«Kimberly D. Smith Analytical Methods for Pesticides and their Degradation Products in Soil By Kimberly D. Smith Doctor of Philosophy Department of ...»
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Kimberly D. Smith Analytical Methods for Pesticides and their Degradation Products in Soil By Kimberly D. Smith Doctor of Philosophy Department of Chemistry P. Barry Ryan, Ph.D.
Advisor Dale E. Edmondson, Ph.D.
Committee Member Vincent P. Conticello, Ph.D.
Lisa A. Tedesco, Ph.D.
Dean of the Graduate School Date Analytical Methods for Pesticides and their Degradation Products in Soil By Kimberly D. Smith B.S., University of Texas-Austin, 1999 M.P.H., Emory University, 2002 Advisor: P. Barry Ryan, Ph.D.
of A dissertation submitted to the Faculty of the Graduate School of Emory University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Chemistry Abstract The pesticide industry specifically has made a remarkable impact in the protection of food supplies but has also created unanticipated environmental and human health adverse effects. Evidence has linked pesticide exposure to almost every type of cancer possible in addition to neurodegenerative diseases, newborn deficiencies and endocrine disruption.
Despite this insurmountable evidence against pesticides, the pesticide industry has become so integrated into our society that many believe that reconsidering or abolishing the industry would have multiple economic consequences (Rosenbaum 1998). Inevitably, the industry is here to stay for the time being and it becomes the duty of public health officials and scientists to limit pesticide exposure and educate the public in awareness of toxic side effects to their health and the environment.
A critical part in identifying the presence of pesticides, their toxicity and ultimately their possible effect on people and the environment is the determination of the exact amount of pesticide that is present. Analytical methods are utilized to provide quantitative data to help answer many of these questions. Multiple analytical methods were examined in this research for their utility to analyze and quantitate pesticides and their degradation products in soil. Traditional and cartridge-assisted liquid-liquid extraction, solid-phase extraction including C18, polymeric, ion-exchange and a recent innovation: molecular imprinted polymer, and accelerated solvent extraction are evaluated for extraction of the target analytes. Gas chromatographic and liquid chromatographic techniques are also investigated to determine optimal instrumental analysis. All methods were assessed for analytical parameters typical in method development: accuracy, precision, sensitivity, etc.
Analytical Methods for Pesticides and their Degradation Products in Soil
A dissertation submitted to the Faculty of the Graduate School of Emory University in partial fulfillment of the requirements for the degree of Doctor of Philosophy
To my advisor Dr. P. Barry Ryan, I am deeply indebted as I am here today only because of your belief in me and motivation to transition from public health into chemistry, a challenging transition indeed. Your flexible nature and open-mindedness made it really fun to be your student. I enjoyed it all-from instrument hell to traveling to other countries to meet students with NATO. I also cannot thank you enough for your support of my desire to partner with CDC for this research as it truly opened doors I never thought existed. I will miss your unconventional wisdom in the future – I have no doubt I will come running for you advice again.
To my CDC advisors: Dr. Dana Barr, Dr. Larry Needham and Dr. Gayanga Weerasekerathank you for allowing me to co-exist as a student/professional at CDC. I have learned so much in this working environment and will never forget my experiences at CDC. Danayour appreciation of education in the workplace is quite unique and I hope that you continue to encourage young scientists to collaborate with outside universities.
To Dr. Gayanga Weerasekera-You have been my Yoda throughout this entire experience.
I just cannot express enough thanks for what you have contributed to my graduate career.
I simply would never have completed this successfully without your advisement. I will always appreciate what you have done for me. I hold your opinion very highly and respect your work ethic and innovative way of thinking. You are truly one of a kind and I hope that you have treasured our working relationship as much as I have. Good luck to you and your family in San Francisco!
To Sam Baker and Peter Kuklenyik -A big thank you to you both-You guys are like big brothers-always helping me out in sticky situations, particularly with those pesky instruments. Neither of you ever complained and were always willing to drop whatever you were working on to help me out. I truly appreciate your wisdom and patience with me and my big case of negative instrument karma-thankfully the instruments liked you both better!
To Jose Perez- A very special thank you to all your help with real chemistry problems I could never figure out. By the way, Im still trying to figure your brain out-your brain is a sponge for chemistry knowledge which lets face it-just isn’t natural! Your knowledge is impressive and will take you far-Good luck in beginning this process-I have no doubt you will do great!
To my committee members- Thank you for the opportunity to work with chemists outside my field- it gave me a varied perspective and it definitely kept me on my toes for presentations!
To my collaborators at MIP Technologies AB- I truly enjoyed collaborating with you all – You all have a very cool product that made my life so much easier! Additionally, you all were extremely helpful and expedient answering my parade of questions. Thank you for allowing me to include this research as part of my dissertation.
To my family-You guys are my rock-the foundation for which this has all come to play.
Carla – Thank you for your endless encouragement and appreciation for feminine intellect – you always know how to put a smile on my face! Mom and Dad-you both in your own way set me straight from the beginning and kept me focused during times when it would have been so easy to lose my way. I know as a kid I never showed my appreciation for your discipline and caring but I now know that I am the luckiest girl in the world to have been born into such an encouraging and loving family. This is as much my accomplishment as it is yours. Thank you.
Lastly to Dave Braslow-My best friend thru this entire process-I think God meant for us to meet when I first started school. You have seen me go thru so many ups and downs that it is truly a wonder you still stick around. Thank you so much for you support and kind words when I needed them most-during my stressed out moments and break-downs, I know I had a few! And just think-you get to go thru this allover again! I love you for what you have done for me in these past 4 years. Thank you.
List of Figures CHAPTER 1 Figure 1.1 World Production of Formulated Pesticides in Sixty Years Figure 1.2 Amount of Conventional Pesticide Ingredient Used in the US by Pesticide Type and Market Sector in 2001 Figure 1.3 Human Exposure Pathways Figure 1.4 Analytical Method and Validation Flow Pathways Figure 1.5 Proposed Parent Pesticide Method Development Figure 1.6 Proposed Pesticide Degradation Product Method Development CHAPTER 2 Figure 2.1 Target Parent Pesticides for Method Development Figure 2.2 Electron Ionization Spectra for Selected Analytes Figure 2.3 Total Ion Chromatogram for Target Analytes Figure 2.4 Target Analytes Separated by Mass Filters Figure 2.5 Chromatographic Results for Methyl Parathion and Lambda Cyhalothrin with Different ASE Fillers Figure 2.6 Percent Recovery for Target Analytes Comparing 2 ASE Extraction Solvent Systems Figure 2.7 Percent Recovery for Target Analytes Comparing Various Organic/Aqueous Portions of ASE Extraction Solvent Figure 2.8 Percent Recovery for Target Analytes Comparing 100% Organic vs.
Aqueous/Organic ASE Extraction Solvents Figure 2.9 Methyl Parathion Co-Extracting Interferences Figure 2.10 Loss of Lambda Cyhalothrin Signal after Multiple Injections Figure 2.11 Three Possible Clean-Up Schemes of ASE Soil Extracts Figure 2.12 SPE Wash Analyses Separated by Pesticide Class Figure 2.13 SPE Elution Step Analyses Separated by Pesticide Class Figure 2.14 Chromatographic Interferences with Cyfluthrin, Cypermethrin and Methyl Parathion with SPE Clean-Up Figure 2.15 Chromatographic Improvement with Cyfluthrin, Cypermethrin and Methyl Parathion with Different Elution Solvent for SPE Figure 2.16 Percent Recovery for Target Analytes with LLE using Various Solvents Separated by Pesticide Class Figure 2.17 Percent Recovery for Target Analytes with Cartridge-Assisted LLE using Various Solvents Figure 2.18 Percent Recovery for Target Analytes Comparing Extraction Volumes for LLE Figure 2.19 Percent Recovery for Target Analytes at 2 Levels Comparing 3 Extraction Methods Figure 2.20 SN of Methyl Parathion at 100ppb with SPE Clean-Up Figure 2.21 SN of Diazinon at 5ppb with SPE Clean-Up Figure 2.22 Within-Day and Between-Day Variation of Target Analytes at 100ppb with ASE-Manual LLE Method Figure 2.23 Accuracy of Malathion at 25ppb with ASE-Manual LLE Method Figure 2.24 Accuracy and Precision of Resmethrin at 25ppb with ASE-Manual LLE Method Figure 2.25 Linearity of cis-Permethrin across Calibration Curve and Lower End of Curve Figure 2.26 Lack of Linearity of Chlorpyrifos Due to Background Presence Figure 2.27 Blank Soil Sample with Endogenous Chlorpyrifos Present CHAPTER 3 Figure 3.1 Structures of Specific OP Degradation Products Figure 3.2 Structures of Non-Specific OP Degradation Products Figure 3.3 Structures of Pyrethroid Degradation Products Figure 3.4 APCI Process Schematic Figure 3.5 Possible Pathways for Ion Formation in ESI Figure 3.6 HESI Heating Chambers Figure 3.7 Fluctuations in Ion Current with Increasing Spray Voltage Figure 3.8 Parent-Daughter Ion Formations for 4F3PBA with Various Collision Energies in Q2 in ESI Figure 3.9 MS Spectra of Terbufos Sulfone and Abundant Water Cluster Ion Formation in ESI Figure 3.10 Tuning Parameters for Negative and Positive Modes in MS/MS Figure 3.11 Frequency of Occurrence vs. Molecular Weight of Compounds Figure 3.12 Proposed Dialkylphosphate Fragmentation Patterns Figure 3.13 HILIC Interactions Figure 3.14 CDCA Isomeric Separation Figure 3.15 TIC of Degradation Products with No Buffer in Mobile Phase Figure 3.16 TIC of Degradation Products with 5mM Ammonium Formate in Mobile Phase Figure 3.17 SRM of Degradation Products Separated by Mass Filter Figure 3.18 Structures of Active Compounds in Phenomenex WAX SPE Sorbent Figure 3.19 Phenomenex WAX Active State According to pH Figure 3.20 Structures of Active Compounds in Waters OASIS SPE Sorbent Figure 3.21 Waters OASIS Active State According to pH Figure 3.22 Flowchart of Ion Exchange SPE Method Development Figure 3.23 Flowchart of Wash Analysis for Ion Exchange SPE Figure 3.24 Selected Analyte Break-thru Analysis for the Wash Step Figure 3.25 Initial Soil Extraction Protocol Figure 3.26 Percent Recovery for Target Analytes Comparing 2 Filter Devices at pH4 and pH7 Figure 3.27 Percent Recovery for Target Analytes with Multiple Extractions at pH7 with the Whatman Filter Devices Figure 3.28 Determination of LOD for 4-Nitrophenol with Taylor Method Figure 3.29 SN Ratio for Selected Analytes at 2.84ng/g (DMP 727.27ng/g) Figure 3.30 Percent Recovery for Target Analytes Scanned in Positive Mode at S4 and S7 Figure 3.31 Percent Recovery for Target Analytes Scanned in Negative Mode at S4 and S7 Figure 3.32 Variation over 6 Days for CFCA and 3-PBA Figure 3.33 Linearity of 4F-3PBA Figure 3.34 Ion Suppression of MDA and Enhancement of DMTP Figure 3.35 Difference in Precision with Terbufos Sulfoxide and IMPY with IMPYLabel Internal Standard Figure 3.36 CFCA Ion Suppression with 2 Different Parent-Daughter Ion Pairs Figure 3.37 Number of MIP-Related Publications Since 1930 Figure 3.38 MIP Synthesis Figure 3.39 MIP Extraction vs. Conventional Extraction of Clenbuterol from Calf Urine Figure 3.40 Elution of Clenbuterol with Varying Amounts of Acetic Acid in Acetonitrile Figure 3.41 Percentages of MIPSE Studies by Application Figure 3.42 Structures of Typical Active Ingredients for Triazines and Phenylureas Pesticides Figure 3.43 Structural Differences between MISPE Imprinted with Monocrotophos and 4 OPs Figure 3.44 Extraction Differences between Conventional SPE and MISPE for Various Pesticides Figure 3.45 DCCA and DEDTP Hits with Various MISPE Sorbents Figure 3.46 Structures of IMPY and TCPY Figure 3.47 Retention Behavior of DMP and DEP with Selected MISPE Sorbents at pH1-3 Figure 3.48 Retention Behavior of 4-NP with Selected MISPE Sorbents at pH1-3 Figure 3.49 Elution Step and Break-thru Analysis of DCCA and CFCA Figure 3.50 Break-thru Profiles for Target Analytes Comparing 2 Different Wash Steps Figure 3.51 Flowchart of MISPE Steps Figure 3.52 SN Ratio of IMPY at Different Concentrations Figure 3.53 Percent Recovery for Target Analytes with MISPE Method at S4 and S7 Figure 3.54 Percent Recovery Comparison between MISPE and Ion-Exchange SPE at S7 Figure 3.55 MDA Ion Suppression Comparison between MISPE and Ion-Exchange SPE Figure 3.56 Ion Enhancement of CFCA with MISPE List of Tables
CHAPTER 1Table 1.1 Typical Method Validation Parameters