <1.0 [0S 23 Os
c 9 B |meantab.| 3.8 | <t.0 |<o.3 <0.3 <0.3
c 9 C |meantab.| 1.6 | <1.0 <o.3 <0.3 <0.3
c 9 D |meantab.| 1.4 | <1.0 |<o.3 <03 <03
c 9 |Comp.|meantab.| 4 | <1.0 |<o.3 <0.3 <03

DATA FOR GRID C7
Results from Method 8330

TANK] GRID_]FIELD] LAB. | [AMX] |(RDX]| [TNT] [2+4AmDNT] | [TNB + DNB]

NUMBER | dupt.| dup! | ppm | ppm | ppm ppm ppm
c 7 ry 3 360 | <1] 10 71 <3
c 7 A b 340 | <1.0| 92 1 <0.3
c 7 8 a 530 | <1.0| 46 34 <0.3
c 7 B ’ 470 | <1.0| 1.3 28 <0.3
c 7 c a 270 | <1.0 | <0.3 1 <0.3
c 7 c b 260 | <1.0 | <0.3 14 <03
c 7 o a 470 | <1.0 | 15 <0.3 <0.3
c 7 D b 510 | <1.0| 17 19 <0.3
c 7 |Comp. a 370 | <t.0| 2 15 <0.3
c 7 | Comp b 390 | <t.0| 6.7 <0.3 <0.3

MEAN

c 7 KR [mean tab.] 350] <1.0] 10 7 <O3
c 7 B |meantab.| 500 | <1.0 | 3.0 3.0 <0.3
c 7 c |meantab.| 265 | <1.0 | <0.3 1 <0.3
c 7 D |meantab.} 490 | <1.0] 16 1.9 <0.3
c 7 |Comp.|meaniab.| 380 | <1.0} 5 15 <0.3

30



TNT Concentration (ug/g)

GRID ‘Subgrid [Analytical Lab jeld ‘Acetone ] DTech
NUMBER Rep. 8330 |Colorimetric] HPLC
Rep. ACN.
7 ry a 08 <a Tor fosto1s
b 14
mean 1.0
8 a 16 2.0 |interference |1.5 to 3.0
b 19 by 2,4-DNT?
mean 1.8
c a 12 15 085 © |0.5t015
b 24
mean 17
cc 1 at 18 22 0.88 <0.5
b 06
mean 12
cc 2 a 10 ot 73 3to4
b 10
mean 1.0
D a 12 36 24 3.0 104.0
b 5.6
mean 8.8
ABCD Comp. a 37 25 14 11.5t03.0
b 24 33 24 1.5 103.0
mean 12 29 1.8
[Means, g
[ABCD -a 39
JABCD -b 27
lasco, 33
lc-cc1 -co2 13 42 3.0
Icc1 - cca 141 56 at

ROX Concentration (19/9)

GRID] Subgrid | Field [Analytical] Lab] Acetone
NUMBER Sampling] Rep. | 8330 HPLC
Rep. AcN
07 * a <0 O17
b <1.0
mean
B a <1.0 1.12
b <1.0
mean
c a <1.0 2.16
b <1.0
mean
cc 1 at <1.0 0.91
b <1.0
mean
cc 2 a <1.0 4.02
b <1.0
mean
D a <1.0 0.34
b <1.0
mean
ABCD a <1.0 WA
Comp
b <1.0 0.56
mean
Z z sce

‘Presence RDX in acetone extract confirmed by GC-ECD.

39

‘TNT in acetone extract confirmed by GC-ECD. Found concentration was 1.7 ug/9.



Colorimetric TNT method

The colorimetric on-site method used for TNT
analysis of acetone soil extracts is commercially
available from EnSys. This is a commercialized
version of the method developed by Jenkins (1990)
and utilizes the Janowsky reaction (eq 2). If TNT
is present in the acetone extracts, reaction with 1
drop of the EnSys color reagent produces a pink
to red color indicative of the presence of the
Janowsky anion of TNT:

CH,
R NO,

NO, Janowsky Reaction (1891)

R = NO, for 2,4,6-TNT
R =H for 2,4-DNT

A 25-mL aliquot of the acetone soil extract is
added to a 25-mL glass cuvette and the initial
absorbance measured with a Hach DR/2000 spec-
trophotometer at 540 nm. A drop of the EnSys
color reagent is then added to the cuvette and
mixed by swirling. The solution is allowed to
stand for one minute and then the absorbance is
again measured at 540 nm. Extracts were diluted
as appropriate, such that absorbances after reac-
tion with the EnSys reagent were less than 1.0.
The concentration of TNT is estimated by sub-
tracting twice the initial absorbance from the final
absorbance and dividing by the response factor
obtained from a TNT standard with a solution
concentration of about 4 mg/L. Doubling the
initial absorbance prior to subtraction takes into
account the increased absorbance caused by reac-
tion of humic organics in the extract with base, as
discussed elsewhere (Jenkins and Walsh 1992).

D TECH immunoassay
for RDX and TNT

The D TECH enzyme immunoassay (EIA)
method used for both RDX and TNT is commer-
cially available from EM Science (Teany and
Hudak 1994, Teany et al. 1995). The components
of this EIA include RDX- and TNT- specific anti-
bodies covalently linked to small latex particles,
which are collected on the membrane of the cup
assembly. A color-developing solution added to
the surface of the cup assembly reveals a color
inversely proportional to the concentration of RDX
or TNT equivalent in the sample. RDX and TNT

i)
a Bybee -

are measured as parts-per-million (mg/kg) in soil
samples, in effective ranges between 0.5 and 5
ppm for TNT and between 0.5 and 6 ppm for
RDX. In the case where results higher than 5 ppm
were obtained for TNT (“Hi” reading), dilution of
the extracts were made by factors of two to four
in order to obtain a result within the effective
range of the test.
Soils were extracted with acetone as described
above and analyzed according to the instructions
provided with the D TECH TNT and
RDX explosives test kits. The same ac-
etone extracts used for the colorimet-
ric on-site methods were used for EIA

é—r @) methods as well. A 1.0-mL aliquot of

clear acetone extract was transferred

into a bottle of buffer solution (bottle 2

in the extraction pack). The prescribed

volumes of the soil extracts were added

to the vials containing enzyme-labeled
RDX or TNT and antibody-coated latex particles.
Those mixtures were allowed to stand for 2 min-
utes for the TNT test and 5 minutes for the RDX
test to allow the explosive molecules to interact
with the antibody binding sites. Negative control
references were processed with each analysis.
Samples and references received identical treat-
ments and both solutions were poured onto the
respective sides (test or reference) of the porous
membrane cup assembly. The conjugate solutions
were allowed to pass through the membranes,
and the membranes were washed and treated with
a color-developing solution. The reference sides
of the cup were used to determine the end-point
of the color development. The time for complete
color development was less than 10 and 15 min-
utes for TNT and RDx, respectively. All of these
manipulations and readings were done at room
temperature. RDX EIA tests were performed only
on the first set of samples, since it was clear that
HMxX was the main contaminant, and cross-
reactivity with RDX EIA test was not sufficient
to serve as a HMX evaluation tool. All samples
were tested with the TNT EIA method.

Results from the test kits were determined with
the DTECHTOR environmental field test meter
(EM Science). This device is a hand-held reflecto-
meter powered with a 9-V plug-in battery. It mea-
sures the amount of light reflected from the
surfaces of the color-developed test and reference
sides of the cup assembly. Readings are in per-
centages, which can then be translated into TNT
or RDX equivalent concentration ranges.



TNT Concentration (ug/9)

RDX Concentration (ug/g)

49

GRD] Subga | — Fiat —Patyioal] Lab] Fate —] Restore] BTeeh c :
woMBeR sampiing | "rep: | 8330 |colorimetic| HPLC yoni | Suber] Fig Paratealy Cap] Accone
Rep. AcN Rep. AcN
i) ry a <03 1? Ott 05 os x z = a
b <03 b <1.0
mean neon
8 2 | os | « | « | os 2
an | O° . e fae]
mean mean
BB 1 a <0.3 1.2 0.17 <0.5 ©
>, | 8 ° "] 3 | ao] *
mean mean
2 2 | a Jos} os | oa | os
ne ° e) 3 fas} @
ar mean
c : a d d 0.5 c a 1.0 a
mean Wt b <1.0
mean
cc 1 2 3 3 d 0.06 0.5 cc 1 a 1.0 on
mean ae
naan
1 |
cc 2 “ 33 17 15 12 to 16 cc 2 a <1.0 a
mean b <1.0
mnean
° 2 | os | « | oa | os
b <03 D a PI a
mean sere
mean
aco 2 [os | a7 | ow | os
Comp. ABCD Comp. a <1.0 5.02
b 1 19 <d <0.5 b “1.0 ‘J
mean 13
_ mean
TNT in acetone extract confirmed by GC-ECD. Found concentration was 15 ug/g. EIS Ee
ROX Concentration (ug/g) Other Nitroaromatics Concentration (ug/g)
GRID ‘Subgrid Field Lab Acetone GRID ‘Subgrid Field [Analytical] Lab | Acetone Tab
NUMBER ‘Sampling 8330 HPLC NUMBER Sampling] Rep. [8330 AcN| HPLC [8330 AcN
Rep. AGN. Rep. TNB and DNB
a a a
> | ao a ase
mean b <0.3
mean
8 2 fac] a
bd <1.0 8 a <0.3 trace <0.3
mean > | 33 $3
mean
BB 1 a <1.0 J
b <1.0 BB 1 a <0.3 trace <0.3
mean 3 | 33 $3
mean
BB 2 a <1.0 |
b <1.0 BB 2 a <0.3 dd <0.3
mein sees 23
mnean
c a <1.0 dd
> | So ° 2 | os | « | os
mean > | as 3
mean
c | 1 | a | to]
b <1.0 cc 1 a <0.3 dd <0.3
mean aes 23
mean
co | 2 J a fo]
b <1.0 cc 2 a 0.3 ad <0.3
mean b <0.3 <0.3
mean
D 2 tao] a
bd <1.0 D a <0.3 <d <0.3
mean > | a3 23
mean
sco Comp 2 | ao | soe
b <1.0 Jd ABCD Comp. a <0.3 dd <03
2 | a3 | 3 | a:
mean mean
ne Pe



2-Am-DNT and 4-Am-DNT Concentration (ug/g)

Other Nitroaromatics Concentration (19/9)

GRID | Subgrid ] Field Analytical] Lab | Acetone | Acetone GRID] Subgrid |] Field JAnalytcal] Lab | Acetone] Lab
NUMBER Sampling} Rep. | 8330 | HPLC | HPLC NUMBER Sampling] Rep. |8330 AcN| HPLC |8330 AcN
Rep. AcN_|4-Am-DNT|2-Am-DNT Rep TNB and DNB | 2,4- and
D2 x a 17 O87 oat 2,6-DNT
b 24 0.73 0.83 B2 x a Os a 08
mean 24 0.70 0.82 b <0.3 a 16
mean
8 a 27 0.83 0.81
b 22 0.78 0.85 B a <0.3 d <0.3
mean 25 0.80 0.83 b <0.3 dd <03
mean
c a 32 0.97 1.08
b 3.9 1.06 115 c a <0.3 trace <0.3
mean 36 1.02 1 b <03 | trace | <03
mean
ce 1 a 1.2 0.33 0.24
b 9 co 1 a <0.3 4 <0.3
mean 14 b <0.3 <0.3
mean
cc 2 a 27 0.97 1.03
b 3.0 cc 2 a <0.3 a 13
mean 29 b <0.3 <0.3
mean
D a 09 0.26 0.28
b 08 0.24 0.31 D a <0.3 a 67
mean 0.9 0.25 0.30 b <0.3 a <0.3
mean
i) 1 a 14 0.30 0.34
b 09 pp 4 a <0.3 a <0.3
mean 1.0 b <0.3 <0.3
mean
i) 2 a 1.0 0.49 0.44
b 18 pp 2 a <0.3 a <0.3
mean 14 b <0.3 23
mean
ABCD Comp. a 24 0.64 0.72
b 20 0.58 0.67 ABCD Comp. a <0.3 4 <0.3
mean 0.61 0.70 b 03 a 24
[Means mean
[ABCO -@ 24 068 O75 5 SRS
Jasco -b 23 0.70 0.78
Jasco 22 069 0.7
c-cct - 25
cca
ect - coz 20 0.65 0.63
ID - pot - 14
D2
pot - Doz 1.2 0.40 0.39

47



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REPORT DOCUMENTATION PAGE

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1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE '3. REPORT TYPE AND DATES COVERED
September 1997

4, TITLE AND SUBTITLE 5. FUNDING NUMBERS
Assessment of Sampling Error Associated with Collection and Analysis

of Soil Samples at a Firing Range Contaminated with HMX

6. AUTHORS
Thomas F. Jenkins, Marianne E. Walsh, Philip G. Thorne, Sonia Thiboutot,
Guy Ampleman, Thomas A. Ranney, and Clarence L. Grant

8. PERFORMING ORGANIZATION
REPORT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

U.S. Army Cold Regions Research and Engineering Laboratory
72 Lyme Road
Hanover, New Hampshire 03755-1290

Special Report 97-22

10. SPONSORING/MONITORING
AGENCY REPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

U.S. Army Environmental Center
Aberdeen Proving Ground,
Maryland 21010-5401

Directorate of Ammunition Programme
Management

Engineering Services

Department of National Defence, Canada

SFIM-AEC-ET-CR-97025

41, SUPPLEMENTARY NOTES
For conversion of SI units to non-SI units of measurement, consult ASTM Standard E380-93, Standard Practice for Use of the
International System of Units, published by the American Society for Testing and Materials, 1916 Race St., Philadelphia, Pa.
19103.

12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE

Approved for public release; distribution is unlimited.

Available from NTIS, Springfield, Virginia 22161

13, ABSTRACT (Maximum 200 words)

Short-range and mid-range (grid size) spatial heterogeneity in explosives concentrations within surface soils
was studied at an active antitank firing range at the Canadian Force Base-Valcartier, Val-Bélair, Quebec. The
range has been in use for over 20 years. Intensive sampling was conducted over short distances using a 6-m
square grid (36-m?) pattern including two target tanks. Sixteen grids were installed. Four area-integrated
surface samples were formed into piles, one in each quadrant of each grid, using a circular pattern that included
about 10% of the top 5 cm of the quadrant. After in-situ homogenization of a pile, several random aliquots were
combined to form a representative sample. Replicates were collected to assess the representativeness achieved.
In addition, grid composites were prepared by combining equal portions of the four subgrid samples for each of
sixteen grids. In nine of the subgrids, a second area integrated sample was prepared. On-site analysis showed
concentrations of HMX ranging from as high as 1640 mg/kg near one target to 2.1 mg/kg at a distance of 15 m
from the target. On the other hand, TNT concentrations were much lower than would be expected based on the
70:30 composition ratio of HMX to TNT in the melt-cast explosive used on site. A colorimetric method,
originally developed to analyze for RDX, was found to provide concentration estimates for HMX that were in
excellent agreement with laboratory results. Spatial heterogeneity of HMX concentrations was large on both
short- and mid-range scales and this factor dominated the overall uncertainty associated with site characteriza-
tion. Relatively minor uncertainties were due to analytical error.

14, SUBJECT TERMS 15. NUMBER OF PAGES

Compositing HHMX Soil
Analytical error Explosives On-site analysis Spatial heterogeneity [46 price cope
Colorimetric methods _ Firing range Sampling error TNT

17. SECURITY CLASSIFICATION
OF REPORT

UNCLASSIFIED

18. SECURITY CLASSIFICATION
OF THIS PAGE

UNCLASSIFIED

19, SECURITY CLASSIFICATION,
OF ABSTRACT

UNCLASSIFIED

20. LIMITATION OF ABSTRACT

UL

NSN 7540-01-280-5500

Standard Form 298 (Rev. 2-89)
Prescribed by ANSI Std. 239-18
298-102



DATA FOR GRID D2

HMX Concentration (ug/g)

GRID] Subgrid Field [Analytical] Lab Field ‘Acetone
NUMBER Sampling] Rep. | 8330 |Colorimetric| HPLC
Rep. AcN
D2 a a 470 309 340
b 420 249 27
mean | 445 279 308
B a 430 284 297
b 480 258 293
mean_| 455 271 295
c a 350 290 301
b 410 341 349
mean 380 316 325
ce 1 a 230 210 231
b 260
mean 245
ce 2 a 270 337 370
b 290
mean 280
D a 68 37 62
b 72 45 7
mean 70 44 69
op 1 a 120 m1 122
> 120
mean 120
Dp 2 a 150 165 165
b 87
mean 119
ABCD Comp. a 250 226 254
b 290 199 206
mean 270 212 230
ane RE 5
[ABCD -a 330 230 750
|ABCD -b 346 223 249
|ABCD 338 227 249
lc-cc1 -cc2 302
Icc1 -cc2 263 273 301
lb - ppt - poz 103
Joo - poz 119 138 144

45



Table 7. HMX concentrations from on-site colorimetric method for duplicate

subgrid subsamples.

HMX concentration (mg/kg) Replicate Variance RSD

Subgrid Replicate 1 Replicate 2 Mean variability* %
D2C 210 337 273 1.60 8097 32.9
D2D m 165 138 1.49 1446 277
D4A 341 444 393 1.30 5321 18.5
D7c 649 845 747 1.30 19281 18.6
D9B 116 120 118 1.03 9 24
DIC 14 51 26 64 1209 135
DI0A 4.2 4d 42 1.02 0 17
C4A 1170 1260 1220 1.08 4151 5.3
cac 984 871 928 1.13 6432 8.6

Mean replicate variability (all values) 5.15

Mean replicate variability (values >50 mg/kg) 1.24

Mean RSD (all values) = 27.9%
Mean RSD (conc. > 50 mg/kg) = 16.3%

* Replicate variability is the higher value /lower value for replicates.

error, and the sampling error due to spatial het-
erogeneity in analyte distribution within the
subgrid. To assess the magnitude of these various
contributions to the total uncertainty, a series of
replicate subsamples were collected. For the nine
subgrids that were resampled, duplicate pile
subsamples were collected and analyzed by the
on-site colorimetric method (Table 7). For eight of
the nine subgrids, the ratios (higher duplicate
value divided by the lower value) ranged between
1.02 and 1.60, with a mean of 1.24 indicating that
we were able to reproducibly obtain subgrid
subsamples. The replicates for subgrid D9C dif-
fered by a factor of 36.4, but the concentrations
for both replicate samples were low. This anoma-
lous result appears atypical. With the contribu-
tions of spatial heterogeneity excluded as a source
of uncertainty, the results were in very good agree-
ment. An ANOVA was not conducted for this
data set since variances were not homogeneous;
however, RSD values were much more normally
distributed and were once again inversely related
to concentration.

Taking the results from Tables 6 and 7 together,
we can compare the relative magnitudes of un-
certainty due to spatial heterogeneity and
subsampling error. The mean RSD estimate when
sampling a subgrid with concentrations above 50
mg/kg was 30.1% (Table 6). This can be consid-
ered an estimate of total uncertainty due to the

17

combination of spatial heterogeneity of analyte
distribution, subsampling error, and error due to
analysis. Likewise the mean RSD in Table 7 for
duplicate subsamples for samples with concen-
trations above 50 mg/kg was 16.3% and is due to
the contribution of subsampling error and analy-
sis error. From a series of measurements on a
single extract, the RSD for analysis was only 3.2%,
so the major portion of this 16.3% estimate is as-
sociated with subsampling and extraction. Based
on a comparison of the variances associated with
RSDs of 30.1% and 16.3%, only about 30% of the
total variance is associated with subsampling and
analysis while 70% is due to spatial heterogeneity
within the subgrid. It is interesting to compare
this result with those from the seven core samples
in a wheel pattern, both here and in the earlier
studies (Jenkins et al. 1992). The mid-range spa-
tial heterogeneity error for area integrated samples
was only a little more than twice as large as the
subsampling plus analytical error, whereas the
comparable relationship for the core samples
yielded a difference of about 10 times. Clearly the
area integrated samples do a better job of mini-
mizing error due to spatial heterogeneity. We
should note that area integrated samples can be
obtained by a variety of protocols which might be
equal to or better than the circular path used in
this study.



DATA FOR GRID Di
Results from Method 8330

35

TANK] GRID [FIELD] LAB. | (HMX]| [ROX] [TNT]] [2+ 4 Am ONT] | [TNB+ DNB}
NUMBER | dupl. | dup!. | ppm | ppm | ppm ppm. ppm
D 7 x a T7 | <10 | <05 03 <03
D " A b 1.9 | <1.0 | <03 <0.3 <0.3
D " B a 1.2 | <1.0 | <0.3 <0.3 <0.3
D " B b 6 | <t.0 | <03 <0.3 <0.3
D " c a <1.0 | <1.0 | <03 <0.3 <0.3
D "1 c b as | <1.0 | <03 <0.3 <0.3
D " D a <1.0 | <1.0 | <0.3 <0.3 <0.3
D " D b 3.2 | <1.0 | <03 <0.3 <0.3
D 11 |Comp. a <1.0 | <1.0 | <0.3 <0.3 <0.3
D 11 }Comp.} b 79 | <1.0 | <03 <0.3 <0.3
IEAN
D 17 K[meantab] 15 | <1.0] 03 <03 03
D " B |meantab.| 4 | <1.0| <03 <0.3 <0.3
D " c |meantab.| 8.8 | <1.0 | <03 <0.3 <0.3
D " D |meantab.| 3.2 | <1.0 | <0.3 <0.3 <0.3
D 11 |comp.|meantab.} 7.9 | <1.0 | <0.3 0.3 <0.3
DATA FOR GRID D2B
HMX Concentration (ug/g)
GRID] Subgrid [Analytical] Lab Field | Acetone
NUMBER REP 8330 [Colorimetric] HPLC
AcN.
D2 B a 220 TOT 112,
(Wheel) b 120 99 109
mean 170 100 1
z a 17 20 18
b 67 "1 13
mean 12 16 16
3 a 320 198 797
b 250 168 189
mean 285 183 190
4 a 150 115 144
b 120 107 139
mean 135 411 142
5 a 290 313 318
b 310 329 337
mean 300 321 327
6 a 390 329 332
b 420 319 317
mean 405 324 324
7 a 110 46 69
b 54 62 82
82 54 75
Comp 240 161 782
120 182 180
185 190
180 176 184
a Means
1-Ta 214 160 169
1-7b 183 156 169
1-7 198 158 169



CONTENTS

0

By
aq

o)

Preface ....
Introduction.
Background
Objectives
Experimental
Sampling site description and sample collection
Sample storage and processing......
On-site sample extraction and filtration
On-site analytical methods .....
Laboratory analysis of acetone extracts ..
Laboratory analysis using Method 8330
Water samples
Chemicals and reagents
Statistical analyses
Results and discussion
Depth of contamination
Short-range heterogeneity
Results for characterization of grid-sized areas for HMX
Comparison of HMX concentration estimates from on-site colorimetric
and laboratory methods for subgrid and grid-composite samples.......
Concentration estimates for TNT in subgrid and grid-composite
samples ..
Co-contaminant:
Water analysis ...
Analysis of explosives residues remaining on metallic debris
GC comparisons...
Summary and conclusions
On-site methods...
Short-range spatial heterogeneity
Midscale spatial heterogeneity ...
Accumulation of explosives residues at an active antitank firing range .
Concluding remarks ....
Literature cited...
Appendix A: Individual analyses for surface soil samples obtained in each
subgrid and for grid composites .
Abstract...

iii

ROoCoonmnDDADNWwWnNnee

wey
a

mn
oe



Teany, G.B., and R.T. Hudak (1994) Develop-
ment of an enzyme immunoassay based field
screening system for the detection of RDX in soil
and water. In Proceedings of the 87th Annual Air
and Waste Management Association, paper no. 94-
RP 143.05, Cincinnati, Ohio, June 1994.

Teany, G.B., R.T. Hudak, and J.M. Melby (1995)
On-site soil and water analysis using D-Tech
Immunoassay for RDX and TNT. In Proceedings
of Field Screening Methods for Hazardous Wastes
and Toxic Chemicals, Las Vegas, Nevada, 22-24
February 1995, p. 965.

Thiboutot, S, G. Ampleman, T.F. Jenkins, M.E.
Walsh, P.G. Thorne, T.A. Ranney, and C.L. Grant
(in press) Characterization of an antitank firing

28

range at CFB-Valcartier. DREV report, Defence
Research Establishment-Valcartier.

Thorne. P.G., and D.C. Leggett (in press). Hydro-
lytic release of bound residues from composted
TNT contaminated soil. Environmental Toxicology
and Chemistry.

Walsh, M.E., and Jenkins, T.F. (1991) Develop-
ment of a field screening method for RDX in soil.
USA Cold Regions Research and Engineering
Laboratory, Special Report 91-7.

Walsh, M.E., T.F. Jenkins, P.S. Schnitker, J.W.
Elwell, and M.H. Stutz (1993) Evaluation of
SW846 Method 8330 for characterization of sites
contaminated with residues of high explosives.
USA Cold Regions Research and Engineering
Laboratory, CRREL Report 93-5.



from Method 8330 for individual subgrids and
grid composites is presented in Figure 10. The
Method 8330 results are shown because these data
are available for all 16 grids, whereas the on-site
results were only obtained for the 10 grids that
were jointly sampled by the Canadian and U.S.
team. Concentrations ranged from over 1000
mg/kg in several subgrids adjacent to the target
tanks to values of about 1 mg/kg at a distance of
20 m in front of the targets.

Table 4 presents the on-site colorimetric results
for HMX in the 10 grids where on-site analysis
was conducted. Data are shown for individual
subgrids, the mean of the four subgrids within a
given grid, and the results for analysis of the grid
composites. Results from the acetone HPLC analy-
sis and those from Method 8330 are not shown
here, but they were very similar. Ratios of highest
concentrations divided by lowest concentrations
for individual subgrids within a grid (subgrid
variability ratio) varied by factors of 2.6 to 18
with a mean ratio of 6.6. This ratio is somewhat
inflated, though, by the variability for two sub-
grids (D9 and D10) with concentrations near or
below 50 mg/kg, but even when these values
were removed, the mean subgrid variability ratio

was 4.7. These ratios are considerably smaller than
observed for the seven core samples taken in a
wheel pattern to represent short-range heteroge-
neity. Those ratios, as found here and in our pre-
vious study had values as high as 688 with a
mean of about 60 (Table 5). The area-integrated
subgrid samples representing mid-range hetero-
geneity include considerably more soil and, there-
fore, would be expected to show less variability
than the cores. Despite this spatial heterogeneity,
the means of the four subgrids and their corre-
sponding grid composites were in good agree-
ment, never differing by a factor greater than about
2. The mean percent difference was 20.2% for all
values, and it was only 14.1% when two values
with mean concentrations less than 50 mg/kg were
excluded. Thus, at this location, subgrid-scale het-
erogeneity was large, despite taking area inte-
grating samples, but the ability to produce grid-
composite samples that represent the arithmetic
mean of the four subgrid samples was quite good.

The question remains, however, how closely
does a subgrid analytical result represent the mean
surface concentration within the subgrid? To ad-
dress this question we randomly selected 9 sub-
grids from the 40 discussed above to resample.

12
82
Grid D7
405 375 | 1000
1250] 835
GridC4 Grid C5 Gidd1 Grid D2 GridD4 Grid DS
TANK C 1600] 970] 545 | 114] | 180 | 134] 445 | 455] TANKD 595 | 280] 94 | 19
1900] 955] 580 | 114] ] 84 | 43 | 70 | 380 575 | 105] 12 | 28
890 | 835, 800 | 350
950 | 810 165 | 135
Grid o6 Grid D8
350 | 500 13 | 100
490 | 265 18 | 236
Grid 07 Grid D9
65 | 130 58 | 44
7.4 | 26 18 | 24
Grid C8 Grid D10
<1 | 38] 15 | 39 15 | 36
14] 16] 1.8] 20 a1] 49
Grid C9 Grid C10 Grid 11

Figure 10. HMX concentrations from commercial laboratory analysis using Method 8330.

14



Table 8. Comparison of concentration estimates for TNT from various
on-site and laboratory methods.

TNT (mg/kg)
On-site On-site

Sample (colorimetric) (EIA) Acetone-HPLC Method 8330
DIA <1 05-15 <0.3 <0.3
DIB <l 05-15 <0.3 0.6
DIC <1 <05 <0.3 <0.3
DID <1 <05 0.8 <0.3
DiComp a <l <05 <0.3 03
DiComp b <l 05-15 <0.3 03
D2Aa 65 3.0-4.0 56 <0.3
D2Ab <l 3.0-4.0 03 <03
D2Ba 5.6 4.0-5.0 5.1 1.0
D2Bb 18 15-3.0 13 0.6
D2Ca 2.2 <0.5 <0.3 3.8
D2Cb <1 15-3.0 1.0 3.8
p2cc 1 34 3.0-4.0 28 11
D2cc 2 4.0 3.0-4.0 29 35
D2Da <1 <05 <0.3 1d
D2Db <1 <05 1.0 04
D2DD1 1.0 <05 <0.3 07
D2DD2 19 <05 15 11
DIA 21 05-15 0.7 13
D4AA1 15 15-3.0 04 04
D4AA 2 17 <0.5 1.0 04
D4B <1 <0.5 <0.3 07
DAC 3.0 <0.5 13 0.6
D&D 14 <05 07 06
D4Comp a 3.3 1.5-3.0 37 07
D4Comp b 34 0.5-1.5 2.2 0.6
D5Aa <1 <0.5 <0.3 <0.3
DSAb <1 <0.5 <0.3 <0.3
D5Ba <1 <0.5 <0.3 <0.3
DS5Bb <1 <0.5 <0.3 <0.3
DS5Ca <1 <0.5 <0.3 <0.3
DSC b <l <0.5 <0.3 <03
DSDa <1 <0.5 <0.3 <0.3
DSDb <1 <0.3 <03
D5Comp a 27 19 <03
D5Comp b <l <0.3 <0.3
D7A <l 1.0 10
D7B 2.0 1.7 18
p7c 15 09 17
D7CC 1 2.2 09 1.0
p7cc 2 9.1 73 1.0
D7D 3.6 241 88
D7Comp a 25 14 37
D7Comp b 33 21 21
D8A 21 7 21
D8B 15 07 11
D8c 18 11 15
DsD 19 19 <0.3
D8Comp a 6.2 41 56
D8Comp b 3.4 22 97
DIA 17 <0.3 <0.3
D9B <l <03 04
D9BB1 1.2 <0.3 <0.3
D9BB 2 <l 04 <03
D9c <1 <0.3 ui
DSCC 1 <l <0.3 <0.3
D9CC 2 v7 15 <0.3
D9D <1 <03 <0.3



Table 6. HMX concentrations from on-site colorimetric analysis for

subgrids subjected to repeat sampling.

Thus for the replicate samples, a
different 10% of the surface area
within a subgrid was sampled.

HMX (mg/kg) Replicate *

Subgrid Replicate 1 Replicate2 __onriabiity* Variance RSD(%)_ BMX results om od replleate
Dec salt 210" 16 8581 33.6 samples are presented in Table
D2D a7t wit 3.0 2738 70.7 6. The variability observed for

the two replicates for a given

D4A 631 aaa 14 17485 24.6 subgrid was much lower than
p7c 729 64gtt 16 3200 8.2 observed between subgrids
Dep 180 nett 16 avis 306 within the grid. Thus even with
: this enormous short- and mid-

D9 20 1att 14.2 173 123 range variability present, we
DIOA 25 aatt 61 28 102 were able to reproduce most
subgrid values within a factor

c4A 1910 1170" 16 276025 34.0 of two, especially when the
cac 995 zit al 7688 94 HMxX concentration was above
50 mg/kg. We did not conduct

Meant 50) oF analysis of variance on these

Mean replicate variability (all values)
Mean replicate variability (conc. > 50)

data, however, since the vari-
ances obtained for the different
subgrids were clearly not homo-

* Replicate variability is the higher value/lower value of replicates.

* Value randomly selected from two analytical replicates.
* Value randomly selected from two subsampling replicates.

This was done two days following the initial
subgrid sampling. No precipitation occurred be-
tween the period of the initial and subsequent
subgrid sampling events. Resampling was con-
ducted in an identical manner to that used for the
initial subgrid samples except the regions sampled
were offset from the center of the subgrids as
shown in Figure 4 for each subgrid resampled.

geneous. In fact, the RSDs ob-

tained for individual subgrids,

which ranged from 8.2% to

123%, were inversely related to

concentration (Fig. 11). This relationship is remi-

niscent of the relationship developed by Horowitz

(1982) who demonstrated that analytical standard

deviations were a function of concentration for a

wide variety of analytical methods and for all
types of matrices.

The within-subgrid-scale uncertainty is acom-

bination of analytical error, subgrid subsampling

140. ——7—
120
100 |&

80}

RSD (%)
T

40

20

[se a

0 200 400 600

800 1000 1200 1400 1600

HMX Mean Concentration (mg/kg)
Figure 11. Dependence of RSDs of duplicate subgrid samples on mean

HMX concentration.

16



APPENDIX A: INDIVIDUAL ANALYSES FOR SURFACE SOIL SAMPLES
OBTAINED IN EACH SUBGRID AND FOR GRID COMPOSITES

DATA FOR GRID D1

HMX Concentration (mg/kg) 2-Am-DNT and 4-Am-DNT Concentration (ug/g)
GRID] Subgrid ] Field [Analytical] Lab Field | Acetone GRID] Subgrid | Field Analytical] Lab] Acetone | Acetone
NUMBER Sampling] Rep. 8330 |Colorimetrid HPLC NUMBER Sampling] Rep. 8330 HPLC | HPLC
Rep. AcN Rep. AcN__| 4-Am-DNT_|2-Am-ONT,
Dr rN a 730 720 TH DT ry a 1 035 O32
b 230 b 1.0
mean= | _180 mean= 42
8 a 37 Tat 136 3 a 09 033 038
b 210 b 14
mean= | _134 mean= 412
Cc 2 45 Ev Ea c a 05 0.20 023
b 40 b 08
mean= | __43 mean= | _0.55
D @ 48 38 7 D a 3 =a Oy
b 120 b 03
mean= | __84 mean= |__<0.3
Comp. 2 96 ma 82 Comp. a 09 0.17 024
76 89 a7 b 09 0.27 0.26
- 58 80 80 mean= | 0.90 0.22 0.25
‘Means: z Bae: ASS = =
‘ABCD-a 70 83 4
ABCD -b 150
ABCD 110
Comp. 86 80 90

TNT Concentration (mg/kg)

GRID] Subgrid | Field Analytical] _ Lab ‘Reetone | DTech
NUMBER Sampling] Rep. 8330 HPLC
Rep. AcN
OF rN a <0 <d <a [os1s
b <03
mean= | <03
5 a 03 <d <a [osots
b 08
mean= | __06
c a 03 <a <a <0
04
04
D a <03 <i ore | 05
b 03
mean= | <0.3
Comp. a 03 <d <a <05
b <03 <d <d  osto1s
mean= | _<0.3
Other Nitroaromatics Concentration (mg/kg)
ROX Concentration (mg/kg) GRID] Subgrid ] Field Analytical] Lab | Acetone | Lab
GRID] Subgrid | Field Analytical] Lab | Acetone NUMBER Sampling] Rep. | 8330AcN| HPLC [8330 AcN
NUMBER Sampling] Rep. | 8330 | HPLC Rep. 2,4- and
Rep ‘ACN 2,6-0NT.
ot x 7 <0 328 oT ry 2 <S Wace 70
b <1.0 b <03 03
mean= <1.0 mean= <0.3
ry a <0 a 5 a <0.3 a 08
b <1.0 b <0.3 03
mean= | _<1.0 mean= | <0.3
c ry <1.0 <d c a <03 a os
b <1.0 b <03 <03
mean= | _<1.0 mean= | _<0.3
D a <0 a . a 03 a 08
b <1.0 b <0.3 <03
mean= | _<1.0 mean= | _<0.3
Comp. a 1.0 <a Comp. a 03 a Zs
<1.0 0.28 b <03 d 03
<1.0 mean= | __<0.3

29



levels of HMX. However, this cross-reactivity was
not sufficient to allow it to be exploited to esti-
mate the concentration of HMX, since even high
concentrations of HMX such as 593 mg/kg (D2
location 1, surface) does not produce a D TECH
response higher than 4.0-5.0 mg/kg with an in-
trinsic concentration of RDX of 1.56 mg/kg for
the same sample. Roughly, the ratio of cross reac-
tivity can be estimated as being 10° order of mag-
nitude (Table 1). Using the RDX D TECH EIA test
kit for the determination of HMX would lead to a
sensitivity decrease of about a factor of 100, mean-
ing a detection limit of approximately 50 mg/kg,
which was not acceptable for our purposes.

Results from the analysis of these samples for
HMX and TNT are also presented in Table 1. In
all cases, HMX was present at concentrations about
two orders of magnitude greater than TNT, even
though the munition fired at this site

Short-range heterogeneity

In the next phase of the study, soil samples
were collected from subgrid D2B to compare the
short-range heterogeneity of contaminant distri-
bution to that documented in our earlier study of
TNT, DNT and ammonium picrate (Jenkins et al.
1996). Using a sampling protocol identical to the
one used in the earlier study, we collected seven
discrete samples were collected as shown in Fig-
ure 5 for subgrid D2B. These discrete samples
were homogenized and analyzed in duplicate,
and a composite was prepared and analyzed in
triplicate. The results presented in Table 2 and
Figure 5 include those from analysis using the on-
site colorimetric method, those from laboratory
HPLC analysis with the same acetone extracts
used for on-site analysis, and those from separate
subsamples analyzed at a commercial laboratory

had a 70:30 ratio of HMX to TNT. The Table 2. Results from short-range spatial heterogeneity study
higher retention of HMX in these near for HMX with soil samples from subgrid D2B.

surface soils is probably due to its much

lower water solubility (6 mg/L vs. 150 MX (mg/kg) ee
mg/L at 25°C, Burrows et al. 1989) and sample no. Replicate On-site Acetone HPLC _ Method 8330
slower rate of dissolution. In addition, . ~
HMxX is much less subject to biotrans- Discrete samples a 101 12 20
formation or aerobic degradation than b 99 109 120

is TNT (Grant et al. 1995), and indeed, mean 100 11 170
concentrations of the monoamino trans-

A 2 a 20 18 7
formation products of TNT were often b rT B 67
present in concentrations equivalent to mean 16 16 12
those of TNT (App. A).

A 3 a 198 191 320
HMxX was present in samples from b 168 189 250
grid D2, next to tank D, at concentra- mean 183 190 285
tions about 10 times greater than for
those from grid D5, which was about 9 4 b ne 8 3
m from the target. With respect to depth, mean it 142 135
HMX concentrations were highest in the
surface samples (over 500 mg/kg for 5 b oo saa no
grid D2 and about 100 mg/kg for D5) mean 321 307 300
followed by the 0-7.5-cm segment. HMX
concentrations in soil samples from the 6 a 329 332 390
7.5-15-cm depth were generally a factor man a ay ae
of 5 or more lower than in the 0-7.5-cm
depth soils, ranging from about 50 mg/ 7 a 46 69 110
kg for samples from D2 to about 5 mg/ b & 82 54
mean 54 75 82
kg for samples from D5. These results
confirmed what was observed in an ear- Discrete sample mean 158 169 198
lier study where the depth of contami- Composite samples
nation was investigated (Thiboutot et a 161 182 240
al. in press). Thus for this firing range, 182 180 120
locating HMX contamination sources c 185 190
can be apparently accomplished best
Composite sample mean 176 184 180

using near-surface soil samples.

11



Folding Fins

\

of accumulation of HMX and TNT
on an active firing range, where
the munition fired was a melt-cast
explosive composed of a 70:30

mixture of HMX and TNT. Igniter —

i:

Propellant Charge

Warhead Body

\ Fuse

EXPERIMENTAL

Sampling site description
and sample collection

This study was conducted in
September 1996 at an antitank
range at the CFB-Valcartier, Que-
bec, near Quebec City (Fig. 2). This
is an active firing range where rockets filled with
0.3 kg (0.66 Ib) of the melt-cast explosive octol
(70% HMX:30% TNT) have been fired on a
routine basis for over 20 years (Fig 3). Firing at
the antitank range had occurred the week prior to
this field sampling study, and the ground surface
was littered with shell fragments, pieces of plastic
and ceramic, springs, fins, and other debris. Some
of the rockets were unexploded, but sheared open
to expose the explosive composition octol. Analy-

Motor Body /
i
Comp AS Booster
(ROX)

Explosive
(Octot, 70:30 HMX:TNT)

Figure 3. Diagram of 66-mm M72 rocket fired at CFB-Valcartier.

sis of a chunk of the explosive composition using
HPLC and NMR (nuclear magnetic resonance)
spectroscopy confirmed the 70:30 ratio of HMX
and TNT.

The firing range is about 100 ha in size and has
four target tanks, two in a fairly level region of
the site (labeled tanks C and D) near the access
road. Sampling studies were conducted in an area
encompassing these two target tanks as shown in
Figure 4. The sandy, well-drained soil in front of

DREV HMX
“X Mean of all samples in grid, 16

less duplicates Grid D7
© Location of sample 54 183 WheelforD2B Composite = 812
@ Location of dupticate (0) Composite = 176 X=770

324 144 X= 158 ®
321
GidC4 GridC5 = GridD1._— Grid D2 OH ¢ GridD4 Grid DS

®©/®|®@]|@|®

O) ®|®

1

ails

© ©}|©}|©

Q©

1S

©|©

| ©|©

TANK C Composite Composite Composite Composite TANK D ‘Composite Composite
= 1640 = 180 = 80 = 212 = 479 =41
X=1450 X= 242 X=83 X= 227 ® X= 428 X=57
Grid D8
(O) © Composite = 322
A Ad B Bo c Cd D Od X=394
GridC4 | 1910 [ 1220 | 721 | 995 | 930 | 2160 |
Grids | 461 | 71 129 “301 | | ® ©
(GridD1 [120 [tat | 32 59 | i Grid D9
‘GridD2 | 279 [271 | 316 | 273 41 | 138 | © Composite = 35
(GridD4 | 631 | 303] 148 254 680 X =56
‘Grads | 53 33 | 86 54 i
GridD7 | 209 1000 | 729 [747 | 1140 + i
Grid D8" 878 (286 202 | 208 | Grid D10
“Grid D9 10 180 118 | 20 | 26 14 (0) © Composite = 4.7
Grid D10. 25 a4 5.1) 2.4] 64 X=98

Figure 4. Sampling area at CFB-Valcartier firing range site, showing HMX concentrations from on-site measutre-

ments.



sorb strongly to soils by hydrophobic interactions.
The major explosives contaminants, TNT and RDX,
have aqueous solubilities in the 50-150 mg/L
range and, from a kinetic point of view, dissolve
slowly into aqueous solution. Because of these
factors, high concentrations of these compounds
can persist in near-surface soils for decades. Once
they are dissolved in water, though, they can
migrate rapidly through the unsaturated zone to
the water table and form plumes in underlying
aquifers miles in length.

The particulate nature of these contaminants
in near surface soils leads to substantial spatial
heterogeneity in distribution. Characterization of
the short-range spatial heterogeneity was con-
ducted both here and in an earlier study (Jenkins
et al. 1996). These studies demonstrate that con-
centration estimates for discrete samples collected
less than a meter apart can vary by factors rang-
ing from 3 to 43,000, with a median value of about
50. Thus, the use of a single discrete sample to
represent even a small geographical area will lead
to enormous uncertainty. Using on-site homog-
enization of several discrete samples followed by
compositing, however, produced a sample that
was much more representative of the mean con-
centration over the area sampled.

Midscale heterogeneity was also assessed in
this study. Using an “area-integrated” sampling
scheme, we were able to reproduce concentration
estimates for 3- x 3-m sized subgrids quite well
(Table 7). Even with this scheme, though, the ra-
tio of the highest concentration divided by the
lowest concentration among the four 3- x 3-m
subgrids, within a 6- x 6-m grid, averaged about 5
(Table 4). Combining the samples from the four
“area integrated” subgrid samples to form a grid-

composite proved to be an efficient way to pro-
duce a representative sample for the grid.

Anumber of on-site methods for TNT and RDX
have been developed. Here we assessed colori-
metric methods for TNT and HMx, and an en-
zyme immunoassay method for TNT. The accu-
racy of the colorimetric methods was evaluated
by comparison with a laboratory reference method
and the results for both TNT and HMX were quite
impressive. The slopes of the linear models were
1.008 and 1.05 for HMX and TNT, respectively,
with correlation coefficients of 0.992 and 0.975.
Intercepts were also quite low indicating that the
methods could be used with confidence down to
their detection limits of about 1 mg/kg. The
results for the colorimetric TNT method agree
with those presented elsewhere (Jenkins et al. 1996,
Myers et al. 1994). The enzyme immunoassay
method for TNT produced results in ranges in
contrast to the colorimetric method that provides
a quantitative result. Correlation analysis between
the midpoint of the range established by this
method with laboratory analyses was not quite
as good as that for the colorimetric method, but
entirely adequate.

By combining the ability to produce represen-
tative samples via on-site homogenization and
compositing with the ability to obtain accurate
analytical estimates using inexpensive on-site
methods, site investigators can effectively over-
come the problem of spatial heterogeneity for
explosives-contaminated areas.

This study reports concentrations of explosives
on an active firing range. Very little information
of this type is currently available, particularly
where HMX is the major potential contaminant.
Firing ranges are found on many military bases

Table 11. Fractionation of total error into analytical and sampling components.

Standard deviation Ratio
Analytical Sampling Sampling/analytical
Sampling location Onsite Lab On-site Lab Onsite Lab
Hawthorne location 4 (TNT) 217 265 1,970 2,150 91 81
Hawthorne location 5 (TNT) 53 11.0 121 131 28 n9
Volunteer location 7 (TNT) — 7,680 —_ 19,800 — 26
Volunteer location 7R (TNT) 5,120 6,320 24,700 27,600 61 44
Volunteer location 9 (TNT) 10 1.0 104 12.4 104 124
CFB-V (HMX) 10.9 38.1 123 135 13 35°

* Data unavailable.



Bt

y=0.69x 41.24
r= 0.906

20 n=40

a

TNT (mg/kg) Using On-Site EIA Method

Tile TST

almost always under 2 mg/kg. An
RDX value of 7 mg/kg was found for
subgrid C4D, where the HMX concen-
tration was 2070 mg/kg and an RDX
concentration of 11 mg/kg was ob-
served for one replicate of the com-
posite sample for grid D7. The RDX
concentrations were never sufficiently
high to interfere in the colorimetric de-
termination of HMX.

Water analysis
We also found high concentrations
of HMX in the few water samples col-

piittiiittiiiitiriitirig

4 6 8 10 12 14
TNT (mg/kg) Using Acetone HPLC Method

Figure 16. Correlation analysis of TNT concentration estimates from
the EIA on-site method with those from HPLC analysis of the same

acetone extracts.

tributes to the much lower concentrations of TNT
compared to HMX. The highest concentrations of
the amino-DNTs were about 10 mg/kg behind
tank D (grid D7) where the soil was moist and
appeared to have a higher organic content. Else-
where the amino-DNTs were generally in the 1-2
mg/kg range. Formation and further transforma-
tion and conjugation of the amino-DNTs is prob-
ably a major reason that TNT levels are much
lower than HMx in the soils at CFB-Valcartier.

The lab analysis sporadically detected 2,4-DNT,
sometimes at higher concentrations than TNT
(higher then would be expected if the source of
the 2,4-DNT was as an impurity in TNT). We
previously observed high concentrations of 2,4-
DNT at open burning/open detonation sites
where excess propellant was burned (2,4-DNT is
an ingredient in some propellant compositions).
The disagreement was extreme in the DNT con-
centration estimates for some subsamples of the
same sample. For example, in the composite of
grid D2, the estimates were <0.3 and 24 mg/kg
for the two lab subsamples. Such large heteroge-
neity implies that the contaminant is particulate.
The manufacturing by-product DNB was not de-
tected, nor was TNB.

RDX is not a major contaminant in military
grade HMX. However, RDX is the major compo-
nent in Composition A5, the booster used for the
66-mm M72 rocket. Soil analysis, however, re-
vealed only traces of RDX compared to the levels
of HMX on site. Often the concentrations of RDX
were less than method detection limits and were

23

lected at CFB-Valcartier (Table 10). The
highest HMX concentrations were in
the well water (295 ug/L). TNT con-
centrations were about 100 times lower
than HMX, a similar ratio to what we
observed in soil. These water samples
were not chemically preserved, and
when separate subsamples were subsequently
analyzed at CRREL, HMX concentrations were
similar to those found at CFB-Valcartier, but TNT
was not detected in the well water samples. How-
ever, the amino-DNTs were detected, which adds
more evidence that microorganisms capable of
transforming TNT are present at this site.

The concentration ratio of HMX to RDX in the
well water was approximately six; however, we
only sporadically detected RDX in soil. When RDX
was detected in soil, the concentrations were gen-
erally near detection limits and were always at
much lower concentrations than HMX. In the
sandy soils encountered at CFB Valcartier, RDX
may be more susceptible to leaching then HMX,
perhaps due to a greater rate of dissolution. Al-
though RDxX is about 10 times more water soluble
then HMx, the kinetics of dissolution under envi-
ronmental conditions are not well defined. The
eight-membered ring of HMX has been reported
to be less susceptible to biotransformation than
the six-membered ring of RDX (Spanggord et al.

Table 10. Concentrations of HMX, RDX, and TNT
detected in groundwater and surface water
samples at CFB-Valcartier.

Concentration (ug/L)

HMX RDX TNT __
Well water 295 (42.0) 46 (2.0) 3.1 (41.1)
Surface water 1 125 <d <d
Surface water 2 317 18 <d



Table

10.

11.

5.

Comparison of measures of analytical precision, accuracy and
discrete sample representativeness for CFB-Valcartier results
relative to those found for other explosives analytes at Monite,
Hawthorne, and Volunteer...

HMX concentrations from on-site colorimetric analysis for
subgrids subjected to repeat sampling..... ae

HMxX concentrations from on-site colorimetric method for duplicate
subgrid subsamples .

Comparison of concentration estimates for TNT from various
on-site and laboratory methods se

Apparent false positives and false negatives relative to Method 8330
results for TNT

Concentrations of HMX, RDX, and TNT detected in groundwater
and surface water samples at CFB-Valcartier ..

Fractionation of total error into analytical and sampling
components ..

Page

15
16
17
20
21
23

26



ILLUSTRATIONS

Figure
1. Chemical structure of HMX
Canadian Force Base-Valcartier firing range study site .
Diagram of 66-mm M72 rocket fired at CFB-Valcartier ....
Sampling area at CFB-Valcartier firing range site, showing HMX
concentrations from on-site measurements ..
Sampling scheme for short-range heterogeneity study .
Sampling path for obtaining “area integrated” samples
Subgrid sampling path and sample collection...
HPLC chromatograms for a standard and two acetone soil extracts
showing analytical difficulty in quantifying TNT when large
concentration of 2,4-DNT was present...
9. GC-ECD chromatograms for a standard and two acetone soil
extracts...
10. HMX concentrations from commercial laboratory analysis using
Method 8330
11. Dependence of RSDs of duplicate subgrid samples on mean
HMX concentration ...
12. Correlation analysis of HMX concentration estimates from the
colorimetric on-site method with those from HPLC analysis of
the same acetone extracts .....
13. Correlation analysis of HMX concentration estimates from the
colorimetric on-site method with those from EPA Method
8330 using separate subsamples
14. Sampling area at CFB-Valcartier firing range site, showing TNT
concentrations from on-site colorimetric analyses ......
15. Correlation analysis of TNT concentration estimates from the
colorimetric on-site method with those from HPLC analysis
of the same acetone extracts...
16. Correlation analysis of TNT concentration estimates from the
EIA on-site method with those from HPLC analysis of the
same acetone extracts ....

PON

PNA

TABLES

Table
1. Analytical results from initial samples used to assess depth of
contamination
2. Results from short-range spatial heterogeneity study for HMX
with soil samples from subgrid D2B
3. Statistical analysis of HMX results from discrete and composite
samples taken from subgrid D2B for short-range spatial
heterogeneity assessment .....
4. Comparison of HMX concentration estimates using the on-site
colorimetric results for individual subgrids, mean of four
subgrids, and grid composites

wn

aa ew

14

16

18

18

19

10

i

15



Table 3. Statistical analysis of HMX (mg/kg) results from discrete and composite samples
taken from subgrid D2B for short-range spatial heterogeneity assessment.

Discrete samples

On-site colorimetric HPLC (acetone)

Sample Mean Mean

1 100¢ lic

2 lea 57a

3 183d 190e

4 lic 142d

5 32Le 328 f

6 324e 325 f

7 54b 75.2b
Mean 158 169

Method 8330 (acetonitrile)
___Mean

170b
118a
285¢
135b
300¢
405d
82ab
198

Numbers designated with the same letter within each column are not significantly different using the least

significant difference test at the 95% confidence level.

Discrete samples

ANOVA for on-site and lab analyses

On-site colorimetric HPLC (acetone) Method 8330 (acetonitrile)
F ratios 257" 478" 26.1"
Error MS 118.5 59.9 1453
Least sign. diff. 25.7 18.3 90.1
Analysis s (RSD) = 10.9 (6.9%) 7.7 (4.6%) 38.1 (19.2%)
Sampling s (RSD) = 123 (77.9%) 120 (71.4%) 135 (68.2%)

(s = standard deviation)
(RSD = relative standard deviation)

Linear correlation analysis for on-site colorimetric vs. lab HPLC (acetone) analysis

(r = correlation coefficient)

Slope _Intercept a
Nonzero intercept 1.027 -15.5 0.996
Zero intercept 0.963 0

Linear correlation analysis for on-site colorimetric vs. lab Method 8330 (acetonitrile) analysis (r = correlation

coefficient)

Slope
Nonzero intercept 0.848
Zero intercept 0.813

Composite samples
On-site colorimetric

Intercept r

-9.86 0.945,
0

HPLC (acetone) Method 8330 (acetonitrile)

n 3
Mean value 176
Standard deviation 12.8
RSD 7.3%

3 2
184 180

5.19 84.9

2.8% 47.1%

* Significant at the 99.9% level

using acetonitrile extraction and HPLC analysis
(EPA Method 8330, EPA 1995). Statistical analysis
is presented in Table 3.

Duplicate analyses conducted using the field
colorimetric method and HPLC of the acetone
extracts were quite precise and in excellent agree-
ment (Table 3). Mean values for individual
samples varied from about 16 mg/kg to over 300
mg/kg. RSDs for analysis were 6.9% and 4.6% for
the on-site colorimetric and acetone HPLC results,

12

respectively, indicating that homogenization of
samples using simple, manual procedures was
entirely adequate when 20-g subsamples were
used for analysis. The correlation coefficient (r)
for on-site colorimetric and acetone HPLC results
was 0.996, and the intercept of the linear model
was not significantly different from zero. The slope
of the zero intercept linear regression relation-
ship was 0.963, indicating that the two methods
gave essentially equivalent results.



NO,

\

NO,

ON

N

\

NO,

HMX
Figure 1. Chemical structure of HMX.

previously sampled and found to be contaminated
with energetic compounds, HMX being the major
contaminant. This initial characterization was con-
ducted within the framework of a Canadian pro-
gram on the characterization of sites potentially
contaminated with energetic materials (Thiboutot
et al. in press). The objective of the Canadian
program has been the assessment of the level of
contamination by energetic compounds in vari-
ous type of sites such as firing ranges, open burn-
ing/open detonation ranges, demolition ranges
and production sites. In addition to site charac-
terization, this program includes the development
of bioremediation technologies capable of
remediating explosives contaminated sites.

The first soil sampling of the antitank range
was conducted in May 1995. Four surface com-
posite samples were taken at a distance between
1 and 3 m from each side of four target tanks.
Each surface composite was prepared from 10
discrete samples. Analysis of these initial samples
revealed that HMX was the major contaminant
on site, with lesser amounts of RDX and TNT. A
second sampling was conducted in October 1995
and was concentrated near tank D (Fig. 2). Seven
locations were sampled at three different depths.
Analysis of these samples revealed that greater
than 90% of the contamination was concentrated
in the top 15 cm of soil. Detailed results of both
sampling campaigns are reported elsewhere
(Thiboutot et al. in press).

Objectives

The principal objective of the work described
here was to develop an innovative strategy for
characterizing explosives contaminated sites that
1) takes advantage of the ability to generate near
real time information from on-site analyses, and
2) overcomes the problem of large localized spa-
tial heterogeneity in contaminant concentrations.
A colorimetric method, initially developed for
RDX, was evaluated for estimating HMX soil
concentrations, and two commercially available
on-site methods were compared for rapid deter-
mination of TNT. To overcome problems due to
spatial heterogeneity, a simple compositing
approach was evaluated for obtaining represen-
tative samples within defined geographic bound-
aries. Finally, this study documented the levels

Figure 2. Canadian Force Base-Valcartier firing range study site.



Comparison of HMX concentration
estimates from on-site colorimetric
and laboratory methods for subgrid
and grid-composite samples

HMxX concentration estimates were obtained
for all subgrid and grid-composite samples: 1)
using the on-site colorimetric method (Jenkins et
al. 1995), 2) using HPLC analysis at CRREL for
the same acetone extracts employed for on-site
analysis, and 3) at an independent commercial
laboratory using EPA Method 8330 which is an
HPLC method with acetonitrile extraction of sepa-

rate subsamples of soil (App. A). A few of the
acetone extracts were also analyzed by gas chro-
matography with an electron capture detector

(GC-ECD), primarily for analyte confirmation.
Results for the on-site and acetone HPLC analy-
ses for this group of 106 samples were compared
using a paired t-test and linear correlation analy-
sis. The ¢ value was 0.0596, indicating that the
results from the two methods were not signifi-
cantly different at the 99.9% confidence level. From
linear correlation analysis, the correlation coeffi-
cient for the model with intercept was 0.992, the
slope of the relationship was 1.008

2500 ot

y = 1.0043x
r= 0.992

2000

1500

1000

500

ITT TT TTT TTT TT

HMX (mg/kg) Using On-Site Colorimetric Method

and the intercept was -2.77. The in-
tercept was not significantly differ-
ent from zero (t = 0.43) at the 99.9%
confidence level. The linear model
with zero intercept had a slope of
1.004 (Fig. 12). This excellent corre-
lation between these two indepen-
dent methods of instrumental
determination and a slope that
matches the theoretically expected
value of 1.00, verifies that the on-
site method is providing concen-
tration estimates for HMX that are
equivalent to the HPLC estimates.

prittitritiiriitiriitirig

0
0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200

HMX (mg/kg) Using Acetone HPLC Method

Figure 12. Correlation analysis of HMX concentration estimates from
the colorimetric on-site method with those from HPLC analysis of the

same acetone extracts.

Results for the on-site method
were also compared with those
from the independent commercial
laboratory (Method 8330). There
were only 76 samples that could be
correlated because duplicates were
not related one-to-one as they were
above where identical extracts were

2500 oot

2000

1500

analyzed. The ¢ value from the
paired f-test was 1.516, indicating
that the results from the two meth-
ods were not significantly different
at the 95% confidence level. From
the correlation analysis, the slope
of the model with intercept for this
analysis was 1.016 with an inter-
cept of -25.0 and a correlation coef-
ficient of 0.972. The intercept was
not significantly different from zero
(t= 1.51) at the 95% confidence level

HMX (mg/kg) Using On-Site Colorimetric Method

TOTP TTT TTT TTT

pitliriitiriptisiitiiit

1000

500

Py al PD
oO 200 400 600 800 1000 1200 1400 1600 1800 2000 2200

Mean HMX (mg/kg) Using HPLC Method 8330

Figure 13. Correlation analysis of HMX concentration estimates from
the colorimetric on-site method with those from EPA Method 8330 using
separate subsamples.

18

so the zero intercept model was ob-
tained. The slope of this relation-
ship was 0.988 (Fig. 13). The corre-
lation between these two methods
is also quite good, but not as good
as that shown above where the
same extract was analyzed by two



Assessment of Sampling Error
Associated with Collection and
Analysis of Soil Samples at a

Firing Range Contaminated with HMX

Thomas F. Jenkins, Marianne E. Walsh, Philip G. Thorne,
Sonia Thiboutot, Guy Ampleman, Thomas A. Ranney,
and Clarence L. Grant September 1997

19971022 047 ese



DATA FOR GRID D10

HMX Concentration (ug/g)

RDX Concentration (ug/g)

GRID] Subgrid | Field Analytical] Lab | Acetone
NUMBER Sampling] Rep. | 8330 HPLC
Rep. ACN.
DIO ry a <0 <a
b <1.0
mean
AA 1 a <1.0 <d
b <1.0
mean
AA 2 a <1.0 <d
b <1.0
mean
B a <1.0 <d
b <1.0
mean
c a <1.0 <d
b <1.0
mean
D a <1.0 <d
b <1.0
mean
ABCD a <1.0 <a
Comp.

GRID ‘Subgrid Field jAnalytical| Lab Field Acetone
NUMBER Sampling] Rep. 8330 [Colorimetric] HPLC
Rep. ACN
Dio * 2 30 7 70.6
b 56
mean 5.8
AA 1 a 15 44 65
> "
mean | 13.0
AR 2 a 22 44 83
b 45
mean 3.4
B a 56 5.4 14
b 34
mean_|_44
c a 32 24 34
b <1.0
mean _|_24
1) a 32 64 B87
b 44
mean_| 18.1
ABCD a 16 5.0 54
Comp
> 38 43 86
mean_| 27 47 69
[Means E =
ABCD -a i 38 60
JABCD -b 35
JABCD 76
JA - AAT - AA2 TA Wd 85
JAA1 - AA 82 44 74
TNT Concentration (19/9)
GRID] Subgrid | Field Analytical Lab Restone | DTech
NUMBER Sampling} Rep. | 8330 |Colorimetric] HPLC
Rep. ACN
DIO x 2 <03 <a a | 05
> <03
mean
AA 1 a <03 <i <a | <0s
b <0.3
mean
AA 2 a <03 <4 <i | <05
b <03
mean
B a <0.3 <d <d <0.5
b <03
mean
c a <0.3 <d <d <0.5
> <03
mean
° a <03 <i «a | os
b <0.3
mean
ABCD Comp. a <0.3 <d <d 05
b <0.3 <d <d <0.5
mean

41



subgrids, duplicate area integrated samples were
prepared in a manner identical to that described
above, except that the sampled area was offset
from the initial one as shown for each of the se-
lected subgrids in Figure 4. This was done to assess

7
20cm Sampling Path for
Sub-grid Sample
8
3
i=
°
“1
r 3 meters

Figure 6. Sampling path for obtaining “area-integrated”

samples.

ie ae ey

ON OE :
Figure 7. Subgrid sampling path and sample collection.

the uncertainty due to the fact that only about 10%
of a subgrid was included in any one area inte-
grated sample. All samples were returned to the
processing area in plastic Ziploc bags in a cooler.

Sample storage and processing

Soil samples were kept cold and in the dark
until processed. Processing was conducted
either the same day soils were collected or the
morning following collection the previous
afternoon. Soil samples varied somewhat in
moisture content and texture from location to
location. Some soils were quite dry and con-
sisted mainly of sands and gravels, while
others had a much greater level of moisture
and had a much greater organic content.

Individual soil samples in Ziploc bags were
shaken and kneaded and then emptied into
aluminum pans. Soils were further homog-
enized by breaking up clumps with gloved
hands and stirring. Small stones and any other
debris were removed, samples were coned
and quartered, and 20-g subsamples were
weighed into 125-mL plastic wide-mouth
bottles for extraction with acetone. For the
wheel samples, used to assess short-range
heterogeneity, samples were processed in an
identical manner to that described elsewhere
(Jenkins et al. 1996) and duplicate subsamples



54 Colorimetric 16 Colorimetric
75 Acetone HPLC 46 Acetone HPLC
82 Method 8330 12 Method 8330

100 Colorimetric
111 Acetone HPLC
170 Method 8330

324 Colorimetric
325 Acetone HPLC
405 Method 8330

321 Colorimetric
328 Acetone HPLC
300 Method 8330

Samplers
(stainless steel auger)
5.cm diameter

183 Colorimetric
190 Acetone HPLC
285 Method 8330

O;
ne

111 Colorimetric
142 Acetone HPLC
135 Method 8330.

Figure 5. Sampling scheme for short-range heterogeneity study (HMX concentrations are
shown from subgrid D2B). Numbers 1-7 are discrete samples collected in a localized area.

Values are in milligrams/kilogram.

and between these two tanks was unvegetated.
Behind tank D, the soil was moist and moss cov-
ered. In the initial stage of the investigation, pre-
liminary soil samples were collected in two areas
to assess the near-surface concentration gradient
of HMX and TNT with soil depth. This sampling
was done using a 2.5-cm soil corer, and samples
were collected over two depth regions: 0 to7.5cm
and 7.5 to 15 cm. Colocated surface samples (0-
2.5 cm) were also collected for comparison. Cores
were divided in the field and returned to the
sample processing area in plastic bags.

The second set of soil samples was collected
near tank D (in an area subsequently labeled
subgrid D2B) to provide an estimate of short-
range heterogeneity in HMX and TNT concentra-
tions that could be compared with results ob-
tained for other explosives-contaminated sites
(Jenkins et al. 1996). For this portion of the work,
a plastic template was placed on the ground with
the center at the selected sampling location, and
seven samples were collected in a wheel pattern,
with sample number 1 in the center (Fig. 5). The
radius of the wheel was 61 cm and samples ar-
ranged around the wheel were separated by 61
cm. All seven soil samples were collected from 0
to 15 cm using a manual 5.6-cm-diam. stainless-
steel hand auger. Vegetation when present was
removed. Cores were transferred to plastic Ziploc
bags and taken to a processing area. The auger

was carefully cleaned with a brush prior to its
next use.

Based on the results of the on-site analyses
from the first two sets of samples, we divided the
area around tanks C and D into ten 6-x 6-m grids
(labeled D1 through D10, and C4 and C5) and
subdivided each grid into four 3- x 3-m subgrids
as shown in Figure 4. Subsequently the Canadian
researchers alone added grids C6 through C10
and D11. These samples were analyzed only by
Method 8330. The following procedural details
applies only to the characterization of the first 10
grids. Samples within each subgrid were obtained
as follows. A spading shovel was used to scrape
the top 5 cm of soil from a 20-cm wide circular
path of radius 77 cm located in the center of each
subgrid; this path sampled about 10% of the sur-
face within the subgrid (Fig. 6). The soil scraped
from the surface was piled in the center of the
circle and mixed thoroughly with the spading
shovel and a small hand shovel (Fig. 7). Pieces of
metallic and ceramic debris from munition deto-
nation were removed by hand and a subsample
of about 1 kg of soil was collected from random
locations in the pile. Duplicate portions of soil
from these soil piles were collected in nine ran-
domly selected subgrids from a total of 40 to as-
sess the degree of uncertainty due to subsampling
the piles. Samples prepared in this manner were
designated area integrated. In these same nine



DATA FOR GRID C5
HMX Concentration (ug/g)

2:Am-DNT and 4-Am-DNT Concentration (9/9)

Presence of RDX in acetone extract confirmed by GC-ECD.

37

GRID] Sub: Field Analytical] Lab Field] Acetone GRID] Sub Field JAnalyticall Lab] Acetone ] Acetone
NUMBER Sampling] Rep. | 8330 [Colorimetric] HPLC NUMBER Sampling] Rep. | 8330 | HPLC HPLC
Rep. AcN Rep. AcN_| 4-am-DNT | 2.Am-DNT
cS a a 360 76r 3aT io ry a o7 a 0.30
b 530 b og
mean= | 545 mean= | 0.8
5 @ 38 7 108 cy a 13 028 029
b 130 b 12
mean= | 114 mean= | _13
tc 3 78 725 aa e 2 3 Ts vat
b 150 b 12
mean= | 114 mean= | 09
D a 540 307 Ba D ar <3 a va
b 620 b <03
mean= | 580 mean=
Comp a 250 195 208 comp = 75 z a3
b 520 165 479 . ta 0% 023
mean= | 385 180 194 . _ O33
Weak mean= | _1 —
‘ABCD -a 319 242 228 ss
ABCD-b 358 Presence of amino-DNTs in acetone extract confirmed by GC-ECD.
‘ABCD 338
Comp 385 180 194
TNT Concentration (9/9)
GRID] Subgrid] Field [Analytical] Lab Field] Acetone] DTech
NUMBER Sampling) Rep. | 8330 [Colorimetric] HPLC
Rep. AcN
ry a O7 58 a4 | 12015
b 09
mean= | 08
5 a 82 14 ZaDNT | 15103
b 14 linterferencet
mean= | _4.8
c a <0.5 <d = [OSes
b 08
mean=
D a 78 28 ZaDNT |3010 40
b 67 interference?
mean= | __73
Comp. a 62 48 43 [40050
35 1.6 12 [051015
49 32 28
Weans =
ABCD -@
‘ABCD -b 18
‘ABCD
TINT in acetone extracts confirmed by GC-ECD. Found concentrations were 1.9 and 2.6 gig for
C5B and CSD, respectively
Other Nitroaromatics Concentration (u1g/9)
ROX Concentration (ua/g) GRID] Subgrid | Field [Analytical] Lab | Acetone Tab
GRID | Subgrid | Field Analytical! Lab | Acetone NUMBER Sampling] Rep. |8330AcN| HPLC | 8330 AcN
NUMBER Sampling] Rep. | 8330 | HPLC Rep. TNB and DNB |2,4-and 2,6-|
Rep. AcN DNT
cS rN a =1.0 O3T cs ry 2 3 trace 03
b <1.0 b <0.3 03
mean= mean=
5 a <0 020 8 a <3 a 04
b <10 b <0.3 04
mean= mean=
c @ <10 a c a OS a 06
b <10 b <0.3 <0.3
mean= mean=
D a <10 705 D at 03 a os
b <10 b <0.3 <0.3
mean= mean=
Comp. a <0 a Comp. a os a A
<1.0 a b <03 d 14
mean: 18

were 4.2 and 17 gig for C5B and CSD, respectively.

TDNTs in acetone extract confirmed by GC-ECD. Found concentrations of 2.4-DNT;



was substantial and similar in magnitude to those
documented in an earlier study of TNT, DNT,
and ammonium picrate (Jenkins et al. 1996).
Using the results from the on-site HMX method,
the standard deviation due to sampling error was
11 times that due to analysis when discrete core
samples were used for characterization. The use
of on-site sample homogenization and composit-
ing of discrete soil samples and the use of 20-g
subsamples of soil for analysis were shown to
minimize the problems caused by short-range
spatial heterogeneity.

Midscale spatial heterogeneity

The degree of midscale spatial heterogeneity
of explosives contamination was assessed for the
first time at CFB-Valcartier. The site was divided
into sixteen 6- x 6-m square grids, and each grid
was further subdivided into four 3- x 3-m sub-
grids. Analysis of replicate samples from nine
randomly selected subgrids indicated that we
were generally able to reproduce results within a
factor of two, using a simple integrating method
that samples about 10% of the surface within the
subgrid.

The variability of the concentrations in the four
subgrids making up a geographically defined
grid area was also estimated and found to aver-
age about 5 when concentrations were above 50
mg/kg. Even in the presence of this substantial
spatial heterogeneity, we were able to produce
grid-composite samples from the four area inte-
grated subgrid samples that were in good agree-
ment with the arithmetic mean of the four. The
mean difference observed for the 10 grids where
this was evaluated was about 20% with values
never differing by a factor greater than about 2.

Accumulation of explosives residues
at an active antitank firing range

This study documented, apparently for the first
time, the levels of explosives residues that accu-
mulate in the soil at an active firing range. HMX
accumulated in the surface soils to a much greater
degree than did TNT, the other major component
in the melt-cast explosives used in the 66-mm
M72 rocket fired at CFB-Valcartier. Concentra-
tions of HMX as high as 2000 mg/kg were found
in surface soil near to the targets. This concentra-
tion appears to be too high to be due to residues
from detonations and may have resulted from
rupture of unexploded rockets and ejection of
particles of the explosives. The much lower accu-
mulation of TNT in these soils is probably due to

25

the rapid biotransformation of TNT to amino-
DNTs, and rapid leaching or chemi-sorption (bind-
ing) of the amino metabolites (Thorne and Leggett
in press).

CONCLUDING REMARKS

The ultimate goal of site characterization ac-
tivities is to provide sufficient information so that
informed decisions can be made about the devel-
opment of an optimal approach for remediation
when it is required. To accomplish this goal, po-
tentially contaminated sites are generally divided
into small geographically defined units (grids),
and samples are collected and analyzed to char-
acterize the concentrations of contaminants within
these zones. The dimensions of these grids can
range from tens of meters on a side to hundreds
of meters on a side and often a single core sample
is collected within the grid, divided into depth
intervals, and the various depth related samples
analyzed at an off-site commercial laboratory.
Decisions regarding the need for cleanup are
made by comparing contaminant concentrations
obtained from sample analysis to action levels
determined by risk assessment.

An unstated assumption of this approach is
that the concentration of contaminants of interest
in the samples collected and analyzed adequately
represents the average concentration of those con-
taminants at the collected depths within grid
boundaries. Discussion with both the personnel
conducting site characterization activities and
those within the government that oversee these
activities indicate that some of the shortcomings
of this approach are recognized, but that financial
considerations preclude the analysis of sufficient
numbers of samples to adequately address the
problem. The high cost of laboratory analyses, in
particular, is often quoted as an impediment to
the analysis of the required number of samples to
truly characterize the distribution of contaminants.

Explosives represent a fairly unusual set of en-
vironmental contaminants. The most commonly
encountered secondary explosives are solids at
environmental temperatures and were generally
released into the environment as particulates. Thus
the bulk of contamination generally resides in
near surface soils. These explosives have low
vapor pressures and hence no special precautions
are needed during sample collection to mitigate
vapor losses. They are relatively polar, particu-
larly for neutral organic compounds, and do not



2-Am-DNT and 4-Am-DNT Concentration (19/9)

GRID] Subgrid jeld [Analytical] Lab] Acetone | Acetone
NUMBER Sampling] Rep. | 8330 HPLC HPLC
Rep. AcN | 4-Am-DNT_|2-Am-DNT.
Dio ry a <O3 <i <a
b <03
mean
AR 1 a <0.3 <d <d
b <0.3
mean
AA 2 a <03 <d <d
b <0.3
mean
B a <0.3 <d <d
bd <0.3
mean
c a <0.3 <d <i
’ <0.3
mean
D a <0.3 <4 <d
b <03
mean
ABCD Comp a <0.3 <d <d
b <03 <d <d
mean
Other Nitroaromatics Concentration (ug/g)
GRID] Subgri Field [Analytical] Lab | Acetone Tab
NUMBER Sampling] Rep. |8330AcN| HPLC  |8330 AcN
Rep. NB and DNB 2,4- and
2,6-DNT
Dio * a <0 <a 03
b <0.3 <03
mean
AA 1 a <0.3 <i <0.3
> <03 <03
mean
AA 2 a <0.3 <d <0.3
b <0.3 <03
mean
8 a <0.3 <d <0.3
ry <03 <0.3
mean
c a <0.3 <d <0.3
b <0.3 <0.3
mean
° a <0.3 <d <0.3
b <03 <0.3
mean
ABCD Comp a <0.3 trace <0.3
b <03 <d <0.3
mean

42



1983, McCormick et al. 1984), but biodegradation
of both are thought to be primarily anaerobic pro-
cesses.

Analysis of explosives residues
remaining on metallic debris

Although the site had been “cleared” by safety
personnel prior to site characterization, the ground
was littered with small pieces of metallic debris
from detonated projectiles, empty rocket bodies,
fins and booster cups. A 7-g sample of metallic
debris was collected and subsequently extracted
with acetone in the CRREL laboratory. RP-HPLC
analysis revealed the presence of HMX and TNT
at 50 mg/kg and 0.1 mg/kg, respectively. The
higher residual HMX is probably due to its lower
aqueous solubility and rate of dissolution com-
pared with TNT. The concentrations associated
with this debris do not seem to be high enough to
be the major mode of contamination for the soils
at CFB-Valcartier, but does demonstrate that not
all the explosive charge is consumed during deto-
nation.

GC comparisons

The GC proved to be useful for analyte confir-
mation following HPLC analysis, especially for
confirmation of DNT. For example, when acetone
extracts were analyzed by HPLC using the LC-
CN column, a peak eluting just prior to the reten-
tion time for TNT and corresponding to the reten-
tion time for DNT was observed in several samples
(Fig. 8). Because of the close retention times for
these two analytes on LC-CN, the analytes are not
resolved if one analyte is at a much higher con-
centration than the other. Based on site character-
ization conducted prior to this study, the pres-
ence of DNT was not anticipated; hence confir-
mation was required. Analysis of the acetone
extracts by GC confirmed the presence of DNT,
and permitted quantification of the lower concen-
tration analyte (Fig. 9).

SUMMARY AND CONCLUSIONS

On-site methods

The results of this study provide information
in a number of areas that should be quite useful
for planning site characterization activities at ex-
plosives-contaminated areas. First, the utility of
on-site methods for obtaining concentration esti-
mates for TNT and HMX is clearly demonstrated.
Colorimetric methods for HMX and TNT pro-

24

vided concentration estimates that were essen-
tially equivalent to those from the standard labo-
ratory method. Linear correlation analysis for
HMxX results from the on-site colorimetric method
with a laboratory HPLC method using the same
acetone extract resulted in a slope of 1.008 and a
correlation coefficient of 0.992; the intercept was
small and nonsignificant at the 95% confidence
level. Correlations of the on-site HMX results with
those from Method 8330 conducted at an inde-
pendent commercial laboratory were also good,
but less so. The slope of the model with intercept
for this analysis was 1.016 with an intercept of
-25.0 and a correlation coefficient of 0.972. The
poorer relationship found here was attributed to
the analysis of separate subsamples of soil, rather
than the analysis of aliquots of the same extract
used in the former comparison.

For TNT, a similar correlation of the on-site
colorimetric result with that from HPLC analysis
of the same acetone extract resulted in a slope of
1.05, and intercept of 0.63 (significant at the 95%
confidence level), and a correlation coefficient of
0.975. No correlation with Method 8330 results
was obtained due to substantial variability en-
countered among subsamples for TNT, which was
present at much lower concentrations than HMX.
This result indicates that care should be used when
comparing results from on-site and laboratory
analyses conducted with separate subsamples,
unless soils are homogenized carefully before
splitting.

It is important to remember that the results from
these on-site colorimetric methods were available
to site investigators the day following soil sample
collection, allowing their use to adjust site activi-
ties to reflect an increasing knowledge of con-
taminant distribution. The use of EIA RDX tests
was abandoned after the first set of samples, since
HMx is present as the main contaminant and the
cross-reactivity for this nitramine is not adequate
to provide sensitive detection. The comparison of
results from the D TECH EIA method and those
from acetone HPLC for TNT determination led to
a slope of the linear model of 0.69 with an inter-
cept of 1.24 and a correlation coefficient of 0.91,
which indicates a somewhat poorer correlation
between the two methods compared to the excel-
lent general correlation observed between the colo-
rimetric and acetone HPLC methods.

Short-range spatial heterogeneity
Short-range spatial heterogeneity of HMX con-
centrations at the CFB-Valcartier antitank range



Assessment of Sampling Error Associated with
Collection and Analysis of Soil Samples at a
Firing Range Contaminated with HMX

THOMAS F. JENKINS, MARIANNE E. WALSH,
PHILIP G. THORNE, SONIA THIBOUTOT, GUY AMPLEMAN,
THOMAS A. RANNEY, AND CLARENCE L. GRANT

INTRODUCTION

Background

Recently, we reported large short-range spatial
heterogeneity of explosives contaminant concen-
trations in surface soils at explosives-contaminated
sites (Jenkins et al. 1996). Nine locations were
sampled at three installations; the sampling loca-
tions varied in the principal contaminant present,
mode of contamination, and soil type. Seven dis-
crete samples were collected at each sampling
location from a 1.22-m circle. The samples were
analyzed on-site using colorimetric methods
(Jenkins and Walsh 1992), and in the laboratory
using SW846 Method 8330, the standard reversed-
phase high performance liquid chromatography
(RP-HPLC) method for the determination of
nitroaromatics and nitramines in soil (EPA 1995).
The results indicated that regardless of whether
the major contaminant was 2,4,6-trinitrotoluene
(TNT), 2,4-dinitrotoluene (DNT) or ammonium
picrate (AP), or whether on-site or laboratory re-
sults were used, extreme heterogeneity in con-
taminant concentrations was found among the
seven samples at each location. Ratios of the high-
est concentration obtained among the seven dis-
crete samples divided by the lowest of the seven
ranged from about 3 to greater than 600, with a
mean value of about 73 (median value was 50).

These results have implications for developing
sampling designs to characterize explosives-
contaminated sites, if data are expected to repre-
sent average site conditions. For example, the TNT
concentration at one location varied from about
40,000 mg/kg for one discrete sample to only

about 150 mg/kg for a second discrete sample
collected only 61 cm distant. Either of these were
legitimate discrete samples that could be used to
represent this grid location, according to typical
sampling plans now being used at explosives-
contaminated installations. Very different deci-
sions relative to the need for site remediation
might be made, though, depending on which of
these results happened to be the sample collected
to represent the grid location.

A positive result from this work, however, was
the demonstrated ability to prepare composite
samples on site that were a good physical average
of the mathematical mean of the discrete samples
making up the composite (Jenkins et al. 1996).
The use of composite sampling with on-site analy-
sis provides an attractive alternative to the con-
ventional use of discrete sampling strategies and
analysis at off-site laboratories.

While a fairly large body of information is avail-
able relative to explosives concentrations at sites
impacted by manufacturing operations (Walsh et
al. 1993), very little information is available on
the levels of accumulation of explosives residues
at active firing ranges. In addition, we have been
unable to locate reports of site characterization
where HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-
tetrazocine) (Fig. 1) was the principal contami-
nant. We recently reported that a colorimetric on-
site method for RDX (hexahydro-1,3,5-trinitro-
1,3,5-triazine) would detect HMX (Jenkins et al.
1995), but no on-site evaluation of this method for
quantitative estimation of HMX has been reported.

The firing range characterized in this study is a
Canadian antitank firing range, which had been



Table 4. Comparison of HMX concentration estimates (mg/kg) using the on-site
colorimetric results for individual subgrids, mean of four subgrids, and grid com-

posites.
_ Subgrid a Subgrid
Grid no. A B c D Mean Composite _% Diff.*_variability**
D1 120 121 32 59 83 80 3.6 3.8
D2 279 271 316 ca 227 212 6.6 77
D4 631 148 254 680 428 479 119 46
DS 53 33 86 54 57 41 28.1 26
D7 209 1000 729° 1140 770 812 55 55
D8 878 286 202 208 394 322 18.3 43
D9 10 180 20 14 56 35 375 18.0
Di0 25 5.1 24 64 98 47 52.0 10.4
c4 1910 721 995 2160 1447 1636 13.1 3.0
cs 461 79 129 301 242 180 25.6 5.8
Means 371 380 Mean (all) 6.6
Mean (except D9 and D10) 4.7
Paired t-test (Composite vs. subgrid mean) t= 0.382"
% Diff. Mean (all values) 20.2%
% Diff. Mean (cone. > 50) 14.1%

* Absolute value of [100% — (composite /subgrid mean x 100)].
** Highest subgrid concentration/lowest subgrid concentration.
* Composite and mean of subgrids not significantly different at 99.9% confidence level.

Table 5. Comparison of measures of analytical precision, accuracy and discrete sample representa-
tiveness for CFB-Valcartier (CFB-V) results relative to those found for other explosives analytes at
Monite (M), Hawthorne (H), and Volunteer (V).

Precision __ Accuracy Local heterogeneity
Largest Ratio of highest mean
concentration Slope of concentration vs. lowest
Sample RSD of duplicates ratio of duplicates O-intercept model for discrete samples
location On-site Lab On-site Lab On-site vs. lab On-site Lab
CFB-V (HMX) 69 19.2 1818 2.537 0.988 20.2 34.3
CFB-V (INT) ” “ 16 36 1.051" >7 7
M-1 (INT) 39 m1 1.157 1.473 0.815 243 315
M-2(DNT) 23.0 10.0 1.655 1.461 0.350 106 33.4
M-3 (INT) 16.7 65 1.822 1.186 1.464 50.0 98.1
H-4 (TNT) 125 135 1.696 1.986 091 69.0 58.1
H-5 (TNT) 33 49 1.126 1.157 0.847 28.9 295
H6 (picrate) 116 19 1.500 1.875 0.967 688 43,000
V-7R (TNT) 49 51 1.265 1.214 0.677 38 3.0
V-8 (TNT) 19.7 45 1.731 1.185 1.070 53.1 55.6
v-9 (INT) 41 51 1.131 1.167 1.032 8.2 57
Mean
(INT only) 93 72 1.418 1.338 0.983 65.1 80.7

* Slope for model with intercept. Intercept was 0.63, but was found to be statistically significant at the 95% confidence

level.

** RSDs could not be computed because many values were less than detection limits for one of the duplicates.

15



2-Am-DNT and 4-Am-DNT Concentration (ig/9)

Other Nitroaromatics Concentration (ug/g)

*Presence of amino-DNTs in acetone extracts confirmed by GC-ECD.

52

GRID ‘Subgrid Field Analytical] Lab Acetone Acetone GRID ‘Subgrid Field JAnalytical] Lab ‘Acetone Lab
NUMBER Sampling] Rep. | 8330 HPLC HPLC NUMBER Sampling] Rep. |8330AcN| HPLC | 8330 AcN
Rep. ACN | 4-Am-ONT | 2-Am-DNT Rep. TNB aind DNB 2,4- and 2,6-
oy rN @ 32 a 736 ONT
b 52 oF a 3 <03 a 03
mean | 42 b <03 <03
mean
AA 1 a 28 1.04 0.84
b 35 cv 1 a <0.3 a <0.3
mean | 3.2 b <0.3 <0.3
mean
AA 2 a 04 1.02 091
b 24 AA 2 a <0.3 d <03
mean, 13 b <0.3 <0.3
mean
8 a 27 a 0.79
b 17 B a <03 d <0.3
mean | 52 b <03 <03
mean
c at 25 4 101
b 25 c at <0.3 < <03
mean | 25 b <0.3 <0.3
cc 1 at 35 131 1.07
b 28 cc 1 at <0.3 d <0.3
mean | 32 b <0.3 <0.3
cc 2 at 26 1.34 1.14 ‘ean
b 34 cc 2 at <03 a 05
mean | 29 b <03 <0.3
D a 73 a 237 meen
b 78 D a 05 < <0.3
mean | 7.4 . 08 42
mean
lABCD Comp. a 4 1.60 119
> 46 JABCD Comp. a <0.3 a 18
mean | 43 b <0.3 a <0.3
[Means mean
ABCD a a8
|ABCD -b 87 ——
{ABCD 48 "Presence of DNTs in acetone extracts confirmed by GC-ECD.
JA -AAt- 29
Jaz
JAA1 - AZ 22
lo-ccr 28
Icca
lect -co2 3.0



TNT Concentration (ug/g)

GRID ‘Subgrid Field [Analytical Lab Field Acetone | DTech
NUMBER sampling} Rep. | 8330 colorimetric] HPLC
Rep. AcN RDX Concentration (ug/g)
DS A a <0.3 <d 0.27 <0.5 GRID Subgrid Field |Analytical) Lab Acetone
b <0.3 <d <d <0.5 NUMBER: Sampling Rep. 8330 HPLC
mean= Rep. AcN
8 a <03 <a <a <05 DS ry a <10 a
> <03 <d <d <05 b 0 s
mean= meanz
c 2 03 TO a 05 5 + at z
b <03 <a <d | <05 : ae g
mean= mean=
D 2 <a a <a] 55 = 2 at 5
> <03 <4 <d | 05 a se of
mean= 7
ABCD Comp a <0.3 27 1.91 0.5 to 1.5 mean=
b <0.3 07 <d <0.5 D a <10 a
mean= 17 b <10 a
Wears mean=
RBCD a ABCD Comp a <0 O24
ABCD -b bd <1.0 a
ABCD mean=
Depth Sampled [Depth Samples}
D204") a <0.3 <d <d <05 D(2 to 4") a <1.0 ad
bd <03 b <1.0
mean= mean=
D4 to 6") a <0.3 <d <d <0.5 D(4 to 6") a <1.0 a
b <03 b <1.0
mean= mean=
Other Nitroaromatics Concentration (j:9/9)
2.Am-DNT and 4-Am-DNT Concentration (ug/9) RIO] Subgrid | Field Analytical] Lab] Acetone] Lab
GRID] Subgri Field [Analytical] Lab] Acetone] Acetone NUMBER Sampling] Rep. [8330 AcN| HPLC [8330 AcN
NUMBER Sampling] Rep. | 8330 | HPLC | HPLC Rep. TNB aind DNB
Rep. AcN 4-Am-DNT_[2-Am-DNT
De x 2 09 a O22 oS ry = <3 a <3
> 05 a 021 b <03 a <03
means | _07 0.22 mean=
3 2 <0.5 a 020 B 2 03 a 2S
> <03 a 013 > <03 a <03
mean= 0.17 mean=
tc 2 03 a ad T 2 Os a 2S
b <03 d 0.10 b <03 d <0.3
mean= mean=
D 2 2S a a D 2 Os a 2S
b <03 dt 0.22 b <0.3 dd <0.3
mean= mean=
ABCD Comp 2 06 a a6 ABCD Comp 2 S| trace P05
b <03 Jd 0.18 b <03 ad <0.3
mean= OAT mean=
Depth Sample Depth Sample:
D(2to4") a 04 ad d D2to4") a <03 Jd <0.3
b 0s > <03 03
mean= | 05 mean=
D (4106) a <03 a a D (4 to") a <03 d 03
b <03 b <03 <03
mean= mean=

32



DATA FOR GRID D8

HMX Concentration (ug/g)

RDX Concentration (9/9)

GRID. ‘Subgrid Field Analytical] Lab] Acetone
NUMBER Sampling] REP 8330 | HPLC
Rep. AcN
De ry a <0 a
’ <1.0
mean=
Cy a <0 a
b <1.0
mean=
c a a0 a
b <10
mean=
i} a <0 022
b <1.0
mean=
Comp, a = a
’ <1.0 0.14
mean=
Depth
Samples
B (to 4") a <1.0 0.51
b <1.0
mean=
B 4 t06") a <10 1.24
b <10
mean=

GRID] Subgrid Field JAnalytical] Lab Field] Acetone
NUMBER Sampling] REP | 8330 |Colorimetric! HPLC
Rep. AcN
Ds ry a 750 78 Ex
b 850
mean= | 800
S @ 260 286 258
b 440
350
Cc 720 202 787
150
135
D 740 208 175
190
165
Comp: ry 370 325 30
b 350 319 366
mean= | 360 322 338
oars, i ae:
ABCD-a 318 394 364
ABCD -b 408
ABCD 363
Comp. 360 322 338
Depth
Samples
B(Zt04") 520 560 477
540
530
B (4 106") a 870 1083 990
b 360
mean= | 465
TNT Concentration (ug/g)
GRID ‘Subarid Field [Analytical] Lab Field [Acetone] DTech
NUMBER Sampling] REP | 8330 |Colorimetric| HPLC
Rep ACN
ry ry a 24 2 7 | 161020
b 18
mean= | __2t
8 a 12 TS O77 | Ts0s
b 09
mean= | 1.1
c @ 13 78 Tit [1503
b 17
mean= | _15
D a 03 79 Tie [1513
b <03
mean=
Comp a 56 62 a1 | 4005
b 97 34 22 | 4105
mean= | 7.7 48 34
Means
ABCD-a 66 5.0
ABCD-b
ABCD
Depth Samples|
B2to4") a 15 17 1.11 [051015
b 18
means | 1.7
B (4 to 6") at 8 199 190 25
b 1.3
mean= | _1.55

THigh TNT concentration in acetone extract confirmed by GC-ECD

33



DATA FOR GRID D9

HMX Concentration (ug/g)

GRID] Subgrid Field [Analytical] _ Lab Field] Acetone
NUMBER Sampling} Rep. | 8330 |Colorimetric| HPLC
Rep AcN
DS x a 14 70 74
b 12
mean 13
B a 89 180 163
b 110
mean | 100
BB 1 a 65 116 128
b at
mean 73
8B 2 a 74 120 122
b 400
mean 87
c a 460 20 a1
b 12
mean | 236
cc 1 a 64 14 52
b 46
mean | 55
cc 2 a 73 5t 59
b 74
mean | 7.4
D a 23 “4 20
b 12
mean 18
ABCD Comp a 35 45 a7
b 32 26 40
mean 34 35 44
[Means 7 :
ABCD -a 147 36 35
ABCD - b 37
JABCD 92
IB -BB1 -BB2 87 139 138
leet -BB2 80 118 125
Ic-cc1 -cc2 83 24 28
loc - cc 64 26 32

48



Table 8. (cont'd)

TNT (mg/kg)
On-site On-site

Sample (colorimetric) (EIA) Acetone-HPLC Method 8330
D9Comp a L7 <05 <0.3 <0.3
D9Comp b 19 <05 <0.3 1.0
DIOA <l <05 <03 <0.3
DIOAA1 <l <05 <0.3 <0.3
D10AA2 <l <05 <03 <0.3
D10B <l <0.5 <03 <0.3
D10C <l <0.5 <03 <03
D10D al <05 <03 <03
D10Comp a < <0.5 <0.3 <0.3
D10Comp b <l <0.5 <0.3 <03
C4A 13 215 u 75
C4AA1 65 4.0-5.0 56 65
C4AA2 48 39 26
C4B 5.6 43 16
Cac rt 15.9" 48
c4CC 1 3.0 25 43
Cc4acc 2 17 3.4 47
c4aD 23 20 10
C4Comp a 19 16 39
5A 19 18 08
CSB 14 19" 48
fore <l <0.3 04
csD 26 2.6" 3
C5Comp a 48 4.3 62
C5Comp b 16 12 49

* Data from GC-ECD analysis.

Table 9. Apparent false positives and false negatives relative to Method 8330 results

for TNT.

Apparent false positives Apparent false negatives

Detection limit No. pos.* No. confirmed No. pos. byt No. detected

Method _(mughkg) on-site Method 8330 Method 8330 on-site
EnSys 10 48 41 36 32
Colorimetric
D TECH 0.5 44 38 45 35
Immunoassay
Acetone HPLC 0.3 49 42 52 42

* Concentration above detection limit of method.

* Concentration by Method 8330 was above the detection limit of associated confirmatory

method

ent false negatives. To put this in perspective,
though, 52 samples gave Method 8330 concentra-
tion estimates above the 0.3-mg/kg detection limit
of the acetone HPLC laboratory method, which
used the same acetone extracts as used by the
EnSys and D TECH methods. Of these, 10 were
classified as apparent false negatives by acetone
HPLC.

21

In terms of false positive analysis, the EnSys
method resulted in a positive response for 48
samples. Of these, 41 were confirmed positive by
Method 8330 while seven were non-detects. In a
similar manner, the D TECH method had 44 posi-
tive responses and 38 were confirmed by Method
8330, while six were non-detects. The acetone
HPLC method resulted in 49 positive responses



TNT Concentration (9/0)

ROX Concentration (19/9)

FINT in acetone extract confirmed by GO-ECD. Found concentrations were 15.9, 3.6 ygig and 4.1
for C4C, CACC1 and C4CC2, respectively

51

GRID] Subgrid | Field [Analytical Lab Field ‘Acetone | DTech GRID] Subgrid | Field JAnalytical] Lab | Acetone
NUMBER Sampling] Rep. 8330 [Colorimetric] HPLC NUMBER Sampling! Rep. | 8330 HPLC
Rep. ACN. Rep. ACN
ry x a a0 73 17 721015 cH a a <1.0 49
b 1 b <10
mean 15 mean
AA 1 a 20 65 56 4105 AA 1 a <10 1.68
b 1 b <1.0
mean 65 mean
AA 2 a 13 48 39 4105 AA 2 a <1.0 075
b 3.9 b <1.0
mean 2.6 mean
B a 10 56 43 4105 B a <1.0 1.65
b 24 b <1.0
mean 16 mean
c at 59 "1 2,4-0NT | 4.5109 c at <1.0 6.26
b 36 interference b <1.0
mean 48 mean
ce 1 at 27 3.0 2.5 4to5 ce 1 at 45 0.52
b 59 b <1.0
mean 43 mean
ce 2 at 43 17 34 405 cc 2 at 1.0 0.63
b 5.0 > 1.0
mean 47 mean
° a 1 23 20 121015 D a <1.0 7.33
b 97 b 13
mean 10 mean
|ABCD Comp. a 46 19 16 45109 |ABCD Comp a 13 1.15
> 31 35 1210 16 b <1.0
mean 3.9 27 mean
= ae BE SE
[ABCD - 77 13 2
ABCD _b "4 *Presence of RDX in acetone extracts confirmed by GC-ECD.
ABCD. 10
JA - At 55 8.0 68
laaz
JAA - AZ 46 57 48
lc-cct- 46 53
loc2
lect - cca 45 23 29



PREFACE

This report was prepared by Dr. Thomas F. Jenkins, Research Chemist, Marianne
E. Walsh, Chemical Engineer, and Philip G. Thorne, Research Physical Scientist,
Geological Sciences Division, Research and Engineering Directorate, U.S. Army
Cold Regions Research and Engineering Laboratory (CRREL), Hanover, New
Hampshire, Dr. Sonia Thiboutot and Dr. Guy Ampleman, Defence Research Es-
tablishment-Valcartier (DREV), Val-Bélair, Quebec, Thomas A. Ranney, Science
and Technology Corporation, Hanover, New Hampshire, and Dr. Clarence L.
Grant, Professor Emeritus, Chemistry Department, University of New Hamp-
shire, Durham, New Hampshire. Funding for participants from the United States
was provided by the U.S. Army Environmental Center, Aberdeen Proving Ground,
Maryland, Martin H. Stutz, Project Monitor. The Canadian portion of this study
was supported by funds from the Directorate of Ammunition Programme Man-
agement, Engineering Services, Department of National Defence, Canada.

The authors gratefully acknowledge Harry Craig (EPA Region 10), Charles
Collins (CRREL), Martin H. Stutz (AEC), and Dr. C.M. Reynolds (CRREL) for their
technical review of this manuscript. In addition, the authors acknowledge Jane
Mason, CRREL, for assistance in preparation of this report.

This publication reflects the personal views of the authors and does not suggest
or reflect the policy, practices, programs or doctrine of the U.S. Army or Govern-
ment of the United States. The contents of this report are not to be used for
advertising or promotional purposes. Citation of brand names does not constitute
an official endorsement or approval of the use of such commercial products.

ii



2.Am-DNT and 4-Am-DNT Concentration (ug/9)

GRID] Subgrid | Field [Analytical] Lab] Acetone | Acetone
NUMBER Sampling] Rep, 8330 HPLC HPLC
Rep. AcN | 4-Am-DNT | 2-Am-DNT
7 ry a 60 173 76
b 53
mean 57.
8 a 12 4.23 5.88
b 14
mean 13
c a 10 2.46 3.04
b 69
mean 85
cc 1 at 96 3.02 3.96
b 94
mean 95
cc 2 a 10 3.29 4.60
b 78
mean 89
D a 99 3.68 3.95
b 78
mean 89
ABCD Comp. a 14 3.30 3.75
b 10 272 3.06
mean 12 3.04 3.40
[Means
JABCD- oS 302 366
JABCD -b 85
Jasco 9.0
lc -ce1 -cc2 9.0 29 3.9
lect coz 92 32 43

"Presence of amino-DNTs in acetone extract confirmed by GC-ECD.

Other Nitroaromatics Concentration (ug/g)

GRID_| Subgrid | Field JAnalytical] Lab | Acetone Tab
NUMBER Sampling] Rep. |8330AcN| HPLC | 8330 AcN
Rep. TNBendDNB — |2,4- and 2,6-
DNT
oF ry a <03 <d o4
b <03 0s
mean 05
B a <0.3 <d 26
b <03 a8
mean 57.
c a <0.3 <d 08
b <03 04
mean 06
cc 1 at <0.3 <d 65
b <0.3 03
mean 34
ce 2 a <0.3 <d 04
b <0.3 15
mean 1.0
D a <0.3 <d 84
b <03 <03
mean
ABCD Comp. a <0.3 <d 63
b <03 <d 7
mean 67

“Presence of ONTS in acetone extract confirmed by GC-ECD.

40



DATA FOR GRID C6

Results from Method 8330
TANK] GRID |FIELD | LAB. | [HMX] | [ROX] | [TNT] | [2 + 4 Am DNT] | [TNB + DNB]
NUMBER | dupt. | dup. | ppm | ppm | ppm ppm ppm
c 6 m a B60 | <10 | 38 37 <03
c 6 A b 920 | <10| 6 4 <0.3
c 6 8 a 830 | <1.0] 38 24 <03
c 6 B b 240 | <1.0 | 26 33 <0.3
c 6 c a aso | <1.0 | 4.4 23 <0.3
c 6 c b 770 | <10| 8 24 <03
c 6 D a 940 | <1.0 | 47 37 <0.3
c 6 D b 960 | <t0 | 24 33 <03
c 6 |comp.} a aso | <10] 12 28 <0.3
c 6 |comp.} b 780 | <1.0 | 54 23 <0.3
MEAN
Cc é A |meantab.] 690 | <1.0 4 <03
c 6 8 |meanlab.| 835 | <1.0 29 <0.3
c 6 C |meantab.| 810 | <1.0 22 <0.3
c 6 D |meantab.| 950 | <1.0 35 <0.3
c 6 — |Comp.|meantab.| 815 | <1.0 26 <0.3
DATA FOR GRID D7
HMX Concentration (119/09)
GRID] Subgrid | Field JAnalyticall Lab Field] Acetone
NUMBER Sampling] Rep. | 8330 |Colorimetric} HPLC
Rep. AcN
D7 ry 3 420 208 228
b 330
mean | 375
8 a 1000 1001 1064
b 1000
mean _| 1000
c a 870 728 Tat
b 800
mean | 835
co 1 a 820 649 826
b 910
mean | 865
cc 2 a 820 845 940
b 950
mean_| 885
D) a 1400 1140 1012
b 1100
mean_| 1250
‘ABCD a 880 844 745
Comp.
b 780 781 649
mean_| 830 812 697
Means
[ABCD -3 923 770 761
JABCD -b 808
JABco 865
c-co1-cc2 862 744 836
lect -cca 875 747 883

38



Laboratory analysis
of acetone extracts

RP-HPLC

The RP-HPLC conditions were modified from
those in EPA Method 8330 (EPA 1995) to accom-
modate the change in extraction solvent from
acetonitrile to acetone, which absorbs in the UV
and can interfere with HMX and RDX determina-
tion. For each sample, 1.00 mL of the acetone
extract was mixed with 5.00 mL of reagent grade
water prior to analysis using an LC-CN column
(Supelco) eluted with 1:1 methanol:water at 1.2
mL/min. Absorbance was recorded at 254 nm on
a Spectra Physics Model 8490 variable wavelength
detector and peaks were recorded on a Hewlett-
Packard 3396 Digital Integrator operated in the
peak height mode.

The elution order for LC-CN is opposite that of
LC-18, and hence acetone did not interfere with
HMxX on LC-CN. Results from the LC-CN analy-
sis for some of the acetone extracts showed the
potential presence of high concentrations of 2,4-
DNT, which, due to the close elution times of 2,4-
DNT and TNT, prevented TNT determination
(Fig. 8). The compounds present in these extracts
and in some others that appeared to contain
HMx, and the amino-DNT transformation prod-
ucts of TNT, were confirmed by GC-ECD (gas
chromatography—electron capture detection) as
described below.

GC/ECD analysis

A 1.0-uL aliquot of the acetone extract was
directly injected (270°C) into an Hewlett-Packard
5890 gas chromatograph equipped with an elec-
tron capture detector (300°C). The tem-
perature of the dimethylpolysiloxane

fused silica column (J&W DB-1, 0.53 mm
ID, 6 m, 1.5-um film thickness) was held
at 100°C for 2 min, then ramped at 10°C/
min to 200°C, and 20°C/min to 250°C and
held for 3 min. The carrier gas was hydro-
gen (LV [linear velocity] = 150 cm/s).
Examples of the GC-ECD chromatograms
obtained for a standard and the same
acetone soil extracts depicted in Figure 8

are presented in Figure 9.

Laboratory analysis
using Method 8330

Subsamples of all the soil samples col-
lected for this study were sent to an inde-
pendent commercial laboratory for analy-
sis. Duplicate 2-g portions of soil were
analyzed using acetonitrile extraction and
reversed-phase HPLC as described in

EPA Method 8330 (EPA 1995).

g
D2B Z
4
a
eg
cace =
Ed
2
5
Ez
BIT Eq
Standard Z/| z
a
=

Water samples

Groundwater was collected from a
monitoring well located between the fir-
ing point and the target tanks. Surface
water was collected from two impact
craters near tanks A and B (located in the
upper reaches of the site). These water
samples were analyzed at DREV within

Retention Time (min)

one day of collection using Method 8330
by the salting-out solvent extraction pro-

Figure 8. HPLC chromatograms (LC-CN) for a standard and two _ tocol. Subsamples were refrigerated and
acetone soil extracts showing analytical difficulty in quantifying analyzed at CRREL three weeks later

TNT when large concentration of 2,4-DNT was present.

using HPLC and GC-ECD methods.



DATA FOR GRID C4

HMX Concentration (ug/g)

GRID | Subgrid | Field [Analytical] Lab Field] Acetone
NUMBER Sampling] Rep. | 8330 [Colorimetric] HPLC
Rep. AcN
oy rN a 7200 i315 7845
b 2000
mean | 1600
AA 1 a 1400 1172 1240
b 1500
mean | 1450
AN 2 a 740 1263 1355
b 1400
mean _| 1070
8 a 940 721 791
ry 1000
mean_| 970
c a 960 995 920
> 950
mean | 955
ce 1 a 1400 984 1056
bd 920
mean | 1160
ce 2 a 880 871 860
b 290
mean | 885
D a 1700 2156 2068
b 2100
mean_| 1900
JABCD Comp. a 1300 1272 1343
b 1500 1999
mean | 1400 1636
[Means
ABCD -a 1200 1447 1407
ABCD -b 1513
lAgco 1356
[A - AAI - 1373 1450 1481
[Aa2
JAA1 - AZ 1260 1218 1297
c-cct - 1000 950 945
coz
ect - cca 1023 928 958

50



These locations were subsequently labeled grids
D2 and D5. Cores were divided into two depth
intervals (0 to 7.5 cm and 7.5 to 15 cm). The two
core segments were each analyzed in duplicate,
while only a single analysis was conducted for
the surface samples.

The EIA RDX test was run on this first set of
samples to evaluate if it could be used to assess
HMX contamination. There is a cross-reactivity
response for HMX in the RDX explosive test kit,
as described by the D TECH documentation. It
was our goal to examine if this cross-reactivity

could be exploited to estimate the concentration
of HMX when present at high concentration in
soil samples. Results of the respective concentra-
tions of RDX determined by both EIA and HPLC
for the acetone extracts are reported in Table 1.
RDX was detected in only seven samples out of
30 samples analyzed by HPLC. However, a posi-
tive response was obtained for two-thirds of the
samples with the EIA D TECH test. This confirms
the low cross-reactivity toward HMX for the RDX
EIA test, leading to a high rate of false positives
for RDX determination in the presence of high

Table 1. Analytical results from initial samples used to assess depth of contamination.

Depth HMX (mg/kg) TNT (mghkg) RDX (mg/kg)
Grid location (cm) Color. on-site HPLC-acetone Color. on-site | HPLC-acetone EIA on-site _HPLC-acetone
D2 Location 1 Surface 593 524 a <l 4.0-5.0 1.56
D2 Location 1 075 341 424 2.9 15 0.5-1.5 0.24
480 344 16 12 45-60 3.27
D2 Location 1 75-15 84 78 <1 <1 0.5-1.5 <d
94 8.5 <i <1 <0.5 <d
D2 Location2 Surface 452 408 <1 <1 4.0-5.0 <d
D2 Location 2 0-7.5 322 284 <l <1 3.0-4.5 4.00
503 411 24 24 4.5-6.0 0.66
D2 Location 2 75-15 72 59 <l <1 3.0-4.5 <d
48 40 <1 <1 0.5-1.5 <d
D2 Location 3 Surface 599 636 <1 <1 >5.0 <d
D2 Location 3 0-7.5 410 400 48 46 1.5-3.0 <d
561 450 12 11 1.5-3.0 <d
D2 Location 3 75-15 12 ll <1 <1 1.5-3.0 <d
125 ill 19 1.6 05-15 0.35
D5 Location 1 Surface 55 70 <1 <1 0.5-1.5 0.27
D5 Location 1 0-7.5 41 36 <1 <1 0.5-1.5 <d
36 36 <1 <1 0.5-1.5 <d
D5 Location 1 7.5-15 77 21 <1 <1 <0.5 <d
11 4.0 <1 <1 <0.5 <d
D5 Location 2 Surface 142 141 <1 <1 0.5-1.5 <d
D5 Location 2 0-7.5 57 50 <1 <1 0.5-1.5 <d
48 35 <1 <1 <0.5 <d
D5 Location 2 75-15 2.3 23 <1 <1 <0.5 <d
7.0 5.9 <1 <1 <0.5 <d
D5 Location 3 Surface 66 88 <1 <1 0.5-1.5 <d
D5 Location 3 0-7.5 17 21 <1 <1 0.5-1.5 <d
10 15 <1 <1 <0.5 <d
D5 Location 3 7.5-15 1.9 18 <1 <1 <0.5 <d
19 18 <1 <i <0.5 <d

10



Special Report 97-22

US Army Corps

of Engineerse

Cold Regions Research &
Engineering Laboratory

Assessment of Sampling Error
Associated with Collection and
Analysis of Soil Samples at a

Firing Range Contaminated with HMX
Thomas F. Jenkins, Marianne E. Walsh, Philip G. Thorne,

Sonia Thiboutot, Guy Ampleman, Thomas A. Ranney,
and Clarence L. Grant September1997

Prepared for

U.S. ARMY ENVIRONMENT CENTER oe
Det DTIC QUALITY INEPECIED 6

DEPARTMENT OF NATIONAL DEFENCE, CANADA

Approved for public release; distribution is unlimited.



DATA FOR GRID C8
Results from Method 8330

TANK] GRID | FIELD] LAB. | [HMX)](ROX]| {TNT]| [2+4AmDNT] | [TNB+ DNB] |
NUMBER | dup! | dupl. | ppm | ppm | ppm Ppm ppm
c 3 x a ee [<0] 48 v8 Os
c 8 A b 64 | <t0] 19 09 <0.3
c 8 B a 150 | <1.0| 08 09 <0.3
c 8 B b 110 | <1.0 | <03 1 <0.3
c 8 c a 38 | <1.0 | <03 <03 <0.3
c 8 c b 13 | <1.0 | <03 <0.3 <03
c 8 D a 5.2 | <1.0 | <03 <03 <0.3
c 8 D b a9 | <1.0 | <03 <03 <0.3
c 8 |comp.| a 78 | <1.0 | <03 06 <0.3
c 8 |comp.| bv 54 | <10 | <03 O7 <03
EAN
c ry K[meantab] 65 | <10] 34 os <3
c 8 B |meantab.| 130 | <t.0| 08 4 <0.3
c 8 c |meantab.} 26 | <1.0 | <03 <0.3 <0.3
c 8 D |meantab.| 7.1 | <1.0 | <0.3 <0.3 <0.3
c 8 |comp.|meaniab.| 66 | <1.0 | <03 07 <03
DATA FOR GRID D5
HMX Concentration (9/9)
“GRID ‘Subgria Field Analytical] Lab Field] Acetone
NUMBER Sampling] Rep. | 8330 |Colorimetric] HPLC
Rep. AcN
DS ry 720 a7 359
67 60 687
94 53 62
5 20 50 198
17 17
13 33
c @ 28 80
b 28 164
mean= | __28 86
D a 5 7
b 87 40
mean= | 12 54
‘ABCD Comp a 34 62
87 19
Et 44
Means: &
‘ABCD -a a6 a
ABCD -b 30 70
ABCD 38 57.
Depth Samples|
D2to4") a 59 7 6.37
Ta
65
D(a tos") a 14 25 0.72
b 13
mean= | 1.4

31



methods. Here, separate subsamples were ana-
lyzed and subsampling heterogeneity increased
random error. The fact that Method 8330 specifies
only 2-g samples would also tend to increase the
impact of heterogeneity. Nevertheless, the slope
of this relationship is not significantly different
from 1.00 at the 95% confidence level which shows
that the two methods are not systematically bi-
ased. It is clear that the 30-minute on-site extrac-
tion with acetone provided equivalent extraction
efficiency for these soils to that for Method 8330,
which is an 18-hour ultrasonic extraction using
acetonitrile.

Concentration estimates
for TNT in subgrid and
grid-composite samples

As noted earlier, TNT concentration estimates
using on-site methods were much lower than for
HMX at CFB-Valcartier. Samples (n = 83) used to
assess short-range heterogeneity, as well as
subgrid and grid-composite samples were also
analyzed for TNT using 1) an on-site colorimetric
method (EnSys), 2) an on-site immunoassay

DREV TNT

“X Mean of all samples in grid,

bs 1
less duplicates <

method (D TECH), 3) the acetone HPLC method
described for HMX analysis, and 4) Method 8330
(Table 8). A diagram of the site with on-site colo-
rimetric results is presented in Figure 14. Of these,
concentration estimates for 31 samples were be-
low the detection limit of 0.3 mg/kg by Method
8330 (0.3 mg/kg is also the detection limit for the
acetone HPLC method), seven had concentrations
between 0.3 mg/kg and the 0.5-mg/kg detection
limit for the D TECH method, nine had concen-
trations between 0.6 and 0.9 mg/kg, the detection
limit for the Ensys colorimetric method, and 36
had concentrations at or above 1.0 mg/kg.

An assessment of the apparent rate of false
positives and false negatives produced by the on-
site and acetone HPLC methods, relative to the
Method 8330, results is presented in Table 9. Of
the 36 samples with concentration estimates at or
above 1.0 mg/kg by Method 8330, 32 were posi-
tive using the EnSys colorimetric method and only
four were apparent false negatives. Likewise for
the D TECH immunoassay method, 45 samples
were found to be above the detection limit of 0.5
mg/kg, and of these, 10 were classified as appar-

J oT Grid D7
O Location of sample Wheel for D28. Composite = 2.9
. Composite = 0.4 X18
Location of duplicate iv .
e p 43 0.7 X=1d ®
23
Gridc4 Grid C5 GridD1 Grid D2 OQ\€ © GridD4 Grid DS

®|©]|®|©

®

“ay

© ©|©

Ql ©|©

|

®©|®©
©|©

“ie Ss

TANK C Composite Composite — Composite Composite TANK D ‘Composite Composite
=23 =3.2 =<1 =1.2 3.4 =1.7
X=13 X=58 Xe<t X=20 ® Xe<1
Grid D8
® | © | Composite = 4.8
A__Ad B Bd Cc Cd Dod X=66
'Gridc4 | 13 57 | 5.6 | 4 24] 23 |
“GridC5 | 19 [14 <1 26 ore)
GridD1 <1 [<tt | <d [<i Grid D9
“Grid D2 3.2 [37 | ti | 37 <t_ | 15 ® Composite = 1.8
“GridD4 2.1 76 | <1 | 3.0 1) X=<l
(Grid DS. <1 iL <t 0.5 <i | S
(Grid 07 <1 2.0 | 15 | 57 36
‘Grids; 21 [15 | 18 19 1 Grid D10
‘GridDo | 1.7 [_<t | 09) <4 65 | a i Composite = <1
‘Grid 10, <1 at <1 et 7 ©Q|© Xe

Figure 14. Sampling area at CFB-Valcartier firing range site, showing TNT concentrations from on-site colorimet-

ric analyses.



Abstract: Short-range and mid-range (grid size) spa-
tial heterogeneity in explosives concentrations within
surface soils was studied at an active antitank firing
range at the Canadian Force Base-Valcartier, Val-Bélair,
Quebec. The range has been in use for over 20 years.
Intensive sampling was conducted over short distances
using a 6-m square grid (36-m?) pattern including two
target tanks. Sixteen grids were installed. Four area-
integrated surface samples were formed into piles, one
in each quadrant of each grid, using a circular pattern
that included about 10% of the top 5 cm of the quad-
fant. After in-situ homogenization of a pile, several
random aliquots were combined fo form a representa-
tive sample. Replicates were collected to assess the
fepresentativeness achieved. In addition, grid compos-
ites were prepared by combining equal portions of the

four subgrid samples for each of sixteen grids. In nine
of the subgrids, a second area integrated sample was
prepared. On-site analysis showed concentrations of HMX
Tanging from as high as 1640 mg/kg near one target to
2.1 mg/kg at a distance of 15 m from the target. On the
other hand, TNT concentrations were much lower than
would be expected based on the 70:30 composition ratio
of HMX fo TNT in the melt-cast explosive used on site. A
colorimetric method, originally developed to analyze for
RDX, was found to provide concentration estimates for
HMX that were in excellent agreement with laboratory
results. Spatial heterogeneity of HMX concentrations was
large on both short- and mid-range scales and this factor
dominated the overall uncertainty associated with site
characterization. Relatively minor uncertainties were due
fo analytical error.

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DATA FOR GRID D4

HMX Concentration (ug/g)

GRID] Subgrid | Field JAnalytical] Lab Field | Acetone
NUMBER Sampling] Rep. | 8330 | Colorimetric] HPLC
Rep. AcN
Ds ry ry 640 61 375
b 550
mean 595
AA 1 a 380 341 439
b 250
mean 315
AA 2 a 490 444 451
b 420
mean 455
B a 240 148 164
b 320
mean_| 280
c a 110 254 292
b 100
mean 105
D a 540 680 609
b 610
mean _| 575
|ABCD Comp. a 500 606 387
b 430 3562 362
mean_| 465 479. 354
ins. x SEs z
JABCD-a 383 428 410
|ABCD - b 395
|ABCD 389
[A -AA1 - AAZ 455 472 488
[AAI - AAZ 385 393 445
‘TNT Concentration (9/9)
GRID] Subgria [Analytical] Lab Field] Acetone | Dlech
NUMBER Rep. | 8330 |Colorimetric| HPLC
AcN
Da x a TT at 07 [osto1s
b 08
mean 1.3
AA 1 a o4 15 04 | 1.503
b <0.3
mean
AA 2 a o4 17 10 <0.5
b 04
mean 4
8 a 08 <d <d <05
b 06
mean o7
c a 06 3.0 13 <0.5
b <0.3
mean
D a 06 14 07 <05
b 06
mean 06
|ABCD Comp a 07 33 37 |151030
b 22 [0.51015
mean 3.0
Means:
|ABCD-a 093 22 08
JABCO - b
|ABCD
JA -AAt 18 07
lAa2
JAA - AA 16 07

43



worldwide and are considered as operational sites.
In the long run, this study might help to establish
recommendations that could minimize the im-
pact of such an activity on the environment.
Firing practices are an important operational
activity for the military and therefore cannot be
banned. In the present case, the major contamina-
tion is found in the top layer of the soil and simple
remedial actions could be proposed in order to
minimize the potential for leaching of the con-
taminants to the groundwater. In fact, such reme-
dial action will be carried out in the near future at
CFB-Valcartier, based on results obtained previ-
ously with the successful biodegradation of
nitramine-contaminated soils (Dubois et al. 1997,
Greer et al. 1997). At this site the contaminated
top layer of soil will be removed and a biopile
willbe constructed where a bioremediation treat-
ment will be applied. Afterward, a treatment fre-
quency will be established depending on the rate
of accumulation of contamination on the soil.

Overall our results, here and in an earlier study
(Table 11), demonstrate sampling error generally
contributes at least 10 times the uncertainty in
results for site characterization than does analyti-
cal error. If we hope to improve the quality of the
data used to make informed decisions, we must
find ways to reduce sampling error. The signifi-
cant effort that has been made to improve the
quality of environmental analyses has centered
on improving laboratory performance. Unfortu-
nately, while very well intentioned, this effort is
attacking only 10% of the total error. We recom-
mend the use of on-site sample homogenization,
compositing of discrete samples, and on-site
analysis, with appropriate confirmation of results
at an off-site environmental laboratory as a means
of addressing the larger problem.

LITERATURE CITED

Burrows, E.P., D.H. Rosenblatt, W.R. Mitchell,
and D.L. Parmer (1989) Organic explosives and
related compounds: Environmental and health
considerations. USA Biomedical Research and De-
velopment Laboratory, Fort Detrick, Maryland,
TR-8901.

Dubois, C.,G. Ampleman, S. Thiboutot, C. Greer,
J. Hawari, and G. Sunahara (1997) Bioremediation
of RDX-contaminated soil: A preliminary field
trial. Presented at the 90th Annual Air & Waste
Management Association, 8-13 June 1997, Toronto,
Ontario, Canada.

27

EPA (1995) Nitroaromatics and nitramines by
HPLC. Second Update, SW846 Method 8330. U.S.
Environmental Protection Agency.

Grant, C.L., T.F. Jenkins, K.F. Myers, and E.F.
McCormick (1995) Comparison of fortification vs.
field contamination for holding time estimates of
soils containing explosives residues. Journal of En-
vironmental Toxicology and Chemistry, 14: 1865-1874.
Greer, C., J. Godbout, B. Zilber, S. Labelle, G.
Sunahara, J. Hawari, G. Ampleman, S. Thiboutot,
and C. Dubois (1997) Bioremediation of RDX/
HMxX-contaminated soil: From flask to field. Pre-
sented at the Fourth International Symposium on In
Situ and On-Site Bioremediation, April 28-May 1,
1997, New Orleans, Louisiana.

Horowitz, W. (1982) Evaluation of analytical meth-
ods used for regulation of food and drugs. Ana-
lytical Chemistry, 54: 67A-76A.

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., M.E. Walsh, P.W. Schumacher, and
P.G. Thorne (1995) Development of colorimetric
field screening methods for munitions compounds
in soil. In Proceedings of Environmental Monitoring
and Hazardous Waste Site Remediation Symposium,
19-21 June, Munich, Germany.

Jenkins, T.F., C.L. Grant, G.S. Brar, P.G. Thorne,
T.A. Ranney, and P.W. Schumacher (1996). As-
sessment of sampling error associated with col-
lection and analysis of soil samples at explosives
contaminated sites. USA Cold Regions Research
and Engineering Laboratory, Special Report 96-15.
Jenkins, T.F., and M.E. Walsh (1992) Develop-
ment of field screening methods for TNT, 2, 4-
DNT, and RDX in soil. Talanta, 39: 419-428.
McCormick, N.G., J.H. Cornell, and A.M. Kaplan
(1984) The fate of hexahydro-1,3,5-trinitro-1,3,5-
triazine (RDX) and related compounds in anaero-
bic denitrifying continuous culture systems using
simulated wastewater. USA Natick Research and
Development Laboratory, TR 85/008. ADA
1490462.

Myers, K.F., E.F. McCormick, A.B. Strong, P.G.
Thorne, and T.F. Jenkins (1994) Comparison of
colorimetric and enzyme immunoassay field
screening methods for TNT in soil. USA Engineer
Waterways Experiment Station, Technical Report
IRRP-94-4, Vicksburg, Mississippi.

Spanggord, RJ., W.R. Mabey, T.W. Chou, S. Lee,
and P.L. Alferness (1983) Environmental Fate stud-
ies of HMX. Phase 2. Detailed Studies. Menlo Park,
California: SRI International. ADA145122.



2-Am-DNT and 4-Am-DNT Concentration (ug/g)

GRID_| Subgrid | Field JAnalytical] Lab | Acetone | Acetone
NUMBER Sampling] Rep. | 8330 | HPLC | HPLC
Rep. ‘AcN_|4-Am-DNT] 2-Am-ONT
D2 B 7 a 22 0.36 042
TNT Concentration (9/9) (Wheel) b 14 0.37 O41
GRID] Subgrid | Field [Analytical] Lab Field ‘Acetone mean | 18 O37 O82
NUMBER Sampling] REP | 8330 |Colorimetric| HPLC 2 a 0s 0.20 O21
Re "Aen b 03 0.13 0.15
D2 5 7 3 03 = <a mean | 04 O17 0.48
(wheel) b <03 14 < . i a) | oss | oss
z mean = os x mean _| 1.9 0.51 0.58
af 28 3 < 7 a 3} 081] 088
mean b 26 0.74 0.90
5 = aT = = mean | 28 077 0.94
i 03 4 4 3 a 34 O34 0.89
mean 03 bt 22 1.19 0.95
z = oT a a mean | 2.8 1.07 0.92
b 08 13 <d iG a 3 113 116
b 38 1.37 1.40
San CA SI oy 7 mean | 34 | 125 | 128
bt 03 26 2,4-DNT 7 a <03 0.64 077
mean 07 2.3 interference b 203 0.60 0.72
3 3 7 33 7a] mean _| <0.3 | 0.62 0.75
b 20 33 <d Comp. a 78 0.76 0.82
mean 47 43 > 19 0.72 0.76
7 7 < 7 © 0.67 0.73
> | iz a 020 mean_|_190 | 0.71 | _o77
mean 2.0 0.20 Means
Comp: a <05 a <d
b <03 <d <d 1-72" 24 0.65 0.72
c 14 O71 t-7bT 18 0.70 072
mean 4.77 19 0.68 0.72
TINT in acetone extract confirmed by GC-ECD. Found concentrations was 2.8 11g/9. "Presence of amino-ONTs in acetone extract confirmed by GC-ECD.
Substituted 0.3 for <0.3 in computation of mean for Lab 8330 ACN.
Other Nitroaromatics Concentration (\g/9)
ROX Concentration (19/9) GRID] Subgrid | Field JAnalytical] Lab Acetone | Lab
GRID] Subgrid | Field [Analytical] Lab ‘Acetone NUMBER Sampling] Rep. |8330AcN| HPLC | 8330 AcN
NUMBER Sampling] REP 8330 HPLC Rep. TNB anid ONS | 2,4-and
Rep. AcN 2,8-DNT
De ry 7 a <0 a Oz Cy T 2 <3 a <03
(Whee!) b <10 013 (Wheel) b <03 d <03
mean mean
2 a <9 oat z 2 <3 a <3
b <1.0 ad b <0.3 ad <03
mean mean
3 2 <1 34 3 a <3 | ace <5
b <10 d b <03 J 08
mean mean
a a <0 a 4 a 03 a 42
b <10 a b <0.3 a <0.3
mean mean
5 a 10 139 3 @ 03 a ra
eo <10 1.27 ot <03 a 62
mean 4:33 mean
é @ <0 0.26 6 a <3 a 38
b <1.0 0.50 b 03 a 23
mean 0.38 mean
7 a 70 Py 7 a os a os
b <1.0 < b <03 a <03
mean mean
Comp. @ 10 O73 Comp a <3 [Wace 05
b <1.0 ad > <03 @ 14
c PT c
mean mean

"Presence of RDX in acetone extract confirmed by GC-ECD.

36

'ONTsin acetone extract confirmed by GC-ECD. Found concentrations of 2.4-

DNT was 18 gig.



Sd ee TT
°
y= 1.05x + 0.63 .
20 r= 0.983
n=44 .

TNT (mg/kg) Using On-Site Colori

Correlation analysis was also con-
ducted on the numerical results from
the on-site colorimetric and acetone
HPLC analyses for the 41 subgrid and
gtid-composite samples where both
analyses resulted in a value above de-
tection limits (Fig. 15). The slope of
the linear model was 1.05 with an in-
tercept of 0.63; the correlation coeffi-
cient was 0.975. The slope was not
significantly different from 1.0 at the
95% confidence level, while the inter-
cept was significantly different from
zero at the 95% confidence level. This

pitittrpitipiitiriirtiris

TNT (mg/kg) Using Acetone HPLC Method

Figure 15. Correlation analysis of TNT concentration estimates from
the colorimetric on-site method with those front HPLC analysis of the

same acetone extracts.

while 42 were confirmed by Method 8330 and
seven were classified as false positives.

The agreement of samples with values above
detection using on-site methods, relative to
Method 8330, has been commonly used to com-
pute the percentage of false positives and false
negatives. Usually the lack of agreement has been
attributed to a failure on the part of the on-site
method. Yet if we look carefully at the data in
Table 8, clearly this interpretation is misleading.
For example, consider sample D9C where Method
8330 gave a concentration of 111 mg/kg, the high-
est value found, whereas the EnSys, D TECH and
acetone HPLC were all non-detects. Clearly this
is not a failing of the on-site methods, since three
independent methods using the same extract con-
cur that the concentration of TNT is low. More
likely this is due to a small chunk of TNT being
present in the subsample used for Method 8330
analysis. In fact the Method 8330 result presented
for TNT was actually a mean of duplicates; the
individual determinations on separate subsamples
were 220 mg/kg and 1.6 mg/kg, respectively. In
a similar manner, if we look at sample D9CC2,
the Method 8330 result for this sample was <0.3
mg/kg while those for the EnSys, D TECH and
acetone HPLC were 17 mg/kg, 12-16 mg/kg, and
15 mg/kg, respectively. This sample came from
the same subgrid as sample D9C discussed above.
Thus both spatial and subsampling heterogeneity
must be kept in mind when attempting to assess
false positives and false negatives with on-site
methods for explosives.

22

p
8B

indicates that the two methods pro-
vide very comparable results, with a
very slight positive bias in the results
from the colorimetric method. This
slight positive bias may be a result of
our decision to subtract twice the ini-
tial absorbance from the final absor-
bance, when computing the TNT concentration
using the colorimetric result (Jenkins 1990). EnSys
recommends subtracting four times the initial ab-
sorbance from the final absorbance (EPA Method
8515) and if we computed it using this approach,
the bias may have been eliminated. However, we
chose the factor of two, rather than four, to guard
against false negative results. Correlation of the
on-site colorimetric results with those from
Method 8330 was not conducted due to the large
problem with heterogeneity discussed earlier.

Correlation analysis was also conducted be-
tween the results from the D TECH EIA method
with those from acetone HPLC (Fig. 16). To con-
duct this analysis, we paired the result of the
acetone HPLC analysis with the midpoint of the
range produced by the D TECH test for the 40
samples, where both methods produced a result
above detection limits. When this was done, the
slope of the linear model was 0.69 with an inter-
cept of 1.24 and a correlation coefficient of 0.91.
Neither the slope or the correlation was as satis-
factory as with the colorimetric method.

Co-contaminants

At sites contaminated with TNT, co-contami-
nants may include biotransformation products (2-
amino-DNT, and 4-amino-DNT), photodegrada-
tion products (TNB), and manufacturing by-
products (DNT and DNB). In several of the grids
sampled at this site, we found both isomers of
amino-DNT, indicating that biotransformation of
TNT is taking place and this process likely con-



were collected for on-site analysis and for sub-
sequent laboratory analysis using Method 8330.
In all cases separate subsamples were used for
moisture content determination, and analysis
results were corrected to a dry weight basis.

Weighed portions from each of the four area-
integrated subgrid samples from within a grid
were combined and homogenized to prepare a
composite sample to represent each grid. Dupli-
cate 20-g portions were collected for on-site analy-
sis of each composite grid sample, and also for
area integrated subgrid samples for subgrids D2
and D5. We used the results from these dupli-
cates to compute analytical uncertainty, i.e., the
uncertainty associated with subsampling, extrac-
tion and analysis.

On-site sample
extraction and filtration

Each 20-g soil subsample was extracted with
100 mL of acetone. Based on a short extraction
kinetic study with the initial samples collected, a
30-minute extraction on a vortex mixer was
needed, rather than the 3-minute period specified
by the manufacturers of the on-site tests. The ex-
tracts were allowed to settle for at least 30 min-
utes and a 50-mL aliquot was removed from the
extraction bottle with a disposable Plastipak
syringe and filtered through a Millex SR filter
membrane. All samples collected by the joint
Canadian-United States team were analyzed
using the TNT and RDX methods by EnSys Cor-
poration (now Strategic Diagnostics, Inc.). Some
of the soil extracts were also analyzed using the
D TECH enzyme immunoassay TNT and RDX
methods (EM Science). The acetone extracts were
subsequently returned to CRREL and analyzed
using RP-HPLC separations similar to those
described in SW846 Method 8330 (EPA 1995).

On-site analytical methods

Colorimetric HMX method

The colorimetric method used to estimate HMX
at CFB-Valcartier was originally developed for
RDX (Walsh and Jenkins 1991) and is now com-
mercially available through EnSys as their RDX
field method. When RDX is either not present, or
present ata much lower concentration than HMX,
this method can be used to estimate HMX con-
centrations (Jenkins et al. 1995). The method is
based on the Franchimont and Griess reactions as
shown in eq 1:

NO,
|
a Acetic Acid
N \ + Zn ——————» 3HNO,
~~
onTM no,
RDX Franchimont Reaction (1897)

NH, no
NO + Q — Q )
R a
ne NR
eneeneeer,
2
A R

Azo Dye
Griess Reaction (1864)

Extracts were analyzed as described elsewhere
(Walsh and Jenkins 1991) except that the extracts
were not passed through an anion exchanger
prior to further processing. The use of the anion
exchanger is required to remove interferences
from nitrate and nitrite ions, often present in
areas where soils have been given chemical
fertilization. Since the history of this site was
known and fertilization had not been used, the
anion exchange step was eliminated.

A 5.0-mL aliquot of each acetone extract was
mixed with 0.5 mL of glacial acetic acid and
poured into the barrel of a 10-mL syringe loaded
with 0.3 g of zinc dust and equipped with a Millex
SR-filter unit. The plunger was fitted to the barrel
of the syringe and after 15 seconds of contact with
the zinc, the solution was filtered into a vial
containing 20 mL of deionized water and the con-
tents of a Hach NitriVer 3 powder pillow. The
vial was shaken to mix and allowed to stand for a
minimum of 15 minutes.

The development of a pink color is indicative
of the presence of either a nitramine such as RDX
or HMxX, or an organonitrate ester such as nitro-
glycerine (NG), nitrocellulose (NC) or penta-
erythritol tetranitrate (PETN). At the tank firing
range at CFB-Valcartier, the only munition fired
is an antitank device containing HMX and TNT,
and so the development of a pink color here
indicates the presence of HMX. Concentrations
of HMX were estimated by measuring the ab-
sorbance at 507 nm using a Hach DR/2000, a
battery-operated spectrophotometer. If absorbance
values were above 1.0, extracts were diluted with
acetone (3% water added) and re-analyzed.



RDX Concentration (ug/g)

GRID] Subgrid | Field [Analytical] Lab] Acetone
NUMBER Sampling] Rep. | 8330 ] HPLC
Rep ACN
Oe ry 2 <0 a
b <1.0
mean
AA 1 a <1.0 a
b <1.0
mean
AR 2 at <10 | 0.36
b <1.0
8 a <1.0 | 0.20
b <1.0
c a <1.0 “J
b <1.0
mean
D a <10 | 0.16
b <1.0
‘ABCD Comp. a <10 | 1.86
b <1.0 »
mean
‘Presence of RDX in acetone extract confirmed by GC-ECD.
2:Am-DNT and 4-Am-DNT Concentration (19/9)
GRID] Subgrid | Field | Analytical | Lab] Acetone | Acetone
NUMBER Sampling} Rep. 8330 | HPLC | HPLC
Rep AcN | 4.Am-DNT | 2.Am-
DAT
OF rN a aS Taz [153
b a6
mean 7.0
AA 1 a 3.0 109 | 1.10
b 22
mean 26
AA 2 at 33 098 | 103
b 32
mean 33
B a 18 032 | 029
b 17
mean 18
c a 12 o77 | 081
b 08
mean 1.0
D a 40 141 1.32
b 34
mean 37
JABCD Comp. 2 25 109 | 1.10
b 23 0.98 | 1.03
mean 24 1.03 | 1.06
[Means
[ABCD -a a4 058 0.88
JABCD - b 36
Jasco 34
l= Aat - 43 12 12
Janz
Jaat Anz 29 1.0 m1

‘Presence of amino-DNTs in acetone extracts confirmed by GC-ECD.

44

Other Nitroaromatics Concentration (119/9),

GRID] Subgrid | Field [Analytical] Lab | Acetone Tab
NUMBER Sampling] Rep. |8330 AcN| HPLC |8330 AcN
Rep. TNB and DNB 2,4-and
2,6-DNT
De ry a <3 a <3
b <0.3 <0.3
mean
AK 1 a <03 ad <0.3
<0.3 <0.3
mean
AA 2 a <0.3 ad <0.3
b <03 <0.3
mean
B a <03 Jd <0.3
b <03 <0.3
mean
c a <03 ad <0.3
b <0.3 <0.3
mean
D a <0.3 ad <0.3
b <03 <0.3
mean
JABCD Comp. a <0.3 trace <0.3
b <0.3 dd <0.3
mean



TNT Concentration (ug/g) RDX Concentration (ug/g)

GRID] Subgrid Field [Analytical] Lab Id] Acetone | DTech GRID] Subgria Field Analytical] Lab] Acetone
NUMBER Sampling} Rep. 8330 | Colorimetric] HPLC NUMBER Sampling] Rep. | 8330 HPLC
Rep. AcN Rep. ACN
2 x a 03 65 Be | 301040) 2 w a <0 zy
b <0.3 <d 03 | 3.0t040) b <1.0 0.47
mean | <0.3 3.0 mean
B a 10 5.6 5.1 | 4.01050) B a <1.0 0.49
b 06 18 1.3 | 1.5t03.0 b <1.0 0.92
mean 08 37. 3.2 mean O74
c a 38 22 trace <0.5 c a <1.0 0.24
b 38 <i 1.0 | 1.5t03.0 b <1.0 dd
mean 38 mean
cc 1 a 11 34 28 3t04 cc 1 a <1.0 0.22
b 12 b <1.0
mean 12 mean
cc 2 a 12 4.0 29 3104 ce 2 a <1.0 a
b 58 b <1.0
mean 35 mean
D a 14 <d trace <05 D a <1.0 a
b 04 <d 02 <0.5 b <1.0 a
mean 08 mean
DD 1 a 08 10 0.23 <05 oD 1 a <1.0 ont
b 0S b <1.0
mean 07 mean
io) 2 a 1.4 19 18 <05 pp 2 a <1.0 ad
b 08 b <1.0
mean 441 mean
‘ABCD Comp. a 06 14 09 <0.5 ABCD Comp a <1.0 d
b 06 09 06 | 05t0 1.5) b <1.0 o17
06 1.2 08 mean
ane a
ABCD -a
JABCD -b
ABCD
Ic-cc1 -co2 28
Icct -cc2 23 37 29
ID - 001 - poz 08
bot - poz 0.9 15 0.85

46



Chemicals and reagents

All standards for HMX, TNT and the other
explosives analytes were prepared from Standard
Analytical Reference Materials (6ARMS) obtained
from the U.S. Army Environmental Center,
Aberdeen Proving Ground, Maryland. Standards
of HMX and TNT in acetone were prepared using
OmniSolv grade acetone from EM Science.

All acetone used for soil extraction and glass-
ware cleaning was reagent grade obtained from
Anachemia. Methanol used in the laboratory for
preparation of HPLC eluents was either Caledon
or Sigma-Aldrich HPLC grade. Deionized water
from the DREV central system was used in the
field for cleaning, and for addition to extracts to
ensure that an adequate water content was present
for the color-forming reaction. Laboratory grade
water used for preparation of HPLC eluents at
CRREL was obtained from a Millipore Milli-Q
Type 1 reagent grade water system.

Statistical analyses

To detect significant concentration differences
among the seven sample positions for the short-
range heterogeneity study (wheel samples from
D2B), we subjected analytical results for HMX
from the on-site colorimetric method, from the
acetone HPLC method, and from Method 8330 to
one variable of classification, completely random-
ized analysis of variance (ANOVA) using
Microsoft Excel 5.0. Since the ANOVA demon-
strated significant differences among sample
positions for this sampling location, least signifi-
cant differences (LSDs) were computed to iden-
tify specific differences. Variances were fraction-
ated to yield estimates of the standard deviations
for subsampling plus analysis (S,4) and for sam-
pling error (Sg). All references to analytical error
for this portion of the study should be under-
stood to include contributions from mixing and
subsampling, extraction, dilution, measurement
and concentration computations, while

IE
2
\6

=

1s

— TNT

RDX
4-Am-DNT
2-Am-DNT

=
t

2B sampling error refers to spatial heteroge-
neity at the sampling location. We also
computed means and standard deviations
of duplicates, overall means of the seven
duplicates, plus means and standard de-
viations of composites. Analytical preci-
sion of the seven duplicates for each sam-
pling location and each analysis method
was expressed as the average of the seven

RSDs (relative standard deviations).

— TNT
HMX|

4-Am-DNT
2-Am-DNT

Intensity

— ROX

6-DNT
2,4-DNT

LJ

cace Correlations based on the linear least
squares model with intercept were made
between the HMX results from the on-
site colorimetric method and both the
Method 8330 results and those from
acetone HPLC analysis. Computations
were conducted separately for the results

A from the short-range heterogeneity study

and for the data from subgrid and grid-

composite samples. Intercepts were tested

TNT
RDX|

2,6-DNT E 1
a

4-Am-DNT
2-Am-DNT|

HMX

—— 2,4-DNT

DNB.

—— TNB

|
\!
| \|

UL pO

Standard to determine whether they were signifi-
cantly different from zero at the 95%
confidence level. When appropriate, zero
intercept models were fitted.

RESULTS AND DISCUSSION

Depth of contamination

Retention Time (min)

In the initial stages of this work we
collected three 0-15-cm cores plus three

Figure 9. GC-ECD chromatograms for a standard and two ac-  colocated 0-2.5-cm surface samples at

etone soil extracts.

each of two locations near target tank D.