Institute: District of Columbia
Year Established: 2016 Start Date: 2016-03-01 End Date: 2017-02-28
Total Federal Funds: $9,954 Total Non-Federal Funds: $4,778
Principal Investigators: Xueqing Song
Abstract: Glyphosate, first marketed by Monsanto as Roundup , has become the world’s leading agrochemical , especially in recent years with the widespread of genetically modified glyphosate-resistant crops . The increased use raises the potential for residue accumulation in both soil through adsorption and water due to their high solubility and leaching. The World Health Organization’s (WHO’s) cancer authorities – the International Agency for Research on Cancer (IARC) – recently determined that glyphosate is “probably carcinogenic to humans” (Group 2A). Glyphostae can be degraded by soil microorganisms, yielding glyoxylate and (aminomethyl) phosphonic acid (AMPA) as primary intermediates. However, AMPA is more toxic than the parent molecule and more persistent in water and soil. Furthermore, the rate of degradation of Glyphosate and AMPA in water is generally slower because there are fewer microorganisms in water than in soil. Glyphosate and its metabolite may still be detected long after application or even far from the site of application. Although its physical, chemical, environmental, and toxicological properties have been well-documented, its effects on non-target organisms and overall environmental impact have not been fully investigated, questions should be addressed regarding the environmental safety, in light of its increasing use. Therefore, Knowledge about the persistency of glyphosate and its derivatives would be beneficial in the handling of contaminated dredged material, and it is essential to understand the speciation of these organophosphorous compounds to gain a better understanding of their interaction in soil and aquatic environment. The long term effect of the major metabolite of glyphosate AMPA cannot be neglected, as AMPA has very strong affinity to sediment sample. Therefore, there is a need to further degrade AMPA to non-toxic phosphorous specifies. It has been reported in the literature that Manganese oxide can be used as catalyst to degrade glyphosate and its meytabolite AMAP even in water samples through an oxidative radical process. We are proposing in this project to test the catalytical activity of other non-toxic metal ions, such Fe3+, Zn2+ and Co3+ in the degradation of glyphosate and AMPA in soil and water samples. The degradation species and its residues will be detected by phosphorous-31 NMR spectroscopy. We propose to use 31P NMR spectroscopy, in an effort to eliminate the need for pre- or post-column derivatization procedures to improve both the chromatographic behavior and the detection ability by gas chromatography (GC) or high-performance liquid chromatography (HPLC). The strength of NMR spectroscopy has been in characterization of the chemical structures, and in giving information about OP-compound degradation processes in the environment, as well as OP-compound metabolism in organisms. Because NMR is also a quantitative technique, it has been applied in quality control of the OP pesticides and other agrochemicals. Finally, NMR is nondestructive, meaning that the sample can be analyzed without consuming it during the process as happens with GC–MS or LC–MS techniques, and the sample can be stored after analysis for later studies. This project is also designed to involve at least undergraduate student at the University of the District of Columbia in research.