United States
                   Environmental Protection
                   Agency
Environmental Monitoring Systems
Laboratory
Research Triangle Park NC 27711
                   Research and Development
EPA/600/S4-85/055  Sept. 1985
v>EPA         Project Summary
                   Evaluation  of Polyurethane
                   Foam Cartridges for
                   Measurement  of  Polynuclear
                   Aromatic Hydrocarbons in  Air
                   C. C. Chuang, W. E. Bresler, and S. W. Hannan
                     The objective of the project was to
                   evaluate polyurethane foam (PUF) cart-
                   ridges as collection media for quantifi-
                   cation of vapor  phase polynuclear
                   aromatic hydrocarbons (PAHs) in air.
                     Two cleanup methods for PUF cart-
                   ridges—compression rinsing, and com-
                   bined compression rinsing and Soxhlet
                   extraction—have been evaluated. Both
                   methods successfully remove interfer-
                   ing material and background PAHs from
                   the PUF. The compression rinsing meth-
                   od is recommended because it is easier,
                   faster, and cheaper.
                     Two procedures for extraction of
                   PAHs from the PUF matrix, Soxhlet
                   extraction and compression rinsing.
                   were compared. Modified EPA medium
                   volume  samplers having quartz fiber
                   filters to  collect  particles and PUF
                   cartridges  to trap vapors were used.
                   Prior to sampling, known quantities of
                   perdeuterated PAHs were spiked into
                   each  cleaned PUF  cartridge.  Eight
                   samplers were  operated outdoors in
                   parallel for 24 hours. After sampling,
                   four PUF  samples were Soxhlet-ex-
                   tracted with 10 percent ether/hexane
                   and the  other four PUF samples were
                   extracted by alternate compression and
                   decompression 50 times in the same
                   solvent.  These sample  extracts were
                   analyzed by on-column injection, elec-
                   tron impact gas chromatography/mass
                   spectrometry (El GC/MS) to determine
                   PAHs. The results showed that com-
                   pression rinsing is comparable to con-
                   ventional Soxhlet extraction, and that
                   both methods  successfully remove
PAHs from the PUF cartridges. The
compression rinsing method was then
used in the stability study.
  The stability study was carried out to
determine the stability  of PAHs ad-
sorbed on PUF cartridges as a function
of storage time between collection and
extraction. Two sets of  PUF samples
were collected for this study. The first
set of samples was stored in the pre-
sence of light, and the second set of
samples  was kept in the dark. The
storage temperature for both sets of
samples was approximately 20°C. The
samples were stored for 1,10.20. or 30
days and then extracted with 10 percent
ether/hexane. Sample extracts were
analyzed by El GC/MS. The levels of
perdeuterated  benzo(a)pyrene de-
creased significantly during storage.
The rate of decrease was much faster
when the PUF cartridges were stored in
the  light.  Other PAH levels were not
adversely  influenced by the storage
time.
  This Project Summary was developed
by EPA's Environmental Monitoring
Systems Laboratory. Research Triangle
Park, NC. to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).

Introduction
  Polynuclear aromatic compounds have
been extensively studied  and have re-
ceived increased attention in studies of
air pollution in recent years because some

-------
of the compounds are highly carcinogenic
or mutagenic. To understand the extent of
human exposure to polynuclear aromatic
compounds, reliable sampling and analyt-
ical methodology must be established for
monitoring the concentrations of these
compounds in air. In general, the analyti-
cal  methodology is well developed, but
the sampling procedures can often reduce
the validity of analytical results. Several
studies have shown  that the three- to
four-ring polynuclear aromatic hydrocar-
bons (PAH) in air may be mainly in the
vapor phase and are not retained by filters
because of volatilization. A wide variety of
adsorbents such  as  Tenax-GC,  XAD-2
resin and  polyurethane foam (PDF) has
been used to sample organic vapors. The
PDF cartridge is easy to handle in the field
and has good airflow characteristics; it
has been successfully used for collection
of pesticide and polychlorinated biphenyl
(PCB) vapors.
  Recently, Battelle conducted a study to
collect ambient and indoor air PAH using
a sampler  with a quartz fiber filter and a
PDF back-up trap. It was observed that
the PDF cartridges changed from a pale
white to a light  yellow color over a one-
week storage period. It  is not  known
whether this color change is associated
with any change  in the PUF cartridge's
ability to retain PAHs. In a large-scale air
monitoring program, placement  of the
samplers  in  the field and the return of
filters and traps  after  air collection to
analytical  laboratories may take  several
weeks.  Therefore, it is  necessary to
conduct a  study to assess the stability of
PAHs adsorbed on the PUF  cartridges
during storage.
  The objective of this project  was to
evaluate PUF cartridges for collection and
subsequent  analysis of vapor phase PAH
in air.

Procedure

  Two studies  were performed in this
project:

 a.  Extraction  study to  evaluate two
    extraction procedures,  Soxhlet ex-
    traction and compression rinsing, for
    removal of PAH from the PUF matrix.
 b.  Stability study to determine the sta-
    bility of  PUF traps by examining the
    measured PAH concentration  as a
    function of  storage  time between
    collection and extraction.
  The sample extracts were analyzed by
electron  impact  gas chromatography/
mass spectrometry (El GC/MS) to deter-
mine both native PAHs and spiked per-
deuterated PAHs.

Results

  Both methods of cleaning the PUF
cartridges left only small quantities of
naphthalene in the cartridges. The ex-
traction study gave  generally good re-
coveries  (>85 percent) for spiked Dn-
PAHs with the exception of De-naphtha-
lene using either the Soxhlet extraction
or the compression method. The loss of
De-naphthalene was anticipated since
this  compound is  highly volatile. The
sampling temperature during this exper-
iment was 0°C to 10°C.  Even greater
losses of this volatile compound can be
expected at higher sampling  tempera-
tures.
  Levels of native PAHs found in the PUF
cartridges were very similar using these
two methods. The levels of PAHs found in
the PUF cartridges, expressed  as ng per
cubic meter of air sampled, ranged from
0.10 ng/m3 to 29.39  ng/m3  and 0.17
ng/m3to28.41 ng/m3 using the Soxhlet-
extraction and the compression methods,
respectively. These data demonstrate that
the compression technique is comparable
to Soxhlet-extraction in removing PAHs
from the PUF cartridges. Since significant
time and cost savings can be achieved by
using the  compression  method, this
method was used in the stability study.
  Only volatile and semi-volatile PAHs
were found in the PUF cartridges. Higher
molecular weight PAHs (m/e>252), such
as benzo(a)pyrene and  coronene, and 1-
nitropyrene were not detected in the PUF
cartridges,  indicating  that  these  com-
pounds are predominantly  retained  on
the filter.
  The stability study was conducted to
determine whether a significant loss of
PAHs captured by PUF cartridges occurs
during the storage period. Two sets of
PUF samples were obtained for this study.
The first set of PUF samples were stored
at room temperature (~20°C) in the light,
and the second set of samples was stored
at room temperature in the dark.
  Recoveries of the perdeuterated PAHs
for the first set of PUF samples (stored in
the light) ranged from 0.6 percent for D8-
naphthalene  to 102.3 percent for D12-
chrysene. Low recoveries were obtained
for  Da-naphthalene, which decreased
from 2.6 percent to 0.4 percent after 20
days storage. The low recovery and the
decreasing recovery trend for Da-naphtha-
lene during storage are mainly due to the
volatilization of this compound. The stor-
age time does not appear to have adverse
effects on the recoveries of D10-phenan-
threne,  D-io-pyrene, and Di2-chrysene.
The  variations of recovery for these
compounds were less than 15 percent
and  may be due to small variations in
sampling  and analysis procedures.  It
should be noted that the recoveries of
Di2-benzo(a)pyrene decreased  signifi-
cantly with increased storage time; the
recoveries decreased from 92.1 percent
to 11.7 percent after storage for 20 days.
It is possible that oxidation or other degra-
dation  reactions of D12-BaP may occur
during storage.

  I n the second set of PUF samples (stored
in the dark), the relative recovery data are
similar to those obtained with the first set
of samples. But the recovery of Di2-BaP
decreased  less  in  the second set of
samples than in the first set. The recover-
ies decreased from 95.4 percent to 44.3
percent after 20 days storage. Even after
30 days, 29.5 percent of the Di2-BaP was
recovered. It appears that the PUF-ad-
sorbed D12-BaP  is  more stable in the
absence of light.
  Similar recovery trends were observed
for the native PAHs. The storage time
does not significantly affect the levels of
phenanthrene, pyrene,  and  chrysene
found in  the PUF samples.  Slightly de-
creasing  concentrations were detected
for naphthalene. Similar decreasing levels
were observed for anthracene, an isomer
of phenanthrene. The reactive PAH,
cyclopenta(c,d)pyrene,  higher-molecular
weight PAHs  (m/e>252), and  1-nitro-
pyrene were  not detected  in  the  PUF
samples.

Conclusions and
•Recommendations
  Two PUF cleanup methods, compres-
sion rinsing and combined compression
rinsing and Soxhlet extraction have been
evaluated for their ability to  remove
interfering material and background PAHs
from PUF cartridges. The results show
that  the compression-only technique is
comparable to the combined compression
and Soxhlet extraction method. Thus the
compression method is recommended for
use in the future for time and cost savings.
  The  results of the   extraction study
indicate that levels of  both native and
perdeuterated  PAHs found  in the  PUF
cartridges are similar  using either the
Soxhlet extraction method or compres-
sion rinsing. It has been demonstrated
that  both  methods can successfully re-
move PAHs from the  PUF  cartridges.
Since significant time and cost savings

-------
can  be achieved by using compression
rinsing, this method  was used in  the
stability study.
  Generally, good  recoveries  for  the
spiked perdeuteratedPAHs were obtained
for  PUF samples extracted immediately
after collection, with the exception of De-
naphthalene. This finding demonstrated
that PUF cartridges cannot quantitatively
retain  volatile two-ring PAHs under the
sampling  conditions employed.  Greater
loss of volatile components would be
expected  at higher sampling tempera-
tures. It should be noted that cyclopenta-
(c,d)pyrene and higher molecular weight
PAHs (m/e>252) Were not detected in
the PUF samples. 1 -Nitropyrene was also
not found in the PUF samples.
  The  stabilities of PAHs adsorbed on
PUF cartridges during storage with and
without  light were  investigated. The
results indicated that  levels  of BaP  de-
creased significantly during storage. The
rate of decrease was much faster when
PUF cartridges  were stored  in the pre-
sence of light. The levels of the remaining
PAHs were not significantly influenced by
the storage time.
  Both XAD-2 resin and PUF are com-
monly  used to collect  PAH  vapors  in
ambient air  sampling.  A comparative
study is recommended to evaluate the
flow characteristics and the collection
efficiency for PAH vapors by using the
two  adsorbents (XAD-2 and PUF) as
backup traps in ambient air sampling.
Recently,  several  research groups indi-
cated that extracts of clean PUF  plugs
show  mutagenic  activity and interfere
with bioassay results. Therefore, bioassay
analysis  is  recommended for samples
collected from these two adsorbents. The
bioassay results can provide information
as to whether PUF plugs or XAD-2 resin
would interfere with bioassay. To charac-
terize and to compare these  two adsor-
bents thoroughly, studies are also rec-
ommended to determine the stability of
PAHs  captured on  XAD-2 resin as a
function of time.
  In this study, quartz fiber filters were
used to collect air particulate matter.
However,  there are other types of filters
which can be considered for collection of
particles.  Very few studies  have been
conducted to evaluate filter material for
collection  of particle-bound PAHs. It is
recommended that an evaluation  study
be conducted to compare different types
of filters such as quartz fiber, glass fiber,
and Teflon-coated for collection of PAHs
in ambient air sampling. Several impor-
tant  filter  characteristics such as flow
characteristics and collection efficiency
can be addressed for different types of
filters.
  Studies to determine sample stabilities
for different types of filters and to deter-
mine the effects of storage timewn PAH
samples  collected on different types of
filters are also recommended.
   C.  C. Chuang, W. E.  Bresler, and S.  W.  Hannan are with Battelle Columbus
     Laboratories. Columbus, OH 43201.
   Nancy K, Wilson is the EPA Project Officer (see below).
   The complete report,  entitled "Evaluation of Polyurethane Foam Cartridges for
     Measurement of Polynuclear Aromatic Hydrocarbons in Air," (Order No. PB
     85-245 645/AS; Cost: $9.95, subject to change) will be available only from:
           National Technical Information Service
           5285 Port Royal Road
           Springfield, VA22161
           Telephone: 703-487-4650
   The EPA Project Officer can be contacted at:
           Environmental Monitoring Systems Laboratory
           U.S. Environmental Protection Agency
           Research Triangle Park, NC 27711

-------
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300

EPA/600/S4-85/055
              00003??   PS

-------