&EPA
United States    Environmental Monitoring Systems
Environmental Protection Laboratory
Agency       Research Triangle Park NC 2771 1
                               EPA/600/4-87-006
                               September 1986
         Research and Development
Supplement to
EPA/600/4-84/041
Compendium of
Methods for the
Determination of
Toxic Organic
Compounds in
Ambient Air

-------

-------
                                 NOTICE



                 SUPPLEMENT TO COMPENDIUM OF METHODS FOR THE

          . DETERMINATION OF TOXIC ORGANIC COMPOUNDS IN AMBIENT AIR


To holders of Compendium of Methods for the Determination of Toxic Organic

Compounds in Ambient Air (EPA-600/4-84-041). dated April 1984:


     The accompanying document is a supplement to the Compendium referenced

above and contains the pages necessary to update the Compendium as of

September 1986.  The supplement is only an update and is intended to be used

in conjunction with the original  Compendium published by the U.S. Environmental

Protection Agency, Environmental  Monitoring Systems Laboratory, Quality

Assurance Division, in April 1984 (EPA-600/4-84-041).  Copies of this document

may be obtained, as supplies permit, from:

              U. S. Environmental Protection Agency
              Center for Environmental Research Information
              Compendium Registration
              26 W. St. Clair Street
              Cincinnati, Ohio 45268
              Attention: Distribution Record System

Copies of the Compendium dated September 1986 will  contain the supplement.

     Included in this supplement  are all revisions  pertinent to the update,

along with instructions for merging the supplementary pages with the original

document.  Four new methods are added to the Compendium, and a new title page,

Table of Contents, and new Tables 1 and 2 are included to reflect the added

methods.

-------
     Any questions, comments, or suggestions regarding this supplement  or the
Compendium should be directed to the U. S. Environmental  Protection Agency,
Environmental Monitoring Systems Laboratory, Quality Assurance Division,
MD-77, Research Triangle Park, NC, 27711; (919) 541-2665, (FTS:   629-2665).

         Instructions for Merging the Supplement with the Compendium:
       Delete                                  Insert	
Original Title Page  (4/84)                New Title Page (9/86)
Original Disclaimer, page ii (4/84)        New Disclaimer, page ii (9/86)
Original CONTENTS, page iii (4/84)         New CONTENTS, page iii (9/86)
Pages iv through viii (4/84)               Pages iv through viii (9/86)
                                           Method T06 (9/86)
                                           Method T07 (9/86)
                                           Method T08 (9/86)
                                           Method T09 (9/86)

-------
                                        EPA/600/4-87/006
                                        September  1986
 COMPENDIUM OF METHODS FOR THE DETERMINATION
  OF TOXIC ORGANIC COMPOUNDS IN AMBIENT AIR
                      by

                 R.M. Riggin
        Battelle-Columbus Laboratories
               505 King Avenue
            Columbus, Ohio  43201

                     and
           William T. Winberry,  Jr.
               Norma V. Tilley
             Engi neeri ng-Science
         One Harrison Park, Suite 200
         401 Harrison Oaks Boulevard
         Cary, North Carolina  27511
           Contract No.  68-02-3888
                 Task No. 44
             EPA Project Officer:

                 L.J. Purdue
          Quality Assurance Division
 Environmental Monitoring Systems  Laboratory
     U.S. Environmental  Protection Agency
Research Triangle Park,  North Carolina   27711
 ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
      OFFICE OF RESEARCH AND DEVELOPMENT
     U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA  27711

-------
                                   Disclaimer

     This report has been reviewed by Environmental Monitoring Systems
Laboratory, U. S. Environmental Protection Agency, and approved for publi-
cation.  Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.

     The information in this document has been funded wholly or in part by
the U. S. Environmental Protection Agency under contract number 68-02-3888.
It has been subjected to the Agency's peer and administrative review, and it
has been approved for publication as an EPA document.

-------
                                 CONTENTS
FOREWORD                                                         iv
INTRODUCTION                                                      v
METHODS
     Tenax GC Adsorption                                Method TO-1
     Carbon Molecular Sieve Adsorption                  Method TO-2
     Cryogenic Trapping                                 Method TO-3
     High Volume Polyurethane Foam Sampling             Method TO-4
     Dinitrophenylhydrazine Liquid Impinger             Method TO-5
       Sampling
     Liquid Impinger with High Performance              Method TO-6
       Chromatography (HPLC)
     Thermosorb/N Adsorption with Gas                   Method TO-7
       Chromatography/Mass Spectrometry (GC/MS)
     Sodium Hydroxide Liquid Impinger with              Method TO-8
       High Performance Liquid Chromatography (HPLC)
     High Volume Polyurethane Foam Sampling (PUF)        Method TO-9
       with High Resolution Gas Chromatography/High
       Resolution Mass Spectrometry (HRGC/HRMS)

APPENDIX A - EPA Method 608
                                       iii

-------
                                 FOREWORD
     Measurement and monitoring research efforts are designed to
anticipate potential environmental problems, to support regulatory
actions by developing an in-depth understanding of the nature and
processes that impact health and the ecology, to provide innovative
means of monitoring compliance with regulations, and to evaluate the
effectiveness of health and environmental  protection efforts  through
the monitoring of long-term trends.  The Environmental Monitoring
Systems Laboratory Research Triangle Park, North Carolina,  has
responsibility for:   assessment of environmental monitoring technology
and systems; implementation of Agency-wide quality assurance  programs
for air pollution measurement systems; and supplying technical support
to other groups in the Agency, including the Office of Air  and Radiation,
the Office of Toxic Substances, and the Office of Enforcement.

     Determination of toxic organic compounds in ambient air  is a
complex task, primarily because of the wide variety of compounds of
interest and the lack of standardized sampling and analysis procedures.
This methods compendium has been prepared to provide a standardized
format for such analytical  procedures.  A core set of five  methods is
presented in the original  document.  In an effort to update the original
Compendium, an addition of four specific methods has been made. With this
addition, the Compendium now contains nine standardized sampling and
analysis procedures.  As advancements are made, the current methods
may be modified from time to time along with new additions  to the
Compendium.
                              John C.  Puzak
                             Deputy Director
               Environmental  Monitoring Systems  Laboratory
                  Research Triangle Park,  North  Carolina

-------
                               INTRODUCTION
     This Compendium has been prepared to provide regional,
state, and local environmental regulatory agencies,  as well  as  other
interested parties, with specific guidance on the determination of
selected toxic organic compounds in ambient air.   Recently,  a
Technical Assistance Document (TAD) was published which provided
guidance to such persons (1).  Based on the comments received con-
cerning the TAD the decision was made to begin preparation  of a
Compendium which would provide specific sampling  and analysis
procedures, in a standardized format, for selected toxic organic com-
pounds.

     The current Compendium consists of nine procedures which
are considered to be of primary importance in current toxic  organic
monitoring efforts.  Additional methods will be placed in the Compendium
from time to time, as such methods become available.  The original
methods were selected to cover as many compounds  as  possible (i.e.,
multiple analyte methods were selected).  The additional  methods are
targeted toward specific compounds, or small groups  of compounds which,
for various technical reasons, cannot be determined  by the  more general
methods.

     Each of the methods writeups is self contained  (including  pertinent
literature citations) and can be used independent of the remaining  portions
of the Compendium.  To the extent possible the American Society
for Testing and Materials (ASTM) standardized format has been used, since
most potential users are familiar with that format.   Each method has been
identified with a revision, number and date, since modifications to  the
methods may be required in the future.

     Nearly all the methods writeups have some flexibility  in the procedure.
Consequently, it is the user's responsibility to  prepare certain standard
operating procedures (SOPs) to be employed in that particular laboratory.
Each method indicates those operations for which  SOPs are required.

     Table 1 summarizes the methods currently in  the Compendium. As shown
in Table 1 the first three methods are directed toward volatile nonpolar
compounds.  The user should review the procedures as well as the back-
ground material provided in the TAD (1) before deciding which of these
methods best meets the requirements of the specific  task.

     Table 2 presents a partial listing of toxic  organic compounds  which
can be determined using the current set of methods in the Compendium.
Additional compounds may be determined by these methods,  but the user
must carefully evaluate the applicability of the  method before  use.

Reference

1.  Riggin, R. M., "Technical Assistance Document for Sampling  and
    Analysis of Toxic Organic Compounds in Ambient Air",  EPA-600/4-
    83-027, U. S. Environmental Protection Agency, Research  Triangle
    Park, North Carolina, 1983.

-------
               TABLE 1.  LIST OF METHODS IN THE COMPENDIUM
Method
Number
TO-1
TO-2
TO-3



TO-4



TO-5



TO-6


TO-7

TO-8




TO-9
   Description
        Types of
  Compounds Determined
Tenax GC Adsorption
and GC/MS Analysis
Carbon Molecular Sieve
Adsorption and GC/MS
Analysis
Cryogenic Trapping
and GC/FID or ECD
Analysis

High volume PUF
Sampling and GC/ECD
Analysis

Dinitrophenylhydrazine
Liquid Impinger Sampling
and HPLC/UV Analysis

High Performance Liquid
Chromatography (HPLC)

Thermosorb/N Adsorption

Sodium Hydroxide Liquid
Impinger with High Per-
formance Liquid Chromato-
graphy

High Volume Polyurethane
Foam Sampling with
High Resolution Gas
Chromatography/High
Resolution Mass Spec-
trometry (HRGC/HRMS)
Volatile, nonpolar organic
(e.g., aromatic hydrocarbons,
chlorinated hydrocarbons)
having boiling points in the
range of 80 to 200C.

Highly volatile, nonpolar
organics (e.g., vinyl chloride,
vinylidene chloride,  benzene,
toluene) having boiling points
in the range of -15  to +120C.

Volatile, nonpolar organics
having boiling points in the
range of -10 to +200C.

Organochlorine pesticides and
PCBs
Aldehydes and Ketones



Phosgene


N-Ni trosodimethyl ami ne

Cresol/Phenol




Dioxin
                                    VI

-------
             TABLE 2.  LIST OF COMPOUNDS OF PRIMARY  INTEREST
Compound
Acetaldehyde
Acrolein
Acrylonitrlle
Ally! Chloride
Benzaldehyde
Benzene

Benzyl Chloride
Applicable
 Method(s)
      Comments
TO-5
TO-5
TO-2, TO-3
TO-2, TO-3
TO-5
TO-1, TO-2, TO-3

TO-1, TO-3
TO-3 yields better recovery
data than TO-2.

TO-3 yields better recovery
data than TO-2.
TO-3 yields better recovery data.
Carbon Tetrachloride     (TO-1?),  TO-2,  TO-3
Chlorobenzene

Chloroform
Chloroprene
 (2-Chloro-l,3-buta-
 diene)

Cresol

4,4'-DDE
4,4'-DDT

1,4-Dichlorobenzene

Dioxin

Ethylene dichloride
 (1,2-Dichloroethane)

Formaldehyde

Methyl Chloroform
 (1,1,1-Trichloroethane)
TO-1, TO-3

(TO-1?), TO-2, TO-3


TO-1, TO-3



TO-8

TO-4
TO-4

TO-1, TO-3

TO-9

(TO-1?), TO-2, TO-3


TO-5

(TO-1?), TO-2, TO-3
                     Breakthrough volume is very low
                     using TO-1.
Breakthrough volume is very Tow
using TO-1

The applicability of these methods
for chloroprene has not been
documented.
Breakthrough volume very low
using TO-1.
Breakthrough volume very low
using TO-1.
Methylene chloride       TO-2, TO-3

Nitrobenzene             TO-1, TO-3

N-Nitrosodimethyl amine   TO-7
                                   vn

-------
     Compound
                          TABLE 2,  (Continued)
   Applicable
    Method(s)
Comments
Perchloroethylene
 (Tetrachloroethylene)

Phenol

Phosgene

Polychlorinated bi-
phenyls (PCBs)

Propanal
 Toluene

Tri chloroethy 1 ene
Vinyl Chloride
Vinylidine Chloride
 (1,1-di chloroethene)

o,m,p-Xylene
TO-1, (TO-2?), TO-3  TO-2 performance has not been
                     documented for this compound.

TO-8

TO-6
 TO-4

TO-5
TO-1, TO-2, TO-3

TO-1, TO-2, TO-3
TO-2, TO-3
TO-2, TO-3
TO-1, TO-3
                                   vm

-------
                               METHOD  T06                   Revision 1.0
                                                           September,  1986
                 METHOD FOR THE  DETERMINATION  OF  PHOSGENE
       IN AMBIENT AIR USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY
1.   Scope

     1.1   This document describes  a method  for  determination  of
           phosgene in ambient  air, in which phosgene  is  collected  by
           passage of the air through a solution of  aniline, forming
           carbanilide,,  The carbanilide is  determined by HPLC.   The method
           can be used to detect phosgene at the 0.1 ppbv level.
     1.2   Precision for phosgene spiked into a  clean  air stream  is
           jH5-20% relative standard deviation.   Recovery is quantita-
           tive within that precision, down  to less  than  3 ppbv.  This
           method has been developed and tested  by a single
           laboratory^), and,  consequently, each laboratory desiring
           to use the method should acquire  sufficient precision
           and recovery data to verify performance under  those
           particular conditions.  This method is more sensitive,
           and probably more selective, than the standard colorimetric
           procedure currently in widespread use for workplace monitor-
           1ng(2).

2.   Applicable Documents

     2.1   ASTM Standards

           D1356 - Definitions of Terms Related to Atmospheric Sampling
           and Analysis^).

     2.2   Other Documents

           Standard  NIOSH Procedure  for Phosgene(2).
           U.S. EPA  Technical Assistance Document^).

-------
                                  T06-2
3.   Summary of Method

     3.1   Ambient air is drawn through a midget impinger containing
           10 ml of 2/98 aniline/toluene (by volume).  Phosgene
           readily reacts with aniline to form carbanilide (1,3-
           diphenylurea), which is stable indefinitely.
     3.2   After sampling, the impinger contents are transferred to
           a screw-capped vial having a Teflon-lined cap and
           returned to the laboratory for analysis.
     3.3   The solution is taken to dryness by heating to 60C on an
           aluminum heating block under a gentle stream of pure
           nitrogen gas.  The residue is dissolved in 1 ml of
           acetonitrile.
     3.4   Carbanilide is determined in the acetonitrile solution
           using reverse-phase HPLC with an ultraviolet absorbance
           (UV) detector operating at 254 nm.

4.   Significance

     4.1   Phosgene is widely used in industrial  operations, primarily
           in the synthetic organic chemicals industry.  In addition,
           phosgene is produced by photochemical  degradation of
           chlorinated hydrocarbons (e.g.,  trichloroethylene) emitted
           from various sources.   Although  phosgene is acutely
           toxic, its effects at  low levels (i.e.,  1 ppbv and below)
           are unknown.  Nonetheless, its emission  into and/or
           formation in ambient air is of potential  concern.
     4.2   The conventional  method for phosgene has utilized a
           colorimetric procedure involving reaction with
           4,4'-nitrobenzyl  pyridine in diethyl phthalate.  This
           method cannot detect phosgene levels below   10 ppbv and
           is subject to numerous interferences.   The method described
           herein is more sensitive (0.1 ppbv detection limit) and
           is believed to be more selective due to  the chromatographic
           separation step.  However, the method  needs to be more
           rigorously tested for  interferences before its degree
           of selectivity can be  firmly established.

-------
                                  T06-3

5.   Definitions

           Definitions used in this document and in any user-prepared
           SOPs should be consistent with ASTM D1356 (3).  All
           abbreviations and symbols are defined within this
           document at the point of use.

6.   Interferences

     6.1   There are very few interferences in the method, although
           this aspect of the method needs to be more thoroughly
           investigated.  Ambient levels of jiitrogen oxides, ozone,
           water vapor, and S02  are known not to interfere.  Chloroformates
           can cause interferences by reacting with the aniline to form
           urea, which produces a peak that overlies the carbanilide
           peak in the HPLC trace.  Presence of Chloroformates should be
           documented before use of this method.  However, the inclusion
           of a HPLC step overcomes most potential interferences from
           other organic compounds.  High concentrations of acidic materials
           can cause precipitation of aniline salts in the impinger, thus
           reducing the amount of available reagent.
     6.2   Purity of the aniline reagent is a critical factor, since
           traces of carbanilide have been found in reagent-grade
           aniline.  This problem can be overcome by vacuum distil-
           lation of aniline in an all-glass apparatus.

7.   Apparatus

     7.1   Isocratic high performance liquid chromatography (HPLC)
           system consisting of a mobile-phase  reservoir, a high-pressure
           pump, an  injection valve, a Zorbax ODS or C-18 reverse-phase
           column, or equivalent (25 cm x 4.6 mm  ID),  a  variable-wavelength
        (, ,T.Uy  detector  operating at 254 nm, and a data system or strip-
           chart recorder  (Figure 1).
     7.2   Sampling  system  - capable of accurately  and precisely
           sampling  100-1000 mL/minute  of ambient air  (Figure 2).

-------
                                  T06-4
     7.3   Stopwatch.
     7.4   Friction-top metal can, e.g., one-gallon (paint can) - to
           hold sampling reagent and samples.
     7.5   Thermometer - to record ambient temperature.
     7.6   Barometer (optional).
     7.7   Analytical balance - 0.1 mg sensitivity.
     7.8   Midget impingers - jet inlet type, 25 mL.
     7.9   Nitrogen evaporator with heating block - for concentrating
           samples.
     7.10  Suction filtration apparatus - for filtering HPLC
           mobile phase.
     7.11  Volumetric flasks - 100 mL and 500 ml.
     7.12  Pipettes - various sizes, 1-10 mL.
     7.13  Helium purge line (optional) - for degassing HPLC
           mobile phase.
     7.14  Erlenmeyer flask, 1-L - for preparing HPLC mobile
           phase.
     7.15  Graduated cylinder, 1 L - for preparing HPLC mobile
           phase.
     7.16  Microliter syringe, 10-25 uL - for HPLC injection.

8.   Reagents and Materials
     8.1   Bottles, 16 oz. glass, with Teflon-lined screw cap  -  for
           storing sampling reagent.
     8.2   Vials, 20 mL, with Teflon-lined screw cap -  for holding
           samples and extracts.
     8.3   Granular charcoal.
     8.4   Acetonitrile, toluene, and methanol  - distilled in  glass
           or pesticide grade.
     8.5   Aniline - 99+%, gold label from Aldrich  Chemical  Co.,  or
           equivalent.

-------
                                  T06-5
     8.6   Carbanilide - highest purity available;  Aldrich Chemical
           Co., or equivalent.
     8.7   Nitrogen, compressed gas cylinder - 99.99% purity for
           sample evaporation.
     8.8   Polyester filters, 0.22 urn - Nuclepore,  or equiv.

9.   Preparation of Sampling Reagent

     9.1   Sampling reagent is prepared by placing  5.0 ml of aniline in
           a 250-mL volumetric flask and diluting to the mark with toluene.
           The flask is inverted 10-20 times to mix the reagent.  The
           reagent is then placed in a clear 16-ounce bottle with a
           Teflon-lined screw cap.  The reagent is  refrigerated until use.
     9.2   Before use, each batch of reagent is checked for purity by
           analyzing a 10-mL portion according to the procedure described
           in Section 11.  If acceptable purity (<50 ng of carbanilide
           per 10 ml of reagent) is not obtained, the aniline or toluene
           is probably contaminated.

10.  Sampling

     10.1  The sampling apparatus is assembled and  should be similar
           to that shown in Figure 2.  EPA Method 6 uses essentially
           the same sampling system (5).   All glassware (e.g.,
           impingers, sampling bottles, etc.) must  be thoroughly
           rinsed with methanol and oven-dried before use.
     10.2  Before sample collection, the entire assembly (including
           empty  sample impingers) is  installed and the flow rate
           checked at a value near the desired rate.  Flow rates
           greater than 1000 mL/minute (+_2%) should not be used because
           impinger collection efficiency may decrease.  Generally,
           calibration  is  accomplished using a soap bubble flow

-------
                             T06-6
      meter or calibrated wet test meter connected to the flow
      exit, assuming that the entire system is sealed.  ASTM Method
      D3686 describes an appropriate calibration scheme that does
      not require a sealed-flow system downstream of the pump (3).
10.3  Ideally, a dry gas meter is included in the system to record
      total flow, if the flow rate is sufficient for its use.
      If a dry gas meter is not available, the operator must measure
      and record the sampling flow rate at the beginning and end of
      the sampling period to determine sample volume.  If the
      sampling time exceeds two hours, the flow rate should be
      measured at intermediate points during the sampling period.
      Ideally, a rotameter should be included to allow observation of
      the flow rate without interruption of the sampling process.
10.4  To collect an air sample, the midget impingers are
      loaded with 10 ml each of sampling reagent.  The impingers
      are installed in the sampling system and sample flow is
      started.  The following parameters are recorded on the
      data sheet (see Figure 3 for an example):   date, sampling
      location, time, ambient temperature, barometric pressure
      (if available), relative humidity (if available), dry
      gas meter reading (if appropriate),  flow rate, rotameter
      setting, sampling reagent batch number, and dry gas meter
      and pump identification numbers.
10.5  The sampler is allowed to operate for the  desired period,
      with periodic recording of the variables listed above.
      The total flow should not exceed 50  L.  If it  does, the
      operator must use a second impinger.
10.6  At the end of the sampling period, the parameters listed
      in Section 10.4 are recorded and the sample flow is stopped.
      If a dry gas meter is not used, the  flow rate  must be checked
      at the end of the sampling interval.  If the flow rates at the
      beginning and end of the sampling period differ by more than
      15%, the sample should be marked as  suspect.

-------
                                T06-7
    10.7  Immediately  after sampling, the  impinger  is  removed  from
          the  sampling system.   The  contents  of the impinger are
          emptied  into a  clean  20-mL glass  vial with a Teflon-
          lined  screw  cap.   The impinger is then  rinsed with
          2-3  mL of  toluene and the  rinse  solution  is  added to the
          vial.   The vial  is then capped,  sealed  with  Teflon tape,
          and  placed in a friction-top  can  containing  1-2 inches
          of granular  charcoal.  The samples  are  stored in the
          can  and refrigerated  until analysis.
    10.8  If a dry gas meter or equivalent  total  flow  indicator
          is not used, 'the average sample  flow rate must be calculated
          according  to the following equation:
                                      Q
                                         N
                                 N  '

          where
          QA = average flow rate (mL/minute).
Qls Q2	QN = flow rates determined at  the  beginning,  end,
               and intermediate points during  sampling.
           N = number of points averaged.

    10.9  The total flow is then calculated  using the following
          equation:

                           -  .  (T24)QA
                                  1,000
                                  tul 
            where                  '
                      Vm = total  sample volume (L)  at measured
                           temperature and pressure.
                      T2 = stop  time.
                      Tj = start  time.         .     -
                    T-]-T2 - total  sampling time (minutes).
                      Qa = average flow rate  (mL/minute).

-------
                                  T06-8
11.  Sample Analysis

     11.1  Sample Preparation
           11.1.1 The samples are returned to the laboratory in 20-ml
                  screw-capped vials and refrigerated  in  charcoal
                  containing cans until  analysis.
           11.1.2 The sample vial is placed in an aluminum
                  heating block maintained at 60C and  a  gentle
                  stream of pure nitrogen gas is  directed
                  across the sample.
           11.1.3 When the sample reaches complete dryness,  the vial
                  is removed from the heating block, capped, and
                  cooled to near room temperature.  A 1-mL volume
                  of HPLC mobile phase (50/50 acetonitrile/water)
                  is placed in the vial.   The vial  is then capped
                  and gently shaken to dissolve the residue.
           11.1.4 The concentrated sample is  then  refrigerated
                  until  HPLC analysis,  as described in  Section  11.2.

    11.2   HPLC Analysis
           11.2.1  The HPLC  system is assembled and  calibrated as described in
                  Section 12.   The operating  parameters are  as  follows:
                               Column:  C-18  RP
                         Mobile  Phase:  30% acetonitrile/70% distilled water
                             Detector:  ultraviolet, operating at 254 nm
                            Flow Rate:  1  mL/min
                  Before  each  analysis, the detector baseline is checked
                  to  ensure  stable  operation.
          11.2.2  A 25-uL aliquot  of the  sample, dissolved in HPLC
                 mobile  phase,  is drawn  into a clean HPLC injection
                  syringe.  The  sample injection loop is loaded and
                  an  injection is made.   The data system is  activated
                 simultaneously with the injection and the  point of
                  injection is marked on the strip-chart recorder.

-------
                                 T06-9
           11.2.3  After  approximately one minute, the injection valve
                  is  returned  to the "load" position and the syringe and
                  valve  are  flushed with mobile phase in preparation
                  for the  next sample analysis.
           11.2.4  After  elution of carbanilide, data acquisition is
                  terminated and the component concentrations are
                  calculated as described in Section 13.
           11.2.5  Once a stable baseline is achieved, the  system can be
                  used for further sample analyses as described above.
           11.2.6  If  the concentration of carbanilide exceeds the
                  linear range of the instruments, the sample should
                  be  diluted with mobile phase, or a smaller volume
                  can be injected into the HPLC.
           11.2.7  If  the retention time is not duplicated, as determined
                  by  the calibration curve, you may increase or decrease
                  the acetonitrile/water ratio to obtain the correct elution
                  time,  as specified in Figure 4.  If the  elution time is too
                  long,  increase the ratio; if it is too short, decrease the
                  rat i o.
           11.2.8  If  a dirty column causes improper detection of carbanilide,
                  you may  reactivate the column by reverse solvent flushing
                  utilizing  the following sequence: water, methanol,
                  acetonitrile, dichloromethane, hexane, acetonitrile,
                  then 50/50, acetonitrile in water.
12.  HPLC Assembly and Calibration
     12.1  The HPLC system is  assembled and operated according to the
           parameters outlined in Section 11.2.1.  An example of a typical
           chromatogram  oabtained using the above parameters is shown  in
           Figure  4.
     12.2  The mobile phase  is prepared by mixing 500 mL of  acetonitrile
           and 500 mL of reagent water.  This mixture is filtered
           through a  0.22-um polyester membrane filter in  an all-glass
           and Teflon suction  filtration.  A constant back pressure   
           restrictor (50  psi) or short length  (6-12 inches) of 0.01-inch
           .1.0. Teflon tubing  should be placed after the detector to
           eliminate  further mobile  phase outgassing.

-------
                             T06-10
12.3  The mobile phase is placed in the HPLC solvent reservoir and
      the pump is set at a flow rate of 1 mL/minute and allowed to
      pump for 20-30 minutes before the first analysis.  The detector
      is switched on at least 30 minutes before the first analysis
      and the detector output is displayed on a strip-chart recorder
      or similar output device at a sensitivity of ca 0.008 absorbance
      units full scale (AUFS).  Once a stable baseline is achieved,
      the system is ready, for calibration.
12.4  Carbanilide standards are prepared in HPLC mobile phase.
      A concentrated stock solution of  100 mg/L is prepared by
      dissolving 10 mg of carbanilide in 100 ml of mobile phase.
      This solution is used to prepare calibration standards
      containing concentrations of 0.05-5 mg/L.
12.5  Each calibration standard (at least five levels) is analyzed
      three times and area response is tabulated against mass injected.
      All calibration runs are performed as described for sample
      analyses in Section 11.  Using the UV detector, a linear
      response range (Figures 5a through 5e) of approximately 0.1 to
      10 mg/L should be achieved for a 25-uL injection volumes.  The
      results may be used to prepare a calibration curve, as illus-
      trated in Figure 6.  Linear response is indicated where a corre-
      lation coefficient of at least 0.999 for a linear least-squares
      fit of the data (concentration versus area response) is obtained.
12.6  Once linear response has been documented, an intermediate
      concentration standard near the anticipated levels for ambient
      air, but at least 10 times the detection limit, should be
      chosen for daily calibration.  The response for carbanilide
      should be within 10% day to day.  If greater variability is
      observed, more frequent calibration may be required to ensure
      that valid results are obtained  or a new calibration curve
      must be developed from fresh standards.
12.7  The response for carbanilide in the daily calibration standard
      is used to calculate a response factor according to the following
      equation:

-------
           where


RFc =

T06-11
Cc X Vj

RC
                  RFC = response factor (usually area counts) for
                        carbanilide in nanograms injected/response
                        unit.
                  Cc  = concentration (mg/L) of carbanilide in the
                        daily calibration standard.
                  Vj  = volume (uL) of calibration standard injected,
                  Rc  = response (area counts) for carbanilide in
                        calibration standard.
13.  Calculations
     13.1  The volume of air sampled is often reported unconnected for
           atmospheric conditions (i.e., under ambient conditions).
           The value should be adjusted to standard conditions
           (25C and 760 mm pressure) using the following equation:
           where
                       Vs - Vm
298
                                 760   273 + TA
                  Vs = total sample volume (L) at 25C and 760 mm Hg
                       pressure.
                  Vm = total sample volume (L) under ambient conditions,
                       calculated as in Section 10.9 or from dry gas
                       meter reading.
                  PA = ambient pressure (mm Hg).
                  T/\ = ambient temperature (C).

-------
                             T06-12
13.2  The concentration of carbanilide is calculated for each
      sample using the following equation:
                  wd = RFC x Rd x _
                V
                 E
                VI
      where
             W,j  = total  quantity of carbanilide (ug) in the sample.
             RFC = response factor calculated in Section 12.7.
             R
-------
                                  T06-13
                       CA (ppbv)  = CA (ng/L)  x 24.4
                                                99
           where
                       CA (ng/L)  is calculated using Vs.
14.  Performance Criteria and Quality Assurance
     This section summarizes required quality assurance (QA)  measures and
     provides guidance concerning performance criteria that should be
     achieved within each laboratory.

     14.1  Standard Operating Procedures (SOPs).

           14.1.1 Users should generate SOPs  describing the following
                  activities in their laboratory:   1)  assembly,  calibra-
                  tion, and operation of the  sampling  system  with make
                  and model  of equipment used; 2)  preparation, purifica-
                  tion* storage,  and handling of sampling  reagent and
                  sample:;;  3) assembly, calibration, and  operation of
                  the HPLC  system with make and model  of  equipment used;
                  and 4)  all aspects of data  recording and processing,
                  including lists of computer hardware and software used.

           14.1.2 SOPs should provide specific stepwise instructions
                  and should be readily available  to and  understood
                  by the  laboratory personnel  conducting  the  work.

     14.2  HPLC System Performance

           14.2.1 The general appearance of the HPLC chromatogram
                  should  be similar to that illustrated in Figure 4.
           14.2.2 The HPLC  system efficiency  and peak  asymmetry
                  factor  should be determined in the following manner:

-------
                               T06-14


               A solution of carbanilide  corresponding to  at

               least 20 times the  detection  limit  should be
                                  T06-16

                                REFERENCES
1.  Spicer, C. W., R. M. Riggin, M. W. Holdren,  F.  L.  DeRoos,  and
    R. N. Lee. Atmospheric Reaction Products from Hazardous Air
    Pollutants, Final Report on Contract 68-02-3169 (WA-33/40),
    U.S. Environmental Protection Agency, Research  Triangle Park,
    N.C., July. 1984.

2.  Method 219, "Phosgene in Air," Manual of Analytical  Methods,
    National Institute for Occupational Safety and  Health.

3.  Annual Book of ASTM Standards, Part 11.03, "Atmospheric Analysis,"
    American Society for Testing and Materials,  Philadelphia,
    Pennsylvania, 1983.

4.  Riggin, R. M., "Technical Assistance Document for  Sampling and
    Analysis of Toxic Organic Compounds in Ambient Air," EPA-600/
    4-83-027.  U.S. Environmental Protection Agency, Research  Triangle
    Park, North Carolina, 1983.

5.  "Method 6 Determination of S02 Emissions from Stationary Sources,"
    Federal Register, Vol. 42., No. 160, August, 1977.

-------
       T06-17
< uj

< V)
Q >
  V)
             eo
             m
uj I"   CC
S   t
><   Q
                                   UJ

                                   CO

                                   CO
                                   o
                                   o
                                   Q.
                                   HI
                                   QC

-------
UJ
o
<
u
Z]
55
c.i
f
                                 T06-18
PS,
1 >-
CO
UJ CC
CL C9
5 z



K\) <- 3
i r
)i>WV*-



	 ::



S *
O) o>
>^s
*- 
o *~
- "o
E c
o c
^~~ ^





          Ul uj
                                                             E
                                                             o


                                                             o
                                                  cc
                                                  O
                                                  UJ <
         Q.
       UI

       <

       O
       cc
    Millilllll
                                                             I-

                                                             M"
                                                             -LU
EO
                                                             CM
                                                             LLJ
                                                             cc

-------
PROJECT:

SITE:
LOCATION:
INSTRUMENT MODEL NO:

PUMP SERIAL NO: 	

SAMPLING  DATA
                                       T06-19

                                -SAMPLING DATA SHEET
                             (One Sample per Data Sheet)
                    DATES(S) SAMPLED:
                    TIME PERIOD SAMPLED:

                    OPERATOR:
                    CALIBRATED BY:
                       Sample  Number:

                 Start Time:
                     Stop Time:
Time
1.
2.
3.
4.
N.
Dry Gas
Meter
Reading





Rotameter
Reading





Flow
Rate,*Q
mL/mi n





Ambient
Temperature
C





Barometric
Pressure,
mm Hg





Relative
Humidity, %





Comments





  Total Volume Data**


     Vm = (Final  -  Initial) Dry Gas Meter  Reading, or

       _ Qj +Q2  +Q3   QN
                  N
x                1
  1000  *  (Sampling Time in Minutes)
   * Flow rate  from  rotameter or soap bubble calibrator
     (specify which).
  ** Use data from dry gas meter if available.
                 FIGURE 3. TYPICAL SAMPLING DATA FORM

-------
                                T06-20
             9)
             in
              
             ro
     f
    o
                                               OPERATING PARAMETERS
                                                        HPLC
                                   Column: C-18 RP
                                   Mobile Phase: 30% Acetonitrile/70% Distilled Water
                                   Detector: Ultra violet operating at 254 nm
                                   Flow Rate: 1 ml/min
                                   Retention Time: 3.59 minutes
                                  AUG. 22, 1986  15:25:17 CHART 0.50 CM/MIN
                                                  RUN #50  CALC #0
                                  COLUMN           SOLVENT  OPR ID:
                                  EXTERNAL STANDARD QUANTITATION

                                  PEAK*    AMOUNT RT   EXP RT
                                          2.75300  2.74
                                       10020.20000  3.59
                                  TOTAL 10023.00000
  AREA
   2753 L
10020345 L
    RF
O.OOOOOOEO
O.OOOOOOEO
FIGURE 4.  CHROMATOGRAM FOR 3 ppbv OF
              PHOSGENE SPIKED INTO CLEAN AIR

-------
                                 T06-21

                                      3.59
          OPERATING PARAMETERS
                 HPLC
Column: C-18 RP
Mobile Phase: 30% Acetonitrile/70% Distilled Water
Detector: Ultra violet operating at 254 nm
Flow Rate: 1 ml/min
Retention Time: 3.59 minutes
                         (a)
                                        3.55
                                           (b)
                                                       3.57
(c)
                                                 TIME-
                                                             o
                                                             UJ
                                                             3
                                                      V	

                                                    TIME-
      CONG
 AREA
COUNTS
 2126577
 4243289
 6312128
 8373790
10020345
                                            3.60
                                               (d)
                                                 3.59
                                                   (e)
                                      UJ
                                      3
                             TIME-
                              4/tg
                                           o   TIME-
                                           z    5/ig
      FIGURE 5a-5e. HPLC CHROMATOGRAM OF
                      VARYING  CARBANILIDE CONCENTRATIONS

-------
                   T06-22
                          CORRELATION COEFFICIENT:
                                   0.9999
                    OPERATING PARAMETERS
                             HPLC

       Column: C-18 RP
       Mobile Phase: 30% Acetonitrile/70% Distilled Water
       Detector: Ultra violet operating at 254 nm
       Flow Rate: 1  ml/min
       Retention Time: 3.59 minutes
   2345
     CARBANILIDE
FIGURE 6. CALIBRATION CURVE FOR
          CARBANILiNE

-------
                      T06-23
                              BC
               Asymmetry Factor = -jr=r


               Example Calculation:
                Peak Height = DE = 100 mm
                10% Peak Height = BD = 10 mm
                Peak Width at 10% Peak Height = AC = 23 mm
                   AB = 11 mm
                   BC = 12 mm

               Therefore: Asymmetry Factor =  = 1.1
FIGURE 7. PEAK ASYMMETRY CALCULATION

-------
                T06-24
TABLE 1:  PRECISION AND RECOVERY DATA
          FOR PHOSGENE IN CLEAN AIR
Phosgene
Concentration,
ppbv
0.034
0.22
3.0
4.3
20
200
Recovery,
%
63
87
99
109
99
96
Standard
Deviation
13
14
3
12
14
7

-------
                                                             Revision 1.0
                                                             September,  1986
                                METHOD  T07
          METHOD FOR THE DETERMINATION OF  N-NITROSODIMETHYLAMINE
                 IN AMBIENT AIR  USING  GAS  CHROMATOGRAPHY
1.   Scope

     1.1   This document describes a method for determination  of  N-
           nitrosodimethylamine (NDMA)  in  ambient  air.   Although  the
           method, as described, employs gas chromatography/mass
           spectrometry (GC/MS), other  detection systems are allowed.
     1.2   Although additional  documentation of the performance  of this
           method is required,  a detection limit of better than  1 ug/m^
           is achievable using  GC/MS (1,2).  Alternate,  selective GC
           detection systems such as a  thermal  energy analyzer (2), a
           thermionic nitrogen-selective detector (3),  or a Hall  Electro-
           lytic conductivity detector  (4) may  prove to  be more  sensitive
           and selective in some instances.

2.   Applicable Documents

     2.1   ASTM Standards
                             /
           D1356 Definitions of Terms Related to Atmospheric Sampling
           and Analysis (5)
     2.2   Other Documents
           Ambient air studies  (1,2)
           U.S. EPA Technical Assistance Document (6)

3.   Summary of Method

     3.1   Ambient air  is drawn through a Thermosorb/N  adsorbent
           cartridge at a rate  of approximately 2 L per minute for
           an  appropriate period of time.   Breakthrough has been shown

-------
                                  T07-2
           not to be a problem with total sampling volumes of 300 L
           (i.e., 150 minutes at 2 L per minute).  The selection
           of Thermosorb/N absorbent over Tenax GC, was due, in part,
           to recent laboratory studies indicating artifact formation
           on Tenax from the presence of oxides of nitrogen in the sample
           matrix.
     3.2   In the laboratory, the cartridges are pre-eluted with 5 ml
           of dichloromethane (in the same direction as sample flow)  to
           remove interferences.  Residual dichloromethane is removed by
           purging the cartridges with air in the same direction.  The
           cartridges are then eluted, in the reverse direction, with 2 mL
           of acetone.  This eluate is collected in a screw-capped vial
           and refrigerated until analysis.
     3.3   NDMA is determined by GC/MS using a Carbowax 20M capillary
           column.  NDMA is quantified from  the response of the m/e 74
           molecular ion using an external standard calibration method.

4.   Significance

     4.1   Nitrosamines, including NDMA, are suspected human carcinogens.
           These compounds may be present in ambient air as a result  of
           direct emission (e.g., from tire  manufacturing) or from atmos-
           pheric reactions between secondary or tertiary amines and  NOX.
     4.2   Several papers (1,2,4) have been  published describing analytical
           approaches for NDMA determination.  The purpose of this document
           is to combine the attractive features of these methods into
           one standardized method.  At the  present time, this method has
           not been validated in its final form, and, therefore, one  must
           use caution when employing it for specific applications.

5.   Definitions

     Definitions used in this document and in any user-prepared SOPs  should
     be consistent with ASTM D1356(5).  All  abbreviations and symbols are
     defined  within this document at the point of use.

-------
                                  T07-3
6.   Interferences
     Compounds having retention times similar to NDMA,  and yielding
     detectable m/e 74 ion fragments, may interfere in  the method.   The
     inclusion of a pre-elution step in the sample desorption procedure
     minimizes the number of interferences.  Alternative GC columns and
     conditions may be required to overcome interferences in unique
     situations.

7.   Apparatus

     7.1   GC/MS System - capable of temperature-programmed, fused-silica
           capillary column operation.  Unit mass resolution or better to
           300 amu.  Capable of full scan and selected  ion monitoring
           with a scan rate of 0.8 second/scan or better.
     7.2   Sampling system - capable of accurately and  precisely sampling
           100-2000 mL/minute of ambient air.  (See Figure 1.)   The dry
           test meter may not be accurate at flows below 500 mL/minute;
           in such cases it should be replaced by recorded flow readings
           at the start, finish, and hourly during the  collection.   See
           Section 9.4.
     7.3   Stopwatch.
     7.4   Friction top metal can, e.g., one-gallon (paint can) - to hold
           clean cartridges and samples.
     7.5   Thermometer - to record ambient temperature.
     7.6   Barometer (o'ptional).
     7.7   Glass syringe - 5 ml with Luer fitting.
     7.8   Volumetric flasks - 2 ml, 10 mL, and 100 mL.
     7.9   Glass syringe - 10 uL for GC injection.

8.   Reagents and Materials

     8.1   Thermosorb/N - Available from Thermedics Inc., 470 Wildwood St.,
           P.O.Box 2999, Woburn, Mass.,  01888-1799, or equivalent.

-------
                                  T07-4
     8.2   Dichloromethane - Pesticide quality, or equivalent.
     8.3   Helium - Ultrapure compressed gas (99.9999%).
     8.4   Perfl uorotributyl amine (FC-43) - for GC/MS calibration.
     8.5   Chemical Standards - NDMA solutions.  Available from various
           chemical supply houses.  Caution:  NDMA is a suspected human
           carcinogen.  Handle in accordance with OSHA regulations.
     8.6   Granular activated charcoal  - for preventing contamination of
           cartridges during storage.
     8.7   Glass jar, 4 oz - to hold cartridges.
     8.8   Glass vial - 1 dram, with Teflon-lined screw cap.
     8.9   Luer fittings - to connect cartridges to sampling system.
     8.10  Acetone- Reagent grade.
9.   Sampli ng
     9.1   Cartridges (Thermosorb/N) are purchased prepacked from Thermedics
           Inc.  These cartridges are 1.5 cm ID x 2 cm long polyethylene
           tubes with Luer-type fittings on each end.  The adsorbent is
           held in place with 100-mesh stainless steel screens at each
           end.  The cartridges are used as received and are discarded
           after use.  At least one cartridge from each production lot
           should be used as a blank to check for contamination.   The
           cartridges are stored in screw-capped glass jars (with Luer
           style caps), and placed in a charcoal-containing metal  can when
           not in use.
     9.2   The sampling system may employ either a mass flow controller or
           a dry test meter.  (See Figure 1.)  For purposes of discussion,
           the following procedure assumes the use of a dry test  meter.
     9.3   Before sample collection, the entire assembly (including a
           "dummy" sampling cartridge) is installed and the flow  rate is
           checked at a value near the desired rate.  In general, flow
           rates of 100-2000 mL/minute should be employed.  The flow rate
           should be adjusted so that no more than 300 L of air is col-
           lected over the desired sampling period.  Generally,- calibra-
           tion is accomplished using a soap bubble flow meter or

-------
                             T07-5
      calibrated wet test meter connected  to  the  flow exit, assuming
      the system is  sealed.   ASTM Method 3686 describes an
      appropriate calibration scheme  not requiring  a sealed flow
      system downstream of the pump.
9.4   Ideally, a dry gas meter is  included in the system to record
      total flow.  If a dry  gas meter is not  available, the operator
      must measure and record the  sampling flow rate at the
      beginning and  end of the sampling period to determine sample
      volume.  If the sampling period exceeds two hours, the  flow
      rate should be measured at intermediate points during the
      sampling period.,  Ideally, a  rotameter  should be  included to
      allow observation of the flow rate without  interruption of the
      sampling process.
9.5   To collect an air sample, a  new Thermosorb/N cartridge  is
      removed from the glass jar and connected to the  sampling
      system using a Luer adapter fitting.  The glass  jar is sealed
      for  later use.  The following parameters are recorded on the
      data sheet (see Figure 2 for an example):  date,  sampling
      location, time, ambient temperature, barometric  pressure (if
      available), relative humidity  (if available), dry gas meter
      reading (if appropriate), flow rate, rotameter  setting,
      cartridge batch number, and dry gas  meter and pump
      identification numbers.
9.6   The  sampler is allowed to operate for the desired period,
      with periodic recording of the variables listed  above.   The
      total  flow should  not  exceed 300 L.
9.7   At the  end of the  sampling period, the parameters listed in  Section
      9.5  are recorded  and the  sample flow is  stopped.  If a dry gas
      meter  is  not  used,  the flow rate must be checked at the end  of
      the  sampling  interval.   If the flow rates  at the beginning and
      end  of the sampling period differ by more  than 15%, the
      sample should be  marked  as suspect.
9.8   Immediately after sampling, the cartridge  is removed from
      the  sampling  system, capped, and placed  back in the 4-oz

-------
9.9
Ql
                            T07-6
     glass jar.  The jar is then capped, sealed with Teflon tape,
     and placed in a friction-top can containing 1-2 inches  of
     granular charcoal.  The samples are stored in the can until
     analysis.
     If a dry gas meter or equivalent total  flow indicator is not
     used, the average sample flow rate must be calculated
     according to the following equation:
                                  Q
                                      N
      where
             QA
      e ..... QN
             N  =
average flow rate (mL/minute).
flow rates determined at beginning,
end, and immediate points during
sampling.
 number of points averaged.
9.10  The total  flow is then calculated using  the  following
      equation:

                  ..      x QA
                           1000
      where
             Vm = total  sample  volume  (L)  at measured
                  temperature and  pressure.
             T2 = stop  time.
             TI = start  time.
          T2-T]  = sampling  time (minutes).

-------
                                  T07-7
     9.11  The total  volume  (Vs)  at  standard  conditions,  25C  and  760
           mm Hg,  is  calculated  from the  following  equation:

                              v  PA   v     298
                       w  _  w X   A   X
                       vs    m
                                 760   273 + tA
           where  Vs = total  sample volume (L)  at  standard
                       conditions of 25 C and  760 mm Hg.
                  Vm = total  sample volume (L)  at  measured
                       temperature and pressure.
                  PA = average barometric pressure (mm Hg).
                  tA = average ambient temperature (C).

10.  Sample Desorption

     10.1  Samples are returned to the laboratory  and prepared for
           analysis within one week of collection.
     10.2  Using a glass syringe, the samples are  pre-eluted to remove
           potential interferences by passing 5 ml of dichloromethane
           through the cartridge, in the same direction as  sample flow.
           This operation should be conducted over approximately a 2-minute
           period.  Excess solvent is expelled  by  injecting  5 ml of air
           through the cartridge, again using the  glass syringe.
     10.3  The NDMA is then desorbed passing 2 ml  of acetone through the
           cartridge, in the direction opposite to sample flow, using a
           glass syringe.  A flow rate of approximately 0.5 mL/minute
           is employed and the eluate is collected in a 2-mL volumetric
           flask.
     10.4  Desorption is halted once the volumetric flask is filled to
           the mark.  The sample is then transferred to a 1-dram vial
           having a Teflon-lined screw cap and refrigerated until
           analysis.  The vial is wrapped with aluminum foil to prevent
           photolytic decomposition of the NDMA.

-------
                                  T07-8
11.  GC/MS Analysis
     Although a variety of GC detectors can be used for NDMA determination,
     the following procedure assumes the use of GC/MS  in the selected  ion
     monitoring (SIM) mode.

     11.1  Instrument Setup

           11.1.1  Considerable variation in instrument configuration
                   is expected from one laboratory  to  another.   There-
                   fore, each laboratory must be responsible for veri-
                   fying that its  particular system yields  satisfactory
                   results.  The GC/MS  system must  be  capable of accom-
                   modating a fused-silica capillary column, which can be
                   inserted directly into the ion source.   The  system must
                   be capable of acquiring and processing data  in the
                   selected ion monitoring mode.
           11.1.2  Although alternative column systems  can  be used, a
                   0.2 mm I.D. x 50 m Carbowax 20M  fused-silica  column
                   (Hewlett-Packard Part No. 19091-60150, or equivalent)
                   is recommended.   After installation,  a helium carrier
                   gas flow of 2 ml per minute is established and the
                   column is conditioned at 250C for  16 hours.   The
                   injector and GC/MS transfer line temperatures  should
                   also be set at  250C.
           11.1.3  The MS and data  system are set up according to manu-
                   facturer's specifications.  Electron  impact  ionization
                   (70 eV)  should  be employed.  Once the entire  GC/MS
                   system is set up, it is calibrated as described in
                   Section 11.2.  The user should prepare a detailed
                   standard operating procedure (SOP) describing this
                   process for the  particular instrument being used.

-------
                             T07-9
11.2  Instrument Calibration
      11.2.1  Tuning and mass standardization  of  the MS  system,is
              performed according to manufacturer's  instructions
              and relevant information from the user-prepared  SOP.
              Perfluorotributyl amine should generally be employed
              for this purpose.   The material  is  introduced
              directly into the  ion  source  through  a molecular
              leak.   The instrumental  parameters  (e.g.,  lens,
              voltages, resolution,  etc.) should  be  adjusted to
              give the relative  ion  abundances shown in  Table  1 as
              well as acceptable resolution and peak shape.  If
              these approximate  relative abundances  cannot  be
              achieved, the ion  source may  require  cleaning
              according to manufacturer's  instructions.   In the
              event that the user's  instrument cannot achieve  these
              relative ion abundances, but  is  otherwise  operating
              properly, the user may adopt  another  set of relative
              abundances as performance criteria.  However, these
              values must be repeatable on  a day-to-day  basis.
     11.2.2   After the mass standardization and  tuning  process has
              been completed and the appropriate  values  entered
              into the data system,  the user should set  the SIM
              monitoring parameters  (i.e.,  mass centroid and window
              to be monitored) by injecting a  moderatley high  level
              standard solution  (100 ug/mL) of NDMA onto the 6C/MS in
              the full scan mode.  The scan range should be 40 to 200
              amu at a rate of 0.5 to 0.8 scans/second.   The nominal
              mass 42, 43, and 74 amu ions  are to be used for  SIM
              monitoring, with the 74 amu ion  employed for NDMA quan-
              tification.

-------
                             T07-10
      11.2.3   Before  injection of NDMA standards, the GC oven
               temperature is stabilized at 45C.  The filament and
               electron multiplier voltage are turned off.  A 2-uL
               aliquot of an appropriate NDMA standard, dissolved in
               acetone, is injected onto the 6C/MS system using the
               splitless injection technique.  Concentrated NDMA
               standards can be purchased from chemical supply
               houses.  The standards are diluted to the appropriate
               concentration with acetone.  CAUTION:  NDMA is a
               suspected carcinogen and must be handled according to
               OSHA regulations.  After five minutes, the electron
              multiplier and filament are turned on, data acquisition
               is initiated, and the oven temperature is programmed
              to 250C at a rate of 16C/minute.  After elution of
              the NDMA peak from the GC/MS (Figure 3), the data
              acquisition process can be halted and data processing
              initiated.
      11.2.4  Once the appropriate SIM parameters have been estab-
              lished, as described in Section 11.2.2, the instrument
              is calibrated by analyzing a range of NDMA standards
              using the SIM prodecure.  If necessary, the electron
              multiplier voltage or amplifier gain can be adjusted
              to give the desired sensitivity for standards
              bracketing the range of interest.  A calibration
              curve of m/e 74 ion intensity versus quantity of NDMA
              injected is constructed and used to calculate NDMA
              concentration in the samples.

11.3  Sample Analysis

      11.3.1  The sample analysis process is the same as that  de-
              scribed in Section  11.2.3  for calibration  standards.
              Samples should be handled  so as to minimize exposure
              to light.

-------
                                 T07-11
           11.3.2   If  a  peak  is observed for NDMA (within +6 seconds of
                   the expected retention time), the areas (integrated
                   ion intensities)  for m/e 42, 43, and 74 are
                   calculated.  The  area of the m/e 74 peak is used to
                   calculate  NDMA concentration.  The ratios of
                   m/e 42/74  and 43/74 ion  intensities are used to
                   determine  the certainty  of the NDMA identification.
                   Ideally, these  ratios should be within 20% of the
                   ratios  for an NDMA standard in order to have
                   confidence in the peak  identification.  Figure 4
                   illustrates the  MS scan  for N-nitrosodimethylamine.

12.  Calculations

     12.1  Calibration Response Factors

           12.1.1   Data from  calibration  standards  are  used  to  calculate
                   a response factor for  NDMA.   Ideally,  the  process
                   involves analysis of  at least  three  calibration
                   levels of NDMA  during  a given  day  and  determination
                   of the response factor (area/ng  injected)  from the
                   linear least squares  fit of a  plot of  nanograms  in-
                   jected versus area (for the m/e  74 ion).   In general,
                   quantities of NDMA greater than  1000 nanograms  should
                   not  be injected because of column  overloading and/or
                   MS response nonlinearity.
           12.1.2  If substantial  nonlinearity is present in the cali-
                   bration curve, a nonlinear least squares fit (e.g.,
                   quadratic) should be employed.  This process involves
                   fitting the data to the following equation:

                        Y =  A + BX + CX2

-------
                             T07-12
      where
             Y = peak area
             X = quantity of NDMA (ng)
             A. B, and C are coefficients in the equation
12.2  NDMA Concentration

      12.2.1 Analyte quantities on a sample  cartridge  are
             calculated from the following equation:
      where
                     = A + BXA + CXA2
             YA  is the area of the m/e  74  ion  for  the  sample
                 injection.
             XA  is the calculated quantity of  NDMA (ng) on the
                 sample cartridge.
             A. B,  and  C are the coefficients calculated from the
             calibration curve  described  in Section 12.1.2.
      12.2.2  If instrumental  response  is  essentially linear over
             the concentration  range of interest, a  linear equation
             (C=0 in the equation above)  can be employed.
      12.2.3  Concentration of analyte  in  the original air sample
             is calculated from the following equation:
     where
                 c  -
                 C-
            CA  is the calculated concentration of analyte (ng/L)
            Vs and XA are as previously defined in Sections 9.11
            and 12.2.1. respectively.

-------
                                  T07-13
13.  Performance Criteria and Quality Assurance
     This section summarizes required quality  assurance  (QA) measures  and
     provides guidance concerning performance  criteria that  should  be
     achieved within each laboratory.

     13.1  Standard Operating Procedures (SOPs).

           13.1.1  User should generate SOPs describing  the
                   following activites in their  laboratory:
                   1) assembly, calibration, and  operation
                   of the sampling system with make and  model  of
                   equipment used; 2) preparation,  purification,
                   storage, and handling of Thermosorb/N cartridges
                   and samples; 3) assembly, calibration, and  operation
                   of the GC/MS system with make and model of  equipment
                   used; and 4) all aspects of data recording  and
                   processing, including lists of computer hardware   ,
                   and software used.
           13.1.2  SOPs should provide specific  stepwise instructions
                   and should be readily available to and understood
                   by the laboratory personnel conducting the  work.

     13.2  Sample Collection

           13.2.1  During each sampling event, at least one clean
                   cartridge will accompany the samples to the field and
                   back to the laboratory, having been placed  in the
                   sampler but without sampling air, to serve as a field
                   blank.  The average amount of material found on the
                   field blank cartridges may be subtracted from the
                   amount found  on the actual  samples.  However, if the
                   blank "level is  greater than 25% of the sample amount,
                   data  for  that  component must be identified as suspect.
           13.2.2  During each sampling  event, at least one set of
                   Parallel  samples  (two or more samples  collected
                   simultaneously) should be collected.   If agreement

-------
                             T07-14
              between parallel samples is not generally within
              +25%, the user should collect parallel samples on a
              much more frequent basis (perhaps for all sampling
              points).
      13.2.3  Backup cartridges (two cartridges in series) should
              be collected with each sampling event.  Backup car-
              tridges should contain less than 10% of the amount
              of NDMA found- in the front cartridges, or be equiva-
              lent to the blank cartridge level , whichever is
              greater.
      13.2.4  NDMA recovery for spiked cartridges (using a solution-
              spiking technique)  should be determined before initial
              use of the method on real samples.  Currently available
              information indicates that a recovery of 75% or greater
              should be achieved.

13.3  GC/MS Analysis

      13.3.1  Performance criteria for MS tuning and mass standard-
              ization are discussed in Section 11.2 and Table 1.
              Additional  criteria can be used by the laboratory, if
              desired.   The following sections provide performance
              guidance and suggested criteria for determining the
              acceptability of the GC/MS system.
      13.3.2  Chromatographic efficiency should be evaluated daily
              by the injection of NDMA calibration standards.  The
              NDMA peak  should be plotted on  an expanded time scale
              so that its width at 10% of the peak height can be
              calculated, as  shown in Figure  5.  The width of the
              peak at 10% height  should not exceed 10 seconds.  More
              stringent  criteria  may be required  for certain appli-
              cations.   The asymmetry factor  (see Figure 5)  should
              be between  0.8  and  2.0.

-------
                       T07-15
       e
13.3.3  The detection limit for NDMA is calculated from the
        data obtained for calibration standards.  The
        detection limit is defined as
             DL = A + 3.3S
where
        DL is the calculated detection limit in nanograms
           injected.
        A is the intercept calculated in Section 12.1.2.
        S is the standard deviation of replicate determina-
          tions of the lowest-level standard (at least three
          such determinations  are required).  The lowest-level
          standard should yield a signal-to-noise ratio (from
          the total  ion  current response)  of approximately 5.
13.3.4  Replicate GC/MS  analysis of NDMA standards and/or
        sample extracts  should be conducted  on a daily basis.
        A precision  of +15% RSD or better should be achieved.

-------
                                  T07-16


                                REFERENCES
(1)   Marano, R. S.,  Updegrove,  W.  S..  and  Machem,  R.  C.,   "Determination
     of Trace Levels of Nitrosamines  in Air  by  Gas   Chromatography/Low
     Resolution Mass Spectrometry," Anal.  Chem., j>4,  1947-1951  (1982).

(2)   Fine,  D. H., et. al,  "N-Nitrosodimethylamine   in Air,"   Bull.   Env.
     Cont.  Toxicol.,^5,  739-746 (1976).

(3)   "EPA Method 607 - Nitrosamines,"  Federal  Register, 49,  43313-43319,
     October 26, 1984.

(4)   Anderson, R. J., "Nitrogen-Selective  Detection in Gas Chromatography,"
     Tracer Inc. Applications  Note 79-3, Austin, Texas.

(5)   Annual  Book of  ASTM   Standards,  Part  11.03, "Atmospheric Analysis,"
     American Society for  Testing  and  Materials, Philadelphia,  Pennsylvania.

(6)   Riggin, R. M.,  "Technical  Assistance  Document for Sampling and
     Analysis of Toxic Organic  Compounds  in Ambient Air,"  EPA-600/4-83-
     027, U.S. Environmental  Protection Agency, Research Triangle  Park,
     North Carolina, 1983.

-------
                                 T07-17
                      MASS FLOW
                      CONTROLLERS
           OILLESS
            PUMP
       VENT  -*
r\
                                        Coupling to
                                        connect
                                        Thermosorb  N
                                        Adsorbent Cartridges
                        (a) MASS FLOW CONTROL
                     ROTAMETER
VENT


DRY
TEST
METER













_

















PUMP










\


T
rV
V

EEDL
/ALVI



^



E








  (DRY TEST METER SHOULD NOT BE USED
  FOR FLOW OF LESS THAN 500 ml/minutes)
                                       coupling to
                                       connect
                                       Thermosorb N
                                       adsorbent
                                       cartridge
                     (b) NEEDLE VALVE/DRY TEST METER
    FIGURE  1. TYPICAL SAMPLING SYSTEM CONFIGURATION

-------
PROJECT:

SITE:
LOCATION:
INSTRUMENT MODEL NO:

PUMP SERIAL  NO: 	

SAMPLING DATA
                                       T07-18

                                SAMPLING DATA SHEET
                             (One Sample per Data  Sheet)
                 DATES(S) SAMPLED:
                 TIME  PERIOD SAMPLED:

                 OPERATOR:
                 CALIBRATED BY:
                       Sample  Number:

                 Start Time:
                   Stop Time:
Time
1.
2.
3.
4.
N.
Dry Gas
Meter
Reading





Rotameter
Reading





Flow
Rate,*Q
mL/mi n





Ambient
Temperature
C





Barometric
Pressure,
mm Hg





Relative
Humidity, %





Comments





   Total  Volume Data**
      Vm = (Final - Initial)  Dry  Gas Meter Reading,  or
                          Q
                  N
1000 *  (Sampling Time in  Minutes)
                                             L


                                             L
    * Flow rate from rotameter or  soap bubble calibrator
      (specify which).
   ** Use data from dry gas meter  if available.
                 FIGURE 2.  EXAMPLE SAMPLING  DATA  SHEET

-------
                         T07-19
              UJ
              Q:
              cr

              o

              z
              o
                       I
I
I
                       345


                      TIME (MIN.)
FIGURE 3. TOTAL ION CURRENT CHROMATOGRAM RESULTING

FROM INJECTION OF 15 jtL SAMPLE OF NDMA STANDARD (10

NG//iL IN ETHANOL).

-------
                                     T07-20
  o
  VD
"> O
          CM

          o>
  (D
                                                          .8
                                                            o
                                                            8
s
                             
o      o
CM
                                                                         O
                                                                         o
                                                                      o<
                                                                      if) o
                                                                      *~ CO
                                                                      O 00
                     H
                    Z if)

                    d6
                    CO .

                    Q. HI
                    o H
                     tt
                    |<

                    0<
                                                                       cog
                                                                       CO Z
                     Ul
                     cc
                     D
                     o

-------
                           T07-21
          Asymmetry Factor =
BC
AB
          Example Calculation:
           Peak Height = DE = 100 mm
           10% Peak Height = BO = 10 mm
           Peak Width at 10% Peak Height = AC = 23 mm
              AB = 11 mm
              BC = 12 mm
                                  12
         Therefore: Asymmetry Factor = 
             1.1
FIGURE  5. PEAK ASYMMETRY CALCULATION

-------
                            T07-22
  TABLE 1:  SUGGESTED PERFORMANCE CRITERIA FOR RELATIVE  ION
            ABUNDANCES FROM FC-43 MASS CALIBRATION
                                                   % Relative
M/E                                                 Abundance

 51                                              1.8 .+ 0.5
 69                                              100
100                                              12.0  1.5
119                                              12.0 j+ 1.5
131                                              35.0 _+ 3.5
169                                              3.0 +_ 0.4
219                                              24.0^2.5
264                                              3.7^0.4
314                                              0.25 + 0.1

-------
                                                             Revision 1.0
                                                             September,  1986
                                METHOD T08
                  METHOD FOR THE DETERMINATION OF PHENOL
             AND METHYLPHENOLS (CRESOLS) IN AMBIENT AIR USING
                  HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

1.   Scope
     1.1   This document describes a method for determination of phenol
           and methyl phenols (cresols)  in ambient air.   With careful
           attention to reagent purity  and other factors, the method
           can detect these compounds at the 1-5 ppbv level.
     1.2   The method as written has not been rigorously evaluated.  The
           approach is a composite of several existing  methods (1-3).
           The choice of HPLC detection system will be  dependent on the
           requirements of the individual user.  However, the UV detection
           procedure is considered to be most generally useful for
           relatively clean samples.

2.   Applicable Documents

     2.1   ASTM Standards
           D1356 - Definitions of Terms Related to Atmospheric Sampling
           and Analysis(4).
     2.2   Other Documents
           U.S. EPA Technical Assistance Document (5).

3.   Summary of Method

     3.1   Ambient air is drawn through two midget impingers, each con-
           taining 15 mL of 0.1 N NaOH.  The phenols are trapped as
           phenolates.
     3.2   The impinger solutions are placed in a vial  with a Teflon-
           lined screw cap and returned to the laboratory for

-------
                                  T08-2
           analysis.  The solution is cooled in an ice bath and adjusted
           to pH <4 by addition of 1 ml of 5% v/v sulfuric acid.  The sample
           is adjusted to a final volume of 25 ml with distilled water.
     3.3   The phenols are determined using reverse-phase HPLC with
           either ultraviolet (UV) absorption detection at 274 nm,
           electrochemical detection, or fluorescence detection.  In
           general , the UV detection approach should be used for
           relatively clean samples.

4.   Significance

     4.1   Phenols are emitted into the atmosphere from chemical opera-
           tions and various combustion sources.  Many of these compounds
           are acutely toxic, and their determination in ambient air is
           required in order to assess human health impacts.
     4.2   Conventional methods for phenols have generally employed
           colorimetric or gas chromatographic techniques with relatively
           large detection limits.  The method described here reduces
           the detection limit through use of HPLC.

5.   Definitions

     Definitions used in this document and in any user-prepared Standard
     Operating Procedures (SOPs) should be consistent with ASTM D1356
     (5).  All abbreviations and symbols are defined within this document
     at the point of use.

6.   Interferences

     6.1   Compounds having the same retention times as the compounds of
           interest will interfere in the method.  Such interferences can
           often be overcome by altering the separation conditions (e.g.,
           using alternative HPLC columns or mobile phase compositions) or
           detectors.  Additionally, the phenolic compounds of interest
           in this method may be oxidized during sampling.  Validation
           experiments may be required to show that the four target
           compounds are not substantially degraded.

-------
                                  T08-3
     6.2   If interferences are suspected in a "dirty"  sample,  prelimi-
           nary cleanup steps may be required to identify  interfering
           compounds by recording infrared spectrophotometry followed
           by specific ion-exchange column chromatography.  Likewise,
           overlapping HPLC peaks may be resolved by increasing/decreasing
           component concentration of the mobile phase.
     6.3   All reagents must be checked for contamination  before use.
7.   Apparatus
     7.1   Isocratic HPLC system consisting of a mobile-phase reservoir,
           a high-pressure pump, an injection valve, a  Zorbax CDS or
           C-18 reverse-phase column, or equivalent (25 cm x 4.6 mm ID),
           a variable-wavelength UV detector operating  at  274 nm, and  a
           data system or strip-chart recorder (Figure  1).  Amperometric
           (electrochemical) or fluorescence detectors  may also be employed.
     7.2   Sampling system - capable of accurately and  precisely sampling
           100-1000 mL/minute of ambient air (Figure 2).
     7.3   Stopwatch.
     7.4   Friction-top metal can, e.g., one-gallon (paint can) - to hold
           samples.
     7.5   Thermometer - to record ambient temperature.
     7.6   Barometer (optional).
     7.7   Analytical balance - 0.1 mg sensitivity.
     7.8   Midget impingers -'jet inlet type, 25-mL.
     7.9   Suction filtration apparatus - for filtering HPLC mobile phase.
     7.10  Volumetric flasks - 100 mL and 500 mL.
     7.11  Pipettes - various sizes, 1-10 mL.
     7.12  Helium purge line (optional) - for degassing HPLC mobile phase.
     7.13  Erlenmeyer flask, 1 L - for preparing HPLC mobile phase.
     7.14  Graduated cylinder, 1 L - for preparing HPLC mobile phase.
     7.15  Microliter syringe, 100-250 uL - for HPLC injection.
8.   Reagents and Materials
     8.1   Bottles, 10 oz, glass, with Teflon-lined screw cap - for
           storing sampling reagent.
     8.2   Vials, 25 mL, with Teflon-lined screw cap - for holding samples.

-------
                                  T08-4
     8.3   Disposable pipettes and bulbs.
     8.4   Granular charcoal.
     8.5   Methanol - distilled in glass or pesticide grade.
     8.6   Sodium hydroxide - analytical reagent grade.
     8.7   Sulfuric acid - analytical  reagent grade.
     8.8   Reagent water - purified by ion exchange and carbon
           filtration, or distillation.
     8.9   Polyester filters, 0.22 urn - Nuclepore, or equivalent.
     8.10  Phenol, 2-methyl-, 3-methyl-, and 4-methylphenol  - neat
           standards (99+ % purity) for instrument calibration.
     8.11  Sampling reagent, 0.1 N NaOH.  Dissolve 4.0 grams  of  NaOH in
           reagent water and dilute to a final  volume of 1 L. Store
           in a glass bottle with Tef1on-lined cap.
     8.12  Sulfuric acid, 5% v/v.  Slowly add 5 mL of concentrated
           sulfuric acid to 95 ml of reagent water.
     8.13  Acetate buffer, 0.1M, pH 4.8 - Dissolve 5.8 ml of  glacial
           acetic acid and 13.6 grams of sodium acetate trihydrate in 1 L
           of reagent water.
     8.14  Acetonitrile - spectroscopic grade.
     8.15  Glacial acetic acid - analytical  reagent grade.
     8.16  Sodium acetate trihydrate - analytical  reagent grade.
9.   Sampling
     9.1   The sampling apparatus is assembled and should be similar to
           that shown in Figure 2.  EPA Federal  Reference Method 6 uses
           essentially the same sampling system (6).  All glassware
           (e.g., impingers, sampling bottles, etc.) must be thoroughly
           rinsed with methanol and oven-dried before use.
     9.2   Before sample collection, the entire assembly (including
           empty sample impingers) is installed and the flow rate checked
           at a value near the desired rate.  In general, flow rates of
           100-1000 mL/minute are useful.  Flow rates greater than
            1000 mL/minute should not be used because impinger collection

-------
                             T08-5
      efficiency may decrease.  Generally, calibration is accomp-
      lished using a soap bubble flow meter or calibrated wet  test
      meter connected to the flow exit,  assuming the entire system
      is sealed.  ASTM Method D3686 describes an appropriate
      calibration scheme that does not require a sealed-flow system
      downstream of the pump (4).
9.3   Ideally, a dry gas meter is included in the system to record
      total flow, if the flow rate is sufficient for its use.   If a
      dry gas meter is not available, the operator must measure and
      record the sampling flow rate at the beginning and end of the
      sampling period to determine sample volume;  If the sampling
      time exceeds two hours, the flow rate should be measured at
      intermediate points during the sampling period.  Ideally, a
      rotameter should be included to allow observation of the flow
      rate without interruption of the sampling process.
9.4   To collect an air sample, two clean midget impingers are
      loaded with 15 mL of 0.1 N NaOH each and sample flow is  start-
      ed.  The following parameters are  recorded on the data sheet
      (see Figure 3 for an example):  date, sampling location, time,
      ambient temperature, barometric pressure (if available),
      relative humidity (if available),  dry gas meter reading  (if
      appropriate), flow rate, rotameter setting, 0.1 N NaOH reagent
      batch number, and dry gas meter and pump identification
      numbers.
9.5   The sampler is allowed to operate  for the desired period, with
      periodic recording of the variables listed above.  The total
      volume should not exceed 80 L.  The operator must ensure that
      at least 5 ml of reagent remains in the impinger at the  end of
      the sampling interval.  (Note:  for high ambient temperatures,
      lower sampling volumes may be required.)
9.6   At the end of the sampling period, the parameters listed in Sec-
      tion 9.4 are recorded and the sample flow is stopped.  If a dry
      gas meter is not used, the flow rate must be checked at  the end
     "of the sampling interval.  If the  flow rates at the beginning and

-------
                             T08-6
      end of the sampling period  differ  by more than 15%, the sample
      should be discarded.
9.7   Immediately after sampling, the  impinger is  removed from the
      sampling system.   The contents of  the  impinger are emptied
      into a clean 25-mL glass vial with a Teflon-lined screw-
      cap.  The impinger is then  rinsed  with 5 ml  of reagent water
      and the rinse solution is added  to the vial.  The vial is then
      capped, sealed with Teflon tape,  and  placed in a friction-top
      can containing 1-2 inches of  granular  charcoal.  The  samples
      are stored in the can and refrigerated until analysis.  No
      degradation has been observed if the time between refrigration
      and analysis is less than 48  hours.
9.8   If a dry gas meter or equivalent total  flow  indicator is not
      used, the average sample flow rate must be calculated
      according to the following  equation:
                  QA =
      where
             QA = average flow rate (mL/minute).
  Ql, Q2,....QN = flw rates determined  at  beginning,  end, and
                  intermediate points during  sampling.
              N = number of points  averaged.

9.9   The total flow is then calculated  using the  following
      equation:

                     _  x "A
                   m
                           1000

-------
                                  T08-7
           where
                  Vm = total  volume (L) sampled at measured
                       temperature and pressure.
                  1"2 '= stop time.
                  TI = start  time.
               T2-Tj_ = total  sampling time (minutes).
                  QA = average flow rate (ml/minute).

     9.10  The volume of air  sampled is often reported unconnected for
           atmospheric conditions (i.e., under ambient conditions).
           However, the value should be adjusted to standard conditions
           (25C and 760 mm pressure) using the following equation:

                               y PA  y   298
                       w  _ u  X  A  X
                       vs    m
                                 760   273 + TA
           where
                  Vs = total  sample volume (L)  at 25C and 760 mm Hg
                       pressure.
                  Vm = total  sample volume (L)  under ambient conditions.
                       Calculated as in Section 9.9 or from dry gas
                       meter reading.
                  PA = ambient pressure (mm Hg).
                  TA = ambient temperature (C).
10.  Sample Analysis

     10.1  Sample Preparation
           10.1.1 The samples are returned to the laboratory in 25-mL
                  screw-capped vials.  The contents of each vial are
                  transferred to a 25-mL volumetric flask.  A 1-mL
                  volume of 5% sulfuric acid is added and the final
                  volume is adjusted to 25 ml with reagent water.

-------
                             T08-8
      10.1.2 The solution is thoroughly mixed and then placed  in a
             25-ml screw-capped vial for storage (refrigerated)
             until HPLC analysis.

10.2  HPLC Analysis
      10.2.1 The HPLC system is assembled and calibrated as described
             in Section 11. The operating parameters  are as follows:
                           Column:   -18 RP
                     Mobile Phase:   30% acetonitrile/70% acetate
                                    buffer solution
                         Detector:   ultraviolet,  operating  at
                                    274 nm
                        Flow Rate:   0.3 mL/minute
                   Retention Time:   phenol -  9.4  minutes
                                    o-cresol  - 12.5 minutes
                                    m-cresol  - 11.5 minutes    Individual
                                    p-cresol  - 11.9 minutes

                                    phenol -  9.4  minutes
                                    o-cresol  - 12.8 minutes     Combined
                                    m/p-cresol -  11.9 minutes
             Before each analysis,  the detector baseline is checked
             to ensure stable operation.
      10.2.2 A 100-uL aliquot of the sample is drawn  into a clean
             HPLC injection syringe.  The sample  injection  loop
             (50 uL)  is loaded and  an injection is  made. The  data
             system,  if available,  is activated simultaneously with
             the injection and the  point of injection is marked  on
             the strip-chart recorder.
      10.2.3 After approximately one minute,  the  injection  valve
             is returned to the "load" position and the  syringe  and
             valve are flushed with water in  preparation for
             the next sample analysis.
      10.2.4 After elution of the last component  of interest,  data
             acquisition is terminated and the component concen-
             trations are calculated as described in  Section 12.

-------
                                  T08-9
           10.2.5  Phenols  have  been  successfully  separated from cresols
                  utilizing  HPLC  with  the  above operating parameters.
                  However, meta-  and para-cresols  have  not been successfully
                  separated. Figure 4 illustrates a  typical chromatogram.
           10.2.6  After a  stable  baseline  is  achieved,  the system can
                  be used  for further  sample  analyses as described
                  above.
           10.2.7  If the concentration of  analyte  exceeds the  linear
                  range of the  instrument, the sample should be diluted
                  with mobile phase, or a  smaller  volume can be injected
                  into the HPLC.
           10.2.8  If the retention time is not duplicated, as  determined
                  by the calibration curve, you may increase or decrease
                  the acetonitrile/water ratio to  obtain the correct elution
                  time, as specified in Figure 4.   If the elution time is
                  long, increase  the ratio; if it  is  too short, decrease
                  the ratio.
11.0  HPLC Assembly and Calibration
     11.1  The HPLC system is assembled and operated  according to
           Section 10.2.1.
     11.2  The HPLC mobile phase  is  prepared  by mixing  300 mL  of acetonitrile
           and 750 mL of acetate  buffer, pH 4.8.   This  mixture is filtered
           through a 0.22-um polyester membrane  filter  in an all-glass
           and Teflon suction  filtration  apparatus.  The filtered  mobile
           phase is degassed by purging with  helium for 10-15  minutes
           (100 mL/minute) or by  heating to 60C  for  5-10 minutes in an
           Erlenmeyer flask  covered  with a watch  glass. A constant back
           pressure restrictor  (50 psi) or short  length (6-12  inches) of
           0.01-inch I.D.  Teflon tubing should  be placed after the
           detector to eliminate  further mobile  phase outgassing.

-------
                             T08-10
11.3  The mobile phase is placed in the HPLC solvent reservoir and
      the pump is set at a flow rate of 0.3 mL/minute and allowed
      to pump for 20-30 minutes before the first analysis.  The
      detector is switched on at least 30 minutes before the first
      analysis and the detector output is displayed on a strip-chart
      recorder or similar output device.  UV detection at 27.4 nm is
      generally preferred.  Alternatively, fluorescence detection
      with 274-nm excitation at 298-nm emission (2), or electrochemi-
      cal detection at 0.9 volts (glassy carbon electrode versus
      Ag/AgCl) (3) may be used.  Once a stable baseline is achieved,
      the system is ready for calibration.
11.4  Calibration standards are prepared in HPLC mobile phase from the
      neat materials.  Individual  stock solutions of  100 mg/L are
      prepared by dissolving 10 mg of solid derivative in 100 ml of
      mobile phase.  These individual  solutions are used to prepare
      calibration standards containing all of the phenols and cresols
      of interest at concentrations spanning the range of interest.
11.5  Each calibration standard (at least five levels) is analyzed three
      times and area response is tabulated against mass injected.
      Figures 5a through 5e illustrate HPLC response to various phenol
      concentrations (1 mL/minute flow rate).  All calibration runs
      are performed as described for sample analyses in Section 10.
      Using the UV detector, a linear response range of approximately
      0.05 to 10 mg/L should be achieved for 50-uL injection volumes.
      The results may be used to prepare a calibration curve, as
      illustrated in Figure 6 for phenols.  Linear response is
      indicated where a correlation coefficient of at least 0.999
      for a linear least-squares fit of the data (concentration
      versus area response)  is obtained.  The retention times for
      each analyte should agree within 2%.
11.6  Once linear response has been documented, an intermediate con-
      centration standard near the anticipated levels for each compo-
      nent, but at least 10 times  the  detection limit, should be chosen
      for daily calibration.  The  response for the various components
      should be within 10% day to  day.   If greater variability is
      observed, recalibration may  be required or a new calibration
      curve must be developed from fresh standards.

-------
                                  T08-11
     11.7  The response for each  component  in  the  daily calibration  standard
           is  used to  calculate a response  factor  according to the following
           equation:
                       RFC  =
                             cc*Vl
                               RC
           where
                  RFC = response factor (usually  area  counts)  for  the
                        component of  interest  in  nanograms  injected/response
                        unit.
                  Cc  = concentration (mg/L) of analyte  in. the daily cali-
                        bration standard.
                  Vj  = volume (uL) of calibration  standard injected.
                  Rc  = response (area counts)  for  analyte  in  the  calibration
                        standard.
12.  Calculations
     12.1  The concentration of each  compound  is  calculated for each
           sample using the following equation:
Wrt = RFr X Rd X  i  X _
           where
                                             v
                                             _
                                             VA
                  Wd  = total  quantity of analyte (ug)  in  the  sample.
                  RFC = response factor calculated in  Section  11.6.
                  RCJ  = response (area counts or other response units)
                        for analyte in sample extract.
                  VE  = final  volume (ml) of sample extract.
                  Vj  = volume of extract (ulr)  injected onto the HPLC
                        system.
                  VD  = redilution volume (if sample was redi luted).
                  VA  = aliquot used for redilution (if sample was
                        redi luted).

-------
                                  T08-12
     12.2  The concentration of analyte in the original  sample is
           calculated from the following equation:

                       Cfl =      d     x 1000
                            Vm (or VS)
           where
                  CA = concentration of analyte (ng/L)  in the original  sample.
                  Wd = total quantity of analyte (ug)  in sample.
                  Vm = total sample volume (L) under ambient conditions.
                  V$ = total sample volume (L) at 25 C  and 760 mm Hg.
     12.3  The analyte concentrations can be converted  to ppbv using the
           following equation:
                       CA (PPbv)  = CA (ng/L) x 24.4
                                               MWA
           where
                  CA (n9/L) is calculated using Vs.
                  MWA = molecular weight of analyte.
13.  Performance Criteria and Quality Assurance
     This section summarizes required quality assurance  (QA) measures and
     provides guidance concerning performance criteria that should be
     achieved within each laboratory.
     13.1  Standard Operating Procedures (SOPs).
           13.1.1 Users should generate SOPs describing  the following
                  activities in their laboratory:  (1) assembly,
                  calibration, and operation of the sampling system,
                  with make and model of equipment used; (2) prepara-
                  tion, purification, storage, and handling of sampl-
                  ing reagent and samples; (3) assembly, calibration,

-------
                             T08-13
             and operation of the HPLC  system,  with  make and  model
             of equipment used;  and (4)  all  aspects  of data  recording
             and processing,  including  lists of computer hardware
             and software used.
      13.1.2 SOPs should provide specific stepwise instructions
             and should be readily available to and  understood
             by the laboratory personnel  conducting  the work.
13.2  HPLC System Performance
      13.2.1 The general appearance of  the HPLC chromatogram should
             be similar to that  illustrated in  Figure 4.
      13.2.2 The HPLC system  efficiency and peak asymmetry factor
             should be determined in the following manner:  A
             solution of phenol  corresponding to at  least 20 times
             the detection limit should be injected  with the re-
             corder-chart sensitivity and speed set  to yield a peak
             approximately 75% of full  scale and 1 cm wide at half
             height.  The peak asymmetry factor is determined as
             shown in Figure  7,  and should be betweeen 0.8 and 1.8.
      13.2.3 HPLC system efficiency is  calculated according  to the
             following equation:

                  N = 5.54
                            	_
                            wl/2
                           i
            where
                     N    = column efficiency  (theoretical  plates).
                     tr   - retention time (seconds) of analyte.
                     Wj_/2 = width of component peak at half height
                            (seconds).
             A column efficiency of >5,000 theoretical plates
             should be obtained.
      13.2.4 Precision of response for replicate HPLC injections
             should be _+10% or less, day to day, for calibration
             standards.  Precision of retention times should be
             +2%, on a given day.

-------
                             T08-14
13.3  Process Blanks
      13.3.1  Before use, a 15-mL aliquot of each  batch  of 0.1  N
              NaOH reagent should be analyzed as described in
              Section 10.  In general,  analyte levels  equivalent  to
              <5 ng/L in an 80-L sample should be  achieved.
      13.3.2  At least one field blank, or 10% of  the  field samples,
              whichever is larger, should be shipped  and analyzed
              with each group of samples.  The number  of samples
              within a group and/or time frame should  be recorded
              so that a specified percentage of blanks is obtained
              for a given number of field samples. The  field  blank
              is treated identically to the samples except that no
              air is drawn through the  reagent. The  same performance
              criteria described in Section 13.3.1 should be met  for
              process blanks.
13.4  Method Precision and Accuracy
      13.4.1  At least one duplicate sample, or 10% of the field
              samples, whichever is larger, should be  collected
              during each sampling episode.  Precision for field
              replication should be +20% or better.
      13.4.2  Precision for replicate HPLC injections  should be
              +10% or better, day to day, for calibration
              standards.
      13.4.3  At least one spiked sample, or 10% of the  field
              samples, whichever is larger, should be  collected.
              The impinger solution is  spiked with a  known quantity
              of the compound of interest, prepared as a dilute
              water solution.  A recovery of >80%  should be achieved
              routinely.
      13.4.4  Before initial use of the method, each  laboratory
              should generate triplicate spiked samples  at a
              minimum of three concentration levels,  bracketing the
              range of interest for each compound. Triplicate
              nonspiked samples must also be processed.   Spike
              recoveries of >80 ^10% and blank levels  of <5 ng/L
              (using an 80-L sampling volume) should  be  achieved.

-------
                                  T08-15


                                REFERENCES
(1)   NIOSH P &  CAM Method  S330-1,  "Phenol,"  National  Institute  of
     Occupational  Safety and  Health,  Methods Manual,  Vol.  3,  1978.

(2)   Ogan, K. and, Katz, E..  "Liquid  Chromatographic  Separation of
     Alkylphenols  with Fluorescence and  Ultraviolet Detection," Anal.
     Chem., 53, 160-163 (1981).

(3)   Shoup, R.  E., and Mayer, 6. S.,  "Determination of  Environmental
     Phenols by Liquid Chromatography Electrochemistry," Anal.  Chem.,
     J54,  1164-1169 (1982).

(4)   Annual Book of ASTM Standards, Part 11.03,  "Atmospheric  Analysis,"
     American Society for  Testing  and Materials,  Philadelphia,
     Pennsylvania, 1983.

(5)   Riggin, R. M., "Technical  Assistance Document  for  Sampling and
     Analysis of Toxic Organic Compounds in  Ambient Air,"  EPA-600/4-83-
     027, U.S.  Environmental  Protection  Agency,  Research Triangle Park,
     North Carolina, 1983.

(6)   "Method 6  Determination  of S0 Emissions from  Stationary Sources,"
     Federal Register, Vol. 42., No.  160, August,  1977.

-------
T08-16
                               01


                               00


                               CO
                              _J
                              Q.
                              o
                              Q.

                              h-
                              UJ
                              Q:

-------
                    T08-17
                     O
                     CO
         0.
CC
UJ

UJ



1
O
CC
                                                CD
                                                Z

                                                CC
                                                O
                                           O
                                           SBC

                                           tt<
                                           OH-
                                           "-Z

                                           5^
                                           in QQ

                                           S|

                                           C0Z

                                           Oco

                                           130
                                           Q.CO
                                           oe UJ
iim+mii
          UJ
o_ yj
>l
HO-
                                                UJ
                                                cc

-------
PROJECT:

SITE:
LOCATION:
INSTRUMENT MODEL NO:

PUMP SERIAL NO: 	

SAMPLING DATA
                                       T08-18

                                 SAMPLING DATA SHEET
                             (One Sample per Data Sheet)
DATES(S)  SAMPLED:
TIME PERIOD SAMPLED:

OPERATOR:
CALIBRATED BY:
                       Sample  Number:
                 Start Time:
  Stop  Time:
Time
1.
2.
3.
4.
N.
Dry Gas
Meter
Reading





Rotameter
Reading





Flow
Rate,*0
mL/mi n





Ambi ent
Temperature
C





Barometric
Pressure,
mm Hg





Relative
Humidity, %





Comments





   Total Volume Data**


      Vm = (Final - Initial) Dry Gas Meter Reading, or

       _Q1+ Q2+Q3   QN
                                              1
                  N           1000 * (Sampling  Time in Minutes)

   * Flow rate from rotameter or soap bubble  calibrator
     (specify which).
  ** Use data from dry  gas meter if available.
                            L


                            L
               FIGURE 3. EXAMPLE SAMPLING DATA SHEET

-------
                         T08-19
                      O
                      ro
      OPERATING PARAMETERS
                 HPLG
Column: C-18 RP
Mobile Phase: 30% Acetonitrile/70% Acetate Buffer
Detector: Ultra violet operating at 274 nm
Flow Rate: 1 ml/min
Retention Time: 3.4 minutes
          M/P-CRESOL
                             0-CRESOL
                               JUL. 30, 1986 15:07:17 CHART 0.50 CM/MIN
                                              RUN #43  CALC #0
                               COLUMN           SOLVENT  OPR ID:
                               EXTERNAL STANDARD QUANTITATION
                                      AMOUNT
                                     790.82600
                                    2686.95000
                                    1645.46000
                                    5123.24000
              RT
               8.81
              11.30
              12.22
                  EXP RT
 AREA
 790826 L
2686966 F
1645466 L
    RF
O.QOOOOOEO
O.OOOOOOEO
O.OOOOOOEO
     TIME
FIGURE 4. TYPICAL CHROMATOGRAM ILLUSTRATING
             SEPARATION OF PHENOLS/CRESOLS BY HPLC

-------
                     T08-20
                                                   (c)

                                                  3.39
             (a)

             3.39
                 3.44
                              3.43
                                              r--
                                              oj
                                              04

                               TIME
                                 TIME
                                 3fig
                      (e)

                     3.39
                                          CONC.
                                  AREA
                                 COUNTS
                                           4/*g
                                           5|*g
                                  249054
                                  554609
                                  804918
                                 1038422
                                 1296781
                                          -rf
TIME
                                   TIME
            UJ
            -3

FIGURE 5a-5e. HPLC CHROMATOGRAM OF VARYING
             PHENOL CONCENTRATIONS

-------
                                T08-21
     o
     o
     in
=)
o
     o
     o
     o
LU

QC
     o
     o
     in
Column: C-18 RP

Mobile Phase: 30% Acetonitrile/70% Acetate Buffer

Detector: Ultra violet operating at 274 nm

Flow Rate:  1 ml/min

Retention Time: 3.4 minutes
             Q,
CORRELATION COEFFICIENT:

          0.999
                 I        2       3       4        


                                 PHENOL  (fig)



          FIGURE 6. CALIBRATION CURVE FOR PHENOL

-------
                        T08-22
         Asymmetry Factor =
                        BC
         Exampto Calculation:
          Peak Height = DE = 100 mm
          10% Pak Height - BD * 10 mm
          Peak Width at 10% Peak Height -
             AB = 11 mm
             BC = 12 mm
   AC = 23 mm
         Therefore: Asymmetry Factor
1?
11
= 1.1
FIGURE 7. PEAK ASYMMETRY CALCULATION

-------
                                                             Revision  1.0
                                                             September.  1986
                                METHOD  T09
         METHOD FOR THE DETERMINATION OF  POLYCHLORINATED  DIBENZO-
        p-DIOXINS (PCDDs)  IN AMBIENT AIR  USING  HIGH-RESOLUTION  GAS
       CHROMATOGRAPHY/HIGH-RESOLUTION MASS SPECTROMETRY  (HRGC/HRMS)
1.   Scope
     1.1  This document describes  a method  for the  determination  of
          polychlorinated  dibenzo-p-dioxins (PCDDs)  in  ambient  air.  In
          particular,  the  following PCDDs have been  evaluated  in  the
          laboratory utilizing this method:
            0   1,2,3,4-tetrachlorodibenzo-p-dioxin  (1,2,3,4-TCDD)
            0   1,2.3,4,7,8-hexachlorodibenzo-p-dioxin  (1,2,3,4,7,8-HXCDD)
            0   Octachlorodibenzo-p-dioxin (OCDD)
            0   2,3,7,8-Tetrachlorodibenzo-p-dioxin  (2,3,7,8-TCDD)
          The  method consists  of sampling ambient air  via an inlet filter
          followed  by  a cartridge  (filled with polyurethane foam) and
          analysis  of  the  sample using  high-resolution  gas chromatography/
          high-resolution  mass spectrometry (HRGC/HRMS).  Original laboratory
          studies have indicated that the use  of polyurethane  foam (PUF) or
          silica gel  in the  sampler will give  equal  efficiencies  for retain-
          ing  PCDD/PCDF isomers; i.e..  the  median retention efficiencies
          for  the PCDD isomers ranged from  67  to 124 percent with PUF and
          from 47 to 133 percent with silica gel.   Silica gel,  however,
          produced  lower levels' of background  interferences than  PUF.
          The  detection limits were, therefore, approximately  four times
          lower for tetrachlorinated isomers and ten times lower  for
          hexachlorinated  isomers  when  using silica  gel as the  adsorbent.
          The  difference in  detection limit was approximately a factor of
          two  for the  octachlorinated isomers.  However, due to variable
          recovery  and extensive cleanup required with  silica  gel, the
          method has been  written  using PUF as  the adsorbent.
     1.2  With careful  attention to reagent purity and  other factors, the
          method can detect  PCDDs  in filtered  air at levels below 15 pg/m^.

-------
                                  T09-2
     1.3  Average recoveries ranged from 68 percent to 140 percent in
          laboratory evaluations of the method sampling ultrapure filtered
          air.  Percentage recoveries and sensitivities obtainable for
          ambient air samples have not been determined.
2.   Applicable Documents
     2.1  ASTM Standards
          2.1.1  Method D1356 - Definitions of Terms Relating to Atmospheric
                 Sampling and Analysis.
          2.1.2  Method E260 - Recommended Practice for General  Gas Chro-
                 matography Procedures.
          2.1.3  Method E355 - Practice for Gas Chromatography Terms and
                 Relationships.
     2.2  EPA Documents
          2.2.1  Quality Assurance Handbook for Air Pollution Measurement
                 Systems, Volume II - "Ambient Air Specific Methods,"
                 Section 2.2 - "Reference Method for the Determination of
                 Suspended Particulates in the Atmosphere," Revision 1,
                 July, 1979, EPA-600/4-77-027A.
          2.2.2. Protocol for the Analysis of 2,3,7,8-Tetrachlorodibenzo-
                 p-Dioxin by High Resolution Gas Chromatography-High
                 Resolution Mass Spectrometry, U.S. Environmental Protection
                 Agency, January, 1986, EPA-600/4-86-004.
          2.2.3  Evaluation of an EPA High Volume Air Sampler for Polychlori-
                 nated Dibenzo-p-dioxins and Polychlorinated Dibenzo-
                 furans. undated report by Battelle under Contract 68-02-
                 4127, Project Officers Robert G. Lewis and Nancy K.
                 Wilson, U.S. Environmental Protection Agency, EMSL, Research
                 Triangle Park, North Carolina.
          2.2.4  Compendium of Methods for the Determination of Toxic  Organic
                 Compounds in Ambient Air, U.S. Environmental  Protection
                 Agency, April, 1984, 600/4-84-041.
          2.2.5  Technical Assistance Document for Sampling and Analysis of
                 Toxic Organic Compounds in Ambient Air, U.S. Environmental
                 Protection Agency, June, 1983, EPA-600/4-83-027.

-------
                                  T09-3
     2.3  Other Documents
          2.3.1  General Metal Works Operating Procedures for Model  PS-1
                 Sampler, General Metal Works. Inc., Village of Cleves,
                 Ohio.
          2.3.2  Chicago Air Quality:  PCB Air Monitoring Plan, Phase 2,
                 Illinois Einvironmental Protection Agency, Division  of Air
                 Pollution Control,  .April , 1986,  IEPA/APC/86-011.
3.  Summary of Method
     3.1  Filters and adsorbent cartridges (containing PDF)  are cleaned  in
          solvents and vacuum-dried.  The  filters and adsorbent cartridges
          are stored in screw-capped jars  wrapped in aluminum foil  (or
          otherwise protected from  light)  before  careful  installation
          on a modified high volume  sampler.
     3.2  Approximately 325 m3 of ambient  air is  drawn through a cartridge
          on a calibrated General Metal Works Model  PS-1  Sampler,  or equi-
          valent (breakthrough has not been shown to be a problem  with
          sampling volumes of 325 m3).
     3.3  The amount of air sampled  through the adsorbent cartridge  is
          recorded, and the cartridge is placed in an appropriately
          labeled container and shipped along with blank  adsorbent
          cartridges to the analytical laboratory for analysis.
     3.4  The filters and PUF adsorbent cartridge are extracted together
          with benzene.  The extract is concentrated, diluted with hexane,
          and cleaned up using column chromatography.
     3.5  The High-Resolution Gas Chromatography/High-Resolution Mass Spect-
          rometry (HRGC/HRMS)  system is verified  to  be operating properly
          and is calibrated with  five concentration  calibration solutions,
          each analyzed in triplicate.
     3.6  A preliminary analysis  of  a sample  of the  extract  is performed to
          check the system performance and  to ensure that the samples are
          within the calibration  range of  the instrument.   If necessary,
          recalibrate the instrument, adjust  the  amount of the sample
          injected, adjust the calibration  solution  concentration, and
          adjust the data processing system to reflect observed retention
          times, etc.

-------
                                  T09-4
     3.7  The samples and the blanks are analyzed by HRGC/HRMS and the
          results are used (along with the amount of air sampled)  to
          calculate the concentrations of polychlorinated dioxins  in
          ambient air.
4.  Significance
     4.1  Polychlorinated dibenzo-p-dioxins (PCDDs)  are extremely  toxic.
          They are carcinogenic and are of major environmental concern.
          Certain isomers, for example, 2,3,7,8-tetrachlorodibenzo-p-
          dioxin (2,3,7,8-TCDD), have LD50 values in the parts-per-tril-
          lion range for some animal species.  Major sources of these
          compounds have been commercial processes involving polychlorinated
          phenols and polychlorinated biphenyls (PCBs).  Recently, however,
          combustion sources have been shown to emit polychlorinated
          dibenzo-p-dioxin (PCDD), including the open-flame combustion of
          wood containing chlorophenol wood preservatives, and emissions
          from burning transformers and/or capacitors that contain PCBs
          and chlorobenzenes.
     4.2  Several documents have been published which describe sampling  and
          analytical approaches for PCDDs, as outlined in Section  2.2.  The
          attractive features of these methods have  been combined  in this
          procedure.  This method has not been validated in its final
          form, and, therefore, one must use caution when employing it for
          specific applications.
     4.3  The relatively low level of PCDDs in the environment requires
          the use of high volume sampling techniques to acquire sufficient
          samples for analysis.  However, the volatility of PCDDs  prevents
          efficient collection on filter media.  Consequently, this method
          utilizes both a filter and a PUF backup cartridge which  provides
          for efficient collection of most PCDDs.

-------
                                  T09-5
5.   Definitions
     Definitions used in this document and in any user-prepared standard
     operating procedures (SOPs)  should be consistent with ASTM Methods
     D1356 and E355 (Sections 2.1.1 and 2.1.3).   All  abbreviations  and
     symbols within this document are defined the first time they are
     used.
6.   Interferences
     6.1  Chemicals that elute from the gas chromatographic (GC)  column
          within +10 scans of the standards or compounds of interest  and
          which produce, within the retention time windows, ions  with any
          mass-to-charge (m/e) ratios close enough to those of  the  ion
          fragments used to detect or quantify the analyte compounds  are
          potential  interferences.  Most frequently encountered potential
          interferences  are other sample components that are extracted
          along with PCDDs,  e.g., polychlorinated biphenyls (PCBs), metho-
          xybiphenyls,  chlorinated hydroxydiphenylethers,  chlorinated naph-
          thalenes,  DDE, DDT, etc.  The actual incidence of interference
          by these compounds also depends  upon relative concentrations,
          mass spectrometric resolution, and  chromatographic conditions.
          Because very  low levels of PCDDs must  be measured, the  elimina-
          tion of interferences is essential.  High-purity reagents and
          solvents must  be used and all  equipment must  be  scrupulously
          cleaned.  Laboratory reagent  blanks must be analyzed  to demon-
          strate absence of contamination  that would  interfere  with the
          measurements.   Column chromatographic  procedures are  used to
          remove some coextracted sample components;  these procedures must
          be performed carefully  to minimize  loss of  analyte compounds
          during attempts  to increase their concentration  relative to
          other sample components.
     6.2  In addition to chemical  interferences,  inaccurate measurements
          could occur if PCDDs  are  retained on particulate matter, the
          filter,  or PUF adsorbent  cartridge, or  are  chemically changed
          during sampling  and storage in ways that  are  not  accurately
          measured by adding isotopically  labeled  spikes to  the samples.

-------
                             T09-6
6.3  The system cannot separately quantify gaseous PCDDs and parti-
     culate PCDDs because the material  may be lost from the filter
     by volatilization after collection and may be transferred to
     the absorbent cartridge.  Gaseous  PCDDs may also be adsorbed on
     particulate matter on the filter.
Apparatus
7.1  General Metal Works (GMW) Model PS-1 Sampler.
7.2  At least two Model PS-1 sample cartridges and filters per PS-1
     Sampler.
7.3  Calibrated GMW Model 40 calibrator.
7.4  High-Resolution Gas Chromatograph/High-Resolution Mass
     Spectrometer/Data System (HRGC/HRMS/DS)
     7.4.1  The GC must be equipped for temperature programming, and
            all required accessories must be available, including
            syringes, gases, and a capillary column.  The GC injection
            port must be designed for capillary columns.  The use of
            splitless injection techniques is recommended.  On-
            column injection techniques can be used but they may
            severely reduce column lifetime for nonchemically bonded
            columns.  In this protocol, a 2-uL injection volume is
            used consistently.  With some GC injection ports, however,
            1-uL injections may produce some improvement in precision
            and chromatographic separation.  A 1-uL injection volume
            may be used if adequate sensitivity and precision can be
            achieved.
     [NOTE: If 1 uL is used as the injection volume, the injection
            volumes for all extracts, blanks, calibration solutions
            and performance check samples must be 1 uL.]
     7.4.2  Gas Chromatograph-Mass Spectrometer Interface.
            The gas chromatograph is usually coupled directly to the
            mass spectrometer source.  The interface may include a
            diverter valve for shunting the column effluent and
            isolating the mass spectrometer source.  All components
            of the interface  should be glass or glass-lined stainless

-------
                        T09-7
       steel.  The interface components should be compatible with
       300C temperatures.  Cold spots and/or active surfaces
       (adsorption sites) in the GC/MS interface can cause peak
       tailing and peak broadening.  It is recommended that the
       GC column be fitted directly into the MS source.  Graphic
       ferrules should be avoided in the GC injection area
       since they may adsorb TCDD.  Vespel or equivalent
       ferrules are recommended.
7.4.3  Mass Spectrometer.  The static resolution of the instru-
       ment must be maintained at a minimum of 10,000 (10 percent
       valley).  The mass spectrometer must be operated in a
       selected ion monitoring (SIM) mode with a total  cycle time
       (including voltage reset time) of one second or less
       (Section 12.3.4.1).  At a minimum, ions that occur at
       the following masses must be monitored:
    2,3,7,8-TCDD         1 ;2;3,4,7,8-HYCDD          OCDD
      258.9300               326.8521             394.7742
      319.8965               389.8156             457.7377
      321.8936               391.8127             459.7347
      331.9368
      333.93338
7.4.4  Data System.  A dedicated computer data system is employed
       to control  the rapid multiple ion monitoring process and
       to acquire the data.  Quantification data (peak  areas or
       peak heights)  and SIM traces (displays  of intensities of
       each m/z being monitored as a function  of time)  must be
       acquired during the analyses.  Quantifications may be
       reported based upon computer-generated  peak  areas or upon
       measured peak  heights (chart recording).   The detector
       zero setting must allow peak-to-peak measurement of the
       noise on the baseline.

-------
                              T09-8
      7.4.5   GC  Column.  A fused  silica  column  (30 m x 0.25 mm  I.D.)
             coated  with DB-5, 0.25  u film thickness (J & S Scientific,
             Inc., Crystal  Lake,  IL) is utilized to separate each of
             the several  tetra-  through octa-PCDDs, as a group,  from all
             of  the  other groups.  This column  also resolves 2,3,7,8-TCDD
             from all  21 other TCDD  isomers; therefore, 2,3,7,8-TCDD
             can be  determined quantitatively  if proper calibration
             procedures  are followed as per Sections 12.3 through 12.6.
             Other columns may be used  for determination of PCDDs, but
             separation  of the wrong PCDD isomers must be demonstrated
             and documented.  Minimum acceptance criteria must be
             determined  as per Section  12.1.   At the beginning of each
             12-hour period (after mass resolution has been demonstrated)
             during  which sample extracts or concentration calibration
             solutions will be analyzed, column operating conditions
             must be attained for the required separation on the
             column  to be used for samples.
 7.5  All  required syringes, gases,  and other  pertinent supplies to
      operate the HR6C/HRMS system.
 7.6  Airtight,  labeled  screw-capped containers to hold the sample car-
      tridges (perferably glass  with Teflon seals or other noncontaminat-
      ing  seals).
 7.7  Data sheets for each sample for recording the location and sample
      time,  duration of  sample,  starting time, and volume of air sampled.
 7.8  Balance capable of weighing accurately to _+0.001 g.
 7.9  Pipettes,  micropipets, syringes,  burets, etc., to make calibra-
      tion and spiking solutions, dilute samples  if necessary, etc..
      including  syringes for accurately measuring  volumes such
      as 25 uL and 100 uL of isotopically labeled  dioxin solutions.
7.10  Soxhlet extractors capable of  extracting GMW PS-1 PUF adsorbent
      cartridges (2.3" x 5" length).  500-mL  flask, and condenser.

-------
                             T09-9
7.11  Vacuum drying oven system capable of maintaining the PUF car-
      tridges being evacuated at 240 torr (flushed with nitrogen)
      overnight.
7.12  Ice chest - to store samples at 0C after collection.
7.13  Glove box for working with extremely toxic standards and
      reagents with explosion-proof hood for venting fumes from
      solvents reagents, etc.
7.14  Adsorbtion columns for column chromatography - 1 cm x 10 cm
      and 1 cm x 30 cm, with stands.
7.15  Concentrator tubes and a nitrogen evaporation apparatus with
      variable flow rate.
7.16  Laboratory refrigerator with chambers operating at 0C
      and 4C.
7.17  Kuderna-Danish apparatus - 500 mL evaporating flask, 10 ml
      graduated concentrator tubes with ground-glass stoppers,
      and 3-ball macro Snyder Column (Kontes K-570001-0500,
      K-50300-0121, and K-569001-219, or equivalent).
7.18  Two-ball micro Snyder Column, Kuderna-Danish (Kontes
      569001-0219, or equivalent).
7.19  Stainless steel  spatulas and spoons.
7.20  Minivials - 1 mL, borosilicate glass, with conical  reservoir
      and screw caps lined with Teflon-faced silicone
      disks, and a vial holder.
7.21  Chromatographic columns for Carbopak cleanup - disposable
      5-mL graduated glass pi pets, 6 to 7 mm ID.
7.22  Desiccator.
7.23  Polyester gloves for handling PUF cartridges and filter.
7.24  Die - to cut PUF plugs.
7.25  Water bath equipped with concentric ring  cover and  capable
      of being temperature-controlled within j^2C.
7.26  Erlenmeyer flask, 50 mL.
7.27  Glass vial, 40 mL.
7.28  Cover glass petri dishes for shipping filters.
7.29  Fritted glass extraction thimbles.
7.30  Pyrex glass tube furnace system for activating silica
      gel at 180C under purified nitrogen gas  purge for  an hour,
      with capability  of raising temperature gradually.

-------
                                  T09-10
     [NOTE:  Reuse of glassware should be minimized to avoid the risk  of
     cross-contamination.  All glassware that is used, especially glassware
     that is reused, must be scrupulously cleaned as soon as possible  after
     use.  Rinse glassware with the last solvent used in it and then with
     high-purity acetone and hexane.  Wash with hot water containing
     detergent.  Rinse with copious amount of tap water and several
     portions of distilled water.  Drain, dry, and heat in a muffle  furnace
     at 400C for 2 to 4 hours.- Volumetric glassware must not be heated
     in a muffle furnace; rather, it should be rinsed with high-purity
     acetone and hexane.  After the glassware is dry and cool, rinse it with
     hexane, and store it inverted or capped with solvent-rinsed aluminum
     foil in a clean environment.]

8.   Reagents and Materials

     8.1  Ultrapure glass wool, silanized, extracted with methylene
          chloride and hexane, and dried.
     8.2  Ultrapure acid-washed quartz fiber filters for PS-1
          Sampler (Pallfex 2500 glass, or equivalent).
     8.3  Benzene (Burdick and Jackson, glass-distilled, or equivalent).
     8.4  Hexane (Burdick and Jackson, glass-distilled, or equivalent).
     8.5  Alumina, acidic - extracted in a Soxhlet apparatus with
          methylene chloride for 6 hours (minimum of 3 cycles
          per hour) and activated by heating in a foil-covered
          glass container for 24 hours at 190C.
     8.6  Silica gel - high-purity grade, type 60, 70-230 mesh;
          extracted in a Soxhlet apparatus with methylene chloride
          for 6 hours (minimum of 3 cycles per hour) and activated
          by heating in a foil-covered glass container for 24 hours
          at 130C.
     8.7  Silica gel impregnated with 40 percent (by weight) sulfuric
          acid - prepared by adding two parts (by weight) concentrated
          sulfuric acid to three parts (by weight) silica gel (extracted
          and activated) and mixiing with a glass rod until free of lumps;
          stored in a screw-capped glass bottle.

-------
                             T09-ll(
8.8   Graphitized carbon black (Carbopak C or equivalent),
      surface of approximately 12 m^/g,  80/100 mesh -  prepared  by
      thoroughly mixing 3.6 grams Carbopak C and  16.4  grams  Celite
      545 in a 40-mL vial  and activating at 130C for six hours;
      stored in a desiccator.
8.9   Sulfuric Acid, ultrapure, ACS grade, specific gravity  1.84.
8.10  Sodium Hydroxide, ultrapure, ACS grade.
8.11  Native and isotopically labeled PCDD/PCDF isomers for
      calibration and spiking standards, from Cambridge Isotopes,
      Cambridge, MA.
8.12  n-decane (Aldrich Gold Label grade [D90-1],  or equivalent).
8.13  Toluene (high purity, glass-distilled).
8.14  Acetone (high purity, glass-distilled).
8.15  Filters, quartz fiber - Pallflex 2500 QAST,  or equivalent.
8.16  Ultrapure nitrogen gas (Scott chromatographic grade, or equivalent).
8.17  Methanol (chromatographic grade).
8.18  Methylene chloride (chromatographic grade,  glass-distilled).
8.19  Dichloromethane/hexane (3:97, v/v), chromatographic grade.
8.20  Hexane/dichloromethane (1:1, v/v), chromatogtraphic grade.
8.21  Perfluorokerosene (PFK), chromatographic grade.
8.22  Celite 545, reagent grade, or equivalent.
8.23  Membrane filters or filter paper with pore  sizes less  than
      25 urn, hexane-rinsed.
8.24  Granular anhydrous sodium sulfate, reagent  grade.
8.25  Potassium carbonate-anhydrous,  granular, reagent grade.
8.26  Cyclohexane, glass-distilled.
8.27  Tridecane, glass-distilled.
8.28  2,2.3-trimethylpentane, glass-distilled.
8.29  Isooctane, glass-distilled.
8.30  Sodium sulfate, ultrapure, ACS grade.
8.31  Polyurethane foam - 3 inches thick sheet stock,  polyether
      type used in furniture upholstering, density 0.022 g/cm^.

-------
                             T09-12
8.32  Concentration calibration solutions (Table 1) - four tridecane
      solutions containing 13Cl2-l,2,3,4-TCDD (recovery standard)
      and unlabeled 2,3,7,8-TCDD at varying concentrations, and
      13C12-2,3,7,8-TCDD (internal standard, CAS RN 80494-19-5).
      These solutions must be obtained from the Quality Assurance
      Division, U.S. EPA, Environmental Monitoring Systems Laboratory
      (EMSL-LV), Las Vegas, Nevada, and must be used to calibrate
      the instrument.  However, secondary standards may be obtained
      from commercial sources, and solutions may be prepared in the
      analytical laboratory.  Traceability of standards must be
      verified against EPA-supplied standard solutions by procedures
      documented in laboratory SOPs.  Care must be taken to use the
      correct standard.  Serious overloading of instruments may occur
      if concentration calibration solutions intended for low-resolution
      MS are injected into the high-resolution MS.
8.33  Column performance check mixture dissolved in 1 mL of tridecane
      from Quality Assurancie Division (EMSL-LV).  Each ampule of  this
      solution will contain approximately 10 ng of the following
      components (A) eluting near 2,3,7,8-TCDD and of the first (F)
      and last-eluting (L) TCDDs, when using the recommended columns
      at a concentration of 10 pg/uL of each of these isomers:
           o  unlabeled 2,3,7,8-TCDD
              13,
           o
           o
         3C12-2,3,7,8-TCDD
        1,2,3,4-TCDD (A)
     o  1,4,7,8-TCDD (A)
     o  1,2,3,7-TCDD (A)
     o  1,2,3,8-TCDD (A)
     o  1,3,6,8-TCDD (F)
     o  1,2,8,9-TCDD (L)
If these solutions are unavailable from EPA. they should be
prepared by the analytical laboratory or a chemical  supplier.
and analyzed in a manner traceable to the EPA performance
check mixture designed for 2,3,7,8-TCDD monitoring.   Similar
mixtures of isotopically labeled compounds should be prepared
to check performance for monitoring other specific forms of
TCDD that are of interest.

-------
                             T09-13
8.34  Sample fortification solution - isooctane solution contain-
      ing the internal standard at a nominal  concentration of 10 pg/uL.,
8.35  Recovery standard spiking solution - tridecane solution con-
      taining the isotopically labeled standard (13C12-2,3,7,8-TCDD
      and other PCDDs of interest) at a concentration of 10.0 pg/uL.
8.36  Field blank fortification solutions - isooctane solutions
      containing the following:
           0  Solution A:  10.0 pg/uL of unlabeled 2,3,7,8-TCDD
           0  Solution B:  10.0 pg/uL of unlabeled 1,2,3,4-TCDD
[NOTE:  These reagents and the detailed analytical procedures described
herein are designed for monitoring TCDD isomer concentrations of
6.0 pg/m3 to 37 pg/m3 each.  If ambient concentrations should exceed
these levels, concentrations of calibrations  and spiking solutions
will need to be modified, along with the detailed sample preparation
procedures.  The reagents and procedures described herein are based
on Appendix B of the Protocol for the Analysis of 2,3,7,8-TCDD
(Section 2.2.2) combined with the evaluation  of the high volume air
sampler for PCDD.
Preparation of PUF Sampling Cartridge
9.1  The PUF adsorbent is a polyether-type polyurethane foam (density
     No. 3014 or 0.0225 g/cm3) used for furniture upholstery.
9.2  The PUF inserts are 6.0-cm diameter cylindrical  plugs cut from
     3-inch sheet stock and should fit, with  slight compression, in the
     glass cartridge, supported by the wire screen (Figure 1).  During
     cutting, the die is rotated at high speed (e.g., in a drill
     press) and continuously lubricated with  water.
9.3  For initial cleanup, the PUF plug is placed in a Soxhlet appara-
     tus and extracted with acetone for 14-24 hours at approximately
     4 cycles per hour.  When cartridges are  reused,  5% diethyl
     ether in n-hexane can be used as the cleanup solvent.
9.4  The extracted PUF is placed in a vacuum  oven connected to a
     water aspirator and dried at room temperature for approximately
     2-4 hours (until no solvent odor is detected).

-------
                                   T09-14
      9.5  The PUF is placed into the glass sampling cartridge  using  poly-
           ester gloves.  The module is wrapped with hexane-rinsed  aluminum
           foil, placed in a labeled container, and tightly sealed.
      9.6  At least one assembled cartridge from each batch must  be
           analyzed, as a laboratory blank, using the procedures  described
           in Section 11, before the batch is considered  acceptable  for
           field use.  A blank level of <10 ng/plug for single  compounds
           is considered to be acceptable.
10.   Sample Collection
      10.1  Description of Sampling Apparatus
            10.1.1  The entire sampling system is diagrammed in Figure 2.
                    A unit specifically designed for this method  is
                    commercially available (Model PS-1 -  General  Metal
                    Works, Inc., Village of Cleves, Ohio).
            10.1.2  The sampling module (Figure 1) consists of  a  glass sampl-
                    ing cartridge and an air-tight metal  cartridge  holder.
                    The PUF is retained in the glass sampling cartridge.
      10.2  Calibration of Sampling System
            10.2.1  The airflow through the sampling system is  monitored
                    by a Venturi/Magnehelic assembly, as  shown  in Figure 2.
                    Assembly must be audited every six months using  an
                    audit calibration orifice, as described in  the  U.S.
                    EPA High Volume Sampling Method, 40 CFR 50, Appendix B.
                    A single-point calibration must be performed  before
                    and after each sample collection, using the procedure
                    described in Section 10.2.2.
            10.2.2  Prior to calibration, a "dummy" PUF cartridge and filter
                    are placed in the sampling head and the sampling  motor
                    is activated.  The flow control valve is fully  opened
                    and the voltage variator is adjusted  so that  a  sample
                    flow rate corresponding to 110% of the desired  flow rate
                    is indicated on the Magnehelic (based on the  previously
                    obtained multipoint calibration curve).  The  motor is
                    allowed to warm up for 10 minutes and then  the  flow control

-------
                             T09-15
             valve  is adjusted  to  achieve  the  desired  flow  rate.  ,The
             ambient  temperature and  barometric  pressure  should be
             recorded on an, appropriate data sheet.
     10.2.3  The calibration orifice  is placed on  the  sampling
             head and a manometer  is.attached  to the tap  on the
             calibration orifice.  The  sampler is  momentarily
             turned off to  set  the zero level  of the manometer.
             The sampler is then switched  on and the manometer
             reading  is recorded after  a stable  reading is
             achieved.  The sampler  is  then shut off.
     10.2.4  The calibration curve for  the orifice is  used  to cal-
             culate sample  flow from  the data  obtained in Section
             10.2.3,  and the calibration curve for the Venturi/
             Magnehelic assembly is  used to calculate  sample flow
             from the data  obtained  in  Section 10.2.2. The calibra-
             tion data should be recorded  on an  appropriate data
             sheet.  If the two values  do  not  agree within  10%, the
             sampler  should be.inspected for damage, flow blockage,
             etc.  If no obvious problems  are  found, the  sampler
             should be recalibrated  (multipoint) according  to the
             U.S. EPA High  Volume  Sampling Method  (Section  10.2.1).
     10.2.5  A multipoint calibration of the calibration  orifice,
             against  a primary  standard, should  be obtained annually.
10.3  Sample Collection
     10.3.1  After the sampling system  has been  assembled and
             calibrated as  described  in Sections 10.1  and 10.2, it
             can be used to collect  air samples, as described in
             Section  10.3.2.
     10.3.2. The samples should be located in  an unobstructed area,
             at least two meters  from any obstacle to  air flow.
             The exhaust hose should  be stretched  out  in  the down-
             wind direction to  prevent  recycling of air.

-------
                        T09-16
10.3.3  A clean PUF sampling cartridge and quartz filter are
        removed from sealed transport containers and placed  in
        the sampling head using forceps and gloved hands. The
        head is tightly sealed into the sampling system.  The
        aluminum foil  wrapping is placed back in the sealed
        container for later use.
10.3.4  The zero reading of the Magnehelic is checked.    Ambient
        temperature, barometric pressure, elapsed time  meter
        setting, sampler serial number, filter number,  and
        PUF cartridge number are recorded on a suitable data
        sheet, as illustrated in Figure 3.
10.3.5  The voltage variator and flow control valve are placed
        at the settings used in Section 10.2.3, and the power
        switch is turned on.  The elapsed time meter is acti-
        vated and the start time is recorded.  The flow (Magne-
        helic setting) is adjusted, if necessary, using the
        flow control valve.
10.3.6  The Magnehelic reading is recorded every six hours
        during the sampling period.  The calibration curve
        (Section 10.2.4) is used to calculate the flow  rate.
        Ambient temperature and barometric pressure are
        recorded at the beginning and end of the sampling
        period.
10.3.7  At the end of the desired sampling period, the  power is
        turned off and the filter and PUF cartridges are wrapped
        with the original aluminum foil and placed in sealed,
        labeled containers for transport back to the laboratory.
10.3.8  The Magnehelic calibration is checked using the cali-
        bration orifice, as described in Section 10.2.4.  If
        calibration deviates by more than 10% from the  initial
        reading, the flow data for that sample must be  marked
        as suspect and the sampler should be inspected  and/or
        removed from service.

-------
                                  T09-17
          10.3.9   At least one field filter/PUF blank  will  be  returned  to
                   the laboratory with each group of samples.   A field
                   blank is treated  exactly as  a sample except  that  no air
                   is drawn through  the filter/PUF cartridge assembly.
          10.3.10  Samples are stored at 20C in an ice chest  until  receipt
                   at the analytical  laboratory, after  which they are
                   refrigerated at 4C.
11.  Sample Extraction
     11.1  Immediately before use, charge the Soxhlet apparatus with 200
           to 250 ml of benzene and  reflux for  2 hours.   Let the apparatus
           cool, disassemble it, transfer the benzene to a clean glass
           container, and retain it  as a blank  for later analysis, if
           required.  After sampling, spike the cartridges and  filters
           with an internal standard (Table 1).  After  spiking, place the
           PUF cartridge and filter  together in the Soxhlet  apparatus
           (the use of an extraction thimble is optional). (The filter and
           PUF cartridge are analyzed together  in order to reach detection
           limits, avoid questionable interpretation of the  data, and mini-
           mize cost.)  Add 200 to 250 ml of benzene to the  apparatus and
           relux for  18 hours at a  rate of at  least 3  cycles  per hour.
     11.2  Transfer the extract to a Kuderna-Danish (K-D)  apparatus, concen-
           trate it to 2 to 3 mL, and let it cool.  Rinse  the column and
           flask with 5 ml of benzene, collecting the rinsate  in the concen-
           trator tube to 2 to 3 mL.  Repeat the rinsing and concentration
           steps twice more.  Remove the concentrator tube from the  K-D
           apparatus and carefully reduce the extract volume to approximately
           1 mL with a stream of nitrogen using a flow  rate  and distance
           above the solution such that a gentle rippling  of the solution
           surface is observed.

-------
                             T09-18

11.3  Perform the following column chromatographic procedures for
      sample extraction cleanup.  These procedures have been
      demonstrated to be effective for a mixture consisting of:
                    0  1,2,3,4-TCDD
                    0  1,2,3,4,7,8-HXCDD
                    0  OCDD
                    0  2,3,7,8-TCDD
      11.3.1  Prepare an acidic silica gel  column as follows (Figure 4):
              Pack a 1 cm x 10 cm chromatographic column with a  glass
              wool plug, a 1-cm layer of N32S04/K2C03 (1:1), 1.0 g of
              silica gel (Section 8.6), and 4.0 g of 40-percent  (w/w)
              sulfuric acid-impregnated silica gel (Section 8.7).
              Pack a second chromatographic column (1 cm x 30 cm)
              with a glass wool plug and 6.0 g of acidic alumina
              (Section 8.5), and top it with a 1-cm layer of sodium
              sulfate (Section 8.30).  Add  hexane to the columns
              until  they are free of channels and air bubbles.
      11.3.2  Quantitatively transfer the benzene extract (1 ml)
              from the concentrator tub to  the top of the silica
              gel  column.  Rinse the concentrator tube with 0.5-mL
              portions of hexane.  Transfer the rinses to the top of
              the silica gel column.
      11.3.3  Elute the extract from the silica gel column with  90 of
              mL hexane directly into a Kudena-Danish concentrator
              tube.   Concentrate the eluate to 0.5 ml. using nitro-
              gen blowdown, as necessary.
      11.3.4  Transfer the concentrate (0.5 ml) to the top of the
              alumina column.  Rinse the K-D assembly with two
              0.5-mL portions of hexane, and transfer the rinses to
              the top of the alumina column.  Elute the alumina
              column with 18 mL hexane until the hexane level is
              just below the top of the sodium sulfate.  Discard the
              eluate.  Do not let the columns reach dryness
              (i.e., maintain a solvent "head").

-------
                        T09-19
11.3.5  Place 30 ml. of 20% (v/v)  methylene chloride  in  hexane
        on top of the alumina column and elute the TCDDs  from
        the column.  Collect this fraction in a 50-mL Erlenmeyer
        flask.
11.3.6  Certain extracts,  even after cleanup by column  chroma-
        tography, contain  interferences that preclude
        determination of TCDD at  low parts-per-trillion
        levels.  Therefore, a cleanup step is included  using
        activated carbon which selectively retains planar
        molecules such as  TCDDs.   The TCDDs are then removed
        from the carbon by elution with toluene.  Proceed as
        follows:  Prepare an 18%  Carbopak C/Celite 545 mixture
        by thoroughly mixing 3.6  grams Carbopak C (80/100 mesh)
        and 16.4 grams Celite 545 in a 40-mL vial.   Activate
        the mixture at 130C for  6 hours, and store  it  in a
        desiccator.  Cut off a clean 5-mL disposable glass
        pipet at the 4-mL mark.  Insert a plug of glass wool
        (Section 8.1) and push it to the 2-mL mark.   Add  340 mg
        of the activated Carbopak/Celite mixture followed by
        another glass wool plug.   Using two glass rods, push both
        glass wool plugs simultaneously toward the Carbopak/Celite
        plug to a length of 2.0 to 2.5 cm.  Pre-elute the column
        with 2 mL of toluene followed by 1 ml of 75:20:5  methylene
        chloride/methanol/ benzene, 1 ml of 1:1 cyclohexane in
        methylene choride, and 2  ml of hexane.  The  flow  rate
        should be less than 0.5 ml per minute.  While the column
        is still wet with hexane, add the entire elute  (30 mL)
        from the alumina column (Section 11.3.5) to  the top of
        the column.  Rinse the Erlenmeyer flask that contained  the
        extract twice with 1 ml of hexane and add the rinsates
        to the top of the column.  Elute the column  sequentially
        with two 1-mL aliquots of hexane, 1 ml of 1:1 cyclohex-
        ane in methylene chloride, and 1 ml of 75:20:5  methylene

-------
                                   T09-20
                   chloride/mentanol/benzene.  Turn the column upside
                   down and elute the TCDD fraction into a concentrator
                   tube with 6 ml of toluene.  Warm the tube to approxi-
                   mately 60C and reduce the toluene volume to approxi-
                   mately 1 ml using a stream of nitrogen.  Carefully
                   transfer the residue into a 1-mL minivial and, again
                   at elevated temperature, reduce the volume to about
                   100 uL using a stream of nitrogen.  Rinse the concen-
                   trator tube with 3 washings using 200 uL of 1% toluene
                   in CH2C12 each time.  Add 50 uL of tn'decane and store
                   the sample in a refrigerator until GC/MS analysis is
                   performed.

12.   HRGC/HRMS System Performance Criteria

      The laboratory must document that the system performance criteria
      specified in Sections 12.1, 12.2, and 12.3 have been met before
      analysis of samples.
      12.1  GC Column Performance
           12.1.1   Inject 2 uL of the column performance check solution
                    (Section 8.33) and acquire selected ion monitoring
                    (SIM) data for m/z 258.930, 319.897, 321.894, and
                    333.933 within a total  cycle time of 
-------
                             T09-21
             the retention time window for total  TCDD determination.,
             The peaks representing  2,3.7,8-TCDD, and the first  and
             last eluting TCDD isomers must be labeled and identified.]
12.2  Mass Spectometer Performance
      12.2.1 The mass spectrometer must be operated in the electron
             (impact) ionization mode.  Static mass resolution of at
             least 10,000 (10% valley) must be demonstrated before any
             analysis of a set of samples is performed (Section  12.2.2).
             Static resolution checks must be performed at the beginn-
             ing and at the end of each 12-hour period of operation.
             However, it is recommended that a visual check (e.g., not
             documented) of the static resolution be made using  the
             peak matching unit before and after each analysis.
     12.2.2  Chromatography time for TCDD may exceed the long-term
             mass stability of the mass spectrometer; therefore, mass
             drift correction is mandatory.  A reference compound
             (high boiling perfluorokerosene [PFK] is recommended)
             is introduced into the  mass spectrometer.  An acceptable
             lock mass ion at any mass between m/z 250 and m/z 334
             (m/z 318.979 from PFK is recommended) must be used  to
             monitor and correct mass drifts.
     [NOTE:  Excessive PFK may cause background noise problems and
             contamination of the source, resulting in an increase in
             "downtime" for source cleaning.  Using  a PFK molecular
             leak, tune the instrument to meet the minimum required
             mass resolution of 10,000 (10% valley) at m/z 254.986
             (or any other mass reasonably close to m/z 259).  Cali-
             brate the voltage sweep at least across the mass range
             m/z 259 to m/z 344 and  verify that m/z 330.979 from PFK
             (or any other mass close to m/z 334)  is measured within
             5 ppm (i.e., 17 mmu).  Document the mass resolution
             by recording the peak profile of the PFK reference peak
             m/z 318.979 (or any other reference peak at a mass  close
 -vij'."  erii  2fHfcto m/z 320/322).  The format of the peak profile represen-
             tation must allow manual determination of the resolution;

-------
                             T09-22
              i.e., the horizontal  axis must be a calibrated mass
              scale (mmu or ppm per division).  The result of the
              peak width measurement (performed at 5 percent of the
              maximum) must appear  on the hard copy and cannot exceed
              31.9 mmu or 100 ppm.]
12.3  Initial  Calibration
      Intitial calibration is required before any samples  are analyzed
      for 2,3,7,8-TCDD.  Initial  calibration is also required if any
      routine calibration does not  meet the required criteria listed
      in Section 12.6.
      12.3.1  All  concentration calibration solutions listed in Table  1
              must be utilized for  the initial  calibration.
      12.3.2  Tune the instrument with PFK as described in
              Section 12.2.2.
      12.3.3  Inject 2 uL of the column performance check  solution
              (Section 8.33) and acquire SIM mass spectral  data for m/z
              258.930, 319.897, 321.894, 331.937, and 333.934 within
              a total  cycle time of _<1 second. The laboratory must  not
              perform any further analysis until  it has been demon-
              strated and documented that the criterion listed in
              Section 12.1.2 has been met.
      12.3.4  Using the same GC (Section 12.1) and MS (Section 12.2)
              conditions that produced acceptable results  with the
              column performance check solution,  analyze a 2-uL
              aliquot of each of the 5 concentration calibration
              solutions in triplicate with the gas chromatographic
              operating parameters  shown in Table 2.
              12.3.4.1   Total  cycle time for data acquisition must
                         be <1 second.  Total  cycle time includes
                         the sum of all the dwell times and  voltage
                         reset times.

-------
               T09-23
12.3.4.2   Acquire SIM data for the following  selected
           characteristic ions:
                m/z          Compound
              258.930    TCDD - COC1
              319.897    unlabeled TCDD
              321.894    unlabeled TCDD
              331.937    13C12-2,3,7,8-TCDD,
                         13C12-132,3,4-TCDD
              333.934    13C12-2,3,7,8-TCDD,
                         13C12-1,2,3,4-TCDD
12.3.4.3   The ratio of intergrated ion current for m/z
           319.897 to m/z 321.894 for 2,3,7,8-TCDD must
           be between 0.67 and 0.87 (+13%).
12.3.4.4   The ratio of integrated ion current for m/z
           331.937 to m/z 333.934 for 13C12-2,3,7,8-TCDD
           and 13C12-1.2.3,4-TCDD must be between 0.67
           and 0.87.
12.3.4.5   Calculate the relative response factor for
           unlabeled 2,3,7,8-TCDD [RRF(I)3 relative to
           13C12-2,3,7,8-TCDD and for labeled 13C12-
           2,3,7,8-TCDD [RRF(II)] relative to 13C12-
           1,2,3,4-TCDD as follows:
                                A     QTS
                   RRF(D = _________
                  RRF(II)=
                                     AIS
                                AIS  ' QRS
                                 'IS  "  RS

-------
                              T09-24
      where:
              Ax  =  sum of the integrated abundances of m/z 319.897
                     and m/z 321.894 for unlabeled 2,3,7,8,-TCDD.
                     sum of the integrated abundances of m/z 331.937
                     and m/z 333.934 for 13C12-2,3,7,8-TCDD.
                     sum of the integrated abundances for m/z 331.937
                     and m/z 333.934 for 13C12-1,2,3,4-TCDD.
              QIS =  quantity (pg) of 13C12-2,3,7,8-TCDD injected.
              QRS =  quantity (pg) of 13C12-1,2,3,4-TCDD injected.
              Qx  =  quantity (pg) of unlabeled 2,3,7,8-TCDD injected.
12.4  Criteria for Acceptable Calibration
      The criteria listed below for acceptable  calibration must  be  met
      before analysis of any sample is performed.
      12.4.1   The percent relative standard  deviation (RSD)  for the
               response factors from each of  the triplicate analyses
               for both unlabeled  and 13Cl2-2,3,7,8-TCDD must be less
               than +20%.
      12.4.2   The variation of the five mean RRFs for unlabeled
               2,3,7,8-TCDD obtained from the triplicate analyses
               must be  less than +20% RSD.
      12.4.4   SIM traces for 13C12-2,3,7,8-TCDD must  present a
               signal-to-noise  ratio XLO for  333.934.
      12.4.5   Isotopic ratios  (Sections 12.3.4.3  and  12.3.4.4)  must
               be within  the allowed range.
      [NOTE:   If the criteria  for acceptable calibration listed in
               Sections 12.4.1  and 12.4.2 have  been met, the  RRF can
               be considered independent of the analyte  quantity for
               the calibration  concentration  range.  The mean RRF
               from five  triplicate determinations  for unlabeled
               2,3,7,8-TCDD and for 13Cl22,3,7,8-TCDD  will  be used  for
               all  calculations  until  routine calibration  criteria
               (Section 12.6) are  no longer met.  At such  time,  new
               mean  RRFs  will be calculated from a new set  of five
               triplicate determinations.]

-------
                                  T09-25
     12.5  Routine Calibration
           Routine calibration  must be performed  at  the  beginning  of  each
           12-hour period  after successful  mass resolution  and  GC  column
           performance check  runs.
           12.5.1   Inject  2 uL  of the concentration  calibration solution
                   (Section 8.32) that contains 5..0  pg/uL of unlabeled
                   2,3,7,8-TCDD, 10.0 pg/uL of 13C12-2,3,7,8-TCDD5 and  5.0
                   pg/uL 13C12-1,2,3,4-TCDD.   Using  the  same GC/MS/DS
                   conditions as in Sections  12.1,  12.2,  and 12.3, deter-
                  .mine and document acceptable calibration as  provided
                   in Section 12.6.
     12.6  Criteria for Acceptable  Routine  Calibration
           The following criteria must be met before further analysis is
           performed.  If  these criteria are  not  met, corrective action
           must be taken and  the instrument must  be  recalibrated.
           12.6.1   The measured RRF for unlabeled 2,3,7,8-TCDD  must be
                   within  +;20 percent of the  mean values  established
                   (Section 12.3.4.5) by triplicate  analyses of concen-
                   tration calibration solutions.
           12.6.2   The measured RRF for 13Cl2-2,3,7,8-TCDD  must be within
                   +20 percent  of the mean  value  established by triplicate
                   analyses of  concentration  calibration  solutions
                   (Section 12.3.4.5).
           12.6.3   Isotopic ratios  (Sections  12.3.4.3 and 12.3.4.4) must be
                   within  the allowed range.
           12.6.4   If one  of the above criteria is  not  satisfied,  a second
                   attempt can  be made before repeating  the entire initial-
                   ization process  (Section 12.3).
           [NOTE:   An initial calibration must be carried out whenever  any
          -;       HRCC solution is replaced.]
13.  Analytical Procedures
     13.1  Remove  the sample extract or blank from  storage, allow  it  to
           warm to ambient laboratory temperature,  and  add  5 uL of recovery
           standard solution.  With a stream of dry, purified nitrogen,
           reduce  the extract/blank volume  to 20  uL.

-------
                             T09-26
13.2  Inject a 2-uL aliquot of the extract into the GC, which should
      be operating under the conditions previously used (Section 12.1)
      to produce acceptable results with the performance check
      solution.
13.3  Acquire SIM data using the same acquisition time and MS operating
      conditions previously used (Section 12.3.4) to determine the
      relative response factors for the following selected characteristic
      ions:
m/z
258.930
319.897
321.894
331.937
333.934
Compound
TCDD - COC1 (weak at
unlabeled
unlabeled
13C12-2,3
13C _2js
TCDD
TCDD
,7,8-TCDD,
,7,8-TCDD,
detection limit level)

13C12-1S2,3,4-TCDD,
13r _i ? ? 4_Trnn
19 L-5J5M' llUL/,
13.4  Identification Criteria
      13.4.1  The retention time (RT) (at maximum peak height)  of
              the sample component m/z 319.897 must be within -1 to
              +3 seconds of the retention time of the peak for  the
              isotopically labeled internal  standard at m/z 331.937
              to attain a positive identification of 2,3.7,8-TCDD.
              Retention times of other tentatively identified TCDDs
              must fall within the RT window established by analyzing
              the column performance check solution (Section 12.1).
              Retention times are required for all  chromatograms.
      13.4.2  The ion current responses for m/z 258.930, 319.897
              and 321.894 must reach their maxima simultaneously
              (+1 scan), and all ion current intensities must be
              >_2.5 times noise level for positive identification of
              a TCDD.
      13.4.3  The integrated ion current at m/z 319.897 must be
              between 67 and 87 percent of the ion current response
              at m/z 321.894.

-------
                                  T09-27
          13.4.4  The integrated  ion  current  at m/z  331.937 must  be
                  between  67  and  87  percent  of the ion  current  response
                  at m/z 333.934.
          13.4.5  The integrated  ion  currents for m/z  331.937 and 333.934
                  must reach  their maxima  within +1  scan.
          13.4.6  The recovery of the internal standard 13C12-2,3,7,8-
                  TCDD must be between 40  and 120 percent.
14.  Calculations
     14.1  Calculate the concentration of  2,3,7,8-TCDD  (or  any  other TCDD
           isomer) using the formula:
                                 Ay  ' QTC
                        ~          A     J.O
                        CX  =  	
                               AIS   V   RRF(I)
     where:
            Cx  =  quantity (pg)  of unlabeled  2,3,7,8-TCDD (or any other
                   unlabeled TCDD isomer)  present.
            AX  =  sum of the integrated  ion abundances determined for m/z
                   319.897 and 321.894.
            AIS =  sum f the integrated  ion abundances determined for m/z
                   331.937 and 333.934 of 13Cl2-2,3,7,8-TCDD (IS = internal
                   standard).
            QIS =  quantity (pg)  of 13C12-2,3S7S8-TCDD added to the
                   sample before extraction (Qjs =  500 pg).
            V   =  volume (m3) of air sampled.
         RRF(I) =  Calculated mean relative response factor for unlabeled
                   2,3,7,8-TCDD relative  to 13C12-233,738-TCDD.  This value
                   represents the grand mean of the RRF(I)s  obtained in
                   Section 12.3.4.5.

-------
                               T09-28
  14.2  Calculate the recovery of the internal  standard ^C-j ~-2., 3,7,8
        TCDD, measured in the sample extract, using the formula:

                                   IS "   RS
         Internal standard,   _  x 100
         percent recovery =          ___
                              ARS   RRF(II)    QIS

where:
     and QlS = same definitions as above (Section 14.1)
        ARS  = sum of the integrated ion abundances determined for m/z
               331.937 and 333.934 of 13C12-1 ,2,3,4-TCDD (RS = recovery
               standard).
        QRS  = quantity (pg) of 13C12-1,2,3,4-TCDD added to the
               sample residue before HRGC-HRMS analysis  (QRS = 500 pg).
     RRF(II) = Calculated mean relative response factor  for labeled ^C^-
               2,3,7,8-TCDD.  This value represents the  grand mean of the
               RRF(II)s calculated in Section 12.3.4.5.
  14.3  Total TCDD Concentration
        14.3.1  All positively identified isomers of TCDD must be
                within the RT window and meet all identification
                criteria listed in Sections 13.4.2, 13.4.3, and 13.4.4.
                Use the expression in Section 14.1 to calculate the
                concentrations of the other TCDD isomers, with GX be-
                coming the concentration of any unlabeled TCDD isomer.
  14.4  Estimated Detection Limit
        14.4.1  For samples in which no un labeled 2,3,7,8-TCDD was
                detected, calculate the estimated minimum detectable
                concentration.  The background area is determined by
                integrating the ion abundances for m/z 319.897 and
                321.894 in the appropriate region and relating that
                height area to an estimated concentration that would
                produce that product area.  Use the formula:
                                    (2.5)  (Ax)  (QIS)
                             CE =
                                    (AIS)  RRF(I)   (W)

-------
                             T09-29

where:
      Cg  = estimated concentration of unlabeled 2,3,7,8-TCDD required
            to produce Ax.
      Ax  = sum of integrated ion abundance for m/z 319.897 and 321.894
            in the same group of 2.25 scans used to measure AI$.
          = sum of integrated ion abundance for the appropriate ion
            characteristic of the internal standard, m/z 331.937 and
            m/z 333.934.
         ' RRFU); >nd V retain the definitions previously stated  in
      Section 14.1.  Alternatively, if peak height measurements  are used
      for quantification, measure the estimated detection limit  by the peak
      height of the noise in the TCDD RT window.
14.5  The relative percent difference (RPD) is calculated as follows:
      RPD =
                Si - S2
           (Mean Concentration)
 Si  - S2
               x  100
(Si  + S2)/2
      Si and S2 represent sample and duplicate sample results.
14.6  The total sample volume (Vm)  is calculated from the periodic
      flow readings (Magnehelic) taken in Section 10.3.6 using  the
      following equation:
                             Q! + Q2 - QN      T
                     Vm=                    x
                          _     _
                                   N.          TOOO
where:
       Vm        = total  sample volume
       Qp  QN = flow rates determined at the beginning,  end,  and  inter
                   mediate points during sampling  (L/minute).
       N         = number of data points averaged.
       T         = elapsed sampling time (minutes).

-------
                                  T09-30
     14.7  The concentration of compound in the sample is calculated  using
           the following equation:
                   Vs =
                             _
                             760
 298
273 +
     where:
             Vs = total  sample volume (m3)  at 25C and 760 mm Hg pressure.
             V  = total  sample flow (m3)  under ambient conditions.
             PA = ambient pressure (mm Hg).
             tA = ambient temperature (C).
     14.8  The concentration of compound  in the sample is calculated
           using the following equation:
                         A x VE
     where:
             C. = concentration (ug/m3)  of analyte in the sample.
             A  = calculated amount of material  determined by HRGC/HRMS.
             V-j = volume (uL) of extract injected.
             VE = final  volume (ml) of extract.
             V  = total  volume (m3) of air samples corrected to standard
                  conditions.
15.  Performance Criteria and Quality Assurance
     This section summarizes required quality assurance (QA) measures and
     provides guidance concerning performance criteria that should be
     achieved within each laboratory.
     15.1  Standard Operating Procedures (SOPs)
           15.1.1  Users should generate SOPs describing the following
                   activities in their laboratory:  1) assembly, calibra-
                   tion and operation of the sampling system with  make
                   and model of equipment used;  2) preparation, purifica-
                   tion, storage, and handling of sampling cartridges and
                   filters; 3) assembly, calibration and operation of the
                   HRGC/HRMS system with make and model of equipment used;
                   4) all aspects of data recording and processing, in-
                   cluding lists of computer hardware and software used.

-------
                             T09-31
      15.1.2  SOPs should provide specific stepwise instructions  and
              should be readily available to and understood by the
              laboratory personnel  conducting the work.
15.2  Process, Field, and Solvent Blanks
      15.2.1  One PUF cartridge and  filter from each batch of
              approximately 20 should be analyzed, without shipment
              to the field, for the  compounds of interest to serve as
              process blank.
      15.2.2  During each sampling  episode,  at least one PUF cartridge
              and filter should be  shipped to the field  and returned,
              without drawing air through the sampler, to serve as a
              field blank.
      15.2.3  During the analysis of each batch of samples, at least
              one solvent process blank  (all  steps conducted but  no
              PUF cartridge or filter included) should be carried
              through the procedure  and  analyzed.

-------
                     T09-32
                    TABLE 1
COMPOSITION OF CONCENTRATION CALIBRATION SOLUTIONS
Recovery
13r -i
L12-i,
HRCC1
HRCC2
HRCC3
HRCC4
HRCC5

Standards
2,3,4-TCDD
2.5 pg/uL
5.0 pg/uL
10.0 pg/uL
20.0 pg/uL
40.0 pg/uL

Analyte
2,3,7,8-TCDD
2.5 pg/uL
5.0 pg/uL
10.0 pg/uL
20.0 pg/uL
40.0 pg/uL
Sample Fortification Solution
Internal Standard
13C12-2,3,7,8-TCDD
10.0 pg/uL
10.0 pg/uL
10.0 pg/uL
10.0 pg/uL
10.0 pg/uL

       5.0 pg/uL of 13C12-2,3,758-TCDD
       Recovery Standard Spiking Solution
          100 pg/uL 13C12-1,2,3,4-TCDD
      Field Blank Fortification Solutions
    A)  4.0 pg/uL of unlabeled 2,3,7,8-TCDD
    B)  5.0 pg/uL of unlabeled 1,2,3,4-TCDD

-------
                                  T09-33
                                 TABLE 2
                   RECOMMENDED GC OPERATING CONDITIONS
Column coating             SP-2330 (SP 2331)          CP-SIL 88
Film thickness         .    0.20 um                    0.22 urn
Column dimensions          60 m x 0.24 mm             50 m x 0.22 mm
Helium linear velocity     28-29 cm/sec at 240C      28-29 cm/sec at 240C
Initial temperature        200C                      190C
Initial time               4 min                      3 min
Temperature program        200C to 250C at          190C to 240C at
                           4C/min                    5C/min

-------
T09-34
                               O
                               <
                               LU
                               X

                               CD


                               Ij
                               CL

                               :>
                               <
                               CO
                               LU
                               cc
                               u_

-------
                               T09-35
 Magnehelic
   Gauge
  0-100 in.
  Exhaust
    Duct
(6 in. x 10ft)
                    Sampling
                      Head
                  (See Figure 2)
\
                                    Pipe Fitting (1/2 in.)
                                                       Voltage Variator


                                                       Elapsed Time Meter
           FIGURE  2. HIGH VOLUME AIR SAMPLER
                 GENERAL METAL WORKS (MODEL PS-1)

-------
                                           T09-36
o
o
 QJ

 3
4->
 re

 QJ
 O.

 OJ
4J
 C
 CD
i
XI
 E
=C
       00
       
 C-     
c

4- oo re
QJ *v
CQ -a
QJ re o
O i
ecu.
O) O
t- T- T-
<*- re 3
r- XI C
Q -I- QJ
**

re
I ^
t- re
a) a
E -
re 3
OO 4->
(U




(U
u
JJI
r-
_
O

f*7
o re
r- 4->
i 3 ro
re o
_
X)
r~
^~
re
<~>

0
re c
s ^
0 E
i O
u. to
s
o
'? o
QJ C
_f  p-
QJ
C 
re -i-

QJre
re c:
a: T-
E

o "E"
i  O
U- to

A
_
QJ O
4-> O
Q) m
E
C C
re T-
s:
o-
0 0
t_ ~x.
CD CO
E QJ
r- >-
1
o cn
re c
(- 4->
re 4->
> ai
oo
c_
0)
Q.Z
re oo
oo





























i
















i



























































































































































































































































































































































































































































































































































































































                                                                                               OJ
                                                                                              4-5
                                                                                               re
                                                                                              o
                                                                                               o
                                                                                               a;
                                                                                               u

                                                                                               CD
                                                                                               re
                                                                                              o
                                                                                            a>
                                                                                           jQ
                                                                                            3   
                                                                                           I -M
                                                                                            t-  3
                                                                                            3
              yj
              UJ
              3C
              CO

              <
              K-
                                                                                            o  re
                                                                                           r-  OJ
    CD

 O  3
r- I
4-J
 re T-

XI  3
r- 4->
r  C
 re  CD
o >

 L_  L.
 O  O
                                                                                            to  co
                                                                                            a>  CD
                                                                                            re  re
                                                                                            c  c
                                                                                            o  o
                                                                                           X) XI
                                                                                            re  re
                                                                                           o o
                                                                                            re xi
                                                                                                          CL
                                                                                                          CO
                                                                                                          LU
                                                                                                          J
                                                                                                          CL
               X
               LU
                                                                                                          LU
                                                                                                          CC

-------
                                  T09-37
                     SODIUM SULFATE
                     ACIDIC ALUMINA ~ 6.0 g)
                     GLASS WOOL PLUG
      (a) ALUMINA COLUMN
                                             SULFURIC ACID ON SILICA GEL (~ 4.0 g)
                                             SILICA GEL (~ I.Og)
                                             SODIUM SULFATE/POTASSIUM CARBONATE (1:1)
                                             GLASS WOOL PLUG
                                      (b) SILICA GEL COLUMN
FIGURE 4. MULTILAYERED EXTRACT CLEANUP COLUMNS
                U.S. GOVERNMENT PRINTING OFFICE :  1987-748-121/40692

-------

-------