&ER&
           United States
           Environmental Protection
           Agency
           Environmental Sew
           Laboratory
              Triangle Perk NC 27711
EPA-600/2-79-004
January 1979
           Research and Development
Evaluation of
Techniques for
Measuring Biogenic
Airborne Sulfur
Compounds
           Cedar Island Field
           Study 1977

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                RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development. U S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology.  Elimination of traditional  grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:

      1.  Environmental  Health Effects Research
      2.  Environmental  Protection Technology
      3.  Ecological Research
      4.  Environmental  Monitoring
      5.  Socioeconomic Environmental Studies
      6.  Scientific and Technical Assessment Reports (STAR)  .
      7.  Interagency Energy-Environment Research and Development
      8.  "Special" Reports
      9.  Miscellaneous Reports

This report has  been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                          EPA-600/2-79-004
                                          January 1979
   EVALUATION OF TECHNIQUES FOR MEASURING
     BIOGENIC AIRBORNE SULFUR COMPOUNDS
           Cedar Island Field Study 1977
   W.A. McClenny, R.W.  Shaw, R.E. Baumgardner,
             R.  Paur and A. Coleman
      Atmospheric Chemistry and  Physics Division
      Environmental Sciences Research Laboratory
        Research Triangle Park,  N.C.  27711
                     and
          R.S.  Braman and J.M.  Ammons
             Department of Chemistry
           University of South Florida
               Tampa, Florida 33620
ENVIRONMENTAL SCIENCES RESEARCH LABORATORY
     OFFICE OF RESEARCH AND DEVELOPMENT
     U.S. ENVIRONMENTAL PROTECTION AGENCY
 RESEARCH TRIANGLE PARK, -NORTH CAROLINA 27711

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                             DISCLAIMER

     This report has been reviewed by the Environmenal Sciences Research
Laboratory,   U.S.   Environmental  Protection  Agency,  and  approved  for
publication.   Mention  of trade names  or commercial  products does  not
constitute endorsement or recommendation for use.
                                  ii

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                                  ABSTRACT







     Sulfur in both gaseous  and particulate form  has been measured near



biogenic sources using new measurement techniques.  The  preconcentration



of gaseous  sulfur on  gold-coated  glass beads followed by desorption into a



flame photometric detection for sulfur is shown to have a detection limit of



0.1-0.2 ng of  sulfur and  to  allow  for speciation  of  ELS,  CHgSH  and



(CH0)0S at low parts per trillion levels.   Ambient levels  of NO0  and O,,
    o Z                                                         ft       <3


were found to alter  the  molecular  form of sulfur  on the  beads unless



scrubbed from the sampled air.  A collection technique using tandem filters



is extended from  earlier  efforts  on  fine  and  coarse aerosol to  include



collection of SO0 and H0S on chemically coated filters;  these filters  are
                Z       6      <-r-


analyzed by X-ray  fluorescence for sulfur content.  Measurements  of gases



evolved from   biogenic  sources  reveal  HgS  and   (CHo)oS  as  primary



components  with  significant  diurnal  variations.   Recommendations  for



further instrument development are given.
                                   iii

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                                 CONTENTS

Abstract	iii
Figures	vi
Tables	  ix
Abbreviations and Symbols 	   x
Acknowledgements	xv
     1.   Introduction	• •  •   1
     2.   Experimental Procedures . 	   3
               The Cedar Island facility	   3
               Instrumentation	   6
               Measurement of ambient sulfur	11
               Biogenic release of sulfur in gaseous form 	  37
               Atmospheric background measurement of nitrous
                    oxide, Freon 11, and Freon 12	44
               Atmospheric measurement of ozone and nitrogen
                    oxides	47
     3.   Results and Discussion	50
               Gaseous sulfur compounds in ambient air	  50
               Participate measurements in ambient air	  70
               Biogenic release of sulfur in gaseous form 	  76
               Atmospheric background measurements of nitrous
                    oxide, Freon 11, and Freon 12	86
               Atmospheric measurements of ozone and nitrogen 	  90
     4.   Conclusions and Recommendations 	  92

Appendices
     A  — Natural sulfur in the atmosphere	102
     B  — Operating Characteristics of the Sulfur Monitor
          Used at Cedar Island	105

References	,	120

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                                  FIGURES
Number                                                                     Page
                                                          !
  1  Cedar Island and Surroundings 	   4
  2  Blockhouse, Mobile Van, Radar Antenna and Sound
     at the Cedar Island Wildlife Game Refuge	   5
  3  Apparatus for desorption of preconcentrated sulfur compounds
     to cold trap	16
  4  Apparatus for transfer of sulfur compounds from cold
     trap	16
  5  Recorder trace of sulfur compounds desorbed from liquid
     nitrogen cooled, cold trap after preconcentration step	17
  6  Calibration curve for H2S by Bennett (EPA)	19
  7  Typical 50^ scrubber tube	21
  8  Comparison of permeation tube and thioacetimide standards 	 25
  9  Calibration data for H2S, (CH3)2S, and CH3SH	27
  10  Holder and filter assembly for Tandem Filter Pack 	 36
  11  Environmental chamber for measurement of biogenic emissions 	 39
  12  Monitoring Site B. Marsh adjacent to Lewis Creek	39
  13  Monitoring Site A. Intertidal edgewater location near
     blockhouse on Cedar Island	42
  14  Monitoring Site C. Intertidal flats on Outer Banks	42
  15  Tower study sites near Cedar  Island blockhouse	52
  16  Typical chart recordings from the gold-coated glass
     bead  analysis 	 53
  17  Tower 1.  Vertical concentration profiles of sulfur
     compounds	54
                                         VI

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                             FIGURES
Number                                                                Page

 18  Tower 2. Vertical concentration profiles of sulfur
     compounds	55

 19  Tower 3. Vertical concentration profiles of sulfur
     compounds	56

 20  Tower 4. Vertical concentration profiles of sulfur
     compounds	57

 21  Tower 5. Vertical concentration profiles of sulfur
     compounds	58

 22  Sulfur  dioxide and H2S content of the ambient air using the TFP
     and x-ray  fluorescence 	 71

 23 Gas chroipatographic analysis of an air sample taken from
     the environmental chamber at Site A-l. Dimethyl
     sulfide is dominant	77

 24  Gas chroipatographic  analysis at Site A-2. Hydrogen
     sulfide is dominant	78

 25  Dimethyl sulfide content of environmental chamber samples at
     Site A-l (edgewater) as a function  of time  .	79

 26  Dimethyl sulfide content of environmental chamber samples at
     site near  Site A-l as a function of time	80

 27  Dimethyl sulfide content of environmental chamber samples
     (same  as Figure  24)  as a function of temperature	81

 28  Dimethyl sulfide content of environmental chamber samples
     (same  as Figure  25)  as a function of temperature	82

 29  Total  sulfur content of environmental chamber  samples  as
     a function of time at Site B  	 84

 30  Total  sulfur content of environmental chamber  samples  as
     a function of time at Site C	85

 31  Typical gas  chromatographic analysis of  Freon  11  and
     Freon  12	87
  32  Typical  gas chromatographic analysis of N20.
                                     vii

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M  u                         FIGURES
Number
 33  A one day data recording of ambient NO and 03 concentrations ... 91
 34  Total sulfur content of environmental chamber samples as a
     function of flow rate through the chamber	96
 35  Chamber concentration prior to study shown in Fig. 34	96
 36  Comparison of results from stirred and unstirred
     environmental chambers 	 97
 37  Dimethyl sulfide infrared spectrum (960-1070 cm"1) 	 99
                                      * * •
                                     vm

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                                   TABLES
Number                                                                Page
  1  Instrumentation Utilization 	 10
  2  Effect of N02 on H2$ Recovery 	 31
  3  Effect of 03 on H2$ and (CH3)2S Recovery	32
  4  Effect of Outdoor Air on (CH3)2$ Recovery 	 ... 34
  5  Tower Sample Data	62
  6  Tower Samples at 20 Meters	65
  7  Miscellaneous Samples 	 66
  8  Percentage  Composition of Reduced Forms of Sulfur 	 69
  9  Elemental Analysis of Fine Particulate Fraction 	 72
  10  Elemental Analysis of Coarse Particulate Fraction for
     Dichotomous Sampler and Tandem Filter Pack	73
  11  Nitrous  Oxide Results using Gas Chromatographic-Electron
     Capture  Detection	89
  12  Freon 11 and Freon 12 Results Using Gas Chromatographic-
     Electron Capture Detection	89
 A-l  Principal Elements in the Global Sulfur Budgets	115
 A-2  Steady State Global Atmospheric Sulfur from Natural
     Sources	116
 A-3  Rates of Natural Sulfur Evolution	116
                                      IX

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                  LIST OF  ABBREVIATIONS AND SYMBOLS







ABBREVIATIONS






AIB           — Atmospheric Instrumentation Branch



atm           -- atmosphere



cc            — cubic centimeter
                       i


GIFS          — Cedar Island Field Study



cm            — centimeter



CSI           — Columbia Scientific Instruments



DST          — daylight savings time



EPA          — Environmental Protection Agency



ERC          — Environmental Research Center



FPD          — flame photometric detector



ft            — feet



g            — gram



GPT          — gas phase titration



H            — high tide



hr            — hour



ID            — inside diameter



in            -- inch

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            LIST OF ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS (Continued)
kW
L
1
m2
m3
max
MDL
min
ml
MT
MV
ng
nm
NSF-RANN

OD
ppb
ppm
psig
RH
— kilowatt
-- low tide
— liter
— square meter
— cubic meter
— maximum
— minimum detectable level
— minute
— milliliter
—• megaton
         \
— maximum measured value
— nanogram
— nanometer
~ National Science Foundation — Research Applied to
   National Needs
— outside diameter
— parts-per-billion
— parts-per-million
— pounds-per-square-inch^of-gravity
— relative humidity
                                 xi

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            LIST OF ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS (Continued)
RS

RTF
sec
T
TFP
TS
TSP
UV
v/v
WD
WS
-- imseparated sulfur compounds in the sample released from
   cold trap into the Meloy
-- Research Triangle Park
— second
— temperature
— tandem filter pack
— total sulfur
-- total sulfur particulate
— ultraviolet
— volume-per-volume
— wind direction
— wind speed
-- year
 SYMBOLS
 AuCl3
 CC19F9
    Lt  £t
 CC13F
 CH3CHOHCH3
 CH3CSNH2
 -- gold chloride
 -- Freon 12
 -- Freon 11
 -- isopropanol
 •- ttoacetamide
                                 xii

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            LIST OF ABBREVIATIONS AND  SYMBOLS
SYMBOLS  (Continued)
(CH3)2S2
(CH3)2S
COS
CO
C2H4
C2H5SH
Cu(N03)2
HC1
H2S
H304P
NaCO3
NaOH
N(CH2CH2OH)3
NH3
NH4C1
NO
N02
NOX
N20
- dimethyl disulfide
- dimethyl sulfide
- carbonyl sulfide
- carbon monoxide
- ethylene
- ethyl mercaptan
- copper nitrate
- hydrochloric acid
— hydrogen sulfide
•- sulfuric acid
— phosphoric  acid
•- micron
— sodium carbonate
•- sodium hydroxide
- triethanolamine
— ammonia
— ammonium chloride
— nitric oxide
— nitrogen dioxide
— nitrogen oxides
•- nitrous oxide
                                 xiii

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           LIST OF ABBREVIATIONS AND SYMBOLS
SYMBOLS (Continued)
O«           — ozone
S            — sulfur
SO2          — sulfur dioxide
                               iciv

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                        ACKNOWLEDGEMENTS

     The authors wish to acknowledge the advice and  support of Mr. R.K.
Stevens, Chief,  AIB, who initiated the request for the study;  the help of
Mr.  C.A.   Bennett and  Mr.   J.M.   Bowennaster  of  the  AIB  staff  in
performing monitoring tasks during the study; the cooperation and help of
Mr.  Brohawn and Mr.  Lewis,  the Cedar Island representatives  of the Fish
and  Wildlife Service and of Mr. J. Roberts,  Cedar Island Refuge Manager;
the advice of Dr. V. Aneja of Northrop Services  concerning environmental
chambers  and for providing the  experimental data shown as part of Figure
36 and  of Ms. D. Hitchcock on the nature of biogenic sulfur sources; and
the work of Ms.  R. Barbour in preparing the manuscript.
                                 xv

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                             SECTION I

                           INTRODUCTION

     The  Cedar Island Field Study  (CIFS), conducted from August 22,  1977
to September 2, 1977,  was a concentrated effort to monitor selected gaseous
and  particulate species  at  an isolated location on the North Carolina coast.
Prototype  instrumentation  and  newly  developed  measurement techniques
were used.  The gold-coated glass  bead technique (1) for the sampling and
preconcentration of volatile  sulfur compounds  was of particular  interest:
the  CIFS  provided  the first  chance to evaluate this technique in a field
test.  The use of  a  tandem  filter technique  (2)  was also of considerable
interest  as it  has  recently been adapted  (3)  to measure hydrogen sulfide
(ELS) and sulfur   dioxide  (SO^x  as well as  coarse  and  fine particulate.

     The   objective  of  the  CIFS   was   to   establish  the  status   of
instrumentation development with  respect  to the volatile  sulfur compounds
which are of biogenic origin as well as  those  gases which  influence  the
composition of biogenic emissions at  receptor locations,  e.g., ozone (Og).
Information pertaining to the elemental.., composition of particulate  matter,
meteorological  parameters,   and  the  species  of sulfur compounds  emitted

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from  nearby  marsh areas were recorded  so that variations in the ambient
mix  of the  sulfur compounds  could be  related to characteristics of  the
particular air mass being sampled.

     Many  of  the  activities  related  to  the  GIFS  represent  learning
experiences  for the AIB staff.   These experiences  will lead to  a  better
appreciation of the effort needed to launch a field study and to sustain a
concentrated   monitoring effort  in  the  field.   Furthermore  (and   most
importantly),  the  performance characteristics of various instruments under
field conditions have focussed attention on instrumentation needs, resulting
in a set  of recommendations for future  initiatives.   These initiatives should
help to  better define the relationship between biogenic  emissions of sulfur,
nitrogen, and carbon compounds, and the atmospheric  loading of sulfate,
nitrate,  and  carbonate particulate.

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                             SECTION 2
                     EXPERIMENTAL PROCEDURES
THE CEDAR ISLAND FACILITY

     The  Cedar  Island National Wildlife Refuge on  the coast of  North
Carolina was selected as the site for the summer 1977 field test.  As  shown
in Figure 1,  the  Refuge is adjacent  both to  extensive marsh lands  and to
the  sheltered  waters  between  the  Outer  Banks  and  the North Carolina
mainland.  Initial survey  trips to the  island confirmed that the area  was
isolated  from  traffic and  that  adequate support  facilities were available.

     The  stationary monitoring  site on  Cedar Island is shown in Figure 2.
Two areas were prepared  for the field  test.  One of  these  was a room in
the  blockhouse shown  in Figure  2.   The room  was  cleared  and  an air
conditioner  was  installed  in  anticipation of  the  intensive  staff  effort to
come.   An area adjacent  to the blockhouse  was prepared for  a mobile van
which  was  to  house several air monitoring  instruments.   The  van  was
supplied with electrical power of up to 12 kW from the  blockhouse.

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                                                          PAMLICO SOUND
       MAINLAND
                                                          A2
                                                            SOUND
                                                                               J	I
                                                                              miles
                                                                                      ATLANTIC
                                                                                       OCEAN
Figure 1. Cedar Island and surroundings - Lola is at 76° 17' 13" longitude and 34° 57' 30" latitude.

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171
                                                                  CHEVROLET
      Figure 2.  Blockhouse, Mobile Van, Radar Antenna arid Sound at the Cedar Island Wildlife
               Game Refuge

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     Ambient monitoring was  performed from both the blockhouse and  the



van.   Particulate  and gas  collection devices and meteorological equipment



were  deployed  in the yard  surrounding  the  blockhouse.   The antenna



structure shown in Figure  2  was used as a platform from which to  sample



ambient  sulfur compounds.   Environmental chamber  samples  were  taken at



Sites A,  B,  and  C  of  Figure  1 to determine  the  composition of  sulfur



compounds being emitted from the local land areas.







INSTRUMENTATION







     The following instruments were used during  the  study:







1.   Meloy  SA 285 Total  Sulfur  Analyzer  SN 6DO63:  The SA 285 provides



     for  thermal  control of  the burner  block,  photomultiplier,  and flow



     control devices  to achieve  a stabilized flame and  a detection limit of



     0.5  ppb,  i.e.,  twice  the  rms  noise with a  time  constant  of  0.7



     seconds.   Sample air  is  drawn  continuously through the detector at a



     controlled  flow  rate of  200  cc/min  and  hydrogen for the flame is



     supplied  at  190  cc/min.   Some additional performance  characteristics



     are  given in Appendix B.







 2.   Tracor 560 Gas Chromatograph with  Flame Photometric Detector:   The



     Tracer 560  resolves  H9S,  SO0,  methyl mercaptan (CH0SH), ethyl
                             tt       Lt                         O


     mercaptan (CgHgSH),  and dimethyl sulfide  ((CHg^S) using a column



     (36  in long,  1/8  in OD  of FEP  Teflon) packed with  60/80  mesh



     Chromosorb T coated with polyphenyl ether  and conditioned

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     with phosphoric  acid  (H3O4P).  Using a column temperature  of 60°C
     and  a flow rate  of  100  cc/min of nitrogen carrier,  a 10 ml sample
     provides a sensitivity of  3 ppb  for HgS, SO2,  and CHgSH, and of 7
     ppb for the remaining compounds,  based on peak height.

3.   Meloy SA 185  Total Sulfur Monitor:  The SA 185 is a commercial flame
     photometric detector  (FPD) used to monitor sulfur compounds.  It is
     less   sensitive than  SA  285  and  is  used with  a  preconcentration
     technique to detect  ambient sulfur. The detection  limit is 2 ppb with
     a 5 sec time constant.

4.   Columbia  Scientific Instruments  (CSI) Series 1600 Oxides  of Nitrogen
     Analyzer:   The  CSI  Nitrogen  Analyzer  is  new  to  the  commercial
     market.   Several features  such  as   temperature  control  of  critical
     orifices in the sample and  
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6.    Bendix Ozone Analyzer, Model 8002:  This  commercial O0  analyzer  is
                                                            O

     based on the  chemiluminesence  of Og  and excess  ethylene  (C«H4).


     The detection limit is 2 ppb with a 3 sec time constant.





7.   Dasabi Ozone Analyzer,  Model 1003-AH:   This commercial Og  analyzer

                                                                       o

     is  based on  the absorption of mercury  resonance  radiation at 2537 A.


     The detection limit is 2 ppb with a 1 min digital update.





8.   Climet Portable Meteorological Station,  Model EWS:   This  instrument


     measures wind speed,  wind direction,  temperature,  and relative


     humidity.





9.   Manual  Dichotomous  Sampler:   This  sampler  is used for  particulate


     collection and  size  fractionation  in two ranges  with the cut  point


     between fine and  coarse particle  fractions at  3.5  pm particle diameter


     and the  upper cutoff at about 20  pin.





 10.  Tandem  Filter  Sets:   This  sequence   of  four  filters collects  fine


     particulate,   coarse  particulate,   HgS,  and  SO2>   See  detailed


     explanation in  text.






 11.  Collection  Tubes and Accessory Equipment for  the  Gold-Coated Glass


     Bead Preconcentration Technique:   This method is being developed  by


     Dr.  R. Braman and Mr. M. Ammons of the University of South Florida


     under the sponsorship of the National Science

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     Foundation — Research Applied to National Needs (NSF-RANN)  —  to

     measure  ambient sulfur compounds  with existing FPD instrumentation.

     See detailed explanation in  text.


12.   Portable  Calibration  System:  This system  provides  a double dilution

     stage which  gives low  ppb levels  using standard permeation tubes.

     The system  uses  mass flow  controllers  to regulate air  flow  over a

     temperature controlled permeation tube (first dilution) and through a

     dilution  stream  (second dilution).  A  glass  capillary allows a fraction

     of  air from  the first  dilution  stream  to mix with  the second dilution

     stream.   This unit is one-of-a-kind made  by  the Research Triangle

     Institute,  Research  Triangle  Park  (RTP), North Carolina,  for the

     Environmental Protection Agency  (EPA).


13.   Gas  Phase   Titration   Apparatus  for Nitrogen   Oxides   and  Ozone

     Calibration:   The  unit assembled for  this  field  trip  used electronic

     flow controllers  and gas mixing  chambers.   As suggested by Rehme,

     et al.  (4), it was used with a secondary standard  NO cylinder.

     <•                                                              *'
14.   ^Portable Bag  Samplers and Constant Flow Pump System:   These were

     used for sample  collection on the gold-coated glass bead traps.


These  instruments were used according to the schedule  given  in Table  1.

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                                         TABLE  1. INSTRUMENT UTILIZATION
Instrument
AeroChem
Bendix 8002
Climet
CSI
Dasihi
Parameter
Measured
N0v + NHQ + . . .
A. O
°3
WSWD, RH, T
NO
NO
AlWrt
NOx
o
AUGUST SEPTEMBER
MTWTFSSMTWTFSS
22 23 24 25 26 27 28 29 30 31 1 2 3 4
~

—


Dichotomous
Sampler
Gold Beads    H2S
Preconcentrator
Meloy 285
Tandem
Filters
TS-SO,
      i

Fine
Tracor
so2

H2S,

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MEASUREMENT OF AMBIENT SULFUR

     Both  gaseous and particulate sulfur were measured during the CIFS.
Gaseous  sulfur  compounds were marginally detectable by direct, real-time
measurement  techniques.   Preconcentration  techniques  were used for a
more  definative measurement.   Particulate  sulfur samples were collected on
filters over 24 hour sampling periods.

Gaseous  Sulfur  Compounds by Flame Photometry

     The  FPD  is  used routinely  in ambient  monitoring of  sulfur gases.
The FPD  is based on the reactions attendant to burning  gaseous sulfur
compounds in  a  hydrogen-rich  flame  (5).   One  reaction  leads to  the
formation  of  excited  sulfur  which  can de-excite with  the  emission of a
photon  (300-450  nm).    Separation   of   sulfur  compounds  on  a   gas
chromatographic column prior to analysis in the flame allows for  speciation.
In commercial instrumentation  an  interference filter centered for  maximum
transmission  at   394  nm  is  positioned  between  the  flame   and  a
photomultiplier  and defines the instrument's response characteristics.

     For the CIFS,  the Meloy Model SA 285 was chosen as a total sulfur
monitor  (see Instrumentation).  Hydrogen sulfide and  SO2  were detected
separately by using chemical in-line scrubbers supplied  by Meloy.
                                   11

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     The Model  560  Tracer Chromatograph with an FPD was chosen for the



study.   A  gas  chromatographic   column  similar  to   that  described by



Stevens,  et al. (6),  separated the  sulfur  compounds.  The column is



described under Instrumentation.   The retention times for  the  column  were



as foUows:  H0S  and carbonyl  sulfide (COS), 1.3 min.;  CHoSH,  4.1  min;
             Lt                                              O


(CH3)2S,  6.4 min.



                    M



     Calibration  was performed using  permeation tubes of  the individual



gases to be measured.   The tubes were  weighed on a  Cahn electrobalance



to determine permeation  rates  at  set temperatures.  Both preliminary and



field calibrations were performed with  a prototype  portable calibration



system  capable  of  generating less  than 1 ppb of the sulfur gases at flow



rates required by the FPD instrumentation.







     The zero  air   (carbon  dioxide (CCv,)  in  air) used in calibration was



obtained  from  Scott-Marrian,  Inc.  and contained less than 1 ppb  of  SO2-



Both the zero  air  and calibration mixtures were humidified to  a relative



humidity  of 60-90%.  Initial calibration  was performed  at the Environmental



Research  Center (EEC)  Annex  prior  to the  CIFS  and  consisted  of  a



multipoint  calibration  of  the  Meloy  SA  285  using  HpS  and  a  multipoint



calibration  of the Tracor  560  for  HgS using  peak height and  for  (CHo)2S



using peak area.   Hydrogen  sulfide response  on the Meloy  SA  285 was



linear with a nearly constant  sensitivity of 1.11 + .01 ppb/chart division for



H9S and of 0.91 +  .01 ppb/chart  division for (CH0)0S.  These sensitivity
  /                                               O ii


checks  were  consistent  during daily  span  checks at  Cedar Island  from
                                   12

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August 23 until  September 1, and again following a 2-day  study September
23 and 24.  The Tracer 560 was  initially calibrated in the laboratory and
checked in the field for HgS and (CHg^S.  Gas  chromotographic  column
performance deteriorated  during the study with a  significant  reduction in
sensitivity.  The total sulfur minus  the SO2 readings on the Meloy were no
more  than  20% higher  than  the H2S plus  (CH3>2S  readings  on the Tracor
560  during  analysis  of  the emission products  from  Cedar  Island  marsh
areas,  indicating  the  presence  of  some  low concentrations  of higher
molecular weight sulfur compounds.

Gaseous Sulfur Compounds by  Preconcentration of  Gold-Coated Glass  Beads

     The concentration of H^S and  organosulfur compounds  in ambient air
is often  too low  for  direct detection by an FPD.  However,  the  sulfur
compounds  in a large volume of ambient air can be collected; they can then
be released from  the  collection surfaces  in considerably less  time than it
took  to  collect  them.   This  method  can  be  used  to raise  the  sulfur
compound concentrations above the  lower detection limit of the  FPD - . The
original ambient air  concentrations can then  be estimated  if the efficiency
of collection  and of release are known  and prior calibration  is available.

     Ammons (7)  studied  a  variety of  metal  surfaces for  collection of
sulfur-containing molecules  and selected  gold.  Method development related
to the use  of gold-coated glass beads as,  a collection medium  has

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been carried out at the University of South Florida under the direction of
Dr.  R.S.  Braman  with  the  sponsorship  of  the  NSF-RANN.   Technical
information  exchange  between  the  groups at  the  University  of  South
Florida and EPA led to the use of collection techniques in the GIFS.   The
GIFS  was  the  first environmental  study to test of the  gold-coated  glass
bead technique.

     The sample collection of  sulfur compounds using the gold coated glass
bead  technique occurs  when  a measured volume of ambient air is  pulled
through 1 cm  ID quartz  tubes packed  with a 3 cm length  of  60/80 mesh
gold coated glass beads held in place with quartz wool.   Measurements with
the technique  consist of five  steps:  1) blanking of the collection tubes; 2)
collection of an ambient  sample; 3)  desorption of  collected  molecules  from
the beads onto a liquid nitrogen-cooled,  cold trap;  4) release from the cold
trap into a FPD; and 5) reblanking of the collection tube.

     Blanking   establishes the  signal  response from  a  "clean" collection
tube.   Blanks  taken  before and after the  collection and analysis of  sample
air are averaged  to  obtain the zero response.   The zero response  varies
 depending on  the  batch of glass beads being used and their previous use.
A  typical  blank  for HgS  during the  GIFS  was  1-2  ng/sample  with an
uncertainty  estimated at  0.1-0.2 ng/sample.  Typical sample responses for
H0S were 5-10 ng/sample.  No  blank response for (CH0)0S and  CH0SH was
  L                                                   o Z         o
evident.
                                    14

-------
     Ambient air samples were  taken by attaching a small electric air pump
to the tube through a line containing a critical orifice.   Samples  of up to
30 minutes  were  taken at a flow rate of  2  1/min.   After collection,  the
collection tube was  connected to  a nitrogen-rcooled, cold trap as shown in
Figure  3.   The  U-shaped  cold trap  was packed for over half its length
with 60/80 mesh  glass beads.   Hydrogen gas was passed through  the tube
at a flow rate of 100  cc/min  and the tube was heated to  600°C by a coil of
20 gauge nichrome  wire.  At the  end of a  5-minute period the desorption
of sulfur compounds from the  tube onto the  cold trap was complete.  The
liquid  nitrogen  was then  removed  from the  trap and  nitrogen  gas was
passed  through the trap for approximately  20 seconds as  shown in Figure
4.  The trap was  then heated and the trapped sulfur compounds desorbed
in order of boiling points.   The nitrogen was vented to a "T" connection
at the  intake  to a Meloy  SA  185.  The  total flow into  the Meloy  SA 185
consisted of  the nitrogen and sulfur-free air supplied  at  the  "T".  A
recorder, Linear Instruments,  Model 252 A, was used with the Meloy.  A
typical  output recorder  trace  for H2S, CHLSH and  (CHL^S  is shown in
Figure  5.   The  recorder also  provided for integration  of  area under the
individual peaks.

     Typical ambient concentrations encountered at Cedar Island were: H«S
= 80  ppt;  (CH3)2S = 30 ppt;  and dimethyl disulfide  ((CH3>2S2) = 20 ppt.
Samples collected for 30 minutes at  2 1/min resulted  in  a sulfur loading of
8 ng  HnS,  3  ng (CHo)2S,  and 4  ng   (CHjJrtS,,,  as  compared  to  an
uncertainty in the collection tube blank of 0.1-0.2 ng.
                                    15

-------
            DESORPTION
                             TO VARIAC
H2
            AU-BEADTUBE
                                                                     VENT
                                                                LIQUID N2
 Figure 3.  Apparatus for desorption of preconcentrated sulfur compounds to cold
 trap.

           TRANSFER
                                                                      CLEAN
                                                                      AIR
       Figure 4. Apparatus for transfer of sulfur compounds from cold trap.
                                     16

-------
                            (CH3)2S
                                        I
    HEAT ON
 1             2

TIMEdninutesj
Figure 5.  Recorder trace of sulfur compounds desorbed from liquid
nitrogen-cooled, cold trap after preconcentration step.
                             17

-------
     Stated mathematically,  the response "R"  of  the Meloy, assuming that



the  photomultiplier  signal  is  linearized   with   respect  to   sulfur gas



concentration, is such that:






                             R -x.  FIEEAT,                       (Eq. 1)
where F  is  the  collection  rate  of ambient air during  a sampling  period



"AT",  LA is the  ambient  sulfur  loading,  and Ep  Eg,  and  Eg are  the



efficiencies of  transfer from the  ambient air to  the  tube,  from the tube to



the  trap,  and  from the trap  to  the  Meloy, respectively.   Ordinarily  the



ambient  air  loading  is  determined  by  comparing  the  response  (chart



divisions)  to a calibration curve which  was  generated  under  controlled



conditions using the same apparatus.  For example,  if E, = E« = E« = 1 and



a  calibration curve for H^S  such as  that shown  in Figure  6 has been



obtained,  a  response of 20 divisions  would indicate  a tube  loading of  6.5



ng.   The  ambient concentrations  could  then be  estimated as 6.5 ng/FAT in



ng/1.







      Several  precautions  must be taken  to insure  quality  control  of  the



technique.   Quantities-such as the efficiencies of transfer E,, E9,  and EQ
                                                            1    £t        O


as  well  as the  flow  rate  F in Equation  1  must be checked.   Calibration



concentrations  must be checked  to ensure  that sulfur-free carrier gases



are  used and that the calibration  gas  standard,  e.g., the permeation tube,



is accurately characterized.
                                   18

-------
V0
         x!
         <
         tt
110




100




 901




 80;




 70




 601




 50




 40




 30




 20




 10




  0
                  I    I   I   !    I   1   I   |   I   I    I   I   I   I   I    I   I   I   I    I   I   I    I
                  I   I
I   I   L   I   I   I   I   I   I   I   I  I   I   I   I   I   I   I   I   I   I
                                   •i--
                    10     12j     141


                      NANOGRAMS H2S ;
                                                        161	  181
20i     22:
24(
 Figure 6.  Calibration curve  for  H9S by Bennett (EPA).  HP refers to a Hewlett Packard
             Integrator.             *

-------
Sulfur Dioxide Scrubbers







     Sulfur dioxide has  the  most potential to interfere in the detection  of



reduced  forms of  sulfur and must be removed prior to  trapping.   This is



done  using an  acid-base  reaction  with  glass beads treated with sodium



carbonate  (NaCOg).   Sulfur dioxide  was  found  to be  trapped by  glass



beads  treated  with small  amounts  of NaCO0 while H0S  and  organosulfur
                                           O         ft


compounds were not trapped.







     The design of the  SO2  scrubber tubes together with  the rest of the



preconcentration stack is shown in  Figure 7.  Some 5 grams of 80/120 mesh



glass beads were cleaned by acid washing,  dried, treated  with 8.4 mg  of



NaCOQ  per gram of  beads, redried,   and  packed into  the  glass tubes.
     O


These  tubes   were   then   treated  with  H2S  at  approximately  10  ppb



concentration  which was passed  through them for 30 minutes to condition



the tubes.  The conditioning process avoids  losing a fraction of  the H^S in



the first several analyses.







     The SO2 absorbing tubes were also tested for absorption efficiency by



the  addition  of 10-100  ng   of  SO9 while  analyzing for  passage  of  SO0.
                                 z                                     &


Suitably  prepared SO0  scrubbing tubes pass less than 1%  of the  SOn,  do
                      it                                              Z


not  absorb  more  than 1-2%  of JUS  or  organosulfur  compounds passed



through them,  and have an  estimated  capacity of  500 liters  at 10  ppb SO0
                                                                        £


levels.
                                  20

-------
   FILTER HOLDER WITH I
    GLASS FIBER FILTER I
           I
                    II I I II
ll ^

_^
111 1 11
S02 SCRUBBER
. TEFLON* CONNECTOR ;
^ nrrn J
'
i/ n 1 1 ii

                                                                   It I 111
                                                                   II I I ik
                                                                          AIR SAMPLING TUBE
Figure 7.   Typical SOg scrubber tube.

-------
Particulate Filters







     Sulfate particulates are also a potential interferent if they are allowed



to collect on the beads.   As shown later in the text,  the average loading



of particulate sulfur at Cedar Island corresponds  to  approximately  14 ng



for a 30-minute sample at 2 1/min.  To avoid this type of interference,  a



particulate filter was placed in front of  the SO0  scrubber-collection tube
                                               Ct


combination.   Gelman Type A  glass  fiber filters were used throughout the



tests except for Tower studies 4  and 5 (as described later) in which 0.2



pm Nuclepore filters  were used.   The volatile sulfur compounds SO2, HgS,



CHoSH,  and  (CHo)2s were found to  pass the glass fiber filters.







Preconcentration Tube Preparation







     Preconcentration tubes were prepared  using  60/80 mesh  glass  beads



(Varian  Instruments,  Inc.)  and gold chloride  (AuCL) prepared  from gold



foil.   The beads  were washed with concentrated hydrochloric  acid  (HC1),



dried, and treated with  enough AuCL  to  give approximately  a 10% (wt.)



coating of gold metal after hydrogen reduction.  The  sampling tubes were



approximately  8 in  long,  including  connectors,   and were  packed with



approximately 3 cm of coated beads.







     Prepared  tubes  were put  through blanking and efficiency tests  prior



to  use.    Blanking  consists  of  simply heating  the  tube while  passing



hydrogen  or a  hydrogen-nitrogen  mixture through for  5  minutes.  Any
                                  22

-------
residual  sulfur  is  transferred  to the  cold trap and to the Meloy, as in a
standard  analysis.  If blanks  are  not easily  reduced to a low value, the
tube  is  washed with  a  few miULIiters of concentrated  HC1, washed with
water, and then  reblanked.   Blank values  of 1-2 ng and sometimes lower
should be attainable  although  sulfate sulfur is  often only slowly removed
from  the tubes.

      Gold-coated tubes may be used repeatedly.   No  specific test has been
conducted to  confirm  this, but some gold tubes have been used over fifty
times in  laboratory experiments.  Acid washing reduces the useful tube life
by loosening the gold coating on the beads.

      Small pieces of  organic matter  on the tubes  turn to carbon  during
analysis  and  can absorb sulfur compounds  if used again.  Tubes  can be
cleaned   of   carbon  contamination  by  heating   the  tubes  to  analysis
temperature  in  the presence of oxygen.  Organic compounds in air samples
apparently do not cause  this type of interference.

      In  later work  the glass beads were found to contain small amounts of
sulfur  compounds  which  slowly reduce  and produce the  small  blanks
encountered.   The  beads were also found to contain  substantial amounts of
                                                                 &
iron  and zinc;  compounds of these elements are generally removed  in the
bead cleaning process with acid or by oxidation with oxygen while  heating
the tubes to  700-800°C.   Iron is a particularly troublesome interferent and
should be removed from all  parts of the analysis  system which  encounters
the sample.

                                   23

-------
Standards and  Calibration







     Two  types of standards have been studied for calibration  of the FPD



detectors  used  in  sulfur  air analyses and  for  determining  the  operational



characteristics  of  the  analysis  system.  These  are  the permeation  tube



standards of the type developed by O'Keeffe and Ortman (8),  as well as



the aqueous solutions of thioacetamide (CH0CSNHg).
                                         O     ti






     Thioacetamide  in  aqueous   solutions  was   found  to  be  a   good



reproducible calibration standard for E^S.   Stock solutions (approximately



2000 ppm) were  diluted to 4 ppm  and microliter sized samples of the latter



were  injected   onto  gold-coated bead columns.   The  reproducibility  of



thioacetamide standards was found to be + 4.9%  relative for 21 samples of 16



ng H9S on  five different  gold tubes.   A  comparison of two  gold  tubes
      £t


indicated  no significant difference at the 80% confidence interval.   Similar



reproducibility  was experienced using  permeation tubes as  standards for



H2S,  (CH3)2S,  CH3SH, and SOg.







     Ammonium  chloride   (NH^Cl)  and sulfuric  acid  (H2SO4)  were  also



tested  as  standards.  The  thioacetamide was  the most  stable calibration



standard  over a period of  time.   This standard  was compared  to weighed



permeation  tube  standards  using the  Meloy  SA  185  detector  in work at



Cedar  Island.   Figure 8  shows  that  both  give approximately the  same



calibration curve.
                                  24

-------
         16
         12
      UJ
      v>
      o  _

      Si  8
      LU
      cc

       I
                     \          \


                 I PERMEATION TUBE STANDARD

                 • THIOACETIMIDE STANDARD
                     10
20
30
40
50
                                   NANOGRAMS H2S
Figure  8.   Comparison  of permeation tube and  thioacetimide  standards.
                                    25

-------
     Figure 9 shows the calibration curve data obtained for HgS,
and  CHgSH using  U-trapped  standards  and  the Meloy 185 FPD.  Despite
the linearizer on  the  detector instrumentation,  some curvilinear character
is  observed  in these  calibration  curves.   This is  not  surprising since
fluorescence  self absorption effects are involved and  must be a function of
sample size.


Efficiency Tests of the Sampling System


     All  gold tubes tested for H0S retention from air  at flow rates up to at
                               z
least  3 liters  per minute show better than 99% efficiency under a variety of
humidity conditions between 50% and  95% relative humidity.  Gold tubes do
exhibit  a  finite capacity  for  sulfur  compounds.  This  is approximately
500-1000  ng depending upon the gold tube tested but  related to the amount
of gold present.   Since the gold tube preconcentration is intended for use
with  sample  sizes well below 100 ng, the sulfur  capacity is not approached.
A  similar capacity effect and  efficiency was  observed for (CHo)2S.


      Several comparisons were made of HgS adsorbed by and removed from
the  gold  tubes versus the H2S evolved from the permeation tube dilution
system;  no  difference was  noted.   The   agreement  of  the  thioacetamide
standards  to  the  diffusion tube standards  also supports the H0S efficiency
                                                             z
observed.   No  losses of H9S, (CHQ)H0S,  or CHQSH  were  noted on either
                           4        O   Z         O
the glass fiber filters or  in the SO0 scrubbing tubes.
                                  4
                                  26

-------
ta
o
DC
O
=  2.0
    0.4
                       ng ANALYTE
 Figure 9. Calibration data for h^S, (CH3)2S, and
                        27

-------
Procedure for Sampling and Analysis


     Several routine  procedures for sampling  and analysis  were adopted.
Gold sampling tubes  were reblanked prior to reuse and  assembled with  the
filters  and  SO2  scrubber tubes into sampling  stacks.   These were sealed
with laboratory  paraffin film  and stored until used.  Sampling was timed by
stopwatch.   Sampling stacks  were calibrated for flow rates  while attached
to the same  pump used in  sampling.   Sample flow rates were found to be
reproducible within  ± 5% relative over the several days of field  sampling.
Gold tubes  were analyzed as  soon as possible after  sampling.  Tubes were
also reblanked  directly  after  sampling.   Data were  obtained  using  an
integrating  recorder and compared to  the calibration curves  for  analyses.
Hydrogen sulfide,  CHgSH, and (CH3)2S  were  reported in ng/liter and in
ppb by volume.  Unidentified organosulfur compounds were analyzed using
the H2S calibration curve.


Effects of Nitrogen Oxides and  Ozone


     A sometimes ignored aspect of  trace HJ3  analysis is  the effect of O«
and nitrogen oxides  (NO ) on the collection system used.  From the known
                       " X
oxidizing  nature of  O,, and nitrogen dioxide (NO0)  one would predict that
                     O                          ^
either should  oxidize  HgS and perhaps  also  some  of  the  other  reduced
forms  of sulfur.  Moreover,  the amounts  of Og  and  nitrogen  present in air
are generally much  larger than the HgS  or other reduced forms of sulfur
present.  Non-urban concentrations of NO2 and Og  are  in the 5-20  and
                                  28

-------
5-50 ppb  concentration range  according  to  recent reviews (9).  Since H2S
may be expected to be from 0.05-1.0 ppb, it is  apparent that the oxidizers
form a substantial excess.

     Preliminary  experiments  indicated  that  NO2 and  €>„  oxidize  sulfur
compounds  trapped on  gold  surfaces while  nitrous  oxide  (N2O) had no
effect.   Nitric  oxide  does  not appear  to  be  an interferent  although  it
oxidizes to  NO2 which is  an interferent.

     The effect  of NO0  and  (X  on  H0S  and  (CHQ)0S coUected on  gold
                       Z        o       it          o  Z
tubes   was   studied  in  laboratory  apparatus  designed  to  produce low
concentrations  of  these  gases.   Nitrogen  dioxide  was  supplied  by  a
syringe-driven  apparatus and  diluted  by air.   The NO2 concentration was
analyzed by the  Saltzman  (10),  method.    Ozone was produced at low
concentrations by  a Welsbach Instrument Co. O3  generator and determined
by iodometric titration.   Samples  of HgS and  (CHg)2S were  pumped  onto
blanked  gold  tubes   from  a  dynamic  gas  sampling   system  employing
permeation   tube  standards.   The  tubes  were then  exposed  to  various
amounts of  Og or NO2 and analyzed for sulfur compounds.

     This type of experiment was carried out both  with and without the
use of  the  SO2  scrubbing  tubes to  determine if  the  latter  afforded
protection  against  the  oxidizing  compounds.  Tables  2 and 3  give the
results of the two  studies.
                                   29

-------
     Unprotected  tubes  lose  HgS,  probably  as  SOn displaced from  the



tubes by  the  oxidizing agents which were present in amounts sufficient to



entirely  saturate  the absorption  sites on  the gold.  Dimethyl sulfide is



altered  in form to HgS.   In both cases, the  use  of an SO2  trap  reduces



the interference effects to an acceptable extent.







     Similar experiments  were carried out using outside air sampling at the



University of  South Florida.   Ozone was  30-50 ppb  during the  time of the



experiments; NO2 was  not  determined  at the time.   The outside  air may be



considered an urban type air as the experiment was  carried out  in  the  city



of  Tampa,  Florida.   The  results,  shown   in  Table  4,  indicate  that



unprotected  tubes having  H0S  or (CHQ)0S  on them exhibit  losses  if air
                            fL.          \J Lt


samples  exceed 24  liters  in  volume.   This  is in  accord with laboratory



experiments which showed  that  the  exposure of tubes to more  than  a  few



micrograms of O^  caused  losses of sulfur compounds or demethylation.   Use



of SO2  absorption tubes afforded protection in the  GIFS.
                                  30

-------
              TABLE 2.  EFFECT OF NO  ON HS RECOVERY
Tubes Not Protected
H«S present
11.5 ng
11.5 ng
11.5 ng
11.5 ng

11.5 ng
11.5 ng
11.5 ng
11.5 ng
HnS recovered
11.5 ng
6.9 ng
5.6 ng
1.4 ng
With
11.6 ng
10.4 ng
12.0 ng
5.2 ng
% NO,
100%
60%
49%
12%
SO2 Scrubber
101%
90%
104%
45%
, Concentration
t
20 ppb
28 ppb
43 ppb
140 ppb

25 ppb
12 ppb
105 ppb
138 ppb
NO« Amount
120 ng
430 ng
1060 ng
1710 ng

305 ng
824 ng
2600 ng
3420 ng
*The amount column is the product of the concentration expressed as ng/1,
 the collection flow rate and the time of collection.

-------
       TABLE 3.  EFFECT OF O0 ON H0S AND (CHQ)0S RECOVERY
                             o      Z         o &
Tubes Not Protected3
H2S Present
11.5 ng
11.5ng
11.5 ng
11.5 ng
(CH3x2S Present
28.6 ng
28.6 ng
28.6 ng
28.6 ng
HLS recovered
10.5 ng
10.0 ng
8.6 ng
4.5 ng
(CHQ)0S Recovered

-------
      TABLE 4.  EFFECT OF OUTDOOR AIR ON (CH3>2S RECOVERY
                          Tubes Not Protected
(CH3)2S Present   (CH3)2S Recovered      %
Air Volume
                           Protected Tubes
Air Time
28.5 ng
28.5 ng
28.5 ng
26.5 ng
19.0 ng
5.0 ng
93%
67%
18%
24 1
48 1
143 1
10 min.
30 min.
60 min.
28.5 ng
28.5 ng
28.5 ng
38 ng
30.0 ng
28.5 ng
28.5 ng
32.5 ng
105%
100%
100%
86%
71 1
71 I
71 1
79 1
30 min.
30 min.
30 min.
33 min.
                                33

-------
Sulfur Loading bjr Filter Collection Techniques

     The  filter collection techniques employed at  Cedar Island involved the
dichotomous  sampler and  tandem filter packs.   The  dichotomous sampler
divides  the   sampled  particles  by  inertial impaction  so  that  two  size
fractions  are  developed:  a fine and a coarse particle fraction. The sampler
is described  in  detail  by Loo, et  al  (11).  The tandem filter technique is
used  to collect size ranges  (2) and  can  collect  H«S  and SOg if specially
coated filters are added.  The  adaptation of  the technique for H^S and SO2
collection is the result  of work done by  Shaw (3).

The Dichotomous Sampler

     A manual  dichotomous  sampler  (12)  was  put  into  operation  from
August 23 to August  29  and  run for 24-hour intervals  starting at noon.
The sampler  was about 30 yards from  the blockhouse and in  a grassy area.
The flow rate was  14  1/min.   The  filters used for both the  fine and the
coarse  particle fractions were Millipore FALP  (Teflon).   The  filters  were
weighed  before   and  after  exposure  to  determine the  total  suspended
particulate.   An x-ray fluorescence spectrometer  (12)  was used to analyze
the elemental composition of the particulate collected on the filters.
                                   34

-------
The Tandem Filter Pack

     The  tandem filter pack (TFP) consists of a series of filters, each one
of which  extracts a  component of the air stream passing through it.   An
exploded  view of the TFP holder and filter assembly is shown in Figure 10.
For the  GIFS  the  first  two  filters  in line (12  \im and 1 Hm pore  diameter
Nuclepore)  removed  coarse and  fine particles,  respectively.   The next
filter  removed  SO2>   and the  fourth and  last  HgS.   The gas collection
filters  were  Millipore,   FALP  (Teflon)  which  supported  thin layers  of
triethanolamine  (N(CH2CH2OH)3),  isopropanol  (CH3CHOHCHg),and  water,
mixed with sodium  hydroxide  (NaOH)  for  collection  of  SO2  and  copper
nitrate (Cu(NOg)2)  for HgS.  The SOg  and HgS  filters were subsequently
analyzed  for  sulfur  by  x-ray  fluorescence.   The  x-ray  fluorescence
analysis  system used  by AIB has a  sensitivity  to  sulfur  such  that 1
microgram can be detected at a confidence level of 90%.  This  corresponds
to the sulfur loading obtained  by  sampling 1 ppb of either  SO2 or HgS at 1
1/min for 12 hours.   The absolute  sulfur determination  efficiency (collection
efficiency times x-ray  analysis efficiency) has  been  shown to be 60% + 10%
for both  H«S  and SOo at relative humidities above  50% and at 20°C.  An
exploded  view of the  TFP  holder and  filter assembly  is shown in  Figure
10.

      The sampling rate  was set  at  1 1/min and  samples were  taken over
24-hour intervals.   Two sampling  units  were used:  one remained near the
block-house about 10 yards  from  the dichotomous  sampler, the other  was
used in those areas where bag  and chamber samples were taken.

                                  35

-------
w
                                                                                          FILTER ALIGNMENT
                           AIR STREAM
                                              FILTER
                                       FRAME

                                  THE FILTER IN THE FILTER FRAME
             Figure 10.! Holder and filter assembly for Tandem Filter Pack. Only two filter frames are shown although four
             filters were used in the CIFS experiments.

-------
BIOGENIC  RELEASE OF  SULFUR IN GASEOUS FORM
                        i

Introduction

     Biogenically released sulfur near the Cedar  Island site  contributes to
the sulfur loading measured on the Island depending on wind direction and
emission rates.   An  attempt  was made  to  measure  the  biogenic  sulfur
released by the nearby  marsh and to  relate the sulfur compound mix to  the
compounds measured with  the preconcentration techniques.

     The problem  of  measuring biogenic sulfur release  is complicated by
the  fact that local  environmental conditions  affect biogenic activity and
make the assignment  of emission rates  and mix of emitted species based on
localized measurements  questionable.    The  investigators  consider  the
results  presented  in  this  report as relevant only  to the area in  which they
were obtained.        |

Environmental Chambers

     Efforts to measure biogenic release from the Cedar Island marsh were
centered on the use  of an environmental  chamber.   The chambers used in
the  GIFS  were enclosures which  isolated a  small area of ground so that
gases   released  biogenically  were  prevented  from  rapid  dispersion by
prevalent  winds and  could be  channeled into sampling bags for  subsequent
analysis.
                                   37

-------
Description of Environmental Chambers







     The  environmental chambers were similar to those described by Aneja



(13).  However,  to  avoid  cutting the grass over  certain of the monitoring



sites,  the air stirrer was  detached.  Figure 11 shows the chamber that was



used during the  studies.  The chamber frame is just a modified office-type



trash can.  Windows were cut in the sides and top so that radiation could



enter.   Teflon  sheeting  was  attached  to the inside  so  that the Teflon



surface  and the area of  ground covered by the  chamber  constituted an



air-tight  system.   Ambient  air  was  continuously  pulled  through  the



chamber from a small 1/4 in inlet in the lower section,  and left the chamber



from a similar connection  near the  chamber top.   The accessory equipment



shown in Figure 11  includes a pair of 12  volt batteries  in  series to power



the  air  pump  (Brailsford, Model TD4X2)  which  is  mounted on  the rim  of



the  chamber.  Flow rates  through  the air pump  were periodically checked



with a mass flow meter  (Sierra  Instruments, Model  543).  Soil and ambient



temperatures  were  measured  with  a thermister  made by Yellow Springs



(Model 46 TUG).







      To  sample  the air  passed  through  the chamber, a  Teflon bag was



attached  to  the  pump outlet with a Teflon tube.   The  bag was filled and



then transported to the  blockhouse site where they  were placed outside the



blockhouse   in  the  sunlight  to prevent  condensation of  H0O.   During
                                                            A


analysis  a  Teflon line was  run from the bag, through a  window into the



blockhouse,  to a Meloy,  Model  SA 285,  for analysis.   An  SO2 scrubber
                                  38

-------
Figure 11.  Environmental chamber for measurement of biogenic  emissions.
     Figure 12.   Monitoring site B.   Marsh adj=r-ent to Lewis Creek.



                                39

-------
made  by Meloy  was  usually  heated and placed in the  sample  line so that



the readings were total sulfur minus SO,,.






     Sample integrity was of primary concern in  the chamber experiments.



Losses of H0S and (CHQ)0S in the Teflon bags were measured during the
            Lt           O £


field  study at 15% per  hour and 5% per  hour,   respectively.   These loss



rates were  determined by putting known amounts of the two gases in bags



and taking two readings, an initial reading  and  a second reading after 3



hours.   Dry  air  was used  in the tests.   Bag  losses  as well as memory



effects  were of concern.  In this regard, it was found that the  bags had



to  be flushed three  times before a zero response  could  be observed on the



Meloy  sulfur monitor.   Continual  inspection  of  the bags for leaks was



necessary  to avoid spurious  results.






Placement of Chambers






     Chambers were  placed  in  several  locations for limited periods of time



(typically  half-day  periods)  and  in  two locations  for continual analysis



during   2-day  periods.    Order  of  magnitude variations   in   chamber



concentrations  were observed  from  location to  location,   diurnal  and



tidal-related variations were observed during the  long term analyses.







     The  primary location  for chamber studies  is  denoted as Site A  in



Figure  1.  Site  A is  along the  edge of Lewis  Creek.  In this area intertidal



edgewater locations were chosen.   The majority of the  edgewater area (Site
                                   40

-------
A-l) was overgrown with a type of marsh grass -- Spartina alterniflora —
and interlaced with  seaweeds held in place by the stem and  root systems of
the marsh grass.   The  soil was  a mixture of  silt and sand,  tan  to  dark
brown  in color.   Site  A-2 was  located near a  docking  area which fronted
on Lewis  Creek.   This area was sandy with little grass or seaweeds.

     Site B,  as  shown  in  Figure 12,  is  in  the marsh  adjacent  to  Lewis
Creek.   It  was  selected  as  being more  representative of  the marsh area
than Site A (see Figure 13).   Site C  was chosen  as  representative of the
intertidal flats  that border  the sound  side  of the Outer  Banks.  These
flats are shown in Figure 14.

Calculation  of Generation Rates

     The  assumption  of  ideal  mixing  in  the   environmental   chamber
establishes  the following relationship:   the rate of release  "R" of  a sulfur
compound of  gram  molecular weight "G"  from the  area  "A" covered by the
chamber  is  related  to  the  flow  rate  "F"   through  the  chamber  and
concentration at the outlet "f".   The equation goes as follows:
 R(gm/m2-yr) = ^1 F(l/min)  G(gm/mole)         %&&  C(min/yr),  (Eq.  2)
               A (nT)           K (1-atm/mole-deg) T(deg)
 where C = 5.256 x 105,  A = 0.085 m2 for the chamber used in the CIFS, G
 = 62 for (CH0)0S and G = 34 for H0S,  and K = 0.082 1-atm/mole-deg.  P
              O Cl                   tt                     '
                                   41

-------
Figure 13.  Monitoring site A.  Intertidal edgewater location near
            blockhouse on Cedar Island.
Figure 14.  Monitoring site C.  Interdial flats on Outer Banks.
                            42

-------
is  the atmospheric pressure and T the ambient temperature.  Note that for
a  constant  generation  rate  the  value  of concentration  is  inversely
proportional to the flow rate, i.e., f(ppb) ~ [FU/min)]"1.

     Equation  2  must  be  interpreted  with  care if it is  to be  used  to
estimate  the   biogenic  flux which would occur  in  the  absence  of an
environmental  chamber.   The  main questions associated with the use  of
chambers concern  (a)  the  perturbation of the environment being monitored
by the chamber,  e.g.,  the possibility  of  temperature and humidity changes
within  the  chamber;  (b) the effect of increased partial pressures  of the
gases to be  measured over the  area enclosed  by  the  chamber;  (c)  the
degree of stirring required in the chamber;  and (d)  the tightness  of the
air seal around the  chamber.  In the present case,  ambient  air was pulled
through  the  chamber  so that  humidity changes were  minimized; however,
an increase in temperature was evident from  the water condensation  on the
chamber  walls.  The questions (b) and (c) above  are  discussed in  some
detail by Hill, et  al.  (14).  In  the  CIFS,  sampling  was  performed  over
grass, so  that  the chamber could not  be stirred.   Item  d is important
when the sample  air is being pulled through the chamber.   In  this case a
check  should  be  made  to  determine if the flow  rate entering the chamber
and  that leaving the  chamber are  equal.  To measure  the  combination of
the  effects mentioned in (b) (c) and  (d), the chamber concentrations  were
recorded as  the  chamber  flow rate  was  varied.   The departure  of the
                                   43

-------
results  from that given  in  Equation 2, i.e.,  f ~ 1/F, was taken as  an
empirical determination  of the applicability  of  Equation 2.   The  result of
this determination is given in Results and Discussion.

ATMOSPHERIC   BACKGROUND   MEASUREMENTS  OF  NITROUS   OXIDE,
FREON  11, AND FREON 12

     As part of the CIFS, five ambient samples were taken for  subsequent
analysis to determine N2O,   Freon 11  and Freon 12  content.   The five
samples were  all  taken at the  same time on September 1 and at  the  same
place   (height  of  7 m);  they  were  expected  to  be  replicates.   The
containers  were returned to RTF for subsequent analysis  on November 8.
Due to the significant  delay in analysis any differences in the results of
the separate container  samples  were expected to reflect the compromise of
sample  integrity  attendant  to   storage.   The  results  were  expected to
illustrate  AIB's capability to analyze samples for N^O,  Freon 11 and Freon
12  with a set  of optimized  gas chromatographic columns,  and to provide
estimates of sample integrity after  storage in sampling containers.

     Development of better  and more  convenient  analysis techniques seem
especially  appropriate in  the case of NgO, since it has been suggested that
the  N20 level  is constant  and could  be  used as  a  reference  to  check
analytical  instrument  performance.   The   concentration levels  reported,
however,   have ranged from 0.25  ppm in 1974  to  0.32  ppm at  the present
time.    It  is not  clear  whether  this increase is due  to a refinement in  the
                                  44

-------
measurement technique of a  constant  concentration level, or whether N2O
levels are on the increase in  the atmosphere.

     Accurate  measurement of  NgO, Freon 11 and Freon 12  is  extremely
important  since their  presence  in  the  atmosphere  contributes  to  the
greenhouse effect  — the blanketing  action  which leads to  an increase in
the earth surface temperature (15).

Measurement Techniques

     Gas  chromatography  with electron  capture  detection  was  used  to
 determine  the  Freons and N^O.  The  analytical  system was comprised of a
 Barber-Coleman Series  5000  Gas  Chromatograph,  an  Analog Technology
 Corp.  Model 140 Detector, and a  Carle  8-Port Sampling Valve  with  a 6-ml
 loop and a Hewlett-Packard Model 3385  A  Integrator.   The  halocarbon  and
 N2O analyses were done  on separate columns.

      Conditions for the determination of Freon 11 and Freon 12 were:

           Column:   7 ft  x 1/8 in Porasil C, 80/100  mesh;
           Column Temp:   Ambient;
           Carrier:  5% methane in argon;
           Flow rate:  41  ml/min at 22 psig;
           Detector temp:  190°C.
                                   45

-------
    The conditions for the determination of NgO  were:

         Column:   8 ft x 1/8 in Porapak Q, 80/100 mesh;
         Column Temp:  Ambient;
         Carrier:  5% methane in argone;
         Flow  rate:  32 ml/min at 25  psig;
         Detector temp:   190°C.

     A  cursory study indicated  that one analytical column,  packed  with
Chromosil  310,   can  be  used for  the determination  of the  above  three
components.   The  column  unfortunately  was not  ready for this project.
It will be used for  such analyses  in the future.

     Calibration  of  the  system  consisted  of   recording  responses  to
reference  mixtures.   These  reference   mixtures  (one  component   per
container)  were composed in  stainless steel cylinders by a  method of static
pressures.

     Evacuated  containers were used  for  sampling:  four  steel containers
(800  cc  each)  and  one stainless  steel cylinder  (500 cc).   Each container
had been outgassed by heating  and pumped down to a pressure of 20 urn
prior to  use.

     The  containers  were  heated  to 80°C  in  a  drying oven  in  the
laboratory  just  prior  to analysis  in order to increase container pressure to
                                  46

-------
about 21% above collection  pressure.   This  maneuver provided two samples



per container.








ATMOSPHERIC MEASUREMENTS OF OZONE AND NITROGEN OXIDES








     Ozone  measurements  at Cedar  Island  were  expected to  show  some



correlation  with  ambient  sulfur levels  due  to  the  H0S  - OQ  gas  phase
                                                    £      O


reaction.    Also,   the  availability   of  two  types   of   O3  measuring




instruments -  one based  on Og - CoH.  ch^ilunutti8061106  and tne other on



ultraviolet  (UV)  photometry  -- made  possible a comparison of  techniques.








     Measurements of NO   were used as an  indication of the isolation of
                        A.


the  Cedar  Island  site.   In  addition a new  commercial monitor,  the CSI



Series  1600,   was   tested  for sensitivity  and  reliability  under  field



conditions.








Measurement Apparatus








     The O,  instrumentation,  Dasibi, Model  1003-AH,  and Bendix,  Model



 8002,  are established commercial instrumentation.  The Dasibi is based on



UV  photometry and  a chemical scrubber system for Og.   In operation the



 sample stream either bypasses or passes  through an Og  scrubber and  is

                                                                     O

 subsequently  analyzed by the measuring attenuation difference  at 2537 A.



 The Bendix instrument causes mixing  of  the sample  stream with  a pure



 stream of C2H4.  The reaction of Og with C2H4 occurs with an attendant
                                  47

-------
emission  of photons.  Photon  emission  as monitored  on  a photomultiplier



gives  a  signal  proportional  to  the concentration  of  O3 in the  sample



stream.







Measurement of Ozone and Nitrogen Oxide







     Ozone and NO  were monitored from a  common manifold  in the mobile
                   A.


van.   The sample  inlet  line of 1/4 in ID Teflon tubing contained an in-line



Nuclepore  filter  of 5  [im  pore diameter.  Both  O« monitors  (Dasibi  and



Bendix)  as well as the CSI NO  monitor were operated continuously.
                              X.




             i

Calibration of Ozone and Nitrogen Oxides
     The OQ and NOV calibrations  are estimated to  be better than + 20% for
           o        X                                           —


the two week measurement period.
     The Og calibration was  based  on  UV  absorption  photometry.   The



Dasibi  (Serial No.  123?) and  Bendix  (Serial No.  302070-2)  monitors  were



calibrated  at RTF prior to  the  field study.  During the study the Dasibi



experienced  an  obvious intermittent  electronic  malfunction  which  allowed



only  about 70% valid  data from, the instrument.   During the periods  when



the  Dasibi was  functioning  properly the  Bendix and  the Dasibi tracked

                                            /

each  other  within  ±  10%  except  for  a brief period  following  excessive



condensation  of  ambient water  in  the  sample lines.   After  returning the



instruments  to RTF,  the Dasibi did not  function.  The Bendix calibration
                                  48

-------
was  checked by  the gas phase titration apparatus (GPT) and was found to
be  approximately 3%  high.  Since  3%  is  less  than the  typical difference
between GPT and UV Og  calibration,  the  instrument  drift was  considered
to be negligible (i.e.  <5%).


     The NO   calibration  was  based  on an  NO cylinder (the  cylinder
             A.
concentration was  determined  by  comparison to  an Standard Reference
Material (SRM)  cylinder via GPT.   Immediately prior  to'the field  trip  the
NO_ instrument  (CSI,  Model 1600, Serial  No. 8195) was returned to  the
   A
factory  for  repairs  and calibration.  The calibration  was checked  at RTF
prior  to the trip  and was  found  to  be within  2% of the factory value.
Similarly the converter efficiency was  found to be within 1% of the factory
value  (~ 98%).   After the field study  the  instrument  was returned to RTP
and  the NO  calibration  was  found to  be  ~  6% lower.  The converter
efficiency was not rechecked at RTP.


     During  the field  study several  attempts  were made to  check  the
instrument  calibration via GPT.   None  of these  efforts produced results
within  30% of the  instrument's  response.   Upon  later  examination of  the
 GPT system it  appeared that the most  likely cause for the field calibration
 results  was improper purging  of  the  NO  tank regulator.  (The regulator
was  removed from the  tank during transportation both  to and from  the
field  study  site.)   Because  of  the   large  deviation  between  the field
 calibration  results  and  the  instrument response,  no adjustments  to  the
instrument  spans were made in  the  field.
                                   49

-------
                              SECTION 3
                    RESULTS AND DISCUSSION
GASEOUS SULFUR COMPOUNDS  IN AMBIENT AIR

Direct Measurements Using Flame Photometric Detection

     Direct readings of ambient gaseous sulfur with the Meloy SA  285 were
taken during  the  first  part  of  the field  test.   Total sulfur-sulfur dioxide
levels were always below  5  ppb.  Due to the difficulty  in  distinguishing
values   below  5  ppb  with  precision,   the  direct  measurements  were
discontinued.

Preconcentration on Gold-Coated Glass Beads

     Several  types of  sampling  studies were planned,  including:  sampling
of air coming from the ocean, sampling as a function  of  height above the
ground   (tower  studies),  sampling  and  analysis  as  a  function of time
(diurnal  variations),   sampling  of biogenic  emissions,   and  sampling  in
support of other investigators.  Each  study was  performed to some

                                  50

-------
degree;  however  the time variation  study could not  be carried out over
more  than a few  hours because  of difficulties  in maintaining the sampling
tubes in a suitably blank condition.  The  placement  of local vegetation and
wind  direction  appeared to  have a  substantial influence on  the  sulfur
analyses obtained.

Tower Studies

     Air samples  were obtained using a 10 meter high mast which could be
raised  and lowered  to  attach  sampling  tubes  and fittings.   Small vacuum
pumps  (Neptune  Dyna-Pumps,  Fisher Scientific  Co.) were  placed at the
foot of the towers and connected at various heights to the sampling tubes
by tygon tubing.   Tower  samples were  taken  at  10,  5,  2,  1,  and  0.1
meters.   Also  available was an abandoned radar  antenna tower from which
20 meter high  samples could  be taken.   Five 10-meter tower sample sets
were taken in the course of  the field work.   Figure 15 depicts the various
tower  study  sites  on  Cedar  Island.    Figure  16 shows   typical  chart
recordings  from  the gold  bead  analysis.  The  label  "RS"   refers to the
unseparated sulfur  compounds in  the sample  released from  the cold trap
into the Meloy.

      The distribution of reduced forms of sulfur is  given in Table 5, A-F,
and  shown  in  Figures 17-21  as a function  of height above the  ground.
Towers  1 and  2 were taken at a location  as close as practical to the edge
of the  sound.   There were no mud flats  at  this location.  Notable are  the
                                   51

-------
to
               PAMLICO SOUND
                                                           PINE GROVE
   Figure 15.   Tower study sites near Cedar Island blockhouse.

-------
Figure 16.  Typical chart recordings from the gold-coated glass bead analysis.
                                53

-------
10m
 5m
 2m
 1m
0.1m
 H2S 100%
H2S 96.5% DIMS	I
      J H2S 99
.7% R-S 0.3%
H2S 99.5% R-S 0.5
                                                          TOWER 1
                                                         (AFTERNOON)
           J H2S 88.9% QMS 11%       j             I             1
                0.5           1.0            1.5           2.0            2.5
                                         ng S/liter

 Figure 17.   Vertical concentration profiles of  sulfur compounds  — Tower  1

                                        54

-------
10m
 5m
H2S 99% DMS 0.2 R-S 0.7
  H2S 100%
  2ml       |H2S95%R-S5%
  1m
 0.1m
   H2S 100% R-S tr.
                                          I             r
                                                       TOWER 2
                                                        (NIGHT)
1 H2s ii»   |I             I	L
   4             Oi           1.«           1-5           2.0           2.5
                                        ngS/lher

   Figure  18.   Vertical concentration profiles of sulfur compounds  —  Tower 2.

                                         55

-------
10m
 5 m
 2m
 1m
0.1m
II 1 1
H2S 76.7 QMS 2.5 R-S 20.7% 1
TOWERT
(NIGHT)
j
| H2S 79% MeSH 6% DMS 6 R-S 9
^j~H2S f2% QMS 36% DMDS 18% R-S 34%
H2S 58% DMS 3.4% R-S 38% 1

""""I' H2S 12% ( DMS 30% R-S 58% j J
1
1
                0.5           1.0           1.5          .2.0           2.5
                                       ng S/liter
  Figure 19.  Tower 3.   Vertical concentration profiles  of sulfur compounds.
                                       56

-------
10m
  5m
                1	1	1	r
  	
 H2S 38% DMS 23% R-S 39%
H2S 50% MeSH 6% DMS 6% R-S 33%
  2ml      I H2S 53% DMS 13% R-S 34%
  1m
0.1m
H2S 44% DMS 12% R-S 37%
                                                          TOWER 4
                                                        (AFTERNOON)
         H2S 93% DMS 7%  I             I             I
                 0.5           1.0           1.5           2.0            2.5
                                        ng S/liter
  Figure 20.  Tower 4.  Vertical  concentration profiles of sulfur compounds.

                                        57

-------
10m
 5m
                I
                       I
H2S 67% QMS 5% DM PS 23	I
R-S 6%
H2S 54% QMS 6% R-S 40%
  2m
  1m
0.1m
        H2S 26% DMS 9% DMDS 65%
H2S 61% MeSH 7% DMS 3% DMDS 8% R-S 18%
                 i            r
                                                           TOWERS
                                                           (NIGHT)
       H2S 65% DMS 21% R-S 14%

          0.5           TO
 Figure 21.   Tower 5.  Vertical concentration profiles of sulfur compounds.

                                      58

-------
high percentage  of  HgS and the low percentage of other reduced forms of
sulfur.   Towers  3-5 were taken in the open field near the blockhouse with
wind  directions  generally  from  the  marsh  area.   All  of  these  had  a
substantially higher organosulfur  compound content than those taken near
the sound.

     A  regular pattern of  sulfur  concentration was  noted in most of the
tower  studies  with  a maximum at 1 meter and with total reduced  sulfur
concentrations   increasing  with  the  height  above  ground.    Since  the
maximum  in  concentration at 1.0  meters does not  appear to  be consistent
with either a  dry  deposition or biogenic emission  of  the sulfur  gases, the
experiment must be repeated to judge whether this maximum is  an artifact
introduced by the  sampling  train or is due to the micrometeorology  of the
surrounding  area.    In  any case  the  vertical  variation  points out the
problem  of  picking a  representative  vertical position  for  ambient  air
sampling.   Sampling at 10 meters  was more indicative of an average  sulfur
value;  organosulfur  compounds  were  very  low  at  2  meters,  the usual
height  for meteorological sampling.

     Samples were  taken  from the radar tower located near the  blockhouse
at  a height above  ground of approximately 20 meters.  Results of analyses
are given  in  Table  6.   Hydrogen sulfide was the  major reduced  sulfur
component  in  most  cases.    Very  little contribution  was noted from
organosulfur compounds.   Some of the  20-meter samples  were taken at  the
                                   59

-------
same time as the 10-meter tower studies.   Comparison of the 20-meter and



10-meter  tower  samples,  where  feasible,   shows substantial  agreement in



composition  and,  generally,  in  the concentration  of the  reduced  sulfur



compounds found.







     A  number  of miscellaneous  samples   were taken with data given in



Table 7.  These data include  analysis of  samples taken  from  several sites:



Site A, Site B,  and  Site C, as well as  samples taken in the area of  a pine



grove,  and  two measurements taken  at  Cox's Landing,  North  Carolina.







Discussion   of   Results  Obtained   Using   Gold   Coated   Glass   Bead



Preconcentrator







     A  comparison of ocean  air samples to on-shore samples was made  (see



Table  8).   Ocean  air samples were  defined as  air samples taken near the
                                                 .<
                                                 *.

waters' edge with wind from the ocean direction.  On-shore samples were



defined as  samples taken further inland with wind generally  from the  land



direction.  On-shore  samples and the pine grove samples all contained much



higher  amounts of organosulfur  compounds.  This agrees with Rasmussen's



comments  (15),  that a number of  different  organosulfur compounds are



associated with  biological sources.







     During the development of the analytical method,  the major  objective



was to  provide a method principally for HgS,  CKLSH,  and (CHo)2S; these



were  satisfactorily  separated  in  the  U-trap.   However,   a  much more



complex mixture of  sulfur compounds was found (See  Figure 16) and the





                                  60

-------
unseparated, less volatile organosulfur compounds had to be reported as  a
group.  An improved separation method is now under study.

     A  gas chromatographic  type of FPD air analyzer was in use during
the sampling of  ambient  air.   Hydrogen sulfide was detected in ambient air
at concentrations in  agreement with the preconcentration method described
here.    Sulfur  dioxide   was   detected   at  levels   less   than  5  ppb.
Consequently,  the SO2 capacity of the scrubber tubes was  not approached
during  sampling.

     The method has  certain  limitations.   The  sulfur  compounds carbon
disulfide  (CSgN and  COS are interferents, since  both  appear as HLS after
absorption  on the  gold  tubes  and  after  hydrogen reduction.  Although
some of  these are  removed  by  the  SO0 scrubbing  traps,  an improved
                                         It
separation  technique  is needed.   In  addition,  some  decomposition  of
mercaptans to ELS was noted during hydrogen reduction and was generally
a function  of  the total amount present.  No decomposition of (CH3)2S was
observed.

     Finally,  the method does  have the  capability of providing analytical
information on HgS and  (CH3)2S  found in air at ambient concentrations in
non-polluted   locations.    It  should  substantially   aid studies  of  the
 environmental  chemistry  of sulfur.
                                   61

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TABLE 5.  TOWER SAMPLE DATA


Height
m
10
5
2
1
0.1


10
5
2
1
0.1


]
ppb
0.94
0.59
0.26
0.6
0.24


0.90
0.41
0.19
0.88
0.02

(8-24-77,
2 ng/1
1.46
0.90
0.40
0.93
0.37

(8-25-77,
1.38
0.63
0.29
1.35
0.03
A . Tower
1650-1720 hr,
ppb
0.00
0.02
0.00
0.00
0.03
B . Tower
2140-2230 hr,
0.002
0.00
0.00
0.00
0.00
1
70-90 1)
(CH^
tr.
0.06
0.00
0.00
0.08
2
90-109 1)
0.006
0.00
0.00
0.00
0.00


RS
ng/1 as H2S
0.00
0.001
0.00
0.004
0.00


0.011
0.00
0.015
0.001
0.00
         (continued)
             62

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TABLE 5.   (Continued)



C. Tower 3


(8-27-77, 2000-2030 hr, 67-90 1)
10
5
2
1
0.1


10
5a
2
1
0.1
0.70
0.71
0.01
0.80
0.015


0.60
0.73
0.097
0.65
0.23
1.03
1.04
0.01
1.23
0.02

(8-28-77,
0.93
1.13
0.15
1.58
0.35
0.24
0.036
0.28
0.050
0.038
D. Tower 4
1550-1650 hr, 40
0.40
0.092
0,025
0.19
0.017
0.062
0.095
0.73
0.13
0.10

D
1.04
0.24
0.065
0.49
0.045
0.28
0.07
0.037
0.81
o.n


0.95
0.88
0.098
0.99
0.00
     (continued)
          63

-------
TABLE 5. (Continued)
E. Tower 5
(8-28-77, 2000-2100 hr, 40 1)
10a
5
2C
ld
0.1
aCH3SH: 0
*(CH3)2S2:
(Cn.i))nSn'
d
(CH3)2S2:
0.58 0.90 0.046 0.12,
0.69 1.06 0.084 0.22
0.058 0.09 0.021 0.055
0.86 1.33 0.038 0.10
0.11 0.16 0.036 0.095
.20 ng/1
0.15 ng/1 as HgS
0.11 ng/1 as H2S
0.09 ng/1 as H0S; CHQSH: 0.21 ng/1
Lt O
0.78
0.80
0.00
0.48
0.04

         64

-------
TABLE 5.   (Continued)



C. Tower 3


(8-27-77, 2000-2030 hr, 67-90 1)
10
5
2
1
0.1


10
5a
2
1
0.1
0.70
0.71
0.01
0.80
0.015

•
0.60
0.73
0.097
0.65
0.23
, , ,„, . _.._,_
1.03
1.04
0.01
1.23
0.02

(8-?8-77,
0.93
1.13
0.15
1.58
0.35
0.24
0.036
0.28
0.050
0.038
D. Tower 4
1550-1650 hr, 40
0.40
0.092
0.025
0.19
0.017
0.062
0.095
0.73
0.13
0.10

1)
1.04
0.24
0.065
0.49
0.045
0.28
0.07
0.037
0.81
0.11


0.95
0.88
0.098
0.99
0.00
     (continued)
          63

-------
                      TABLE 5.  (Continued)
E. Tower 5
(8-28-77, 2000-2100 hr, 40 1)
10a
5
2C
ld
0.1
0.58
0.69
0.058
0.86
0.11
0.90
1.06
0.09
1.33
0.16
0.046
0.084
0.021
0.038
0.036
0.12
0.22
0.055
0.10
0.095
0.78
0.80
0.00
0.48
0.04
aCH3SH:  0.20 ng/1
b(CH3)2S2:  0.15 ng/1 as HgS
C(CH3)2S2:   0.11 ng/1 as HgS
d(CH3)2S2:   0.09 ng/1 as H2S;  CHgSH:  0.21 ng/1
                                64

-------
            TABLE 6.  TOWER SAMPLES AT 20 METERS
Date
8-27-77
8-27-77
8-27-77
8-27-77
8-27-77a
8-28-77
8-28-77b
Time of Day
1200-1300 hr
1305-1425 hr
1425-1550 hr
1550-1715 hr
2030-2130 hr
1610-1710 hr
1715-1816 hr
H9S
ppb *
0.00
0.29
0.10
0.23
0.20
0.94
0.53
ng/1
0.00
0.45
0.16
0.36
0.30
1.45
0.81
a(CH3)2S:  0.03 ng/1 0.01 ppb; (CH3>2S2:  0.02 ng/1 as
b(CH3)2S:  0.22 ng/1 0.08 ppb CHgSH:  0.02 ng/1
                               65

-------
                 TABLE 7.   MISCELLANEOUS SAMPLES
Time      Location              HLS    3         Others
                            ppb   |jg/m
                       A.  Cox's Landing,  North Carolina
8-29-77                     9.3   14.3      (CHQ)0S: 0.1 ppb, (CHQOS0:  0.25 ppb  as H0S
Evening                                        3 2                3Z L               *
                           11.4   17.6      (CH0)0S: 0.1 ppb, (CHQ)0S0: 0.08 ppb as H0S
                                               O Z                O Z Lt                £*


                            B. Cedar Island,  North  Carolina


8-22-77   Seaside Edge     0.28   0.43      (CHo)9S 0.038 ng/1
1240 hr                                        ^ z
8-22-77   Seaside Edge     1.71    2.64      	
1050 hr

8-23-77   Site 3, 2 ft       3.57    5.5       	
1130 hr

8-23-77   Site 3, 1  ft       1.69    2.6
1110 hr   above ground

8-23-77   Site 2, 2 ft       0.10    0.15      (CHJS:  0.034 ng/1; RS:  0.36 ng/1 as KLS
1250 hr   above water
8-23-77   Site 4, J.  Day's  0.08  0.12
1200 hr   Ditch

-------
TABLE 7. (Continued)
Time
Location ELS
ppb ng/1
Others
B. Cedar Island, North Carolina
8-23-77
1230 hr
8-23-77
1240 hr
8-23-77
2245 hr
8-26-77
(AM)
8-26-77
1200 hr
8-26-77
1630 hr
8-27-77
1830-1910
Bag sample 1 1.04 1.60
Bag sample 2 0.68 1.05
Blockhouse 0.24 0.37
near fence
Boat landing 0.38 0.59
Boat landing 1.25 1.93
Seaside Edge 0.15 0.23
Drum Inlet 0.88 1.36
hr
(CH3)2S: 7.6 ng/1, 2.9 ppb

(CH3)2S: 0.009 ng/1, 0.003 ppb


(CH3)2S: 0.10 gn/1, 0.038 ppb


-------
TABLE 7.  (Continued)
Time Location

8-28-77 Chamber No. 2
1100 hr
8-28-77 Chamber No. 1
1700 hr
8-29-77 Pine Grove
925 hr
« 8-29-77 Pine Grove
925 hr
H2S
ppb ng/1
B . Cedar
3.4 5.24
32.0 49.3
1.57 2.42
0.96 1.48
Others
Island, North Carolina
(CH3)2S: 33 ng/1, 15
(CHq)9S: 68.4 ng/1,
O Lt
(CH«)9S: 0.40 ng/1,
6 * RS: 2.7 ng/1


.6 ppb, RS 8.3 ng/1
26.1 ppb
0.15 ppb; CH.SH: 0
as H2S *
(CH3)2S: 0.03 ng/1 0.01 pp; RS 0.71 ng/1


as H0S
&

.05 ng/1
as H0S
LA

-------
TABLE 8.  PERCENTAGE COMPOSITION OF REDUCED FORMS OF SULFUR
                           Ocean Air Samples

     Towers       No. 1         HgS          96.9 + 4.7% n = 5
                  No. 2         H2S          98.8 + 2.2% n = 5
     Seaside         1 m         HgS          99.5 + 3.6% n = 5
     Radar Tower   20 m         HgS          96.1 + 6.2% n = 4

                            On-Shore Samples
     Towers   17 Samples
                               H2S           53.2 + 23%
                               CH3SH        1.2%
                               (CH3)2S       12.1%
                               (CH3)2S2      7.9%
                               RS           25.34%
                                69

-------
Tandem Filter Measurements
     Results  for the sulfur measurements  in SO2  and H2S are  shown  in


Figure  22.   With the  exception  of  one measurement for SO2>  all  values

                      q
were  less than  1 pg/m .  These  results are consistent with  the generally


low  values   determined via  the  gold-coated  glass beads,  but a  close


comparison is difficult  because the TFP and gold bead sampling  times are


24  and 1/2  hours,  respectively;  and,  as  the previous  attitude profiles


show,   the   concentration   of  sulfur  gases  was  strongly  dependent  on


altitude, stressing the importance of the height of the sampler.
PARTICULATE MEASUREMENTS IN AMBIENT AIR




The Dichotomous Sampler




     The ranges and mean  values  for  individual elemental abundances  as


well as the total mass  for the fine and  coarse particle fractions  are given


in  Tables  9 and 10.   The values in Table  9 indicate that elements heavier

                                        Q
than aluminum contribute about  2-3 \ig/m  or 11-17%  to total fine particulate


mass.   The remaining mass,is likely to  be  adsorbed water and compounds


of  light elements (optical microscopy  shows seed fragments on several of


the fine  particle filters).   The principal  element  determined was sulfur
                                  70

-------
                   1.0
               W 9





               f
                   0.5
'• ' i
- 1 ppb *

—
i
: *
:* +

r i i
i i i i i
SULFUR GASES-TFP
• S02
• H2S
-
f 4 * :
i , r~
1 T 1 1 1
                       8/22 i
 8/25 [



DAY OF STUDY
8/28
Figure 22.  Sulfur dioxide and H2S content of the ambient air using the TFP and x-ray fluroescence.

-------
                TABLE 9.  FINE PARTICLES
              Tandem Filter Pack
                                            Dichotomous
Element
           Range
Mean
Range
Mean
Al
Si
S
Cl
K
Ca
Ti
Fe
Zn
Br
Pb
TSP pg,
<100-600

500-3000
<30-280
<15-90
<11-70
<12-137



3 <9-76
/m
<270 (170)
<140 (140)
1400 (800)
<160 (80)
<50 (30)
<40 (20)
<80 (40)
<17 (20)
<10 (11)
<5 (5)
<30 (20)


<10-51
700-4500
<3-190
<4-59

-------
            TABLE 10.  COARSE PARTICLES (ng/nT)*

Element
Si
S
Cl
K
Ca
Fe
Ni
Cn
Zn
Br
Sr
TSP jjg/H
Tandem Filter Pack
Range Mean (SD)**
<3-190 72 (56)
70-310 200 (80)
140-1400 770 (500)
<20-120 <53 (33)
28-86 58 (21)

-------
and  the  amount  corresponds to a mean value as sulfate  of  6.6 where  the
distribution of sulfate values about the mean exhibited a standard deviation
             o
of 3.6  pg/m .   The  total  sulfate value  measured  by  the National  Air
Surveillance  Network for non-urban sites  in  1974 was 6.2 with a standard
                     q
deviation  of  6.2  |jg/m  , these measurements were  made by Hi Vol samplers
which do  not discriminate between coarse and fine  particles.
     Those  elements in the  coarse  particle fraction  which  are  above our
MDL account for only 0.5% of the total mass.  The  surprising near-absence
of  the elements  aluminum,  silicon,  calcium and iron  which are  usually
associated with particles from the earth's crust and which often make up a
major  part of  the coarse particles, indicates that the coarse particle orifice
section of the  dichotomous sampler may have  been  plugged during these
experiments.   On  the  other hand,  the near absence of these  particles  in
the  coarse  TFP fraction  as  well,  suggests that the  air  sampled was,  in
fact, extraordinarily clean of coarse particles.

The Tandem Filter Pack

     The elemental  abundances for the  TFP coarse and fine particle filters
are  found in Tables 9 and 10.   Roughly speaking, the trends  in the TFP
and dichotomous  sampler data  are  in  agreement.   The  TFP is  not  as
selective  as  the dichotomous in two respects:  1)  the  cut point between fine
and coarse particles is not as sharply  defined,  2)  the upper cut point of
the  coarse fraction is  not defined;  in fact, since the large particle TFP is
                                   74

-------
exposed directly to the  atmosphere, any particle which is entrained in the
air stream will  reach the filter.  The  sample volume over a 24-hour period
                3           3
is about 1.5 m  and 20  m   for the  TFP  and the  dichotomous sampler,
respectively.  Consequently,  the precision of the dichotomous sampler data
is expected  to be better.

     The fine particle  results  for  the TFP show fair  agreement with the
dichotomous   sampler  results  for  sulfur and  lead.   The peculiarly high
values  for  aluminum  in  the   former  may  be  due  to  problems  with  the
least-squares spectral analysis for  the very low  energy aluminum x-ray.

     The coarse particle results show  that, in general,  the TFP  values are
higher than those from the dichotomous sampler.  The following results are
consistent with  the properties of the  sampling systems:   the  TFP   sulfur
results  are  high  because  the fine and coarse particle fractions are not
sharply separated; therefore,  some of the fine particle sulfur remains on
the  coarse  particle  filter.   As  there  is no large particle  cut  off  for the
TFP,  the elements found in large  particles will be more  abundant in the
TFP  coarse  fraction  than in the dichotomous coarse  fraction.   This effect
would  explain  the  large chlorine values in the TFP data if  one assumes
that  the chlorine  is  associated with very  large particles,  e.g., sea salt.
                                   75

-------
BIOGENIC RELEASE OF SULFUR IN GASEOUS FORM







     One  of  the  interesting  discoveries  of  the study  was  the entirely



different nature of  the sulfur gases emitted from the different sites.  For



example, at  Site  A-l,  by far the highest concentration  of  gaseous  sulfur



was  volatilized as  (CHo)0S,  while  at  Site  A-2, H0S  was by  far  the most
                      o £t                        Lt


prevalent.   Figures 23 and  24 substantiate these observations by showing



chromatograms of  samples  taken at  the two  sites.  The chromatograms from



Site  C were  similar to those from Site A-2, while the chromatograms from



Site  B showed both HgS and (CH3>2S.







     The   concentrations  of   sulfur  gases   from   the  chamber  varied



considerably depending on time and location.  Figures 25 and 26 show two



iVday  periods.   During  each period  the chamber  remained  at  one fixed



location,  Site A-l,   operating  continuously.   Soil  temperature, ambient



temperature,  and flow rate  were recorded after each  sampling for the data



represented   in  Figure  26.   Ambient  temperature  and flow  rate were



recorded less  frequently for the data represented in  Figure 25.   The data



shows  a  significant  diurnal  variation,   apparently  due   to  temperature



changes,  as  well as  some fine structure which appears to be  correlated



with tidal  variations.   High  and  low   tides  are  shown   by H and  L,



respectively.    The  correlation   between   chamber  concentration  and



temperature  is shown more  explicitly in  Figures 27 and 28.  As  indicated



in these figures,  the release  of  (CHQ)0S  during periods of increasing and
                                    o Z


decreasing concentration is  an exponential function of the temperature from



August 31  to September 1.  On these  days the effect of the tide  sustained





                                  76

-------
                                                                   31 AUGUST CTWICAU
                                                                     TRACOR §60
                                                                    CHAMBER SAMPLE
                                                                    OVER GRASS, MUD
                                                                    AT WATERS'EDGE,
Figure
Gas chromatographic analysis of an air sample taken from the environmental
chamber at Site A-l.   Dimethyl sulfide is dominant.

-------
Figure 24.
dominant.
Gas chromatographic analysis  at Site A-2 Hydrogen sulfide is
                                  78

-------
           96
Ul
cc
a



oc  86
UJ'
fi»

ui

1-1 81
           76
                31 AUG.-1 SEPT., 1977 I

                        '     D    '
                                                  SOIL
                                                                                O
                                                          O

                                                 0   000
                                                                                                  O


                                                                                                  D
                                                             ^ r
VD
  1000




   800




 1600
 L



 1 400




   200
1 1
	 TIDAL EFFECT?
^jj
^V^^
AJk
— Hi TIDAL DATA1 Lj *&
1
i
TEMPERATURE
*W A *?'
1 " 1 1 1 1
EFFECT?! 	
A A
s.
' f A ^ H j A ^ „
//
           0800!
               1200
1600
2000!       2400        0800

           TIME,(DST)
1200
1600
2000
      Figure 25.   (CH3)2S content of environmental chamber samples at site A-l (edgewater)

                    as a ninction of time.

-------
              88
              73


              68
      I23-24 SEPT., 1977
             D
                  AIR
                                            O
                                      D  a Daa
                                                                  n
                                                                                              SOIL
CD
O
soo

400

300

200

100
                                    S    *
	        A
          A
	   AA*L   TIDAL DATA    H
                          L   TIDAL DATA   H                L               H
                          h          iN      I         1            ill
                 0800
               1200!
                      1600
2000
    24001
TIME, (DST)
0400
0800!
1200
        Figure  26.   (CHo)2S  content of environmental chamber samples at  site near Site A-l
                     as a function of time.

-------
   1000
    800
    600
_   400
     300
Ul
o
z
o
o
     200
    100
       76
             O 1 SEPTEMBER


             O31 AUGUST
78
80
82       84       86



SOIL TEMPERATURE, °F
88
90
92
   Figure 27.  (CHg)2S content of environemntal chamber  samples  (same as Figure 25)

               as a function of temperature.
                                      81

-------
  1000
   800
i—r
                                            i—r
                O 24 SEPTEMBER

                O 23 SEPTEMBER
   600
    400
o
    300
o
o
CO
    200
    100
       72
74
 76
78
80
82
84
                                  SOIL TEMPERATURE, °F
     Figure 28.   (CHo)2S content of environmental chamber samples  (Same as Figure

                 26)  as  a function of temperature.
                                       82

-------
the high  emission rate of  (CH3)2S in the interval between high  tide and
the soil  temperature maximum.   Since the tidal  day is  50 minutes  longer
than the calendar day, the interval between high tide and the occurrence
of maximum soil temperature was shorter on  September 1 than on August 31
and the  daily release  of  (CH3)2S was less.   The release reached  a  steady
value  due  possibly  to  a  limiting environmental condition  such  as the
availability  of reactants  or  the  accumulation  of waste  products,  i.e.,
pollution  in the  bacterial environment.   If  bacteria are producing the
(CH3)2S, the accumulation of waste  could accelerate bacterial losses until
growth and destruction balance  and a steady  state population is achieved.

     The  two days  September  23  and 24  were  accompanied  by tidal
variations  caused by local winds and  variations in cloud cover,  There was
again  a  rough  exponential  correspondence  between  (CH3)2S  and soil
temperature and the  maximum  values achieved  during  the day were less
than those  which occured on  August 31 and September 1.

     Other chamber measurements  taken  on the marsh (Site B) are shown
in  Figure  29.   Chromatograms of chamber  samples indicate comparable
amounts of H2S and (CHg)2S at total sulfur concentrations about one order
of magnitude lower  than  those  found at  edgewater (Site  A).  Site B is on
ground  seldom  covered  with  water during  high tide  and  seems  to be
representative of  the roughly  4  square  miles  of  marsh between  Cedar
Island and the mainland.
                                  83

-------
CD
                50
               40
               30
             03,
               '20
               10
                    MONDAY, 30 AUGUST, 1977
1100
                                  I        I
                     SAMPLES HELD IN BAGS FOR 4 hr MAX,
                        THEN ANALYZED AT ONE TIME
                                           MIDDLE OF MARSH
                                                              P-
                                                              /    ^

                                                                        \
                                          1        1
                        1200
13001
17001
18001
                          1400i     1500     1600,

                                TIME, (DST) i

*BAG CONTENTS LOST DURING TRANSPORT FROM SAMPLING SITE • RESIDUAL CONTENTS
1900
   Figure  29.  Total sulfur content of environmental chamber samples as a function

                of time at site B

-------
                    100
                    75
•8
                     b
                    25
                        _  1	_1
                        MONDAY, 29 AUG.
                                OVER SAND
                              AT OUTER BANKS
                            1300    1330    1400
                                 tlMMDSff
Figure 30.  Total sulfur content of environmental chamber samples as a function
            of time at Site  C.
                                   85

-------
A  limited number of measurements were  taken over  sand on  the Outer
Banks.   Measurements on the afternoon  of  August 29 are given in Figure
30.   Other  measurements  indicated that the  occurrence of  a  high  tide
during sampling coincided with high HLS values.   On one occasion a level
of 1  ppm was obtained just as  the  tide  rose to carry water into the
chamber.
ATMOSPHERIC  BACKGROUND  MEASUREMENTS   OF  NITROUS  OXIDE,
FREON  11 AND FREON 12

     The results of the  CIFS measurements of N«O are shown  in Table 11
while those  for  the Freons  are  shown in Table 12.  Typical chromatograms
for Freon 11  and Freon  12,  and for N2O, are shown in Figures 31 and 32.

     Save for the values found for N0O  in container No.  2,  the remaining
                                    z
values  are  in   agreement  with   those   currently  reported  from  other
laboratories (16).   These results also agree with  analytical data obtained in
our  laboratory on  a sample of rural air collected by the National Bureau of
Standards.   The significance of the anomalous concentrations reported for
container No. 2  is  not understood as of this writing.

     The  lone set of  values for Freon  11 and Freon  12 may be compared
with data gathered by Hanst,  et  al. (17), on two days at Atlantic Beach,
North Carolina.

-------
                                                   PEAKS ARE LABELLED WITH
                                                       RETENTION TIMES
                                                         10
12
                                 TIME (minutes)
Figure  31.   Typical gas  chromatographic analysis of Freon 11 and Freon  12.
                                     87

-------
                                          PEAKS ARE LABELLED WITH
                                             RETENTION TIMES
                                4         6

                                     TIME (minutes)
10
12
Figure  32.      Typical gas chromatographic analysis of N2O.

                                     88

-------
TABLE 11.  NITROUS OXIDE RESULTS USING  GAS CHROMATOGRAPHIC
            DETECTION
Container
Steel No. 1

Steel No. 2

Steel No. 3

Steel No. 4
Stainless Steel

Area
(x)
869
921
1698
1776
809
792
Insufficient3
781
845
Cone. N0O (v/v)
(y)2
0.32 x 10-6
0.34 x 10"6
0.63 x 10-6
0.69 x 10"6
0.30 x 10"5
0.29 x 10"b

0.29 x 10-6
0.31 x 10"6
Calibration Curve:   y = 3.693 (10"10) x = 4.617 (10~9)

o
 One sample had been removed earlier for Freon analysis.  The amount
 remaining was insufficient for any second run.
                        TABLE  12.  FREONS
Container
Steel No. 4
Freon 11 (v/v)
1.7 x 10-10
Freon
2.8 x
12 (v/v)
io-10
TABLE 13.
Date
5-3-75
5-6-75
Freon 11
1.4 x lO'10
1.4 x IO-10
Freon 12
2.9 x 10"10
1.7 x Hf10


On May 6, 1975 the sample was taken after a storm in clear, breezy weather.
                                89

-------
ATMOSPHERIC MEASUREMENTS OF OZONE AND NITROGEN OXIDES

     Typical  diurnal variations of Og and NO2 dioxide are shown in Figure
33.   Similar  results  were  obtained during  several  days  of monitoring.
Throughout  the  tests  O3  concentrations  were  less than  50 ppb  and
remarkably constant except for  a decrease  at  night.  Due  to  the low  ELS
values and the attendant  necessity  of sampling over an extended period to
accumulate a measurable  sample,  the  influence of O« on HLS or (CEL^S
could not be  determined.

     Nitric oxide  and  NO2  concentrations  were  less than  2 ppb  except
during  the  night;  thereby  confirming  the  isolation of  the site.   The
increase  in  NO  at night  has  no  apparent  cause although  the  roughly
simultaneous   decrease  in  O3  concentrations  indicated  that  a  true  NO
increase is likely instead of some sampling artifact.
                                  90

-------
Figure 33.   A one day data recording of ambient NO and O3 concentrations.

-------
                                 SECTION 4







                   CONCLUSIONS AND RECOMMENDATIONS







1.    Real time  and  gas  chromatographic monitoring  of  sulfur  gases  --



     Direct  analysis of ambient air at Cedar  Island substantiated that the



     concentrations  of  gaseous  sulfur compounds  were  consistently  less



     than 5 ppb.   The fact that the Meloy SA-285 Sulfur  Analyzer and the



     Tracer 560 Gas  Chromatographic-FPD have  detection  limits of 0.5 ppb



     and 2-7 ppb,  respectively,  depending on the sulfur  species, makes a



     precise measurement  at ambient levels difficult.







     Recommendations:  The possibility of more  sensitive detection of H2S,



     (CHo)oS,  CHqSH,  etc. by monitoring chemiluminescence with Oo needs



     additional  study.   In-house  results with   a  commercial  O3  monitor



     adapted  for  study  of  Og  chemiluminescence with  H2S  and CKLSH



     showed that  the relative  responses of E^S and  CHoSH  are 1:22 and



     that  10   ppb  of  HoS  can be  detected.   A  low  pressure system



     optimized  for  light collection  could  be more sensitive than  an  FPD,



     especially for  gas  chromatographic analysis.
                                  92

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2.    Preconcentration techniques using  gold  bead traps --  Development of
     a  trapping technique for  sulfur compounds  using gold coated glass
     beads  is  occurring  at   the  University  of  South  Florida  under
     NSF-RANN  sponsorship.    The efficiency of  collection and  release as
     well as  the integrity  of  sulfur compounds  during transfer  between
     analysis  system  components have been  characterized to form a basis
     for  the  technique  as   documented  by Ammons   and  Braman  (7).
     Intercomparison  of  two  calibration  standards,  i.e., permeation tubes
     and known  solutions  of  thioacetemide in  aqueous  solution,  gave
     consistent results  and established  a  sensitivity limit of  0.1-0.2 ng of
     sulfur  with an almost  Linear  response using FPD  detection.  The
     calibration  precision was  +4.9% using 80%  confidence  limits  over a
     range  of 1-50 ng sulfur.

          Three  features  of  the  technique   have  been   identified  as
     requiring  improvement:   1)   speciation  of heavier  molecular  weight
     sulfur  compounds  (see  Figure 16 showing the unresolved  group of
     compounds referred to  as RS);  2) blanking of the gold-coated bead
     trap to  establish  a "zero" level or  blank response;  and,  3) use of
     manpower intensive efforts to  sample  and analyze.

     Recommendation:   Continuation  of  the NSF-RANN  grant  to  South
     Florida  should  be  encouraged  to evolve solutions  to the three factors
     of  concern.  Automatic samplers should  be  designed for future studies
     and an  EPA contract or  grant effort  should be  initiated for automation
     of  the analysis  phase of  the technique.

                                   93

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    The glass  bead technique has been successfully employed in its  initial
    application.   Vertical  profiles  show  increases  in  sulfur  compound
    concentration with  height  and  a  sulfur  compound mix  that changes
    with height and the direction of prevalent winds.

    Hydrogen  sulfide is increasingly  responsible for  sulfur  content  as
    height  is  increased to  10  meters  while  (CH3)2S,  (CH3)H2S2 and
    higher  molecular weight sulfur-containing  compounds  are  detected
    near the ground (see Figures 17-21).  An unexplained perturbation in
    the general  trend of increasing concentration with height occurs  at
    approximately  1 meter  height where  an  increase  in sulfur  is  seen.
    Wind masses from the marsh bring more (CHo)2S,  and (CHg)2S2 while
    samples  taken  in  the local pine forest  show  heavier sulfur compounds.

3.   Biogenic   emissions  —    Chamber   studies  coupled with  GC-FPD
    measurements  were  used  to identify  the  mix of sulfur compounds
    originating  from  the  marsh  and to  identify pertinent  parameters
    effecting  the   release  of   these   compounds.    The   majority  of
    measurements  were  made  over uncut marsh grass near  edgewater
    locations   where   water  was  carried  into  the  chamber   during
    measurement.

         Differences in  the mix of biogenic emissions from sand and  marsh
    were observed using an environmental chamber.   Dimethyl sulfide  is
    prevalent  over the edgewater marsh  areas,  HS over sand
                                  94

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areas; both  compounds occur in the  main marsh area.   Edgewater
emissions  are  estimated  to be  an  order  of magnitude  higher than
emissions  in  the marsh,  i.e.,  roughly 10 g/m2/yr as compared to 1
    2
g/m /yr.   Diurnal  variations in  chamber concentrations were observed
to  correlate  with   soil  temperature.   Tidal  effects  appear  to  be
supported by existing data but need additional confirmation.  Both H2S
and (CH3)2S were  detected in the ambient air,  using the previously
described gold gead technique,  when sampling of air masses from  the
marsh areas was  performed.  However the measurement of  (CH3)2S2
and higher molecular weight, S-containing compounds in  the ambient
air could  not be  satisfactorily  related to evolution  from the  Cedar
Island marshes.

     Because stirring  of  the volume  enclosed by  the environmental
chamber  was precluded  by the  presence  of marsh  grass,  questions
related to channeling of  the  air from  chamber  inlet to outlet  arose.
These questions were answered  by examining  data taken  during  a
period of measurement when chamber concentrations  were constant so
that  the  outlet  concentration  "f" could be measured as  function of
flow rate "F" to test the model presented on p. 41 of the text.  The
results are  shown  in Figures  34 and 35 and  suggest that  the model
agreed with experiment  to  within ± 20% even though stirring  of  the
chamber  volume  was  not  performed.   Comparison with  a   stirred
environmental chamber was performed at the beginning of  the chamber
studies (see Figure 36).   Reasonable  agreement was  obtained  after a
tight  seal has  been made  around the bottom edge of the chamber.

                              95

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                                      EFFECT OF FLOW RATE ON CHAMBER CONCENTRATION


300

250

~ 200
0>
0>
B.
eo 150
H-p
100
so
0
1 1 1 1
1
— o —
\
__ \ -_
\
— \ —

\

•••w* V ^•KIMB
— •»»»
— —
1 1 1 1
  0.5   1.0    1.5!   2.0

CHAMBER FLOW RATE, I/mini
                                                        CO
                                                          40
                                                          20
                                                                THURSDAY, 1 SEPT.!
                                                                                          I      I      L
                                                                  I      I      I      I      I      I      I
                                                           1500   1600  1700  1800!  1900  2000  2100   2200
                                                                               TIME, (DST)!
Figure 34.     Total sulfur content of environmental
               chamber samples as a  function of flow
               rate through the chamber
                                       Figure 35.     Chamber  concnetrations prior to
                                                     study shown in Figure 34.

-------


Wo
TS, percent raj
l<0; 01 -"Ji
01; o 01



_L
SUNDAY, 28 AUG., 1977
0
AT
- °— ^, *
S
	 CHAMBER #1 ^^V\
CHAMBER #2 ^^ ^ <-
1
1300 1400 1500 11

1

VER BRASS
LEWIS CREEK —
SAND PACKED
IOUND CHAMBER —
ov
? °~?
500 1700 1800 1900 2000
TIME, (DST)
SIDE BY SIDE CHAMBER COMPARISONS
Figure 36.
  of results from  stirred and unstirred environmental
          97

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         The effect of an  environmental  chamber on the unperturbed flux
     of  sulfur compounds has  recently been tested  in  some detail by  Hill,
     et  al.  (14).

         Recommendation:   Chamber measurements should be  used  with
     consideration for the  factors which  can alter  the unperturbed flux.
     However, a  simple chamber of the type used in the CIFS can establish
     the mix of sulfur compounds and the factors  which cause  changes in
     the emission rates.  These  results are  expected to be consistent  with
     ambient air measuremetns  made with the gold bead technique.

4.   The occurrence  of (CH3)2S as  the  major  gaseous component emitted
     from  certain  areas  of   the   Cedar  Island   marsh   prompted  an
     investigation into possible alternative measurement techniques for this
     gas.   Dr.  W.F.  Herget of  EPA  obtained   a   qualitative  infrared
     absorption  spectrum of this gas (see Figure  37).   An indication of
     significant  absorption  in  the spectral region around 10.5  microns led
     to  a  measurement of  the   absorption  coefficient  at CO2 laser   line
     positions  in this  region.   The  results,  obtained  by  Mr.  Richard
     Richmond, of Northrop Services  are listed below:
                                  98

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VD
VO
   Figure 37.   (CH3)2S Infrared Spectrum (60-1070 cm"1); top trace indicated zero
               absorption.

-------
    CO2 laser line      R(14)     10.286 pm      6.2 atm^cm"1



                        R(16)     10.272 |jm     13.6 atm^cm"1



                        R(18)     10.258 pm     11.6 atnfW1'
     Although  these  measurements  are   tentative,   they  suggest   the



     possibility of  measuring (CHQ)0S by an  optical technique, i.e., by
                                 O ^


     either an optoacoustic technique or a long path absorption technique.



     The measurement of  gas  emissions  as an  integrated  average over  a



     horizontal distance of several hundred meters at several heights would



     allow  emission rate  measurements  to be  inferred.   This  technique



     would   eliminate   the   uncertainties   associated   with   localized



     measurements.  Such  measurements appear feasible for gases such as



     CO2,  CO,  N2O,  NO,  NHg,  and (CHg)2S,  depending on the actual



     levels of concentration above the emitting area.







5.   Elemental  analysis of  x-ray fluorescence  of fine  and  coarse  particle



     fractions collected by the  dichotomous sampler and the tandem filter



     pack  showed  rough agreement between these  two collection devices.



     The tandem  filter system is not capable of reproducing the collection



     properties of  the dichotomous  sampler, but can  provide  approximate



     data for  suspended  particulates.  The dichotomous  sampler used in



     these  experiments may have had a plugged coarse particle  inlet.   This



     sampler  was  an  early  two-stage model  and  more recent one-stage



     designs are  expected to avoid  this possible difficulty.





                                  100

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5.   Determination of atmospheric  SO2 by the FPD (short collection times)
     and  the  tandem   filters   (long collection  times)  were  consistent.
     Detailed comparison is not possible because ambient SO2  levels were
     often at or below the FPD's minimum detection level.

6.   Determinations  of  atmospheric H2S  by the glass bead technique (short
     collection  tikes)  and  the  tandem  filters (long collection times) were
     consistent.   Detailed  comparison  is   not   possible  because  of  the
     difference  in  collection times  and the  very  sensitive  dependence of
     reduced sulfur gas  concentration  on  sampling location, as  shown by
     the height profiles in Figures 17-21.
                                     101

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            APPENDIX A
NATURAL SULFUR IN THE ATMOSPHERE
  What do the Sulfur Budgets Tell Us?
                by
           Robert W. Shaw
                 102

-------
                             SECTION A-l
                           INTRODUCTION

     A  controversy has  existed for some years  concerning the  relative
contributions  from  man-associated  and  natural  processes  to the level  of
sulfur  compounds  in  the   atmosphere.    Not  surprisingly,   the  bulk
contribution  from  man-associated  activities  are  much better known than
those from natural processes.   In an  effort to  understand the  flux  of
sulfur  compounds   through  the  atmosphere,  some authors  have  devised
budgets of the  "sulfur cycle."  These  budgets have  the following  common
characteristics:   1) they  divide  the earth into  compartments -- generally
lands,  oceans and atmosphere; 2)  various theoretically and experimentally
derived  values  for concentration of sulfur  compounds  (the  input  values)
are  used  to  estimate flow  between  compartments;  and  3) a  "balance"
between flows in and flows  out is assumed for one particular compartment,
and   this  balance   constraint  allows one  to  infer  any  sulfur flux not
accounted  for by  the estimated input  values.   This  inferred  flux  (the
output  value) is   the  contribution  from natural processes for  the sulfur
cycle models  discussed here.

     The various  budgets differ in their choice of input values and their
balance  constraints.  It is my  purpose  here,  to summarize the  various
budget  input  values and constraints. It will become clear that the

                                   103

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natural  sulfur  contributions  inferred  by   different  authors  are  very
sensitive  to  the characteristics, of  the  models used.   These comments are
not  critical   of  the  global  sulfur cycle  models;  the  uncertainties   of
budget-derived sulfur fluxes are  well understood by  their authors.   The
papers described  here may also  serve  as  evaluations and guides to the
literature of  atmospheric  chemistry  and its characterization, and the sulfur
budgets are  only part  of  these  interesting  publications.  This paper  is
simply  intended  to help  judge the  significance of the magnitudes of natural
sulfur fluxes derived from global sulfur budgets.   In the  following section,
budget  inputs and   constraints  will be  presented very  briefly  with  no
discussion of  their validity  or plausibility; for these the reader is  referred
to the  original articles.   In Section A-3 the implications of using a number
of model calculations are discussed.  The models  are  approximate, as are
the  budgets  themselves; they serve as order-of-magnitude  indications  of
the  consequences  of the natural sulfur evolution rate values.  In Section
A-4  the  measurement of natural  sulfur is  discussed.  The summary and
conclusions are in Section A-5.
                                   104

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                            SECTION  A-2

                    DESCRIPTION OF THE MODELS

     Junge  (19) has  developed a sulfur  budget based on a balance in  the
atmosphere; his values are given in Table A-l.  According to Junge,  the
best known sulfur source is  industrial (40 MT/yr, 1 MT  =  106 tons), and
the  best  known sink  is  precipitation (70  MT/yr).   Junge assumes that
natural evolution of sulfur from the land  (70 MT/yr) is balanced by "direct
uptake."  Since the amount of sulfur in precipitation over land  exceeds  the
industrial output  by  3O  MT/yr,  this amount  must be  supplied  by  the
ocean.  The "direct uptake"  by the ocean  is  70 MT/yr, the precipitation
contribution is 60 MT/yr. Therefore,  the ocean must  supply 160 MT/yr of
natural sulfur to balance  the atmosphere.

     Notice  that in this budget,  the natural evolution and absorption over
land  are  equal and form  a  closed system  with  no  effect on  the  other
compartments   of   the  model.    A  consequence  of  the  budget  is  the
accumulation of sulfur in the  ocean  as  a result  of river  run-off.  This
budget proposes total sulfur evolution from natural sources of 230 MT/yr;
of this, 140 MT/yr is absorbed  by direct uptake.   Nothing is known about
                                  105

-------
the lifetime of the  uptake process;  within the  limit  of  short  lifetimes for
evolution-absorption  there would  be  no  contribution to  the  atmospheric
sulfur burden.  A possible measure of the natural contribution to sulfur in
the  atmosphere over land is  given  by the  net sea to  land flux of 30
MT/yr.

     Kellog,  et al.  (20),  developed a global sulfur budget which is similar
to that of Junge.   Sulfur sources to  and sinks from the  atmosphere are
brought into balance by including the necessary flux  from natural sources.
Values from their budget are given in Table A-l.  Their inferred value for
naturally evolved sulfur  is 89  MT/yr; it is much lower than Junge's value
because:  1)  the dry deposition for sulfur  over  land  is much lower; 2) the
dry  deposition over ocean is zero; and 3) part of the wet deposition over
the  ocean is  supplied by sea  spray.   A consequence  of  the budget  by
Kellog, et al. is that the net  sulfur flux through the  atmosphere occurs
from the  land to sea.

      An  interesting global sulfur budget has been presented by Hallberg
(21)  who has  estimated a pre-industrial sulfur  cycle.  Again, the  sources
to  and  the  sinks   from  the  atmosphere  are balanced; but, unlike the
previous  budgets,  another balance  is  included  — a steady  state of the
pedosphere.   Inputs to the pedosphere are weathering, sea spray, and wet
and dry  deposition; outputs are river run off and natural evolution.   The
budget values are given  in Table A-l.
                                   106

-------
     In  Hallberg's  budget  the  natural  contribution  of  evolved  sulfur
compounds  is  inferred  by  satisfying  the  balance  requirements  for the
pedosphere;  it  is  about one  sixth  that estimated  by Junge and  one half
that estimated by Kellog, et al.   The lower value for natural sulfur  is due
to the values for wet and dry deposition.  These  wet and  dry deposition
rates  are  themselves  inferred   from   the  balance  requirement  for the
atmosphere.    A  consequence  of  the  budget  by  Hallberg  is  that  a
pre-industrial  net sulfur flux from  sea to  land  is reversed by industrial
output to become  a net flux from land to sea.

     Granat  (22)  has presented a global atmospheric budget in a companion
paper  to  that  by Hallberg.   Granat's  budget emphasizes  the sources of
sulfur in submicron particles.  Granat assumes a  balance in the atmosphere
and, from an  independent  review  of  the  literature,  develops a budget
which  agrees  well with Hallberg's  results  (see  Table  A-l). Both Granat
and  Hallberg  point  out  that   earlier sulfur  budgets  included  sulfur
deposition rates  which  depended on a rather  scant  and uncertain  data
base.   These sulfur  concentration  data  may have been high because of
influences  of  distant  pollution  sources.   Only  recently  have  workers
appreciated  the influence  of,  for example, industrial  centers  in  creating
pollution  episodes hundreds of kilometers away;  hence the early estimates
of  global  deposition rates and the  consequent natural  evolution rates may
have been too high.
                                   107

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                            SECTION  A-3
                             DISCUSSION
     Our  interest here  is  in the  information derived  from  the  budgets
concerning  the  relative   contributions  of  sulfur  compounds  to  the
atmosphere  by  man and by nature.   As we  have  seen, the estimated
natural contributions range from 40-230 MT/yr.  Can one then assume with
confidence that  the  real  value  lies  somewhere  between  these  limits?  I
believe not.   As we have already seen, these values are inferred from a
balance condition and depend on  values  for deposition rates over the entire
surface of the earth.   The balance condition, i.e., that the inputs to and
the outputs from the atmosphere are  equal, appears plausible.   Very little
is known, however,  about global deposition rates.

     We next  examine the implications of the budgets on sulfur burdens in
the atmosphere.  As the authors of the budgets recognized and discussed
at  some  length,  little  is  known  concerning  the  lifetimes  of  sulfur
compounds  in  the  atmosphere   especially  from  natural sources.    The
relation between lifetime and sulfur burden becomes visible in  a  rough way
when considering a  system with  sulfur input rate "I" (MT/yr), total sulfur
burden "S"  (MT) and output  rate constant "A" (yr"1). Then:

                                  108

-------
     \S = I (1 - e~Xt) ,
      S = I (l - e'Xt) .
This expression  shows that the sulfur burden will approach  a  steady state
value of IA.    Since the half life  "t^" is equal to ln2/A, the  sulfur burden
is  directly proportional to the atmospheric lifetime.

     Table A-2 shows a number of steady state atmospheric sulfur burdens
that are  due to the  natural  evolution rates taken from two of the global
sulfur  budgets  described  above  for  a  number  of  assumed  atmospheric
sulfur half lives (1 day and 10  days);  the simple expression  derived above
was used.  The burden  has  been expressed in  ppb (v/v)  by taking  the
                                      21
mass  of the  atmosphere to be  5  x 10   gm  (23) and assuming one sulfur
atom  per  molecule.   Table 2 gives  the  results for two  assumptions  for
mixing:   1)   the  sulfur compounds mix uniformly throughout the entire
atmosphere;  2) mixing  occurs uniformly throughout the atmosphere below
the altitude of 1 km (approximately 11% of the atmosphere  lies  below 1  km.
In  this calculation  it is  assumed that naturally evolved sulfur compounds
are  spread uniformly through their  mixing  volume  and that  all  have the
same  half  life.   The  wide  range of  values in  Table  A-22 shows  the
sensitivity  of steady state  atmospheric  sulfur  concentrations to  assumed
evolution  rates and atmospheric  lifetimes.
                                   109

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     The  calculation  just  outlined  is  very crude;  as mentioned  above, it
assumes  that  the sulfur compounds  are  uniformly  mixed throughout their
mixing volume  in the atmosphere.   In fact, since they are injected into  the
atmosphere  from the  land or from  a  sea  surface and leave the atmosphere
through  these  surfaces,  a  gradient  will  exist, the  highest  concentration
being  at  the  surface.  Since  we  live mostly  at or  near these  surfaces,
these higher  concentrations are most important; the  calculation,  however,
only roughly indicates a lower limit.
                                   110

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                             SECTION A-4

      MEASUREMENT OF NATURAL SULFUR IN THE ATMOSPHERE

     The  estimated  ratio of  the  natural evolution of sulfur  compounds to
man-associated (industrial) evolution in the models described above ranges
from  6/1 (19) to 1/2 (22).  Although one may argue  that more recent data
were  available to Granat than to Junge, the budgets  themselves present no
compelling evidence  that the natural sulfur evolution rates may not be even
larger than  those  estimated  by Junge or  alternatively,  even smaller than
those by  Granat.   It is clear that resolution of this question  would require
at least the  following:  1) measurement of natural  evolution rates of sulfur,
and 2) identification of the compounds  evolved.

     There are two means of estimating natural sulfur evolution rates: 1)
by  direct  measurement,  2)  indirectly,  by  inferrring  the  natural  sulfur
"background" levels from  measurement of atmospheric samples in areas not
affected  by   mean-associated  activities. The  best  procedure may  be  a
judicious   combination  of   these  two  methods.   The  indirect  method is
complicated by at least two factors: 1)  measurements of atmospheric samples
may   be  affected  by  long  range  effects  of distant industrial or  urban
pollution sources, 2) evolved sulfur compounds are  immediately  diluted by
the atmosphere in a complex and, presumably, varying manner.

                                  Ill

-------
     Direct  measurement can be carried  out by placing an  enclosure over
the surface to be  studied  and  sampling  the sulfur  compounds,  if any,  as
they  evolve  into  it.  A system  of this sort has been described by Aneja
(13)  and  others;   workers  at  the  EPA  are now  evaluating  the  use  of
sampling  enclosures in  the field  (this  report).  The  application  of gas
chromatography   to  the   collected   sample   provides  separation  and
identification  of  the  evolved sulfur  compounds.   Any sampling program
which uses  enclosures  will  have  to examine  the  effect,  if any,  of the
enclosure itself on the evolution rates.

      The obvious   difficulty  with  direct   measurement  is  the  need for
sufficient local data  to characterize adequately  a  global  process.    Some
investigators  believe that -most natural sulfur evolution occurs from marshy
and  estuarine areas.   If  this  is so,  and  if the sulfur evolution  from  a
given marsh  can be correlated  with  some large scale  characteristics of the
marsh, e.g.  soil composition,  the problem reduces  to  one of determining
the  sulfur  evolution from  the  various types of marsh  and multiplying by
the total area of these marshes.
                                   112

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                             SECTION A-5
                    SUMMARY AND CONCLUSIONS

     The  required  evolution of sulfur compounds  from marsh areas may be
estimated  according to the various global sulfur budgets by assuming the
following:   1)  that all marshes emit uniformly;  2) that aU other natural
sulfur sources are  negligible;  and 3) by taking the total marsh  area as 2.8
    5    2
x  10   km   (25).   By  simply  dividing the evolution  rates by  the emitting
area,  we  find that  the  sulfur  budgets of  Junge  and  Granat demand
evolution  rates  of  750  and 120 g/m /yr, respectively. The sulfur evolution
                                                                       Q
rate may  also be calculated, if all the land surfaces of the earth (1.5  x 10
   o                                       22
km )  emit uniformly; these rates are 1.4 g/m /yr  and 0.22 g/m  /yr for the
Junge and Granat budgets, respectively.
     The  calculation  is a crude one;  however it does  serve to tabulate the
natural sulfur evolution rates from the sulfur budgets so that they may be
compared  with the experimental measurements.   In  Table  A-33 the results
from  these calculations are  compared  with the  measurements  for  sulfur
evolution  made by  Aneja  (13)  in  the  Long Island tidal  marshes  and by
McClenny, et  al.  (this report) in the North  Carolina  tidal marshes.  In
these  experiments,   sampling  enclosures   were  used  and  the  sulfur
compounds were identified using gas chromatography.  Aneja1 s

                                  113

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measurements  were made in October  and November,  1974,  during the day
with soil sediment temperatures ranging from 6.6-17.6°C.  He remarks that
                                      o
his  highest  value  for  HgS,  39  g/m /yr is  "anomalously  high."  The
averages were  calculated neglecting the  "anomalously high" value  and also
neglecting  zero measurements.  The averages shown  for the measurements
by McClenny made in August,  1977, also neglect any zero values.

     The   experimental  measurements may  now  be  compared  with the
expected evolution rates based  on the sulfur budgets  and assuming that
only marsh lands evolve sulfur.   According  to Table  A-3,  the evolution
rates of sulfur compounds  from  experimental sites  the  on Long Island and
North  Carolina marshes  are  100-1000 times lower than  expected  from the
sulfur budgets. Therefore, if marshlands are the most important sources of
natural atmospheric sulfur, and,  if  the sulfur budget values  for natural
sulfur evolution rates are  correct, somewhere there  must exist very high
sulfur producing marshes.
                                  114

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                         TABLE A-l.   PRINCIPAL ELEMENTS IN THE GLOBAL SULFUR BUDGETS (MT/yr)



LAND
SEA
Evolution Deposition Evolution
Industrial
Junge
Kellog, et al.
HalTberg
pre- industrial:
present:
Granat
40
50
0
72
72
Natural Wet Dry Spray
70 70 70
89a 86 25 43
3 23"? 48*
1 T? 48d
6 55 40 48
Natural
160C

37
1Z
30e
Net Sulfur Flux
Deposition Through Atmosphere
Wet Dry Land -> Sea Sea -» Land
60 70 30
72 29
21h I?
39b 1
61 2 14
Underlined values are derived from balance constraints.

a)  Natural evolution occurs from land and "coastal areas." b)  wet + dry deposition,   c)  Natural  evolution  occurs  from
    "sea or coast."
d)  Sea spray not included in deposition calculations,   e)  Natural evolution occurs  from  land  and "coastal  areas."

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TABLE A-2.  STEADY STATE GLOBAL ATMOSPHERIC SULFUR FROM NATURAL
            SOURCES
Budget
Junge
Granat
Natural Evolution
Rate (MT/yr)
230
36
Sulfur
t1/2 = 1 day
1.4*
0.15**
0.21*
0.023**
Burden (ppb)
10 days
14*
1.5**
2.1*
0.23**
*Mixing Depth: 1 km (11% of atmosphere)
**Mixing Depth: « (100% of atmosphere)
                  TABLE A-3.  RATES OF NATURAL SULFUR EVOLUTION
A. Model Calculations
Budget From Marshes Only From All Land Surfaces
(2.8 x 10U m2) (1.5 x 1014 m2)
2
Junge 750 g/m /yr
Granat 120 g/m /yr
B.
Location
Aneja: Long Island
coastal marshes (1974)
McClenny: North Carolina —
coastal marshes (1977)
1.4 g/m /yr
0.22 g/m2/yr
Experimental Measurements
2
Sulfur Evolution Rate (g/m -yr)
H2S DMS
39 (max) 2.0 (max)
0.33 (av) 1.4 (av)
7.8 (max) 5.5 (max)
0.5 (av) 0.3 (av)
                              116

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               APPENDIX B
OPERATING CHARACTERISTICS OF THE SULFUR
      MONITOR USED AT CEDAR ISLAND
                    by
                R.W. Shaw
                    117

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     This section  briefly describes the response of the Meloy  SA 285 FPD



used at Cedar Island to CO2; Water Vapor,  and In-line Scrubbers.







     Bench  tests  run at EPA laboratories have shown that CO2  will cause



the detector response  to sulfur  to  decrease.  Over  the  range  0-150 ppb



SO0,  the presence  of  350  ppm   CO0 causes  a nearly linear  decrease in
   L*                                £t


response of 10%.  If, however,  the instrument is calibrated in the presence



of  350  ppm  CO2,  the  reproducibility  and  linearity  of  response  are



excellent.   Similarly,  water  vapor  causes   decreased  response  in  the



detector.   For  example, a  change from  0-100% relative humidity at  22°C



causes a depression of the zero response  by an amount equivalent to 3 ppb



so2.







     In order to  adjust the  instrument response for the effects of CO0 and
                                                                    M


water  vapor outlined above, calibrations in the field were made using air



containing 350 ppm CO2  and at approximately 80% relative humidity.  These



conditions roughly reproduced the properties  of the ambient air.







     During the   field  experiments,  the  sample line  into  the detector



contained a Teflon  filter to remove  sulfate aerosol particles.   In addition,



an SO2  gas  scrubber  (Meloy  Labs)  could  be moved in  and  out  of the



sample line.  The level of reduced  sulfur  gases in the ambient sample was



determined  by  the  difference:   total sulfur gases minus SO,,.   Laboratory
                                   118

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experiments at  EPA laboratories indicate  that, at 50%  relative humidity,
SO2  scrubbers remove 100% of SOg  down  to less than  0.2 ppb  and pass
75-90% HgS.   Warming  the scrubber improves  the H«S pass-through, but
does not bring it up to 100%.
                                    119

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                              REFERENCES
1.    Braman,  R.S.  and  Ammons,  J.M.   1978  —  Preconcentration  and
     Determination of Hydrogen Sulfide.  Anal. Chem.59:  992-996, 1978.

2.    Parker,  R.D.,  G.H. Buzzard,  T.G.  Dzubay and  J.P.  Bell, A  Two
     Stage   Respirable  Aerosol  Sampler  Using  Nucleopore  Filters  in
     Series.  Atmos. Environ., 11(7):617-621,  1977.

3.    Shaw,  R.W.  Atmospheric Instrumentation Branch,  Environmental
     Sciences  Research Laboratory, Research  Triangle Park,  N.C.  1977
     (Unpublished).

4.    Rehme,  K.A.,  B.E.  Martin,  and  J.A.  Hodgeson, 1973.  Tentative
     Method for Calibration of Nitric Oxide,  Nitrogen Dioxide,  and Ozone
     Analysis    by   Gas   Phase  Titration,  EPA-R2-73-246,   U.S.
     Environmental  Protection Agecy,  Research  Triangle  Park, N.C.
     1974.

5.    Brody,  S.S.  and  J.E.  Chaney.  Flame  Photometric Detector J.  Gas
     Chromatogr., 4:42-46,  1966.

6.    Stevens, R.K.  Mulik,  J.D., O'Keeffe,  A.E.  and Krost,  K.J.,  Gas
     Chromatography  of   Reactive   Sulfur   Gases   in   Air   at  the
     Parts-per-Billion Level. Anal. Chem.  43(7):827-831, 1971.

7.    Ammons, J.M.  Selective  Metal Surfaces for the  Analysis  of  Ambient
     Concentrations  of  Hydrogen  Sulfide.  M.S.   Thesis, University  of
     South Florida, Tampa,  Florida. 1976
8.    O'Keeffe,  A.E.  and G.C. Ortman,  Primary Standards for Trace Gas
     Analysis.   Anal. Chem. 38(6):760-763.

9.    National Academy of Sciences,  Washington, D.C.  1977.  "Medical and
     Biological  Effects of Environmental Pollutants, Nitrogen Oxides, 56;
     Ozone and Other Photochemical Oxidants,  126.

10.  Saltzman,  B.E., Colorimetric Microdetermination of Nitrogen Dioxide
     Anal.  Chem.  26(12): 1949-1954.
                                  120

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11.   Loo, B.W., J.M.  Jaklevic  and  F.S. Goulding,  1976. Dichotomous
     Virtual Impactors for Large Scale Monitoring of Airborne Particulate
     Matter.   In Fine Particles. B-Y. H. Liu ed. Academic  Press  Inc.,
     New York, New  York,  1976.
12 *   ???*?•   T'G->  and  R-K-  Stevens,  Ambient  Air Analysis  with
     Dichotomous Sampler and X-ray Fluorescence Spectrometer. Environ.
     Sci.  Technol.,  9(7):663-667,  1975.

13.   Aneja, V.P.,   Characterization of Sources  of  Biogenic  Atmospheric
     Sulfur Compounds, M.S.  Thesis  at N.C. State University, Raleigh,
     IN . u ,  1975 .

14.   Hill,  F.B.,  Aneja,  V.P.   and  R.M.  Felder,   A  Technique  for
     Measurement  of Biogenic  Sulfur  Emission  Fluxes.  J.  Environ.  Sci.
     Health,  A13(3): 199-225. 1978

15.   Wang, W.C.  Yung,  Y.L.,  Lacias,  A. A., Mo.  T.,  Hasen, J.E.,
     Greenhouse Effects Due to Man-Made Perturbations of Trace Gases.
     Science,  194(4266) :685- 690, 1976.

16.   Rassmussen,  R.A., 1974.  Tellus, 26,  254.

17.  Singh,  H.B.,   Salas,  L.J., and Cavanaugh,  L.A.  Distribution,
     Sources,  and  Sinks of Atmospheric Halogenated  Compounds. J.  Air
     PoUut. Control Assoc., 27(4): 332-336, 1977.

18.  Hanst,  P.L.,   Spiller, K.L.  Watts, D.M. Spence,  J.W., and Miller,
     J.W.,     Infrared    Measurement    of    Fluorocarbons,     Carbon
     Tetrachloride,   Carbonyl  Sulfide,  and  Other  Atmospheric Trace
     Gases.  J. Air Pollut. Control Assoc. 25(12): 1220- 1226,  1975.

19.  Junge,C.E. Air  Chemistry and Radioactivity .  Academic Press,  Inc.
     New York, 1963) pp 59-74.

20.  Kellogg,  W.W.,  R.D.  Cadle,  E.R.  Allen,  A.L.  Lazrus  and E.A.
     Marten, The Sulfur Cycle. Science, 175(4022) -.587-596, 1972.

21.  Hallberg,  R.,   The  Global  Sulfur  Cycle.  Ecol.  Bull.  (Stockholm)
     22:89-123, 1976.                                        ,

22.  Granat,  L.,  H.  Rodhe  and R.  Hallberg, The Global Sulfur Cycle,
     Ecol. Bull (Stockholm), 22:89-134, 1976.

23.  Chemical  Rubber Company.   Handbook  of Chemistry  and  Physics,
     Section F.  Cleveland Ohio.

24.  Woodwell,  G.M. P.M.  Rich and  C.A.S.  Hall,  in  G.M. Woodwell and
     E.V. Pecan  (eds.),   Carbon and  the  Biosphere,  U.S.  Dept.  of
     Commerce AEC Symposium Series 30:221-240, 1973  .
                                  121

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
  REPORT NO.
  EPA-600/2-79-Q04
4. TITLE AND SUBTITLE
  EVALUATION OF TECHNIQUES  OFR MEASURING BIOGENIC
  AIRBORNE SULFUR COMPOUNDS
  Cedar Island Field  Study  1977  	
             3. RECIPIENT'S ACCESSION NO.
             5. REPORT DATE
             6. PERFORMING cQANZAf ION COol
7. AUTHOR(S)
  W.A. McClenny, R.W.  Shaw,  R.E.  Baumgardner, R. Paur
  and A. rColeman
             8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  Environmental Sciences  Research Laboratory
  Office of Research and  Development
  U.S. Environmental Protection  Agency
  Research Triangle Park, N.C. 27711	
             10. PROGRAM ELEMENT NO.
               1AD712  BB-12,"16,  & 17(FY-78
             11. CONTRACT/GRANT NO.
 12. SPONSORING AGENCY NAME AND ADDRESS
  Environmental Sciences  Research Laboratory
  Office of Research and  Development
  U.S. Environmental Protection Agency
  Research Triangle Park,  N.C.  27711	
 — RTF, NC
             13. TYPE OF REPORT AND PERIOD COVERED
                 In-house
             14. SPONSORING AGENCY CODE
                 EPA/600/09
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT
       Sulfur in both gaseous  and particulate form has been measured near biogenic
  sources using new measurement techniques. The preconcentration of gaseous sulfur on
  gold-coated glass beads followed by desorption into a flame photometric detection for
  sulfur is shown to have a  detection limit of 0.1-0.2 ng of  sulfur and to allow for
  speciation of H2S, CHgSH and (GEL)  S at low parts per trillion levels.  Ambient
  levels of NO  and 03 were  found to  alter the molecular form of sulfur on the beads
  unless scrubbed from the sampled air.  A collection technique using tandem filters is
  extended from earlier efforts on fine and coarse aerosol to include collection of SO
  and H2S on chemically coated filters; these filters are analyzed by X-ray           2
  fluorescence for sulfur content.  Measurements of gases evolved from biogenic sources
  reveal H,S and (CH^S as  primary components with significant diurnal variations.
  Recommendations for further  instrument development are given.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
  COSATI Field/Group
 *Air pollution           *Evaluation
 *Sulfur  inorganic compounds
 *Sulfur  organic compounds
 *Biological productivity
 *Coasts
 *Measurement
 *Chemical Analysis
 Cedar  Island,  NC
     13B
     07 B
     07C
     08A
     08F
     07D
18. DISTRIBUTION STATEMENT

 RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
      UNCLASSIFIED
21. NO. OF PAGES
20. SECURITY CLASS (Thispage)
      UNCLASSIFIED
  138.
22. PRICE
EPA Form 2220-1 (Rev. 4-77)   PREVIOUS EDITION is OBSOLETE
                                            122

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