Download presentation
Presentation is loading. Please wait.
Published byClyde French Modified over 9 years ago
1
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
2
Objectives Support the information needs of the Lake Ontario Lakewide Management Plan by measuring surface water concentrations of: 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.
3
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 6 Chlorines Hexa- chlorinated biphenyl 6 Chlorines 7 Chlorines Hepta- chlorinated biphenyl 7 Chlorines 8 Chlorines Octa- chlorinated biphenyl 8 Chlorines Nona- 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
4
PCB Homolog Group Commercial PCB Formulation: Aroclor 1248 Us= Polychlorinated Biphenyl (PCB) Terminology Using Homologs to Simplify Data Analysis % Total PCB
5
2’3’ 5’ 2 4 3 66’ 4’ 5 2,2’,4,4’- tetrachlorobiphenyl IUPAC # PCB- 47 Polychlorinated Biphenyl (PCB) Terminology
6
Great Lakes Basin
7
Spatially, temporally integrated Spatially, temporally integrated large volume water samples large volume water samples 24 hour continuous sampling 24 hour continuous sampling Sampled from ~1 m depth Sampled from ~1 m depth Lake Ontario Open Water Sampling Sampling in water depths >75 m Sampling in water depths >75 m Fall 1999
8
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
9
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
10
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
11
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
12
PCB Analytical Method EPA Method 1668A High resolution gas chromatography & mass spectrometry High resolution gas chromatography & mass spectrometry Solvent extracted & cleaned with liquid chromatography Solvent extracted & cleaned with liquid chromatography Samples spiked with 13 C 12 -labelled PCB congeners Samples spiked with 13 C 12 -labelled PCB congeners Selected ion method Selected ion method EI mode at 10,000 resolution EI mode at 10,000 resolution Identifies 160 congeners / coeluting congener groups Identifies 160 congeners / coeluting congener groups
13
Data Handling Lab results corrected based on 19 13 C 12 -labelled PCB congener surrogate recoveries Lab results corrected based on 19 13 C 12 -labelled PCB congener surrogate recoveries Values <3X Lab or Field Blank Reject. Values <3X Lab or Field Blank Reject. Values >3X and 3X and <5X Lab or Field Blank Flag Non-detects = Zero Non-detects = Zero Data Handling
14
Lake Ontario Surface Water PCBs (pg/l) Lake Ontario Surface Water PCBs (pg/l) Picograms/ Liter (parts per quadrillion) New York Water Quality Criteria
15
Can You Believe These Numbers? Can You Believe These Numbers? Importance of Quality Control Importance of Quality Control Field Sampling QA Checks XAD capture efficiency Suspended Solids capture efficiency 13 C 12 Check on XAD “wash-out” effect - 13 C 12 PCB surrogates Duplicate Samples & Field Blanks Manual Check on Flow Meter Accuracy Lab QA Checks 13 C 12 Samples spiked with internal 13 C 12 PCB surrogates Lab Blanks
16
XAD Resin – Use of “Washout” Field Surrogates XAD Resin – Use of “Washout” Field Surrogates 13 C 12 -Labelled PCB-31, PCB-95 PCB-153 13 C 12 -Labelled PCB-31, PCB-95 PCB-153 Picogram / sample 13 C 12 -labelled PCB-153
17
Lake Ontario Surface Water PCBs – Raw pg/sample Field & Lab Blank Issues Field & Lab Blank Issues Picogram / sample
18
Lake Ontario Surface Water PCBs XAD Resin Field Blank Issues XAD Resin Field Blank Issues Picogram / sample
19
XAD Column #1 Checking XAD Field Extraction Efficiency Checking XAD Field Extraction Efficiency XAD Column #2 ( Divinylbenzene-styrene copolymer resin ) Ideally all contaminants will be captured on 1 st XAD column Ideally all contaminants will be captured on 1 st XAD column
20
XAD Resin Capture Efficiency XAD Resin Capture Efficiency Percent of Congeners Captured on First XAD Column 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
21
Duplicate Results Duplicate Results Comparison of PCB Homolog Total Concentrations Pg / l Dissolved Phase XAD Resin Solids Phase Glass Fiber Cartridge Filter PCB Homolog Group
22
Lake Ontario Total PCBs Lake Ontario Total PCBs Homolog Percent Relative Abundance Homolog Percent Relative Abundance % Total PCB PCB Homolog Group
23
PCB Homolog Patterns in Field Blanks PCB Homolog Patterns in Field Blanks % Total PCB PCB Homolog Group
24
Lake Ontario Surface Water PCBs Lake Ontario Surface Water PCBs Suspended Solids Suspended Solids % Total PCB PCB Homolog Group
25
Average Lake Ontario Surface Water Total PCBs Congeners > 1% of Total PCBs Congeners > 1% of Total PCBs PCB Congener IUPAC ID % of Total PCB
26
Lake Ontario Surface Water Total PCBs Fall 1999 Lake Ontario Surface Water Total PCBs Fall 1999 Relative Abundance of Dominant PCB Congeners Relative Abundance of Dominant PCB Congeners % of Total PCBs Di Tetra Tri Penta
27
Dominant Lake Ontario PCB Congeners and Commercial PCB Formulations PCB Congener IUPAC ID
28
Important Great Lakes Monitoring Programs Important Great Lakes Monitoring Programs Understanding Contaminant Sources & Loadings Understanding Contaminant Sources & Loadings Niagara River Upstream- Downstream Monitoring Program International Atmospheric Deposition Network (IADN)
29
Sources of Lake Ontario PCB Loadings (Kg/Year) Net Change -283 Kg/Year
30
PCB Congeners Not Included in IADN & US/DS 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
31
PCB-11 as % Total PCB PCB-11 in Selected Surface Waters
32
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
33
Designing Environmental Assessments Selecting a PCB Analytical Method Selecting a PCB Analytical Method Financial resources Financial resources Available Analytical equipment / labs / staff Available Analytical equipment / labs / staff Regulatory data requirements Regulatory data requirements Historical data sets Historical data sets Expected levels of contamination / interferences Expected levels of contamination / interferences Detection limit requirements Detection limit requirements Factors to Consider:
34
Use full-scan congener methods on some samples to ensure that all environmentally significant congeners are recognized. 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. 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. 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 Environmental Assessment Monitoring Strategies
35
Lake Ontario Surface Water PCBs Fall 1999 Lake Ontario Surface Water PCBs Fall 1999 Total PCBs are ~ 40 pg/L in open waters Total PCBs are ~ 40 pg/L in open waters Tri- & Tetrachlorobiphenyls dominant homologs Tri- & Tetrachlorobiphenyls dominant homologs > 90% of PCBs in dissolved phase > 90% of PCBs in dissolved phase Similar congener & homolog patterns across lake Similar congener & homolog patterns across lake Dominant congener, PCB-11, not included in routine Dominant congener, PCB-11, not included in routine monitoring, unrelated to commercial PCB mixtures monitoring, unrelated to commercial PCB mixtures
36
Acknowledgements Thanks for the support provided by: USEPA Great Lakes National Program Office Captain & Crew of the R/V Lake Guardian
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.