Polyoxyethylene tallow amine: Environmental fate of an "inert" ingredient By Daniel Tush Submitted to the graduate degree program in Chemistry and the Graduate Faculty of the University of Kansas in partial fulfillment of the requirements for the degree of Doctor of Philosophy. ______________________________________________ Michael T. Meyer, Primary Investigator, Co-Chairperson ______________________________________________ Robert C. Dunn, Chairperson ______________________________________________ Susan M. Lunte ______________________________________________ Heather Desaire ______________________________________________ Edward F. Peltier Date Defended: March 31, 2016 The Dissertation Committee for Daniel Tush certifies that this is the approved version of the following dissertation: Polyoxyethylene tallow amine: Environmental fate of an "inert" ingredient ______________________________________________ Michael T. Meyer, Primary Investigator, Co-Chairperson ______________________________________________ Robert C. Dunn, Chairperson Date approved: April 14, 2016 ii Abstract The surfactant polyoxyethylene tallow amine (POEA) is a common inert ingredient in formulations of glyphosate—the most widely applied agricultural herbicide in the world, which is also commonly used in urban settings. Little is known about the environmental occurrence, fate, and effects of ancillary additives such as POEA. POEA is not well characterized in the literature, but has been shown to be toxic to numerous aquatic organisms. Characterization of POEA technical mixtures shows that POEA is a complex combination of a central nitrogen atom, different aliphatic moieties, and varying numbers of ethoxylate units. Analysis of several agricultural and household glyphosate formulations confirmed that different POEA technical mixtures are common additives in these formulations and that a POEA technical mixture with an average of 15 ethoxylate units is the most common additive. Experiments to characterize the adsorption of POEA to soils revealed that POEA adsorbs much stronger to soil than glyphosate; the addition of calcium chloride to the system increases the adsorption of POEA; and the adsorption of POEA to soils was highest in low pH conditions. POEA detected on a soil sample from a row crop agricultural field near Lawrence, Kansas shows a change in the distribution of homologs over time with a loss of homologs that contain an alkene moiety. POEA was also detected on row crop agricultural soil samples collected between February and early March from sites in five other states (Iowa, Illinois, Indiana, Missouri, Mississippi). Soil samples collected from a row crop field in Indiana for over a year were analyzed to examine the dissipation of POEA, glyphosate, and aminomethylphosphonic acid (AMPA) and shows that POEA and glyphosate persist on the shallow soil from growing season to growing season but there is some dissipation over time with little migration into deeper soil. Stream bed sediments (agricultural and urban watersheds) from six states (Georgia, Hawaii, Iowa, Mississippi, North Carolina, iii South Carolina) were analyzed and all were found to have detectable levels of POEA. This is the first indication of the potential widespread contamination of POEA on agricultural soils and stream bed sediments in areas where glyphosate is applied. iv Acknowledgements There are far too many people (both real and fictional) who have influenced my life to bring me to where I am now to thank them all properly within these pages. I’d like to thank you all. I count many of you among my family, my friends, my colleagues, my teachers, and my inspirations. There are a handful of individuals and groups that I would like to mention specifically. I will list them (like some movie credits) in order of appearance. For those who I don’t mention by name, I mean no slight. I am no poet and only have so many words. From the beginning of my story, my parents have always been there. My mother, Nancy Tush, has always been one of my biggest supporters. She would always pick me up when I fell down and always encouraged me no matter which direction the path of my life took. My father, Richard Tush, and I often don’t see eye to eye on a great many topics, but his appreciation of the natural world around us is one of the cornerstones in my appreciation of the sciences. My oldest friend, Rebecca Schoonover, is the reason I survived school, K-12. In some ways she and I are completely different people and yet I’ve always found we were more than enough the same in all the ways that matter. She was the shining morning star that kept me getting up each morning and going to school (and giving at least some effort at it while I was there). Another good friend, Jack Kirkham III, appeared in the story somewhat later, but with no less importance. We both played the role of best man at each other’s wedding, although I must say that he did it better. I often played the straight man to his fool, an odd couple of sorts. There is no one I counted on more to randomly show up and go shoot hoops with (often when I needed it the most). v One of my favorite teachers at any level, Sam Wine, also shares a role in developing my interest in science. He taught Earth/Space Science, Chemistry, and Physics in my high school. His enthusiasm for all of these topics was undeniable and infectious. Although after high school, I went away from pure sciences for a time, his teachings were there to help guide me back. The last of my friends to join the cast during the high school era was Lee Van Dyke. I wouldn’t even hazard a guess to the number of hours we spent waxing philosophical in the tower, and I also can’t begin to explain how important those hours were. No matter how idle or how deep the conversations were in those hours, not one was wasted in my eyes. It seems like a lifetime ago when I left high school for college to study computer science. Although my career path has left that degree largely in the dust, it was still an important time. For one, I met a fellow computer nerd who’s career path has been similar and yet quite different than mine. We both worked as programmers for a time, I left the field to study chemistry and he entered the Seminary. Father Matt Cushing is one of the most caring, most generous people I have ever met. In this day and age, it sounds less and less odd to say you met a person online. I met Wendy Purches on an internet forum. I’d like to say we were immediate friends, but we started out as a nemesis for each other. And yet, through the years and several different forums, we became friends. It was Wendy that, somewhat idly, suggested I go into chemistry after I left the programing world (she was at the time studying chemistry). And, well, I did. So far it looks like it is working out. I would not have made the transition from being a professional programmer to being a chemistry student at Emporia State University without the guidance of my advisor, teacher, and friend—Dr. Jim Roach. From the beginning of my time at Emporia, he showed nothing but vi absolute faith in my abilities. In fact, I’d wager that he still believes I’m capable of more than I think I am. We also found common interests outside of the university (mostly Star Wars, Star Trek, and Lost). I would also like to thank the Chemistry Department at the University of Kansas. They provided great opportunities and even when those didn’t work out, they allowed me to pursue an opportunity to do research outside the chemistry mainstream. We leads me to thank the U.S. Geological Survey—more specifically the Organic Geochemistry Research Laboratory at the Kansas Water Science Center. The director of the lab, Dr. Michael Meyer, took in a wayward student that he had no obligation to. I would not have the opportunity to write this section in this dissertation without his support. Finally, and out of order (sorry!), I would like to thank my wife, Dr. Rachael Lane. I have already listed most of the people in the known universe who can put up with me and she has to put up with a lot more of me more of the time. Her help was immeasurable in completing this dissertation (she had to go through the process first and so had firsthand experience). I don’t know where I would be without her, but it certainly wouldn’t be as good as it is now. Thank you, one and all. Huzzah! vii Table of Contents Chapter 1: Introduction to Polyoxyethylene Tallow Amine ..................................................... 1 1.1 Polyoxyethylene Tallow Amine: Structure, Naming, and Synthesis ............................. 1 1.2 Use of Polyoxyethylene Tallow Amine in Glyphosate Formulations ............................ 3 1.2.1 History of Glyphosate ................................................................................................... 3 1.2.2 Improved Efficacy of Glyphosate ............................................................................... 14 1.3 Effects of Polyoxyethylene Tallow Amine...................................................................... 14 1.3.1 Toxicity to Non-Target Organisms ............................................................................. 14 1.3.2 Human Health ............................................................................................................. 15 1.3.3 Other Effects ............................................................................................................... 15 1.4 Instrumental Analysis of Polyoxyethylene Tallow Amine ........................................... 17 1.5 Other Surfactants in the Environment .......................................................................... 20 1.6 Research Objectives ......................................................................................................... 21 1.7 References ......................................................................................................................... 23 Chapter 2: Characterization of polyoxyethylene tallow amine surfactants in technical mixtures and glyphosate formulations using ultra-high performance liquid chromatography and triple quadrupole mass spectrometry .................................................. 32 2.1 Introduction ...................................................................................................................... 32 2.2 Experimental .................................................................................................................... 38 2.2.1 Reagents and Materials ............................................................................................... 38 viii 2.2.2 Chromatographic Systems .......................................................................................... 39 2.2.3 Mass Spectrometry...................................................................................................... 41 2.2.4 Peak Fitting ................................................................................................................. 41 2.3 Results and Discussion ..................................................................................................... 42 2.3.1 Characterization of POEA .......................................................................................... 42 2.3.1.1 POE (2) Tallow Amine ........................................................................................ 42 2.3.1.2 POE (5) Tallow Amine ........................................................................................ 44 2.3.1.3 POE (15) Tallow Amine and Ethomeen T/25...................................................... 47 2.3.2 Comparison of Analytical Columns............................................................................ 48 2.3.3 Survey of commercial glyphosate formulations ......................................................... 53 2.4 Conclusions ....................................................................................................................... 57 2.5 References ......................................................................................................................... 59 Chapter 3: Polyoxyethylene Tallow Amine, a Glyphosate Formulation Adjuvant: Soil Adsorption Characteristics, Degradation Profile, and Occurrence on Selected Soils from Agricultural Fields in Iowa, Illinois, Indiana, Mississippi, and Missouri .............................. 64 3.1 Introduction ...................................................................................................................... 64 3.2 Materials and Methods .................................................................................................... 68 3.2.1 Chemicals and Reagents ............................................................................................. 68 3.2.2 Soils............................................................................................................................. 69 3.2.3 Adsorption Experiments ............................................................................................. 69 ix 3.2.4 Soil Extraction Method ............................................................................................... 70 3.2.5 Analytical Methods ..................................................................................................... 70 3.3 Results and Discussion ..................................................................................................... 71 3.3.1 Adsorption of POEA to Soil ....................................................................................... 71 3.3.2 Effects of Salt Content on the Adsorption of POEA .................................................. 74 3.3.3 Effects of pH on the Adsorption of POEA ................................................................. 81 3.3.4 Total POEA Freundlich Averages .............................................................................. 83 3.3.5 Field Samples .............................................................................................................. 85 3.4 Supporting Information ................................................................................................... 89 3.4.1 Methods........................................................................................................................ 89 3.4.1.1 Sample Collection ................................................................................................. 89 3.4.1.2 Laboratory Glassware ........................................................................................... 90 3.4.1.3 POEA Standards ................................................................................................... 90 3.4.1.4 POEA-Pyrex Centrifuge Tube Adsorption Experiments ...................................... 90 3.4.1.5 Soil Adsorption Experiments. ............................................................................... 92 3.4.1.6 Soil Extraction Method ......................................................................................... 92 3.4.1.7 Analytical Method ................................................................................................ 93 3.4.2 Effects of Soil Composition on the Adsorption of POEA ........................................... 94 3.4.3 Tables ........................................................................................................................... 96 3.4.4 Figures........................................................................................................................ 100 x