Analytical Assessment, Technology Advancment & Common ...
Analytical Assessment, Technology Advancment & Common Analytical Pitfalls Jim Occhialini Alpha Analytical Labs
Managing PCB Contaminated Caulking in Older Buildings Analytical Considerations EBC Rhode Island Chapter Remediation Program October 22, 2012
www.alphalab.com
Jim Occhialini Alpha Analytical
What are PCBs? • Polychlorinated Biphenyls chemical structure having two benzene rings connected by one bond and having 1 -10 chlorines on the ring
• 10 possible positions leads to 209 possible combinations – 209 individual PCB compounds – CONGENERS • Common analytical subsets: NOAA & WHO lists
• Can be grouped according to the # of chlorine atoms – Level (or Degree) of chlorination – HOMOLOGUES (Homologs) www.alphalab.com
Cl--3
2
2’
3’
--Cl
4’
4
Cl--5
www.alphalab.com
6
6’
5’
Poly – Chlorinated - Biphenyls
Chlorinated Biphenyls by Homolog Empirical Formula C12 H10 C12 H9Cl C12 H8Cl2 C12 H7Cl3 C12 H6Cl4 C12 H5Cl5 C12 H4Cl6 C12 H3Cl7 C12 H2Cl8 C12 H1Cl9 C12 Cl10 www.alphalab.com
Molecular # Isomers Weight 154.1 1 188.0 3 222.0 12 256.0 24 289.9 42 323.9 46 357.8 42 391.8 24 425.8 12 459.7 3 493.7 1
Monochlorobiphenyls Dichlorobiphenyls Trichlorobiphenyls Tetrachlorobiphenyls Pentachlorobiphenyls Hexachlorobiphenyls Heptachlorobiphenyls Octachlorobiphenyls Nonochlorobiphenyls Decachlorobiphenyl
Aroclors • Most commonly known commercial trade name for PCB mixtures • Mixtures of PCB congeners • Nine Aroclors: – 1221, 1232, 1242/1016, 1248, 1254, 1260, 1262, 1268 Last 2 digits: % Cl by mass
1254 # carbon atoms www.alphalab.com
54% Cl
Total 1254 Composition I.S. Cl4 – 16% Cl5 – 60% Cl6 - 24%
Time www.alphalab.com
Analysis of PCBs • Preparative Methods – Extraction (TSCA?) • Soxhlet, microwave, ASE, MSE, sonication
– Clean up • H2SO4 , florisil, silica gel, GPC
• Determinative Methods – Instrumental analysis • GC – ECD Method 8082 – Aroclors, congeners
• Low resolution GC/MS Method 680/8270M • High resolution GC/MS Method 1668 www.alphalab.com
PCB Analysis at TSCA Sites • TSCA Subpart B
761.292
– Extraction method 3540C Soxhlet – Extraction method 3550B Sonication • EPA Reg 1, CAM & RCP do not allow sonication
• TSCA Subpart Q
761.320
– Alternative extraction procedures/Comparability Study – Matrix-matched, i.e. sand, clay, loam, etc. – Not much options with building materials – Study must be approved prior to sampling
www.alphalab.com
PCB Analytical Challenges – Soxhlet: 18 hour extraction – Method 8082, Aroclor Identification • Retention times – Pattern recognition & peak ratios
– Challenges • Complex mixtures of aroclors • Interferences, sample matrix • “weathering” & biodegradation – Unclear match? “stray congeners?” – May need further evaluation, chromatograms – GC/MS congener/homolog analysis option
www.alphalab.com
Aroclors by Method 8082 AR 1242
AR 1248
AR 1254
www.alphalab.com
Analysis of BuildingRelated Materials • Concrete & bricks • Sealers
• Surfaces – Wipe testing, 100 CM2
• Indoor air – Initial indication of a problem? – Methods TO-10 low- vol, TO-4 high-vol • PUF cartridges • Homologs or congeners recommended
• All of the above – soxhlet extraction www.alphalab.com
Caulking and Paints • Soxhlet extraction – Can be difficult matrix
• Potential for high concentrations! – “One bad sample can ruin your whole day(s)” – Alpha personal best – 28% PCB
• Laboratory screening – Minimize potential for cross-contamination
www.alphalab.com
Questions?
Jim Occhialini [email protected] (508) 380-8618
www.alphalab.com
Managing PCB Contaminated Caulking in Older Buildings Analytical Considerations EBC Rhode Island Chapter Remediation Program October 22, 2012
www.alphalab.com
Jim Occhialini Alpha Analytical
What are PCBs? • Polychlorinated Biphenyls chemical structure having two benzene rings connected by one bond and having 1 -10 chlorines on the ring
• 10 possible positions leads to 209 possible combinations – 209 individual PCB compounds – CONGENERS • Common analytical subsets: NOAA & WHO lists
• Can be grouped according to the # of chlorine atoms – Level (or Degree) of chlorination – HOMOLOGUES (Homologs) www.alphalab.com
Cl--3
2
2’
3’
--Cl
4’
4
Cl--5
www.alphalab.com
6
6’
5’
Poly – Chlorinated - Biphenyls
Chlorinated Biphenyls by Homolog Empirical Formula C12 H10 C12 H9Cl C12 H8Cl2 C12 H7Cl3 C12 H6Cl4 C12 H5Cl5 C12 H4Cl6 C12 H3Cl7 C12 H2Cl8 C12 H1Cl9 C12 Cl10 www.alphalab.com
Molecular # Isomers Weight 154.1 1 188.0 3 222.0 12 256.0 24 289.9 42 323.9 46 357.8 42 391.8 24 425.8 12 459.7 3 493.7 1
Monochlorobiphenyls Dichlorobiphenyls Trichlorobiphenyls Tetrachlorobiphenyls Pentachlorobiphenyls Hexachlorobiphenyls Heptachlorobiphenyls Octachlorobiphenyls Nonochlorobiphenyls Decachlorobiphenyl
Aroclors • Most commonly known commercial trade name for PCB mixtures • Mixtures of PCB congeners • Nine Aroclors: – 1221, 1232, 1242/1016, 1248, 1254, 1260, 1262, 1268 Last 2 digits: % Cl by mass
1254 # carbon atoms www.alphalab.com
54% Cl
Total 1254 Composition I.S. Cl4 – 16% Cl5 – 60% Cl6 - 24%
Time www.alphalab.com
Analysis of PCBs • Preparative Methods – Extraction (TSCA?) • Soxhlet, microwave, ASE, MSE, sonication
– Clean up • H2SO4 , florisil, silica gel, GPC
• Determinative Methods – Instrumental analysis • GC – ECD Method 8082 – Aroclors, congeners
• Low resolution GC/MS Method 680/8270M • High resolution GC/MS Method 1668 www.alphalab.com
PCB Analysis at TSCA Sites • TSCA Subpart B
761.292
– Extraction method 3540C Soxhlet – Extraction method 3550B Sonication • EPA Reg 1, CAM & RCP do not allow sonication
• TSCA Subpart Q
761.320
– Alternative extraction procedures/Comparability Study – Matrix-matched, i.e. sand, clay, loam, etc. – Not much options with building materials – Study must be approved prior to sampling
www.alphalab.com
PCB Analytical Challenges – Soxhlet: 18 hour extraction – Method 8082, Aroclor Identification • Retention times – Pattern recognition & peak ratios
– Challenges • Complex mixtures of aroclors • Interferences, sample matrix • “weathering” & biodegradation – Unclear match? “stray congeners?” – May need further evaluation, chromatograms – GC/MS congener/homolog analysis option
www.alphalab.com
Aroclors by Method 8082 AR 1242
AR 1248
AR 1254
www.alphalab.com
Analysis of BuildingRelated Materials • Concrete & bricks • Sealers
• Surfaces – Wipe testing, 100 CM2
• Indoor air – Initial indication of a problem? – Methods TO-10 low- vol, TO-4 high-vol • PUF cartridges • Homologs or congeners recommended
• All of the above – soxhlet extraction www.alphalab.com
Caulking and Paints • Soxhlet extraction – Can be difficult matrix
• Potential for high concentrations! – “One bad sample can ruin your whole day(s)” – Alpha personal best – 28% PCB
• Laboratory screening – Minimize potential for cross-contamination
www.alphalab.com
Questions?
Jim Occhialini [email protected] (508) 380-8618
www.alphalab.com
