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BUILDING STRONG®
2011 UPRM-ERDC Summer Internship Program September 16-17, 2011 Conrad San Juan
Conrad Plaza Hotel, San Juan, Puerto Rico Research Mentors
Frances C. Hill, Ph.D., Acting Branch Chief Ms. Allyson M. Holman, Technician
Environmental Laboratory, Engineering Research and Development Center Academic Mentors
Ismael Pagán Trinidad, Professor Department of Civil Engineering and Surveying
University of Puerto Rico at Mayagüez
Optimization and Modification of New Analytical Methods for Ultra Low Detection of Environmental
Contaminants Claudia Luiggi
Undergraduate Student Department of Chemistry
BUILDING STRONG®
Abstract A new method, QuEChERS- quick, easy, cheap, effective, rugged, and safe, proposes a
better way of extracting organic compounds from complex matrices. Traditionally these extractions are done by Ultrasonic, Soxhlet and Accelerated Solvent extraction techniques. Although these traditional methods have advantages to them, they have some areas that could benefit from improvement. This research was aimed at the optimization and validation of a new commercially available extraction technique (QuEChERS) for detection of polycyclic aromatic hydrocarbons (PAHs) and chlorinated pesticides from complex media for ongoing research on their toxicity and bioaccumulation. In order to evaluate this new method, it is being compared to traditional extraction methods using various samples which include blank fish (Cod and Tilapia), clams, worms, sediments, and standard reference. The QuEChERS extractions were done using Agilent SampliQ QuEChERS AOAC Kits along with the procedure provided by Agilent Technologies™. The detection of PAHs was done by Gas Chromatography/ Mass Spectrometry and for pesticide detection Gas Chromatography with Electron Capture Detection was used. Using Agilent ChemStation software the data from the GC was obtained and analyzed. The QuEChERS extraction method performed on par with the traditional extraction methods. The QuEChERS method delivered as promised a quick, easy, cheap, effective, rugged, and safe extraction technique. Without compromising extraction efficiency, QuEChERS uses much smaller amounts of solvent, reduces extraction time drastically, and can be prepared using the pre-made QuEChERS extraction kits and minimal laboratory equipment and is cost effective.
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Background Organochlorine Pesticides
Substances used to kill, repel, or control certain forms of plant or animal life that are considered to be pests.
Because of the use of these chemicals in food production, people are exposed to pesticides through their diets.
Polycyclic Aromatic Hydrocarbon (PAH) PAHs can be found in oil, coal,
and tar deposits, and are produced as byproducts of fuel burning.
They are of concern because some compounds have been identified as carcinogenic, mutagenic, and teratogenic.
Naphthalene
National Institute of Environmental Health Sciences. (April 21st, 2011) Pesticides. NIEHS-NIH
Freeman, R. (2011) Resolving the Benzo(j)fluoranthene Challenge. Restek.
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Goals of the Project
Test a new extraction method that is Green compared to the ones currently used.
Optimize and validate a new commercially-available extraction technique (QuEChERS) for detection of PAH and chlorinated pesticide extracts from complex media.
Systematically compare this technique to standard EPA-developed preparation methods.
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Traditional Extraction Methods Soxhlet Extraction – EPA Method 3540C
Ultrasonic Extraction – EPA Method 3550C
Pressurized Fluid Extraction – EPA Method 3545A
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Cleanup and Detection Sample Cleanup
► Silica Gel Cleanup – EPA Method 3630C ► Florisil Cleanup – EPA Method 3620C ► Gel-Permeation Cleanup – EPA Method 3640A
Detection Method ► GC/MS – EPA Method 8270D ► GC/ECD – EPA Method 8081B
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QuEChERS Quick Easy Cheap Effective Rugged and Safe Advantages over traditional methods:
► Extraction time reduced to less than 1 hour per sample. ► No specialized glassware or equipment needed. ► Only uses 10mL of solvent = Green ► Multiple samples can be processed simultaneously. ► Field analysis is possible with portable equipment.
Agilent Technologies™
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QuEChERS Methodology
1 • Weigh sample into a 50mL vial.
2 • Add 8mL of water along with a ceramic bar and vortex for 1 min.
3 • Add 10mL of Acetonitrile and vortex for 1 min.
4 • Add QuEChERS AOAC salt packet, vortex and centrifuge at 3000
rpm for 5 min.
5 • Transfer sample into 15mL Dispersive SPE tube, vortex and
centrifuge at 3000 rpm for 5 min.
6 • Transfer 1mL to an autosampler vial for analysis.
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Analysis of PAHs and Pesticides in SRM Sediments Using Different Extraction Techniques by Gas Chromatography.
0100200300400500600700800
Con
cent
ratio
n (p
pm)
PAHs
PFEQuEChERSCertified
0.00100.00200.00300.00400.00500.00600.00
aBH
CgB
HC
bBH
CdB
HC
Hep
tach
lor
Ald
rinH
epta
chlo
r Epo
xide
g-C
hlor
dane
a-C
hlor
dane
4,4-
DD
EE
ndos
ulfa
n I
Die
ldrin
End
rin4,
4-D
DD
End
osul
fan
II4,
4-D
DT
End
rin A
ldeh
yde
Met
hoxy
chlo
rE
ndos
ulfa
n S
ulfa
teE
ndrin
Ket
one
Con
cent
ratio
n (p
pm)
Pesticides
PFE
QuEChERS
Certified
BUILDING STRONG®
Analysis of PAHs and Pesticides in Blank Fish Using Different Extraction Techniques by Gas Chromatography.
0
0.2
0.4
0.6
0.8
1
1.2
conc
entr
atio
n (p
pm)
PAHs
sonication
soxhlet
quechers
05
10152025303540
aBH
CgB
HC
bBH
CdB
HC
Hep
tach
lor
Ald
rinH
epta
chlo
r Epo
xide
g-C
hlor
dane
a-C
hlor
dane
4,4-
DD
EE
ndos
ulfa
n I
Die
ldrin
End
rin4,
4-D
DD
End
osul
fan
II4,
4-D
DT
End
rin A
ldeh
yde
Met
hoxy
chlo
rE
ndos
ulfa
n S
ulfa
teE
ndrin
Ket
one
conc
entr
atio
n (p
pb)
Pesticides
sonication
soxhlet
quechers
BUILDING STRONG®
Conclusions QuEChERS performed on par with the traditional
extraction methods. The QuEChERS method delivered as promised, a quick,
easy, cheap, effective, rugged and safe extraction technique.
Without compromising extraction efficiency: ► Uses much smaller amounts of solvent = Green ► Reduces extraction time drastically ► Can be prepared using the pre-made extraction kits ► Minimal laboratory equipment required ► Cost effective
BUILDING STRONG®
Recomendations
Implement QuEChERS extraction technique for routine analysis of PAHs and chlorinated pesticides in Environmental Laboratory’s Chemistry Branch.
Use QuEChERS along with a field portable GC for on site PAH and pesticides analysis.
Systematically compare SRM tissue using QuEChERS and the traditional methods.
BUILDING STRONG®
References Anastassiades M, Lehotay SJ. (2003) Fast Easy Multiresidue Method Employing
Acetonitrile Extraction Partitioning and Dispersive Solid Phase Extraction for Determination of Pesticide Residues in Produce. J AOAC Int. 86: 412-431.
Ciéslik E., et. al. (2011) Evaluation of QuEChERS Method for the Determination of Organochlorine Pesticide Residues in Selected Groups of Fruits. Food Chemistry. 125: 773- 778.
Method 2007.01. Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate, AOAC International, 2007, pp. 1-9.
Method 3540C, Soxhlet Extraction, Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, 3rd ed., EPA/SW-846, US Environmental Protection Agency Washington, DC, 1996, pp.1-10.
Method 3545A, Pressurized Fluid Extraction (PFE), Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, 3rd ed., EPA/SW-846, US Environmental Protection Agency Washington, DC,1996, pp. 1-16.
Method 3550C, Ultrasonic Extraction, Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, 3rd ed., EPA/SW-846, US Environmental Protection Agency Washington, DC, 2007, pp.1-17.
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References Method 3620C, Florisil Cleanup, Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods, 3rd ed., EPA/SW-846 On-line, US Environmental Protection Agency Washington, DC,2007, pp.1-27.
Method 3630C, Silica Gel Cleanup, Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, 3rd ed., EPA/SW-846 On-line, US Environmental Protection Agency Washington, DC,1996, pp. 1-15.
Method 8081B, Organochlorine Pesticides by Gas Chromatography, Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, 3rd ed., EPA/SW-846 On-line, US Environmental Protection Agency Washington, DC, 2007, pp. 1-57.
Method 8270D, Semivolatile Organic Compounds by Gas Chromatography / Mass Spectrometry (GC/MS), Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, 3rd ed., EPA/SW-846 On-line, US Environmental Protection Agency Washington, DC, 1996, pp. 1-54.
Pule BO, Mmualefe LC, Torto N. (2010) Analysis of Polycyclic Aromatic Hydrocarbons in Fish with Agilent SampliQ QuEChERS AOAC Kit and HPLC-FLD. Agilent Technologies, Inc. pp. 1-7.
Schenck FJ, Hobbs JE. (2004) Evaluation of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach to pesticide residue analysis. Bull. Environ. Contam. Toxicol. 73: 24-30.
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Acknowledgements This undergraduate research project was sponsored by the
Environmental Laboratory, Engineer Research and Development Center, US Army Corp of Engineers, Vicksburg, MS, under the Broad Agency Announcement. This constitutes an alternative learning experience which enriches the Chemistry Program offered at the University Puerto Rico at Mayagüez. This presentation constitutes a requirement for a special research course during summer 2011 and it only represents student’s research point of view.
The help, assistance, and support of the following have been
instrumental for the completion of this project and are greatly appreciated: “Dr. Gustavo Davico; Dr. Frances C. Hill; Dr. Anthony Bednar; Ms. Allyson Holman, Environmental Laboratory Chemistry Branch”.