DETERMINATION OF PBDEs IN CLEAR CREEK MINNOWS

1
DETERMINATION OF PBDEs IN CLEAR CREEK
MINNOWS Corliss Harris, Megan OConnell, Carrie
Seltzer, and Monica Silver CHEM 331
Results
Solid Phase Extraction
Experimental Method
Abstract
2,2,4,4-PBDE concentration
Adapted from Covaci, A., et. al
Column wetting 20 mL hexane Column one 6.0
g salicic acid Column two 2.0 g acid
silica 1.0 g neutral silica 2.0 g
deactivated basic alumina Rinse 20 mL 1
hexane 1 dichloromethane rinse Collected
sample evaporated to near dryness using Rotovapor
R3000.
Polybrominated diphenyl ethers (PBDEs) are common
components of flame retardants used on computer
and TV housing, furniture, textiles, carpets, and
vehicles. While the current level of PBDEs found
in the environment is relatively low,
bioaccumulation can concentrate PBDE levels in
the fat of animals higher on the food chain. In
animals studies, PBDE exposure has been shown to
have detrimental effects as an endocrine
disrupter. Minnows from Clear Creek were
analyzed for the presence of PBDEs using Gas
Chromatography/ Mass Spectrometry (GC/MS).
Extremely low levels of PBDEs were found in the
sample tissue.

• A small peak with an area of 19 appeared the same
  time (9.313 minutes) as the 10 ppm standard.
• The concentration of PBDE in the tissue could not
  be determined from the standard curve because the
  area fell below the peak area for calibration
  curve.
• The correlation coefficient of the standard
  calibration curve was 0.989.
• Small amount of PDBEs was found in sample tissue.

Catch fish using minnow traps
Homogenize fish
Run Soxhlet extraction on 1 g homogenized sample
Calibration Curve

Introduction
Perform Solid Phase Extraction

• Goal To determine the presence of PBDEs in
  local fishes using Gas Chromatography/ Mass
  Spectrometry.
• This method allows for the determination of
  2,2,4,4-tetra PBDE only.
• Due to the very low concentrations of PBDEs found
  in tissues, the Gas Chromatography/ Mass
  Spectrometry method is a suitable choice for
  detection.

Gas Chromatography/ Mass Spectrometry
Gas Chromatography/Mass Spectrometry

• Machine used HP 5890/5972 GC/MS
• Column 30m x 0.25 mm x 0.25 mm DB-5
• Run time 13.20 minutes
• Level one 4.00 C/min
• Temperature 504 K
• Level two 25.00 C/min
• Temperature 554 K

Reference
Conclusions
Covaci, A., J. de Boer, J.J. Ryan, S. Voorspoelf,
P. Schepens. 2000. Determination of
Polybrominated Diphenyl Ethers and
Polychlorinated Biphenyls in Human Adipose Tissue
by Large-Volume Injection-Narrow-Bore Capillary
Gas Chromatography/ Electron Impact
Low-Resolution Mass Spectrometry. Analytical
Chemistry

• Overall results were inconclusive.
• Although the peak area was outside the
  calibration curve, the presence of a small peak
  at the same retention time as the standard
  provides cause for further investigation and
  analysis with more time and resources.
• Standard solutions, as prepared, were
  insufficient for producing a calibration curve
  that fit the sample concentration.

Polybrominated Diphenyl Ether
Standard Solutions for Calibration
Soxhlet Extraction of Lipids

• Standard solutions prepared with dichloromethane
• 1.0 ppm
• 2.5 ppm
• 5.0 ppm
• 10.0 ppm

• Used to extract solute from homogenized sample
  using boiling solvent.
• In Soxhlet thimble
• 1 gram homogenized sample
• 6 grams anhydrous Na2SO4
• Solvent
• 175 mL of 311 solution of hexane acetone
  dichloromethane
• Run time 2 hours

Acknowledgements
Earlham College Chemistry Department, Joseph
Moore Museum, Dr. Corinne Diebel, Dr. Michael
Diebel, Mary Hagerman, and Kalani Seu.
1.2 mL of 50 ppm 2,2,4,4-tetrabromodiphenylether
from Cambridge Isotope Laboratories