Measuring PCBs in Lake Ontario Surface Water Using Full-Scan Congener Methods Frederick Luckey U.S. Environmental Protection Agency, Region 2 Simon Litten New York State Dept. of Environmental Conservation Brian Fowler AXYS Analytical Services (Currently with Waters) Implications for designing environmental assessment programs
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Measuring PCBs in Lake Ontario Surface Water Using
Full-Scan Congener Methods
Frederick Luckey
U.S. Environmental Protection Agency, Region 2
Simon Litten
New York State Dept. of Environmental Conservation
Brian Fowler
AXYS Analytical Services (Currently with Waters)
Implications for designing environmental assessment programs
Objectives
• Support the information needs of the Lake Ontario
Lakewide Management Plan by measuring surface water
concentrations of:
PCBs
Pesticides
Dioxins / Furans
Mercury
PBDEs
• Identify contaminants exceeding water quality criteria.
Mono- chlorinated biphenyl 1 Chlorine
Di - chlorinated biphenyl 2 Chlorines
Tri- chlorinated biphenyl 3 Chlorines
Tetra - chlorinated biphenyl 4 Chlorines
Penta - chlorinated biphenyl 5 Chlorines
Hexa- chlorinated biphenyl 6 Chlorines
Hepta- chlorinated biphenyl 7 Chlorines
Octa- chlorinated biphenyl 8 Chlorines
Nona- chlorinated biphenyl 9 Chlorines
Deca - chlorinated biphenyl 10 Chlorines
Polychlorinated Biphenyl (PCB) Terminology
Congener – One of 209 possible configurations of the
number and position of chlorines on the two phenyl rings.
Homolog – Set of congeners having the same number of
chlorines / molecular weight.
10 PCB
Homolog
Groups
PCB Homolog Group
01020304050
mon
o di tri
tetra
penta
hexa
hepta
octa
nona
deca
Commercial PCB Formulation: Aroclor 1248
Us=
Polychlorinated Biphenyl (PCB) Terminology
Using Homologs to Simplify Data Analysis
%
Total
PCB
2’ 3’
5’
2
4
3
6 6’
4’
5
2,2’,4,4’- tetrachlorobiphenyl
IUPAC # PCB- 47
Polychlorinated Biphenyl (PCB) Terminology
Great Lakes Basin
• Spatially, temporally integrated
large volume water samples
• 24 hour continuous sampling
• Sampled from ~1 m depth
Lake Ontario Open Water Sampling
• Sampling in water depths >75 m
Fall 1999
Research Vessel Lake Guardian
EPA Great Lakes National Program
Office
Lake Ontario Surface Water Large Volume Sampling
Western / Central / Eastern Basin Sampling Grids
Province of Ontario
New York State
Nytex Netting
XAD Resin #1
Glass Fiber
Cartridge Filter
Surface Water Intake
1 um
Total Organics Platform Sampler (TOPS)
XAD Resin #2
~I m deep
filter out large
zooplankton
& debris
capture solids
capture dissolved
Lake
Large Volume Sampler
capture any break thru
Lake Ontario Surface Water Large Volume Sampling
• XAD Resin Columns 35 grams each
flow rate 300 – 600 ml / min
sample volumes ~800 L
• Glass Fiber Cartridge Filters 2.5” diameter x 4”
flow rate 3 L / min
1 micron nominal pore size
sample volumes ~5000 L
Dissolved Phase
Solids Phase
Calculating PCB Water Concentrations
PCB mass (picograms)
TOPS Sample Volume (L)
= Water Conc. (pg/L)
is inversely proportional to Sample
Specific
Detection
Limit
Sample
Volume
PCB Analytical Method
EPA Method 1668A
• High resolution gas chromatography & mass spectrometry
• Solvent extracted & cleaned with liquid chromatography
• Samples spiked with 13C12-labelled PCB congeners
• Selected ion method
• EI mode at 10,000 resolution
• Identifies 160 congeners / coeluting congener groups
Data Handling
• Lab results corrected based on 19 13C12-labelled PCB
congener surrogate recoveries
• Values <3X Lab or Field Blank Reject.
• Values >3X and <5X Lab or Field Blank Flag
• Non-detects = Zero
Data Handling
Lake Ontario Surface Water PCBs (pg/l)
Picograms/ Liter
(parts per quadrillion)
New York Water Quality Criteria
0 10 20 30 40 50
Central
Eastern
Western-1
Western-2
Solids
Dissolved
Can You Believe These Numbers?
Importance of Quality Control
Field Sampling QA Checks
• XAD capture efficiency
• Suspended Solids capture efficiency
• Check on XAD “wash-out” effect - 13C12 PCB surrogates
• Duplicate Samples & Field Blanks
• Manual Check on Flow Meter Accuracy
Lab QA Checks
• Samples spiked with internal 13C12 PCB surrogates
• Lab Blanks
XAD Resin – Use of “Washout” Field Surrogates
13C12-Labelled PCB-31, PCB-95 PCB-153
Picogram / sample
13C12-labelled PCB-153
0
50000
100000
150000
Lab
Blank
Field
Blank
XAD #1 XAD #2 XAD #3 XAD #4 XAD #5
Spike Conc.
Measured Conc.
Lake Ontario Surface Water PCBs – Raw pg/sample
Field & Lab Blank Issues
Picogram / sample
0 10000 20000 30000 40000
Blank
Blank
Blank
Filter
XAD
Filter
Filter
Filter
Filter
XAD
XAD
XAD
XAD
Field Sample
Lab Blank
Field Blanks
Lake Ontario Surface Water PCBs
XAD Resin Field Blank Issues
Picogram / sample
0 2000 4000 6000 8000 10000 12000
Sample - 1
Sample - 2
Sample - 3
Sample - 4
Sample - 5
Field Blank
BZ-44
BZ-45
BZ-68
XAD Column #1
Checking XAD Field Extraction Efficiency
XAD Column #2
( Divinylbenzene-styrene copolymer resin )
• Ideally all contaminants will be captured on 1st XAD column
XAD Resin Capture Efficiency
Percent of Congeners Captured on First XAD Column
• 100% of congener mass captured on the first column
Except for:
% Captured on 1st XAD Column
PCB
Congener
IUPAC ID
0 20 40 60 80 100
3
16
22
26 + 29
37
42
48
60
84
105
135 + 151 + 154
187
Duplicate Results
Comparison of PCB Homolog Total Concentrations
Pg / l
Pg / l
Dissolved Phase
XAD Resin
Solids Phase
Glass Fiber
Cartridge Filter
PCB Homolog Group
0
2
4
6
8
10
12
14
Mono Di Tri Tetra Penta Hexa Hepta Octa Nona Deca
West #1
West #2
0
2
4
6
8
10
12
14
Mono Di Tri Tetra Penta Hexa Hepta Octa Nona Deca
West #1
West #2
Lake Ontario Total PCBs
Homolog Percent Relative Abundance
%
Total
PCB
PCB Homolog Group
0
10
20
30
Mono Di Tri Tetra Penta Hexa Hepta Octa Nona
Central
Eastern
Western #1
Western #2
PCB Homolog Patterns in Field Blanks
%
Total
PCB
PCB Homolog Group
0
20
40
60
80
100
Mono Di Tri Tetra Penta Hexa Hepta Octa Nona Deca
Filter
XAD
Lake Ontario Surface Water PCBs
Suspended Solids
%
Total
PCB
PCB Homolog Group
0
10
20
30
Mono Di Tri Tetra Penta Hexa Hepta Octa Nona Deca
Central
Eastern
Western #1
Western #2
Average Lake Ontario Surface Water Total PCBs
Congeners > 1% of Total PCBs
PCB
Congener
IUPAC ID
0 2 4 6 8
147 + 149
3
56
129 + 138 + 160 + 163
153 + 168
83 + 99
118
37
86 + 87 + 97 + 119 + 125
64
26 + 29
49 + 69
40 + 41 + 71
66
22
1
110 + 115
90 + 101 + 113
15
21+ 33
16
93 + 95 + 98 + 100 + 102
17
4
61 + 70 + 74 + 76
8
18 + 30
52
31
20 + 28
11
% of Total PCB
Lake Ontario Surface Water Total PCBs Fall 1999
Relative Abundance of Dominant PCB Congeners
% of Total PCBs
Di
Tetra
Tri
Penta
0 2 4 6
4
8
11
18 + 30
20 + 28
31
52
61 + 70 + 74 + 76
93 + 95 + 98 + 100 + 102Eastern
Central
West #1
West #2
1242 1016 1248
4 4 4.5
8 9 10
11 0 0
18 + 30 9 11 10
20 + 28 3.6 4
31 4.5 4.7 9.3
52 4 4.3 8.3
61 + 70 + 74 + 76 5.6 3.75 6.64
93 + 95 + 98 + 100 + 102 0.66 0.22
% of PCB Aroclor Mixture
Dominant Lake Ontario PCB Congeners and Commercial PCB Formulations
PCB
Congener
IUPAC ID
Important Great Lakes Monitoring Programs
Understanding Contaminant Sources & Loadings
Niagara River Upstream-
Downstream Monitoring Program
International Atmospheric
Deposition Network
(IADN)
Sources of Lake Ontario
PCB Loadings (Kg/Year)
-400 -300 -200 -100 0 100 200
St. Lawrence R. Outflows
Atmospheric Volatiliz.
Atmospheric Deposition
Point Sources
Lake Ontario Basin Tribs.
Niagara R. Basin
Other Great Lakes
Kilograms Per Year
Net Change -283 Kg/Year
0 2 4 6 8
147 + 149
3
56
129 + 138 + 160 + 163
153 + 168
83 + 99
118
37
86 + 87 + 97 + 119 + 125
64
26 + 29
49 + 69
40 + 41 + 71
66
22
1
110 + 115
90 + 101 + 113
15
21+ 33
16
93 + 95 + 98 + 100 + 102
17
4
61 + 70 + 74 + 76
8
18 + 30
52
31
20 + 28
11
PCB Congeners Not Included in IADN & US/DS
PCB
Congener
IUPAC ID
PCB-11
IADN & US/DS
PCB-1
IADN
PCB-37
US/DS
% of Lake Ontario Surface Water PCBs
PCB-11 as % Total PCB
PCB-11 in Selected Surface Waters
0 2 4 6 8 10 12
Hudson River
Upstrm
Hudson River
Dwnstrm
Newark Bay
Lake Ontario
Long Island
Sound
Known Sources of PCB-11
Diarylide Yellow Pigment Manufacturing
• Associated with 3,3’-dichlorobenzidine salts
• Intermediates in the manufacture of diarylide yellow
• Loss of distal ammonia groups produces PCB-11
Designing Environmental Assessments
Selecting a PCB Analytical Method
• Financial resources
• Available Analytical equipment / labs / staff
• Regulatory data requirements
• Historical data sets
• Expected levels of contamination / interferences
• Detection limit requirements
Factors to Consider:
• Use full-scan congener methods on some samples to ensure
that all environmentally significant congeners are recognized.
• Ensure that detection limits are low enough to determine if
water quality criteria are being met.
• Evaluate full-scan results to determine if selected analytical
approach will adequately characterize target area.
Recommendations for Designing PCB Surface Water
Environmental Assessment Monitoring Strategies
Lake Ontario Surface Water PCBs Fall
1999
• Total PCBs are ~ 40 pg/L in open waters
• Tri- & Tetrachlorobiphenyls dominant homologs
• > 90% of PCBs in dissolved phase
• Similar congener & homolog patterns across lake
• Dominant congener, PCB-11, not included in routine