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The MMT Bag for Emission Source Sampling: Design and
Evaluation
Zhihua Fan a , Junfeng Zhang a , Cheng-Wei Fan b & David M. Pennise c
a Environmental and Occupational Health Sciences Institute, UMDNJ-Robert Wood Johnson
Medical School and Rutgers University , Piscataway , New Jersey , USA
b Graduate Program in Environmental Sciences , Rutgers University , New Brunswick , New
Jersey , USA
c Environmental Health Sciences, School of Public Health , University of California ,
Berkeley , California , USA
Published online: 27 Dec 2011.
To cite this article: Zhihua Fan , Junfeng Zhang , Cheng-Wei Fan & David M. Pennise (2001) The MMT Bag for Emission
Source Sampling: Design and Evaluation, Journal of the Air & Waste Management Association, 51:1, 60-68, DOI:
10.1080/10473289.2001.10464257
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Fan, Zhang, Fan, and Pennise
TECHNICAL PAPER
ISSN 1047-3289 J. Air & Waste Manage. Assoc. 51:60-68
Copyright 2001 Air & Waste Management Association
The MMT Bag for Emission Source Sampling:
Design and Evaluation
Zhihua Fan and Junfeng Zhang
Environmental and Occupational Health Sciences Institute, UMDNJ–Robert Wood Johnson Medical School
and Rutgers University, Piscataway, New Jersey
Cheng-Wei Fan
Graduate Program in Environmental Sciences, Rutgers University, New Brunswick, New Jersey
David M. Pennise
Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
ABSTRACT
INTRODUCTION
This paper presents the design and evaluation results for
a metal-coated multilayer Tedlar (MMT) bag that was de-
veloped for the collection of source emissions. The appli-
cability of the MMT bag was evaluated for a number of
important greenhouse relevant gases: CO, CO2, CH4, N2O,
and total hydrocarbons (THCs). The bag was tested for
durability and stability for a range of concentrations of
the tested compounds using both laboratory-prepared
samples and real source samples. The results show that all
tested compounds were more stable when stored in the
MMT bag than when stored in a regular Tedlar bag. These
compounds can be stored at room temperature for at least
3 months without significant changes in concentration.
When properly packed, the MMT bag is durable and may
be shipped by air. The MMT bag is lower in cost, lighter
in weight, and easier to clean, and it requires less devices
during the subsequent laboratory analysis compared with
a stainless steel canister, which is often used to collect air
and source samples.
There is an increasing interest in measuring greenhouse
gases and other air pollutants emitted from various
sources.1-5 The major species of concern often include CO,
CO2, CH4, N2O, and total hydrocarbons (THCs). A com-
monly used method to measure emissions of these com-
pounds from various sources involves the collection of
source samples into a container. The samples collected
are often subsequently analyzed in a laboratory using gas
chromatography (GC) techniques.6-9 The containers used
for sample collection must be durable, chemically inert,
and easy to handle in the field.
Two types of gas sample collectors (containers) are of-
ten used for source sampling: stainless steel canisters and
Tedlar bags. However, the use of Tedlar bags can result in
significant sample losses, mainly due to molecular diffu-
sion and Tedlar film permeation, during sample transport
and storage.7,10,11 The use of stainless steel canisters can be
difficult for many laboratories for a number of reasons. First,
the canister is expensive (>$500 each). Second, the canis-
ter requires a special device for cleaning and sample prepa-
ration, which leads to a costly initial investment in the
device and a costly long-term consumption of high purity
gases. Third, the inner surface of the canister is designed
mainly for low-concentration (trace gas) applications, not
specifically for source samples that typically contain high
concentrations of air pollutants. After collecting high-
concentration source samples, the canisters are often dif-
ficult to clean completely and can be contaminated or
“poisoned” permanently under extreme conditions. Finally,
as the authors have experienced, shipping the canisters
across international borders can often be problematic be-
cause of their “bomb-like” appearance.
IMPLICATIONS
The development of a reliable, economical, and easy-to-
use storage and shipping procedure for samples of green-
house gases and other air pollutants is important for ac-
curately measuring these emissions from the wide vari-
ety of source types dispersed throughout the world. The
MMT bag presented in this paper has proved to be a reli-
able sampling tool for the collection of gaseous pollut-
ants, such as CO, CO2, CH4, and N2O, from various emis-
sion sources. The bag can be used and reused for collec-
tion, transport, and storage of emission samples, which
can be subsequently analyzed in a laboratory.
60 Journal of the Air & Waste Management Association
Volume 51 January 2001

Fan, Zhang, Fan, and Pennise
To overcome the shortcomings of regular Tedlar bags
and stainless steel canisters for emission source sampling,
we developed a metal-coated multilayer Tedlar (MMT)
sampling bag. The MMT bag is substantially lighter in
weight and lower in cost (<$30 each) compared with a
stainless steel canister. The applicability and performance
of the MMT were evaluated using both laboratory-
prepared gas samples and real source samples. In this pa-
per, we present the bag design and the evaluation results.
grade). After cleaning, the sampling bags were carefully
rolled up to prevent puncturing by the stainless steel fit-
tings. When shipped via air or transported to local fields,
the bags were packed in plastic containers with polyure-
thane foam. The containers were highly rigid and well
sealed to protect the bags. These types of containers are
readily available at most hardware stores. For samples to
be transported by air, the bags were only filled to 60% of
their capacity, to account for possible expansion due to
cabin pressure changes. After sample collection, the sam-
pling bags were replaced into the containers for transport
to the laboratory for analysis.
EXPERIMENTAL METHODS
Design of the MMT Bag
The MMT bag is custom-made by Cole-Parmer Instrument
Co. The bag has three layers. The inner and middle layers
are made of 2-mil Tedlar film, which is believed to be
chemically inert and have little tendency to sorb organic
compounds.7,8,10 The outer layer is made of Mylar film,
which is more durable, less permeable, but chemically less
inert than the Tedlar film. The outer surface of the bag is
coated with a thin layer of aluminum to enhance the du-
rability and further reduce the permeability of the bag. The
bag features two fittings. One is a stainless steel hose/valve
fitting for the attachment of Teflon tubing to fill the bag
with the sample or to flush the bag prior to use. The other
is a Teflon septum fitting, which provides a convenient
means of taking the sample out of the bag with a syringe
for GC analysis or other purposes. The capacity of the bag
is 5 L, which provides sufficient sample volume for GC
analysis and other possible analyses.
The laboratory-prepared samples were made using the
following gas standards: CO2 (10,000 ppm in nitrogen),
CH4 (100 ppm in nitrogen), CO (1000 ppm in nitrogen),
and N2O (50 ppm in nitrogen). All the gas standards were
purchased from Scott Specialty Gases, Inc. Samples with
different concentrations were obtained by diluting the gas
standards with zero-grade nitrogen.
A number of real source samples were obtained lo-
cally and overseas. Local grab samples included those from
a wood combustion source (a simulated campfire burn-
ing firewood) and those from room air while a kerosene
heater was being used in the room. The radiant kerosene
space heater (Kero-Sun Radiant 8) was used in a room with
a volume of 19 m3, and the fuel used was Sunnyside kero-
sene (1-K grade). A fan was running inside the room dur-
ing each test to ensure the pollutants were well mixed.
All grab sample bags were filled using Teflon sampling
tubing and an SKC personal pump.
Evaluation Methods
Two charcoal-making kiln emission samples were
collected in MMT bags from each of three Brazilian round
brick kilns and two Brazilian rectangular metal and brick
kilns. The bags were filled by placing a copper sampling
tube (1/2-in. diam) directly above the chimney of each
kiln and pumping 3 L of emissions through a Whatman
quartz fiber filter and then into the bag. All the samples
used for the stability tests are summarized in Table 1.
The stability of CO, CH4, CO2, N2O, and THCs stored in
MMT bags was evaluated. For comparison purposes, the
stability of those compounds stored in regular Tedlar bags
was also tested. Gas samples containing CO, CH4, CO2,
N2O, and THCs were either prepared from gas standards
in the laboratory or collected from real source samples in
the field. All the samples were then analyzed at desig-
nated time intervals using a Hewlett Packard 6890 GC
system equipped with a flame ionization detector (FID)
and an electron capture detector (ECD). Compound
loss/gain was determined by comparing the concentra-
tion measured at each subsequent time (day X) to the con-
centration measured initially (at day 0). The samples were
all stored at room temperature during the course of the
stability test.
Sample Analyses
All the samples were analyzed using a Hewlett Packard
6890 GC system equipped with an FID and an ECD. For
THC analysis, GC/FID was used. The column was a 2 ft ×
1/4 in. stainless steel column packed with glass beads
(Alltech). The oven temperature was 35 °C, the injector tem-
perature was 35 °C, and the FID temperature was 200 °C.
The flow rates of air and hydrogen were 400 and 30
mL/min, respectively. Zero-grade nitrogen was used as
carrier gas at a flow rate of 10 mL/min. The injections
were made using a gas-tight syringe. The injection vol-
ume was 1 mL for N2O and 50 µL for THCs, CH4, CO, and
CO2. The concentration of THCs was calculated on a CH4
basis, that is, mg/m3 as CH4.
Sample Preparation
All tested MMT and regular Tedlar bags were first leak-
checked by filling the bags with air, examining for leaks
in water, and visually examining for leaks after a 24-hr
period. The leak-free bags were then cleaned 3 times with
house air and 3 times with high-purity nitrogen (zero
Volume 51 January 2001
Journal of the Air & Waste Management Association 61

Fan, Zhang, Fan, and Pennise
Table 1. Information about the samples collected for the stability study on Tedlar and MMT sampling bags.
Source Type
Tedlar Bag
MMT Bag
Sample ID
Number of Samples
Sample ID
Number of Samples
Ambient aira
Air-M1 and Air-M2
Air-M3 and Air-M7
2
5
Standard gases
Standard-T1 and Standard-T2
Kerosene-T1 to Kerosene-T4
2
4
Standard-M1 to Standard-M4
Kerosene-M1 to Kerosene-M5
Wood-M1 to Wood-M5
4
Emissions from kerosene heater
Emissions from wood burning
Emissions from charcoal-making processb
5
5
Charcoal-M1 to Charcoal-M10
10
aSamples Air-M1 to Air-M3 were collected from ambient air in New Jersey, samples Air-M4 and Air-M5 were collected inside a laboratory in New Jersey, and samples Air-M6 and Air-
M7 were collected from ambient air in Brazil; bSamples Charcoal-M1 and Charcoal-M2 were collected at hour 64.5 of a 70-hr charcoal-making process, samples Charcoal-M3 and
Charcoal-M4 were collected at hour 20 of a 96-hr charcoal-making process, samples Charcoal-M5 and Charcoal-M6 were collected at hour 44 of a 74-hr charcoal-making process,
samples Charcoal-M7 and Charcoal-M8 were collected at hour 48 of a 157-hr charcoal-making process, and samples Charcoal-M9 and Charcoal-M10 were collected at hour 51 of a
118-hr charcoal-making process.
A nickel catalyst methanizer and FID were used in
the analyses of CH4, CO, and CO2. Under this GC con-
figuration, CO and CO2 were converted to CH4 by the
nickel catalyst methanizer and then detected by the FID.
A 10 ft × 1/8 in. stainless steel column packed with
80–100 mesh Carbosphere (Waters Associates, Inc.) was
used for the separation of CO, CH4, and CO2. Zero-grade
nitrogen was used as the carrier gas, and the flow rate
was 30 mL/min. The oven temperature was held at 35 °C
for 9 min, ramped to 200 °C at the rate of 25 °C /min,
and held at the final temperature for 5 min. The injector
temperature was 35 °C, the methanizer temperature was
375 °C, and the FID detector temperature was 200 °C.
The flow rates of air and hydrogen were 400 and 30
mL/min, respectively.
Nitrous oxide (N2O) was analyzed by GC/ECD. An
8 ft × 1/8 in. stainless steel column packed with 80–100
mesh Hayesep Q (Waters Associates, Inc.) was used for
the separation of N2O from other pollutants. Zero-grade
nitrogen was used as the carrier gas, and the flow rate was
20 mL/min. The make-up gas flow rate was 60 mL/min.
The oven temperature was held at 50 °C for 3.5 min,
ramped to 200 °C at the rate of 20 °C/min, and held at
the final temperature for 9 min. The injector temperature
was 35 °C, and the ECD temperature was 350 °C.
RESULTS AND DISCUSSION
Analytical System Performance
All calibrations for CO, CO2, CH4, and THCs had R2 val-
ues of >0.997. The difference in the response factors ob-
tained from all calibration sets over the test course was
<10%. The relative standard deviation (%RSD) from 14
repeat analyses of the middle-level standard was 6% for
THCs and ~10% for CO, CO2, and CH4.
The N2O calibration had an average R2 value of 0.978.
The accuracy from 7 analyses was 8% and the precision,
determined from 14 repeat analyses of the middle level
standard over the test course, was 22%. The %RSD of 7
repeat injections of the N2O standard in the same day was
20%. The linearity and reproducibility of the instrument
for N2O analysis were higher in our previous study.1 We
suspect that the larger variation of the instrument for N2O
analysis in this stability study was probably due to an in-
sufficient equilibration time for the ECD. All types of analy-
ses (THCs, CO2-CO-CH4, and N2O) were done by one
GC/FID/ECD system in our laboratory. We had to switch
GC configurations one after another for each different type
of analysis. The ECD, used for the N2O analysis, requires a
longer equilibration time than does the FID. Unfortunately,
the stability test requires the sample analyses to be per-
formed at predesignated time intervals. This resulted in
occasional N2O analysis without a fully equilibrated ECD.
The analytical detection limit (ADL) was determined as
3 times the SD derived from seven “blank” air samples. These
“blank” samples were spiked with trace amounts of some
test compounds (CO and CH4) in order to get near-baseline
lowest detectable responses. The ADL values were ~0.7 ppm
for CO, CH4, CO2, and THCs, and 250 ppb for N2O.
The instrument was calibrated periodically using a
set of standards diluted from cylinders of gas standards
prepared by Scott Specialty Gases. For each batch of analy-
sis, at least one standard (usually at the middle of the
calibration curve) was analyzed to correct for response
factor changes. Two injections were made for each sample.
If the change in response from the 2 injections was >10%
for CO, CO2, CH4, and THCs and 20% for N2O, additional
injections were made until satisfactory reproducibility was
obtained. The concentrations were calculated using the
average response values from replicate injections.
Stability for Laboratory-Prepared Samples
Two samples were prepared in Tedlar bags using gas stan-
dards (Standard-T1 and Standard-T2). For sample 1, the
62 Journal of the Air & Waste Management Association
Volume 51 January 2001

Fan, Zhang, Fan, and Pennise
initial concentration was 46 ppm for CO, 9 ppm for CH4,
and 3045 ppm for CO2. As shown in Figure 1, significant
losses (>75%) of CO, CH4, and CO2 were observed after
storage in the Tedlar bag for 32 days. For sample 2, more
than 80% of CO was lost after storage for 46 days, but
only 18% of CO2 was lost, and CH4 was almost stable
after storage of 46 days (see Figure 1). This was probably
because the concentrations of CO2 and CH4 in sample 2
were much lower than those in sample 1. The CO initial
concentration in sample 2 was 211 ppm, which was
much higher than ambient level; therefore, a large deg-
radation of CO was observed. The CH4 and CO2 initial
concentrations were 1.8 and 482 ppm, respectively,
which were close to the ambient levels of approximately
1.4–1.6 ppm of CH4 and 470 ppm of CO2. There was prob-
ably an equilibrium between the CH4 and CO2 in sample
bag 2 and that present in the ambient air, and thus the
net loss of CH4 and CO2 during storage in sample bag 2
was small (<20%).
for CO2. Results for the percent recovery of each com-
pound over the 75-day storage time are presented in Table
2. As shown in Table 2 and Figure 2, all three compounds
were relatively stable with >80% remaining after storage
for 75 days. We found that CO2 in sample 4 was stable
for the first 25 days and started increasing after that.
This sample had an initial CO2 concentration of 59.3
ppm, much less than the ambient CO2 level of ~470 ppm.
We suspect that multiple needle punctures of the sep-
tum of the sampling bag caused increased infusion rates
of ambient air during each injection, thereby increasing
the concentration of CO2.
Stability of Real Source Samples
Kerosene emission samples were collected in four Tedlar
bags (samples Kerosene-T1 to Kerosene-T4) and five
MMT bags (samples Kerosene-M1 to Kerosene-M5). The
initial concentrations in the four Tedlar bag samples
were 1.0–3.2 ppm for CO, 2.0–2.1 ppm for CH4, and
2314.3–3776.9 ppm for CO2, and the initial concentra-
tions in the five MMT bag samples were 3.9–8.0 ppm
for CO, 2.4–4.3 ppm for CH4, and 2357.1–2581.5 ppm
for CO2. The Tedlar sample bags were tested for 82 days,
and the MMT sample bags were tested for
97 days.
Four samples were prepared in MMT bags using gas
standards (Standard-M1 to Standard-M4). The initial con-
centrations of the four MMT bag samples were 5.6–55
ppm for CO, 5.0–33 ppm for CH4, and 59.3–5922 ppm
A large decay of CO and CO2 (but not
CH4) was also observed when samples were
stored in the regular Tedlar bags (Figure 3).
More than 50% of the CO and CO2 was lost
after storage for 82 days. However, as ex-
plained earlier, the CH4 concentration in the
four Tedlar sampling bags was similar to the
ambient CH4 level; therefore, the loss of the
sample CH4 was negligible. When stored in
the MMT bags, all the compounds were
stable for 96 days for the kerosene emission
samples (see Figure 3), and the average re-
covery was 85% for CO, 89% for CH4, and
76% for CO2. Besides the significant sample
losses found during storage in Tedlar bags, a
large variation of the performance among
the Tedlar sampling bags was also observed.
The %RSD for the four Tedlar bags was 102%
for CO, 12% for CH4, and 58% for CO2, but
the %RSD for the performance of the five
MMT sampling bags was only ~16% for CO,
6% for CH4, and 18% for CO2 (see Table 2),
much smaller than those for Tedlar bags.
Two ambient air samples (Air-M1 to
Air-M2) and 10 charcoal-making emission
samples (Charcoal-M1 to Charcoal-M10)
Figure 1. Stability of CO, CH4, and CO2 from standard gas samples stored in Tedlar bags.
The y axis represents the ratio of the concentration at day X (Cx) over the concentration at
day 0 (C0). The concentrations shown in the figure are C0 values.
were collected in Brazil for this stability
study, but the sample bag for charcoal
Volume 51 January 2001
Journal of the Air & Waste Management Association 63

Fan, Zhang, Fan, and Pennise
Table 2. Recovery of CO, CH4, and CO2 after storage in Tedlar and MMT sampling bags.a
Tedlar Bags
MMT Bags
Storage
Source Type
Sample ID
Storage
Recovery (%)
Sample ID
Recovery (%)
Time (days)
CO
CH4
CO2
Time (days)
CO
CH4
CO2
Standard gases
Standard-T1
Standard-T2
32
46
0
26
13
91
Standard-M1
Standard-M2
Standard-M3
Standard-M4
Average
75
75
75
75
88
96
64
90
85
17
100
98
80
82
68
86
16
92
96
71
89
87
13
94
85
83
90
93
89
6
107
105
69
56
128
152
108
32
Average
%RSD
28
141
0
77
94
52
105
10
%RSD
Emissions from
kerosene heater
Kerosene-T1
Kerosene-T2
Kerosene-T3
Kerosene-T4
82
82
82
82
90
Kerosene-M1
Kerosene-M2
Kerosene-M3
Kerosene-M4
Kerosene-M5
Average
96
96
96
96
96
87
88
101
117
93
44
86
12
24
77
100
50
78
53
Average
%RSD
50
100
12
32
58
76
102
%RSD
18
aRecovery was calculated as the concentration remaining in the sampling bag after the storage time over the initial concentration measured at day 0.
Figure 2. Stability of CO, CH4, and CO2 from standard gas samples stored in MMT bags. The y axis represents the ratio of the concentration at day
X (Cx) over the concentration at day 0 (C0). The concentrations shown in the figure are C0 values.
64 Journal of the Air & Waste Management Association
Volume 51 January 2001

Fan, Zhang, Fan, and Pennise
sample 1 was spoiled during the sam-
pling process. The initial concentrations
of CO2 and N2O in the two ambient air
samples were ~800 and ~400 ppb, re-
spectively. CO, CH4, and THCs were not
detected in the ambient air samples. The
initial concentrations of the nine char-
coal-making kiln emission samples were
10,455–66,221 ppm for CO, 7882–
26,701 ppm for CH4, 775–150,542 ppm
for CO2, 1.22–5.04 ppm for N2O, and
4775–36,361 ppm for THCs. The septum
of the sample bag for charcoal sample 5
was dislodged, so only 10 samples (2
ambient air samples and 8 charcoal-
making kiln emission samples) were
tested for the stability study. The
samples were tested up to 4 months. The
recoveries of CO, CH4, CO2, THCs, and
N2O in the 10 samples after storage for
4 months are presented in Table 3. The
average recovery was more than 80% for
CO, CH4, CO2, and THCs, and the %RSD
for the 10 MMT sampling bags was
<16%. An example of the behavior of
all the compounds stored in the MMT
bag is shown in Figure 4. The average
recovery of N2O was 71%, and the %RSD
for the 10 samples was <27%. As dis-
cussed in the section on Analytical Sys-
tem Performance, the large variations of
the N2O results were probably due to the
variation of the instrument.
Figure 3. Stability of CO, CH4, and CO2 from kerosene heater emission samples stored in the
Tedlar bag (top) and the MMT bag (bottom). The y axis represents the ratio of the concentration
at day X (Cx) over the concentration at day 0 (C0). The concentrations shown in the figure are C0
values.
Table 3. Recovery of CO, CH4, CO2, THCs, and N2O after storage in MMT bags for 125 days.a
Source Type
Sample ID
Storage Time (days)
Recovery (%)
CH4
THCs
CO
CO2
N2O
Ambient air
Air-M1
Air-M2
125
125
125
125
125
125
125
125
125
125
NDb
NDb
92
80
84
70
69
91
63
86
80
13
NDb
NDb
113
96
NDb
NDb
107
88
94
105
93
76
93
93
69
93
59
93
83
16
103
111
73
Ambient air
Charcoal-making emissions
Charcoal-making emissions
Charcoal-making emissions
Charcoal-making emissions
Charcoal-making emissions
Charcoal-making emissions
Charcoal-making emissions
Charcoal-making emissions
Charcoal-M2
Charcoal-M3
Charcoal-M4
Charcoal-M6
Charcoal-M7
Charcoal-M8
Charcoal-M9
Charcoal-M10
Average
72
123
92
107
107
81
73
53
89
86
119
92
107
79
60
107
45
119
105
14
107
98
71
RSD
13
27
aRecovery was calculated as the concentration remaining in the sampling bag after storage of 125 days over the initial concentration measured at day 0; bNot detected. The detection
limit was ~0.7 ppm for THCs, CO, and CH4.
Volume 51 January 2001
Journal of the Air & Waste Management Association 65

Fan, Zhang, Fan, and Pennise
Figure 4. Stability of CO, CH4, CO2, N2O, and THCs from a charcoal-making emission sample (Charcoal-M2) stored in a MMT bag for 125 days. The
y axis represents the ratio of the concentration at day X (Cx) over the concentration at day 0 (C0). The concentrations shown in the figure are C0 values.
Potential N2O Artifact
gases and packed at Rutgers University as previously de-
scribed. These bags were sent to the University of Califor-
nia at Berkeley via FedEx. It was found that the bags were
maintained in their original conditions upon return from
California 2 weeks later, and that the concentrations of
the species contained in the bags were not decreased after
the bags were returned.
After the pilot tests, the MMT bags were deployed
from our New Jersey laboratory to collect samples of
emissions from various charcoal-making kilns in Brazil
and Kenya. All the cleaned empty bags and sample-filled
bags were transported by air, and all analyses were per-
formed in New Jersey. Samples collected in New Jersey
were transported by automobile. Information on the bag
breakage and other failures is summarized in Table 4.
The results from our tests demonstrate that the MMT
bag can be reused several times if no physical damage
occurs to the bag. The successful use of the MMT bag
in the field studies further proved that the MMT bag is
a reliable means for the collection of emission source
samples.
It has been found that N2O can be produced in stain-
less steel canisters during sample storage.12 Significant
N2O formation (artifact) in the canister was observed
within a couple hours after combustion gas samples
were collected.13 Concerning the potential artifact for-
mation of N2O during the sample storage in MMT bags,
we collected three samples from ambient outdoor air
(Air-M3 to Air-M5), two samples from indoor room air
(Air-M6 and Air-M7), and five samples from wood com-
bustion emissions (Wood-M1 to Wood-M5) with MMT
bags. The wood combustion source was the simulated
campfire. The ambient indoor and outdoor samples
were taken on the Busch Campus of Rutgers University
in Piscataway, NJ. These samples were analyzed for N2O
concentrations as a function of storage time from 0.5
to 9 hr. The results, shown in Figure 5, indicate that no
significant changes in N2O concentrations occurred
during the first few hours (a critical time period for the
artifact) when both ambient air (indoor and outdoor)
samples and wood-burning emission samples were
stored in the MMT bags.
CONCLUSIONS
Durability of MMT Sampling Bags
An MMT bag was developed for the collection of gas-
eous pollutants from emission sources. The MMT bag
is more durable and less permeable than a regular Tedlar
sampling bag and lighter than a stainless steel canister.
The durability of the MMT bags was tested in transporta-
tion and handling processes. In the pilot test stage, three
MMT bags were filled with a mixture of diluted standard
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Volume 51 January 2001

Fan, Zhang, Fan, and Pennise
Figure 5. Test for artifact formation of N2O stored in MMT sampling bags. Samples were collected from wood-burning emissions and ambient air.
Compared with the use of stainless steel canisters, the
use of the MMT bag reduces the measurement cost sub-
stantially due to the lower material expense, lower ship-
ping cost, lower cleaning cost, and less accessory
requirements during the subsequent GC analysis. When
properly packed, the MMT bag is durable even when
shipped by air. As a collection and storage container,
the MMT bag is suitable for several gaseous pollutants
of typical concern (e.g., CO2, CO, CH4, THCs, and N2O).
These compounds can be stored in an MMT bag at room
temperature for at least 3 months without significant
changes in concentration.
ACKNOWLEDGMENTS AND DISCLAIMER
We thank Dr. Kirk Smith of the University of California–
Berkeley for his valuable suggestions, Tulio Jardim Raad
and Maria Emilia Rezende for field sample collection in
Brazil, and Dr. Lin Zhang and Mr. Robert Harrington for
their assistance in sample and data analyses. This study
was funded by the U.S. Environmental Protection Agency
(EPA) through a cooperative agreement with East-West
Center in Hawaii. This paper has not gone through offi-
cial EPA review procedures and thus should not be con-
sidered to have EPA official approval. J. Zhang is partly
supported by the NIEHS Center Grant 05022-10.
Table 4. Summary of MMT bag durability test: valid samples collected with MMT bags.
Source Type
Location
Number of
Number of
Number of
Invalid Samplesa
Samples Collected
Valid Samples
Ambient air
New Jersey
5
2
5
2
0
0
0
0
2
1
Brazil
Residential house in New Jersey
Residential house in New Jersey
Brazil
Emissions from kerosene heater
5
5
Emissions from wood burning
5
5
Emissions from charcoal-making process
Emissions from charcoal-making process
51
86
49
85
Kenya
aInvalid samples: sample bags leaked or spoiled.
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Journal of the Air & Waste Management Association 67

Fan, Zhang, Fan, and Pennise
11. Wang, Y.; Raihala, T.S.; Jackman, A.P.; St. John, R. Use of Tedlar Bags
in VOC Testing and Storage: Evidence of Significant VOC Losses;
Environ. Sci. Technol. 1996, 30, 3155-3117.
12. Muzio, L.J.; Teague, M.E.; Kramlich, J.C.; Cole, J.A.; McCarthy, J.M.;
Lyon, R.K. Errors in Grab Sample Measurements of N2O from Com-
bustion Sources; J. Air Pollut. Control Assoc. 1989, 39, 287-293.
13. Muzio, L.J.; Montgomery, T.A.; Samuelson, G.S.; Kramlich, J.C.; Lyon,
R.K.; Kokkions, A. Formation and Measurement of N2O in Combus-
tion System. In 23rd International Symposium on Combustion; 1990;
p 245.
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About the Authors
Dr. Zhihua Fan is a research associate working at the Envi-
ronmental and Occupational Health Sciences Institute,
UMDNJ–Robert Wood Johnson Medical School and Rutgers
University. Mr. Cheng-Wei Fan is a Ph.D. candidate in the
Graduate Program in Environmental Sciences, Rutgers Uni-
versity. Mr. David M. Pennise is a Ph.D. candidate at Envi-
ronmental Health Sciences, School of Public Health, Uni-
versity of California–Berkeley. Dr. Junfeng Zhang (corre-
sponding author; email: jjzhang@eohsi.rutgers.edu) is an
assistant professor at UMDNJ–Robert Wood Johnson Medi-
cal School and a graduate faculty member of Rutgers Uni-
versity.
68 Journal of the Air & Waste Management Association
Volume 51 January 2001