ASTM D7203-05

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 7203 – 05
Standard Test Method for
Screening Trichloroethylene (TCE)-Contaminated Soil Using
a Heated Diode Sensor
This standard is issued under the fixed designation D 7203; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Summary of Test Method
1.1 This test method describes a procedure for screening 4.1 To estimate the concentration of TCE in a soil known to
soil known to contain the halogenated volatile organic com- contain TCE contamination, a sample of the soil is added to a
pound (HVOC), trichloroethylene (TCE), by measuring the glass jar having an open-top cap with a PTFE-bonded silicone
TCE concentration in the headspace above a sample of the soil septum.At the time of screening, the temperature of the soil in
using a heated diode sensor device. From this measurement, an the jar should be approximately 50 to 120 ºF (10 to 49 ºC).The
estimated concentration of TCE in the soil can be determined. soil in the jar is shaken and allowed to settle for 10 min, so the
Any TCE remaining in the soil sample is not measured by this TCE can partition into the headspace above the soil. After 10
test method. Any other HVOC present in the soil will be min,theTCEconcentrationintheheadspaceismeasuredusing
reported as TCE. a heated diode sensor device, which gives a numerical voltage
1.2 This test method can also be used for screening the reading. The voltage reading from the device is converted to a
headspace above a soil suspected of containing HVOC con- mg/m value of TCE in the headspace in the container. Using
tamination to indicate the presence or absence of HVOC this value, an estimated concentration of TCE in the soil in
contamination in the soil. Any HVOC contamination remain- mg/Kg can be calculated. Any TCE remaining in the soil
ing in the soil is not detected by this test method. sample is not measured by this test method. Any other HVOC
1.3 This standard does not purport to address all of the present in the soil will be reported as TCE.
safety concerns, if any, associated with its use. It is the 4.2 To use this test method to screen a soil suspected of
responsibility of the user of this standard to establish appro- containing HVOC contamination, a sample of the soil is added
priate safety and health practices and determine the applica- to a glass jar having an open-top cap with a PTFE-bonded
tion of regulatory limitations prior to use. silicone septum. At the time of screening, the temperature of
the soil in the jar should be approximately 50 to 120 ºF (10 to
NOTE 1—The diode sensor is heated to temperatures ranging between
49 ºC).The soil in the jar is shaken and allowed to settle for 10
approximately 600 and 1000 ºC (see 6.6) and as a result could be a source
min, so the HVOC can partition into the headspace above the
of ignition.
soil. After 10 min, the heated diode sensor device is used to
2. Referenced Documents
screen the headspace in the container. The numerical voltage
reading from the device indicates the presence or absence of
2.1 ASTM Standards:
HVOC contamination in the soil. Any HVOC contamination
D 4547 Guide for Sampling Waste and Soils for Volatile
remaining in the soil is not detected by this test method.
Organic Compounds
E 131 Terminology Relating to Molecular Spectroscopy
5. Significance and Use
3. Terminology
5.1 The heated diode sensor device used in this test method
is selective for HVOCs. Other electronegative compounds,
3.1 Definitions—Fordefinitionsoftermsusedinthisscreen-
such as alcohols, ketones, nitrates, and sulfides, may cause a
ing test method, refer to Terminology E 131.
positive interference with the performance of the heated diode
sensor to detect HVOCs, but to do so, they must be present at
This test method is under the jurisdiction of ASTM Committee D34 on Waste
much higher concentrations than the HVOCs.
Management and is the direct responsibility of Subcommittee D 34.01.05 on
Screening Methods.
NOTE 2—For volatile organic compound (VOC) screening purposes, a
Current edition approved Oct. 1, 2005. Published November 2005.
flame ionization detector (FID) selectively responds to flammable VOCs;
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
a photoionization detector (PID) selectively responds to VOCs having a
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
double bond; and a heated diode sensor selectively responds to haloge-
Standards volume information, refer to the standard’s Document Summary page on
nated VOCs.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7203–05
5.2 Thistestmethodcanbeusedforscreeningsoilknownto within the jar. Back pressure in the jar will change the air flow
contain TCE to estimate the concentration of TCE in the soil. rate of the device and in turn affect the voltage reading.
The test method measures the TCE concentration in the 6.7 Tedlar Bags, 1-L in volume and having a stainless steel
headspace above a sample of the TCE-contaminated soil. An valve with a nipple fitting that can be opened and closed.
estimated concentration of TCE in the soil can be determined. 6.8 Gas Regulators, for use with the TCE standard gas
Any TCE remaining in the soil sample is not measured by this cylinders (see 7.1). Each regulator should have a short length,
1 1
test method. Any other HVOC present in the soil will be about 1 ⁄4-in., of ⁄4-in. inner diameter fluoroelastomer tubing
reported as TCE. attached to the nipple fitting.
5.3 This test method can also be used for screening the
headspace above a soil suspected of containing HVOC con- 7. Reagents and Materials
tamination to indicate the presence or absence of HVOC
7.1 TCE Standard Gas Cylinders—These are transportable
contamination in the soil. Any HVOC contamination remain-
cylinders containing certified concentrations of TCE in air
ing in the soil is not detected by this test method.
pressurized to about 320 psi. If the test method is being used to
5.4 The quantitation limit of the screening test method is
screen a TCE-contaminated soil to estimate the concentration
dependent on the soil-to-headspace ratio in the sample con-
of TCE in the soil, two concentrations of TCE are required.
tainer and the HVOC in the soil. For a 25-gTCE-contaminated
One concentration is 220 6 10 vapor part per million (ppmv)
soil sample in a 250-mL container, the quantitation limit for
TCE in air. This is the high concentration TCE standard gas.
TCE is 0.005 mg/Kg, based on a signal-to-noise ratio of 10.
The other concentration is 22 6 1 ppmv TCE in air, which is
5.5 The detection limit of the heated diode sensor for TCE
the mid concentration TCE standard gas. These concentrations
is 0.1 mg/m in air, based on a signal-to-noise ratio of 2. For a
correlate with the upper and mid range of sensor response for
25-gTCE-contaminated soil sample in a 250-mLcontainer, the
thedevice.A220ppmvTCEstandardgasat25ºCcorresponds
detection limit of the screening test method for TCE is 0.001
to about 890 mg/m TCE in air at 0.75 atm of pressure and to
mg/Kg, assuming complete partitioning of TCE into the
about 1200 mg/m TCE in air at 1 atm of pressure.A22 ppmv
headspace.
TCEstandardgasat25ºCcorrespondstoabout90mg/m TCE
5.6 This test method can be used to screen moist soil
in air at 0.75 atm of pressure and to about 120 mg/m TCE in
samples. Water vapor does not interfere with the performance
air at 1 atm of pressure. See Note 3 and Note 4. If the test
of the heated diode sensor.
method is being used to screen a soil suspected of containing
5.7 Hydrocarbon fuels, including fuels containing aromatic
HVOC contamination to indicate the presence or absence of
compounds, such as gasoline, are not detected by the test
HVOC contamination, only the high concentration TCE stan-
method.
dard gas, 220 6 10 ppmv TCE in air, is required.
6. Apparatus
NOTE 3—For HVOC concentrations in air that are greater than 10
mg/m , the current that is generated by the reaction between the halogen
6.1 Metal or Rigid Plastic Coring Tools, designed for
and the alkali metal vapor when the sensor is exposed to the HVOC is a
collecting and transferring a 25-g soil VOC sample (see Guide
function of the log of the concentration of the halogen in air. The log of
D 4547 and 8.1).
890 is 2.9, and the log of 1200 is 3.1, showing that the log values of these
6.2 Glass Jars, 250-mL (8-oz), approximately 14 cm (5 ⁄2
concentrations vary only slightly. Similarly, the log of 90 is 1.9, and the
in.) tall, with open-top caps having PTFE-bonded silicone
log of 120 is 2.1.These values show that the log of theTCE concentration
in air varies only slightly at different elevations (atmosphere of pressure).
septa.
NOTE 4—The mg/m concentrations of the TCE in the standard gas
6.3 Scale, capable of weighing to 0.1 g.
cylinders can be calculated using the ppmv concentrations of TCE in the
6.4 Thermometer,withtemperaturegivenindivisionsof0.1
cylinders, the atmospheric pressure, the temperature, and Eq 5 and Eq 6,
ºC
which are given in 13.6.
6.5 Barometer, such that pressure in atmospheres can be
7.1.1 Transportation of the TCE gas cylinders must comply
determined to 0.001 atm.
with current Department of Transportation (DOT) regulations.
6.6 Heated Diode Sensor Device, a device having a diode
sensor that is heated between temperatures ranging from
8. Sample Collection and Preparation
approximately 600 to 1000 ºC generating an alkali metal vapor
stream that selectively reacts with halogens present in HVOC 8.1 Collect a soil sample of approximately 25 g using a
molecules,creatingionizedproductspeciesthatcauseacurrent metal or rigid plastic coring tool. See Guide D 4547 for
to flow between a cathode and an anode. The numerical output recommended devices. If the sample will be stored in the
from the sensor in volts is proportional to a microamp current coring tool prior to screening, it should be collected using a
from the diode and ranges from 0.001 to 20Vwith a resolution coring tool designed for sample storage as described in Guide
of 0.001 V. The HVOC molecules in the headspace above the D 4547 and should be stored as specified in Guide D 4547.
soil sample are drawn through a probe to the heated diode 8.2 Preweigh a 250-mL glass jar with an open-top cap
sensorbyapumpinthedevice.Theheateddiodesensordevice havingaPTFE-bondedsiliconeseptum.Recordthemassofthe
should have a needle attached to the probe of the device so the jar with the cap to 60.1 g.
septum in the cap of the sample jar can be pierced and the 8.3 Extrude the soil sample from the coring tool into the
needle can be inserted into the headspace above the sample. pre-weighed 250-mL glass jar and immediately seal the jar
This needle must be designed to allow make-up air to enter the making sure that there are no soil particles on the sealing
sample jar from the top so that back pressure will not build up surfaces.
D7203–05
8.4 Weigh the jar-plus-soil sample and record the mass of 11. Heated Diode Sensor Device Calibration Check and
the jar-plus-soil sample to 60.1 g. Voltage Measurement of TCE Standard Gases
8.5 Determine the mass of soil added to the jar, and record
11.1 After the heated diode sensor device has been cali-
the mass of the soil sample to 60.1 g.
brated (see 9.1), open the valve on the Tedlar bag containing
8.6 The temperature of the soil in the sample jar should be
the high concentration TCE standard gas and connect the
approximately 50 to 120 ºF (10 to 49 ºC) prior to screening the
nipple fitting on the bag to the probe of the heated diode sensor
sample using the heated diode sensor, so that HVOC partition-
device. The device is calibrated if the voltage reading for the
ing into the headspace above the sample will occur (see Note
high concentration TCE standard gas is between 9 and 12 V. If
5). The sample jar should not be opened to determine the soil
the voltage reading is 9 V or less or 12 V or greater, the device
temperature. The ambient temperature where the screening is
should be re-calibrated until the reading for the high concen-
to be performed should be in the range of 50 to 120 º F (10 to
tration TCE standard gas is between 9 and 12 V. Record this
49 ºC), and the soil sample should be allowed to come to
voltagereadingfromthedeviceforthehighconcentrationTCE
approximately that temperature prior to screening (Section12).
standard gas as V .
HighTCEStd
11.2 If the test method is being used to screen a TCE-
NOTE 5—The temperature at which the screening is performed may
affect the HVOC concentration in the headspace. For example, the vapor
contaminated soil to estimate the concentration of TCE in the
pressure of TCE at 120ºF (49ºC) is about seven times greater than the
soil, a voltage reading for the mid concentration TCE standard
vapor pressure of TCE at 50ºF (10ºC). Therefore, more TCE would be
gas is required. This reading is made after it is determined that
expected in the headspace at higher temperatures.
the heated diode sensor device is calibrated (11.1), the voltage
NOTE 6—The ambient temperature where the screening is to be
reading from the device for the high concentration TCE
performed will be recorded as specified in 11.3
standard gas (V ) has been recorded, and the voltage
HighTCEStd
9. Operation of the Heated Diode Sensor Device
reading of the heated diode sensor device has returned to zero.
The valve on the Tedlar bag containing the mid concentration
9.1 The heated diode sensor device used to perform this test
TCEstandardgas(Section10)shouldbeopenedandthenipple
method should be calibrated and operated according to the
fitting on the bag should be connected to the probe of the
manufacturer’s instructions.
heated diode sensor device. The voltage reading from the
9.2 After a sample or standard gas has been screened using
device for the mid concentration TCE standard gas should be
the heated diode sensor device, the voltage reading of the
recorded as V . If the test method is being used to
device must be allowed to return to zero, indicating that the MidTCEStd
screen a soil suspected of containing HVOC contamination to
sensor has been flushed with intake air so that any contamina-
indicate the presence or absence of HVOC contamination, a
tion from the previous sample or standard gas has been
voltage reading for the mid concentration TCE standard gas is
removed from the system.
not required.
10. Preparation of Tedlar Bags Contai
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