Laboratory and computational technologies to reduce the cost and - PowerPoint PPT Presentation

Laboratory and computational technologies to reduce the cost and improve the quality of congener-specific measurement of PCB congeners in air, water, sediments, and human blood serum Keri C. Hornbuckle, Ph.D. 2013, 47 , IIHR-Hydroscience and Engineering 3353-3361 Dept. Civil & Environmental Engineering The University of Iowa, Iowa City, IA USA

meta meta ortho ortho 2 2 2’ 2’ 3 3 3’ 3’ Cl n Cl n Cl n Cl n 4’ 4’ 4 4 para para 6’ 6’ 5’ 5’ 5 5 6 6 meta meta ortho ortho ¡ Aroclors manufactured/sold until 1977 ¡ Current production: inadvertently produced in low levels during pigment manufacture ¡ OH-PCBs are both metabolites and environmental contaminants ¡ Exposure from diet, dermal, inhalation ¡ IARC group 1 carcinogen , endocrine disruption, neurotoxicity 2

Despite PCBs being banned in 1979 by the United States Congress and in 2001 by the Stockholm Convention on Persistent Organic Pollutants, they remain relevant today.

• Extraction & Cleanup of Environmental Samples • Analysis by Triple Quadrupole GC/MS/MS • Major Findings • Discussion

1. 3. PCB 14 PCB D65 1. Samples are places in ASE cell and spiked PCB 166 with 50 ng of Surrogate Standard Sample 2. Samples extracted using an Accelerated Solvent Extraction (Dionex, ASE 300) with a 1:1 Hexane:Acetone mixture. 3. Samples concentrated with a Caliper 4. Turbovap II to 0.5 mL. 4. Samples run through an acidified silica gel (2:1 silica gel:acid by weight) column eluted with 10 ml of Hexane. 2. 5. Samples concentrated to 0.5 ml, transferred to GC vials, and spiked with 5. internal standard. PCB D30 PCB 204 5

¡ Sample Handling § PUF samples are acidified and extracted with hexane:acetone § OH-PCBs were separated from PCBs and derivatized to MeO-PCBs for GC/MS/MS analysis § PCB and OH-PCB fractions were cleaned using acidified silica gel columns ¡ SS § PCB and OH-PCB surrogate standards § Used to assess and correct recovery ¡ IS § PCB and OH-PCB internal standards § Used to quantify target compounds

• Pressurized fluid extraction methods using Dionex ASE 350 are identical to EPA method 3545A. • >100 ͦ C • >1500 psi • 5 min static time after 5 min pre-heat equilibration • 60% flush volume • 60+ sec nitrogen purge • Cleanup Methods are a slight variation from EPA method 3665A • Samples run through a cleanup column with sulfuric acid acidified silica, instead of cleanup by liquid – liquid sulfuric acid separation • If a sample is not fully cleaned (has color), we run it through subsequent columns, as opposed to a liquid-liquid clean up with aqueous potassium permanganate

Method Soxhlets ASE 350 We have cut the time needed to clean PUF by a factor of 8, and Time to clean one batch 4 days 1 day the cost by a factor of 5. With the PUF cleaned per one batch 25 50 ASE, we also get: Time required to clean 400 PUF 64 days 8 days • More consistent cleaning Solvent price per 4L bottle ~$25 ~$25 • More contaminant removal (variable) • Easy QA/QC data on first and last cleaned PUF Solvent volume used per batch ~10L ~4L Batches required to clean 400 16 8 PUF Cost to clean 450 PUF $1000 $200

¡ GC-MS/MS separates congeners by retention time and mass ¡ 209 PCBs and 72 OH-PCBs 9

1. . 2. . 3. . 4. . 5. . Samples analyzed with Gas chromatography with tandem mass spectrometry (Agilent 7000)

Mono Di Tri Tetra Penta Hexa Hepta Octa Nona Deca 11

Method Hornbuckle Lab EPA Method 1668c EPA Method 8082A Scope Identify all 209 PCBs, individually Identify all 209 PCBs, individually Identify PCBs as Aroclors or as resolving approximately 137 and resolving approximately 137 and congeners, however ability to the remainder as coeluting peaks the remainder as coeluting peaks identify as congeners is limited Instrument GC/MS/MS HRGC/HRMS ECD or ELCD Standard Periodically run certified SRM as Include QC Check Sample with Provide SRM data from Reference integral part of QA/QC each sample batch, ideally this is independent labs using method, Material (SRM) a certified SRM do not require SRM as part of method Column Primarily SPB-octyl, also use Primarily SPB-octyl, may employ Column not specified, but states DB-5 and DB-1701 for an alternate column to resolve congener identification should be confirmation purposes ( SP-octyl discrepancies, recommend DB-1 confirmed on a second column separates the DL-PCBs ) Surrogate Use either a mixture of PCB 14, Uses multiple labeled PCBs for Use PCB 209 when determining Standards D65, 166, or a mixture of 10 13C- each homolog group as surrogate PCBs as Aroclors, Use 2,2 ’ ,4,4 ’ , labeled PCBs, one congener from standards 5,5 ’ -hexabromobiphenyl or each homolog group tetrachlor-m-xylene when determining PCB congeners Quantitation All 209 PCBS quantitated using PCBs are quantitated by either PCBs are determined as congeners internal standard method, using isotope dilution or internal using PCB 209 or 2,2 ’ ,4,4 ’ ,5,5 ’ - PCB D30 and PCB 204 as internal standard method using labeled hexabromobiphenyl as internal standards PCBs, depending on toxicity and standard, or as Aroclors using no elution order internal standard

SPB Octyl DB 1701 Mono Di Tri 13

DB 1701 Mono SPB Octyl DB 1701 Di SPB Octyl DB 1701 Tri SPB Octyl

• Field blanks • Laboratory NIST SRM 2585: Organic contaminants in dust method blanks • Instrument blanks Representativeness • Surrogate standard recoveries Precision • NIST SRM: • 2585 (PCBs in dust) Reproducibility & Accuracy

Human Serum, Sediment Water Sediment & Air Air & Soil

The PCB Congener Signal in Chicago Air Cl Cl PCB11 PCBs, in order of increasing number of chlorines Hu et al., ES&T 2008

Pigment manufacturing is an important source of PCB congeners in the environment

DD proprietary magenta HH proprietary red 0.6 0.6 52 52 0.4 0.4 11 11 1,3 0.2 0.2 0.0 0.0 Y1 monoazo yellow 0.6 L1 phthalocyanine blue 0.4 0.6 11 0.2 0.4 1 0.0 0.2 96-26Z monoazo yellow 0.0 0.6 11 0.4 0.2 0.0 96-4D phthalocyanine green 0.6 11 11 TT proprietary yellow 0.6 0.4 0.4 0.2 11 0.2 20 0.0 0.0

Indiana Harbor is source of PCBs to the surrounding community

PCB flow rates through passive samplers are a function of local meteorology

Lower chlorinated PCBs are prevalent in children

¡ Methods with greatest impact on quality also are most efficient and cost- effective ¡ GC/MS/MS provides excellent sensitivity, selectivity, reproducibility ¡ Pressured solvent extraction is useful for preparing sampling media as well as sample extraction ¡ Uniform methods allow useful comparison of congener signals across media, space, and time ¡ https://research.engineering.uiowa.edu/hornbuckle/ 27

Funding sources NIH P42 ES013661 Research Team Rachel Marek, Ph.D. Andres Martinez, Ph.D. Andrew Awad, MS Nick Herkert (Ph.D. student) Jacob Jahnke (Ph.D. student) Aaron Boesen, BSE Dana Boesen 28