United States
                    Environmental Protection
Environmental Research
Athens, GA 30613-7799
                    Research and Development
 EPA/600/S4-90/002  May 1990
&EPA           Project Summary
                     Muitispectral  Identification  and
                     Confirmation  of Organic
                     Compounds in Wastewater
                     John M. McGuire, Timothy W. Collette, Alfred D. Thruston, Jr.,
                     Susan D. Richardson, and William D. Payne
                     Application of multlspectral ident-
                    ification techniques to samples from
                    industrial  and  POTW wastewaters
                    revealed identities of 63 compounds
                    that had  not  been identified  by
                    empirical matching of mass spectra
                    with spectral libraries. Twenty-five of
                    the compounds have not been found
                    in wastewaters  previously. Multi-
                    spectral  techniques used in the
                    identifications were GC/MS  (low
                    resolution), high resolution mass
                    spectrometry (HRMS),  positive
                    methane chemical ionization mass
                    spectrometry (CIMS), and gas
                    chromatography combined  with
                    Fourier transform infrared  spectros-
                    COpy (GC/FT-IR).
                     Some of the same techniques were
                    used to confirm (without obtaining a
                    pure sample  of the   tentatively
                    identified compound) identifications
                    made by  reexamlnation of GC/MS
                    data tapes generated by contractor
                    laboratories.  Eighty percent of the
                    Identifications were confirmed. Some
                    of the wrong identifications made by
                    reexamination  of tapes were
                    attributed  to poor chromatography
                    during the  initial analysis.
                     This  Project  Summary  was
                    developed by SPA's Environmental
                    Research Laboratory, Athens, GA, to
                    announce key findings of the research
                    project that is fully documented in a
                    separate report  of the same title (see
                    Project Report ordering information at

                     Gas chromatography/mass spectro-
                    metry (GC/MS) was determined in  the
early 1970s to be the method of choice
for analysis of organic pollutants in water.
In  support of the 1976 Consent  Decree
between  the U.S. Environmental Pro-
tection Agency (EPA) -and the National
Resources Defense Council,  magnetic
tapes of  GC/MS  analyses of samples
acquired by contract laboratories for the
Industrial  Technology Division (ITD) of
EPA's Office of Water were processed
through a suite of computer programs
designed  to Identify  both priority  and
non-priority pollutants.  The  programs
originally  had  been developed  for
minicomputers and had been applied in
the late 1970s and early 1980s to data
acquired  in the late  1970s.  These
programs  were converted in 1986  and
1987  to  operate  on  the Athens
Environmental Research Laboratory's
VAX-785 computer and were applied to
data  acquired  by ITD  contract
faboratories during the early  1980s,
Tentative  identifications were made by
computerized spectra matching from the
input data, using historical GC relative
retention  times  and  a collection of
110,000 reference mass spectra.
 Few identifications of non-priority
pollutants  or confirmations of tentative
computer  identifications had been made
from the 1970s data. This was attributed
both to the  use of packed GC columns
and to the limited size of the reference
database  (34,000 mass spectra). In the
most recent tape study, the database was
nearly three times the size of the  one
used earlier, and the GC/MSv data  had
been collected using capillary GC column
and protocols similar to  those  of EPA
Methods 625 and  1625.  As  had been
anticipated,  the number of  sample
components recognized by the computer

increased as  a result of the  use of
capillary  columns.  Not anticipated  was
the fact that the programs designed to
select the best spectrum for packed GC
columns were  less effective in selecting
the best  spectrum from a capillary GC
column. In particular, it was determined
that when the peak recognition algorithm
was  tuned to  recognize trace  level
chromatographic peaks, it was quite apt
to ignore  high  level  peaks  due to the
width of the GC peak.

Sample  and Compound
  To check the accuracy of the tentative
identifications,  as  well as to determine
the identity of  compounds not identified
by the tape programs, compounds from~
GO/MS runs  of  19  publicly  owned
treatment works and of 13  organic
         chemical  plants  were  selected  as
         "targets" for our reanalysis.
           The analytical targets were organized
         by sample source into five groups. As a
         result, it is possible that a given target
         might  occur  in  a  publicly   owned
         treatment works sample,  but be  a
         confirmation or identification target only
         in  a specific organic  chemical plant
         study. The majority of the  peaks  in most
         chromatograms  are  due  to the
         isotopically enriched compounds that
         were  used  for  mass  spectrometric
         quantitation  of  specific  analytes  by
         isotope dilution.
           New GC/MS  chromatograms  and,
         where appropriate, GC/Fourier Transform
         Infrared  Spectroscopy  (GC/FT-IR)
         chromatogram^ jwere  obtained  for
         retained^e^tratts^arid were "cbrffparW
         with  one  another  and  with the
         corresponding chromatograms  from the
contract laboratory data. Based on these
comparisons, , sample  similarities  were
recognized  that permitted choosing  11
representative sample extracts for the
confirmations  and  identifications.
Multispectral analysis of these  extracts,
consisting of GC separation  followed  by
appropriate  combinations of low and high
resolution electron  impact  or chemical
ionization mass spectrometry and FT-IR,
resulted in  48  confirmations,  63
identifications, and  recognition of  12
common compounds that should  have
been identified in the tape  study. The
number of  compounds identified by the
tape study could have been increased by
the following:  a strict adherence to the
1625 GC protocol,  a  reduction in the
number of  internal standards added to
                                T the
peak recognition  algorithm used by the
tape study.
    John M. McGulre (also the EPA Project Officer, see below), Timothy W. Collette,
        Alfred D. Thruston, Jr., and Susan  D.  Richardson,  are  with  the
        Environmental Research Laboratory, Athens, GA  30613-7799. William  D.
        Payne is with Technology Applications Inc., Athens, GA 30613-7799.
    ThB complete report, entitled  "Multispectral Identification  and Confirmation of
         Organic  Compounds  in  Wastewater  Extracts," (Order No.  PB-90 160
         995/AS; Cost: $31.00, subject to change) will be available only from:
              National Technical Information Service
              5285 Port Royal Road
              Springfield, VA 22161
              Telephone: 703-487-4650
    The EPA Project Officer can be contacted at:
              Environmental Research Laboratory
              U.S. Environmental Protection Agency
              Athens, GA 30613-7799
 United States
 Environmental Protection
Center for Environmental Research
Cincinnati OH 45268
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