BOREAS TGB-07 Dry Deposition Herbicide and Organochlorine Flux Data

Summary:

The BOREAS TGB-07 team measured the concentration and flux of several 
agricultural pesticides in air, rainwater, and dry deposition samples in order 
to determine the associated yearly deposition rates.  This data set contains 
information on the dry deposition flux of seven herbicides [2,4-
dichlorophenoxyacidic_acid (2,4-D), bromoxynil, dicamb, 2-methyl-4-
chlorophenoxyacetic acid (MCPA), triallate, trifluralin, and diclop-methyl] 
known to appear in the atmosphere of the Canadian prairies.  Also, the 
concentration of three herbicides (atrazine, alaclor and metolachlor), two 
groups of insecticides (lindane and breakdown products and dichlro-diphenyl-
trichloroethane (DDT) and breakdown products), and several polychlorinated 
biphenyls commonly used in the central United States were measured.  All of 
these chemicals are reported, in the literature, to be transported in the 
atmosphere. Many have been reported to occur in boreal and arctic food chains.  
The sampling was carried out from June 16 to August 13, 1993 and May 4 to July 
20, 1994 at the BOREAS site in the Prince Albert National Park (Waskesiu).  The 
data are stored in tabular ASCII files.

Table of Contents

   *  1 Data Set Overview
   *  2 Investigator(s)
   *  3 Theory of Measurements
   *  4 Equipment
   *  5 Data Acquisition Methods
   *  6 Observations
   *  7 Data Description
   *  8 Data Organization
   *  9 Data Manipulations
   *  10 Errors
   *  11 Notes
   *  12 Application of the Data Set
   *  13 Future Modifications and Plans
   *  14 Software
   *  15 Data Access
   *  16 Output Products and Availability
   *  17 References
   *  18 Glossary of Terms
   *  19 List of Acronyms
   *  20 Document Information

1. Data Set Overview

1.1 Data Set Identification

BOREAS TGB-07 Dry Deposition Herbicide and Organochlorine Flux Data

1.2 Data Set Introduction

This data set contains herbicide and organochlorine quantities in dry deposition 
collected from Waskesiu.

1.3 Objective/Purpose

The objective of this study was to measure the dry deposition of herbicides and 
organochlorines in the boreal forest at Waskesiu.
	
1.4 Summary of Parameters and Variables

This data set contains herbicide and organochlorine quantities in dry deposition 
data collected Waskesiu.

1.5 Discussion

The deposition into the boreal forest of seven herbicides [2,4-
dichlorophenoxyacidic acid (2,4-D), bromoxynil, dicamba, 2-methyl-4-
chlorophenoxyacetic acid (MCPA), triallate, trifluralin, and diclop-methyl] 
known to appear in the atmosphere of the Canadian prairies, three herbicides 
(atrazine, alachlor and metolachlor) commonly used in the central United States, 
two groups of insecticides (lindane and breakdown products and dichlro-diphenyl-
trichloroethane (DDT) and breakdown products)plus several polychlorinated 
biphenyls was measured. All of these chemicals are reported, in the literature, 
to be transported in the atmosphere. Many have been reported to occur in boreal 
and arctic food chains.  The sampling was carried out at the BOREAS site in the 
Prince Albert National Park (Waskesiu).

1.6 Related Data Sets

BOREAS TGB-07 Ambient Air Herbicide and Organochlorine Concentration Data
BOREAS TGB-07 Rainwater Herbicide and Organochlorine Concentration Data
BOREAS TGB-09 Above-Canopy NMHC at SSA-OBS, SSA-OJP, and SSA-OA Sites
BOREAS TGB-10 Volatile Organic Carbon Data over the SSA
BOREAS TGB-10 Oxidant Concentration Data over the SSA
BOREAS TGB-10 Oxidant Flux Data over the SSA.

2. Investigator(s)

2.1 Investigator(s) Name and Title

Don Waite
Environment Canada

Allan Cessna
Agriculture and Agri-Foods Canada

Narine Gurprasad
Environment Canada

2.2 Title of Investigation

2.3 Contact Information

Contact 1
---------
Dr. Don Waite
Environment Canada
Regina, Saskatchewan
Canada
(306) 780-6438
(306) 780-7614 (fax)
Don.Waite@EC.GC.CA

Contact 2
---------
Sara K. Conrad
Raytheon STX Corporation
NASA/GSFC
Greenbelt, MD
(301)286-2624
Sara.Golightly@gsfc.nasa.gov

3. Theory of Measurements

The dry/wet deposition sampler employs an XAD-2 resin column to extract dry 
deposits from a continuously flowing sheet of water and also collects separate 
rain samples.  The sampler consists of a 1 x 0.5 m, stainless steel (316 grade) 
tray, with 5 cm high sides,  onto which water is sprayed from a header pipe 
located at one end.  The water runs down the tray, collecting any particles 
which fall onto it.  In addition, aerosols and vapour phase chemicals which 
contact the  water surface may be absorbed. As the water moves through the 
apparatus,  it passes from the tray down into reservoir within the body of the 
sampler.  Water from this reservoir is pumped, through a composite column (glass 
wool/XAD-2 resin) which retains the particulates and dissolved organic 
chemicals, and then returns back to the header pipe where it recirculates across 
the collecting surface.  At the end of the sampling period the glass wool/XAD-2 
resin column is extracted with acetone and the extract analyzed for target 
chemicals.

4. Equipment:

4.1 Sensor/Instrument Description

4.1.1 Collection Environment

The data were collected under all environmental conditions.

4.1.2 Source/Platform

Ground.

4.1.3 Source/Platform Mission Objectives

None given.

4.1.4 Key Variables

The key variable is herbicide or organochlorine quantity in dry deposits per 
day.

4.1.5 Principles of Operation

As the water moves through the apparatus it passes, from the tray, down into a 
32 L reservoir within the body of the sampler.  Water from this reservoir is 
pumped, through a composite column (glass wool/XAD-2 resin) which retains the 
particulates and dissolved organic chemicals, and then returns back to the 
header pipe where it recirculates across the collecting surface.  The tray 
slopes (5%) from about 105 to 100 cm above the ground surface.  A constant 
speed, stainless steel centrifugal pump is used to circulate the water.  The 
flow rate to the header is adjustable by means of a ball valve located between 
the pump and resin column.  Water flow is from 3.5 to 4 L min-1 which produces 
enough water to cover the entire tray surface without causing splash at the 
header.   This flow rate results in the circulation or turnover of the water 
contained in the reservoir every 8 - 9 minutes.  This turnover rate, combined 
with the design whereby water is returned to the top and drawn off from the 
bottom of the reservoir, reduces the potential for particle trapping within the 
reservoir.  All parts of the sampler in contact with the water flow are 
constructed of either 316 grade stainless steel or Teflon.  

The deionized water used is acidified to pH  1.8, using sulphuric, acid to 
facilitate the adsorption of acidic pesticides by the XAD-2 resin.  Because such 
a large volume (~30 L) of deionized water circulates through the XAD-2 resin, it 
is imperative that the water be free of even very small concentrations of the 
compounds to be monitored.  This is achieved by circulating, for 30 min at the 
beginning of each sampling period, the acidified deionized water through the 
sampler and through an XAD-2 clean-up cartridge (described below) identical to 
the one used to collect the samples.  A sample of the process water is taken for 
analysis just prior to replacing the clean-up column.  This process water sample 
is extracted and analysed to verify that no residual contamination is still 
present.  If detectable background contamination is found in the process water, 
the sample can be rejected or corrections can be made. 

The structure and reproducible packing of the XAD-2 resin column are critical to 
the operating efficiency of the sampler.  The column consists of a 5 cm inside 
diameter, stainless steel pipe fitted at one end with a coupling. From two to 
several layers of glass marbles are placed into the bottom or inlet of  the 
column to diffuse the flow of water entering the column.  By varying the volume 
of glass marbles, the volume of resin can be changed.  Our columns contained 2 
layers of marbles and 250 mL of resin, the maximum volume available in the 
length of pipe used. 

Resting on the marbles is a perforated disc of 50 mm thick Teflon followed by a 
plug of approximately 2 g of Pyrex brand borosilicate glass wool.  The glass 
wool retains the 250 mL of XAD-2 resin (Caledon Laboratories Ltd., Georgetown, 
ON) which is packed into the column as a slurry in deionized water.  The resin 
is capped with approximately 12 g of glass wool that is compressed with the 
upper sieve plate (50 mm Teflon) which also functions as a washer.  The upper 
sieve plate/washer is held in place by a short section of pipe attached to the 
lower section with 3 stainless steel bolts.  The upper section of pipe permits 
the water to leave the resin with a free and unrestricted flow, reducing the 
possibility of channelled flow within the resin.  Tests of water flow in the 
column, conducted using dyes, showed uniform contact with the resin.   The upper 
or outlet section of column connects directly with a tube leading to the header 
pipe.

4.1.6 Sensor/Instrument Measurement Geometry

1 - Dust Collector; a newly designed sampler employing an XAD-2 resin column to 
extract dry deposits from a continuously flowing sheet of water and collecting 
separate rain samples;
2 - PUF Sampler; a high volume air sampler collecting ambient concentrations of 
material on a sampling unit consisting of a glass fibre filter followed by a 
polyurethane foam (PUF) plug and XAD-2 resin cartridge.

4.1.7 Manufacturer of Sensor/Instrument

None given.

4.2 Calibration

4.2.1 Specifications

None given.

4.2.1.1 Tolerance

None given

4.2.2 Frequency of Calibration

None given.

4.2.3 Other Calibration Information

The water flow through the sampler was from 3.5 to 4.0 l min-1.

5. Data Acquisition Methods

The herbicide analyses were carried out at the Agriculture and Agri-Food Canada 
Research Station at Regina, Saskatchewan, whereas insecticide and organochlorine 
analysis was carried out by the Environment Canada laboratory in Edmonton, 
Alberta.  All residues were quantified and confirmed using a Hewlett-Packard gas 
chromatograph equipped with a mass selective detector (GC-MSD).  

Elution of XAD-2 Resin Columns used in the Dust Collector  The wet XAD-2 resin 
columns were vacuum aspirated for 30 minutes to remove as much residual water as 
possible.  Air entering the columns was passed through a PUF plug to remove 
organic contaminants.  The columns were then extracted by back flushing with 
1000 mL of acetone at a rate of 10 mL min-1.  This extracted both the organic 
compounds of interest and any remaining residual water from the resin.  The 
acetone extract was concentrated to ~ 100 mL using a rotary evaporator (water 
bath at 30oC) and then transferred to a 250 mL evaporating flask and further 
concentrated as an aqueous phase to ~ 50 mL.  This aqueous phase was then made 
up to volume (100 mL) with water and divided into 50 mL aliquots.  One aliquot 
was acidified to pH 2 with dilute H2SO4 solution, extracted with  dichloromethane 
and the extract methylated with diazomethane and subjected to Florisil column 
clean-up prior to GC-MSD analysis for extracted herbicides (Cessna et al., 
1985).  The second aqueous aliquot was extracted with dichloromethane, subjected 
to Florisil column clean-up and analysed for insecticides and organochlorines by 
GC-MSD.

Extraction of PUF/XAD-2 Sampling Units On alternate weeks the PUF/XAD-2 sampling 
units were extracted for herbicide or for insecticide and organochlorine 
content.  For herbicide analysis, the sampling unit was soxhlet extracted for 8 
h with acetone (Grover et al., 1994).  The acetone extract was concentrated to ~ 
0.5 mL using a rotary evaporator (water bath 30o C) and then methylated with 
ethereal diazomethane.  The methylated extract was subjected to Florisil column 
cleanup prior to analysis by GC-MSD.  For insecticide and organochlorine 
analysis, the PUF sampling unit was soxhlet extracted for 12 h with 
dichloromethane.  The extract was concentrated using a rotary evaporator and 
then subjected to Florisil column cleanup prior to analysis by GC-MSD.

Residue Analysis and Confirmation  The Hewlett-Packard GC-MSD system and 
operating conditions used for herbicide residue analysis have been described 
previously (Cessna et al., 1997).  A similar GC/MSD system was used for 
inseecticide and organochlorine analysis, however the column employed was a 30 m 
x 0.25 mm I.D. Rtx-5 column (0.25 ?m film thickness).  For operation of the GC, 
helium was used as the carrier gas and the temperature program was: initially 
held at 80oC for 1 minute then ramped to 200oC at 15oC/min;  held at 200oC for 5 
minutes then increased at 8oC/min to 300oC and held for 10 minutes. A 
split/splitless injector was used in the splitless mode. Injection port and 
transfer line temperatures were 270oC and 280oC, respectively.  

Depending on the compound, from two to four ions were monitored on the MSD.  The 
presence of each compound was considered to be confirmed if: all ions monitored 
were present; a peak appeared at the retention time (? 0.02 min) obtained for a 
standard solution of the pesticide in the reconstructed chromatiograms of all 
ions; and,  the peak area ratio was within 30% of the ratio obtained using a 
standard solution of the pesticide.

6. Observations

6.1 Data Notes

None.

6.2 Field Notes

None.

7. Data Description

7.1 Spatial Characteristics

7.1.1 Spatial Coverage

The North American Datum 1983 (NAD83) coordinates for the SSA measurement site 
are:
                Longitude       Latitude
               ----------      ---------
Waskesiu       106.0678 W      53.9178 N

7.1.2 Spatial Coverage Map

None given.

7.1.3 Spatial Resolution

The measurements were made at a single location in the SSA.

7.1.4 Projection

Not applicable.

7.1.5 Grid Description

Not applicable.

7.2 Temporal Characteristics

7.2.1 Temporal Coverage

The data were collected from June 16 to August 13, 1993 and May 4 to July 20, 
1994

7.2.2 Temporal Coverage Map

All the data were collected at the same location.

7.2.3 Temporal Resolution

The samplers operated 24 hours per day over each 7 day sampling period. 

7.3 Data Characteristics                                                        
                                                                                
Data characteristics are defined in the companion data definition file 
(tgb7ddho.def).

7.4 Sample Data Record                                                          
                                                                                
Sample data format shown in the companion data definition file (tgb7ddho.def).

8. Data Organization

8.1 Data Granularity

All of the Dry Deposition Herbicide and Organochlorine Flux Data are contained 
in one dataset.

8.2 Data Format(s)

The data files contain numerical and character fields of varying length 
separated by commas. The character fields are enclosed with single apostrophe 
marks. There are no spaces between the fields. Sample data records are shown in 
the companion data definition file (tgb7ddho.def).

9. Data Manipulations

9.1 Formulae

9.1.1 Derivation Techniques and Algorithms

None given.

9.2 Data Processing Sequence

9.2.1 Processing Steps

None given.

9.2.2 Processing Changes

None given.

9.3 Calculations

9.3.1 Special Corrections/Adjustments

None given.

9.3.2 Calculated Variables

None given.

9.4 Graphs and Plots

None given.

10. Errors

10.1 Sources of Error

Irreproducible packing of the XAD-2 resin column.

10.2 Quality Assessment

Standard laboratory procedures involving blanks, spikes and replicates.

10.2.1 Data Validation by Source

None given.

10.2.2 Confidence Level/Accuracy Judgment

None given.

10.2.3 Measurement Error for Parameters

None given.

10.2.4 Additional Quality Assessments

None given.

10.2.5 Data Verification by Data Center

The data were examined for general consistency and clarity.

11. Notes

11.1 Limitations of the Data

None given.

11.2 Known Problems with the Data

None given.

11.3 Usage Guidance

None given.

11.4 Other Relevant Information

None given.

12. Application of the Data Set

The data can be used to quantify the Trace organic contaminants entering the 
site from atmospheric transport and identify chemicals which require further 
research.

13. Future Modifications and Plans

None given.

14. Software

14.1 Software Description

None given.

14.2 Software Access

None given.

15. Data Access

15.1 Contact Information

Ms. Beth Nelson
BOREAS Data Manager
NASA GSFC
Greenbelt, MD 
(301) 286-4005
(301) 286-0239 (fax)
Elizabeth.Nelson@gsfc.nasa.gov

15.2 Data Center Identification

See 15.1.

15.3 Procedures for Obtaining Data

Users may place requests by telephone, electronic mail, or FAX.

15.4 Data Center Status/Plans

The TGB-07 dry deposition herbicide data are available from the EOSDIS ORNL DAAC 
(Earth Observing System Data and Information System) (Oak Ridge National 
Laboratory) (Distributed Active Archive Center). The BOREAS contact at ORNL is: 

ORNL DAAC User Services
Oak Ridge National Laboratory
(865) 241-3952
ornldaac@ornl.gov
ornl@eos.nasa.gov

16. Output Products and Availability

16.1 Tape Products

None

16.2 Film products

None.

16.3 Other products

Comma delimited ASCII files

17. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

None given.

17.2 Journal Articles and Study Reports

Cessna, A. J., Grover, R., Kerr, L. A. and Aldred, M.L. (1985) A multiresidue 
method for the analysis and verification of several herbicides in water.  J. 
Agric. Food Chem.  33, 504-507.

Cessna, A. J., Waite, D. T. and Constable, M. (1997) Concentrations of 
pentachlorophenol in atmospheric samples from three Canadian locations, 1994. 
Bull. Environ. Contamin. Toxicol. 58, 651-658.

Grover, R., Smith, A. E.  and Cessna, A. J. (1994) Fate of bromoxynil  n-
butyrate and iso-octanoate applied as a mixture to a wheat field.  J. Environ. 
Qual.  23(6), 1304-1311.

Sellers, P., F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. 
Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). 

Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. 
Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E. 
Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and 
early results from the 1994 field year. Bulletin of the American Meteorological 
Society. 76(9):1549-1577. 

Sellers, P., F. Hall, K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 
1994 Operations. NASA BOREAS Report (OPS DOC 94). 

Sellers, P., F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. 
Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). 

Sellers, P., F. Hall, K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere Study: 
1996 Operations. NASA BOREAS Report (OPS DOC 96). 

Sellers, P.J., F.G. Hall, R.D. Kelly, A. Black, D. Baldocchi, J. Berry, M. Ryan, 
K.J. Ranson, P.M. Crill, D.P. Lettenmaier, H. Margolis, J. Cihlar, J. Newcomer, 
D. Fitzjarrald, P.G. Jarvis, S.T. Gower, D. Halliwell, D. Williams, B. Goodison, 
D.E. Wickland, and F.E. Guertin. (1997). "BOREAS in 1997: Experiment Overview, 
Scientific Results and Future Directions", Journal of Geophysical Research 
(JGR), BOREAS Special Issue, 102(D24), Dec. 1997, pp. 28731-28770.  

Thompson, T. S., R. G. Treble, D. T. Waite and A. J. Cessna. 1997.  
Identification of pentachloronitrobenzene in ambient air extracts.  Bull. 
Environ. Toxicol. Chem. 58:939-944.

Waite, D. T., A. J. Cessna, N. P. Gurprasad and J. Banner. ___. Evaluation of a 
new sampler for collecting separate dry and wet atmospheric depositions of trace 
organic chemicals. Atmos. Environ. accepted

Waite, D. T., N. P. Gurprasad, A. J. Cessna and D. V. Quiring. ____.  
Atmospheric pentachlorophenol concentrations in relation to air temperature at 
five Canadian locations. Chemosphere accepted.  

Waite, D. T., N. P. Gurprasad and M. B. Constable. 1996 Concentrations of 
pentachlorophenol and some related compounds in seasonally collected atmospheric 
samples from five Canadian locations.  Organohalogen Compds. 28:482-489.

17.3 Archive/DBMS Usage Documentation

None.

18. Glossary of Terms

None given.

19. List of Acronyms

    BOREAS  - BOReal Ecosystem-Atmosphere Study
    BORIS   - BOREAS Information System
    DAAC    - Distributed Active Archive Center
    EOS     - Earth Observing System
    EOSDIS  - EOS Data and Information System
    GSFC    - Goddard Space Flight Center
    NASA    - National Aeronautics and Space Administration
    NSA     - Northern Study Area
    ORNL    - Oak Ridge National Laboratory
    PANP    - Prince Albert National Park
    SSA     - Southern Study Area
    URL     - Uniform Resource Locator (a World Wide Web address)

20. Document Information

20.1 Document Revision Date

     Written:       04-Dec-1997
     Last updated:  14-Sep-1998

20.2 Document Review Date(s)

     BORIS Review:  27-Aug-1998
     Science Review:

20.3 Document

20.4 Citation

20.5 Document Curator

20.6 Document URL

Keywords
organochlorines, herbicides, atmospheric transport, rain, dry deposition, 
ambient air

TGB07_Dry_Herb_Conc.doc
09/14/98