Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Alexandria Stewart - University of Texas at San Antonio
Co-Author(s): Melissa Montoya, University of Texas at San Antonio, San Antonio, TX; Stephan B. H. Bach, University of Texas at San Antonio, San Antonio, TX; Adalberto Perez De Leon, USDA-ARS, Knipling-Bushland U.S. Livestock Insects Research Laboratory, and Veterinary Pest Genomics Center, Kerrville, TX; Robert J. Miller, USDA-ARS, Cattle Fever Tick Research Laboratory, Edinburg, TX.
The Southern Cattle Fever Tick (SCFT), Rhipicephalus microplus, transmits agents that cause deadly cattle diseases, such as bovine babesiosis, making it one of the most economically important external parasites for livestock populations worldwide. The central hypothesis is that natural products like essential oils will provide safer, novel methods for tick control in response to the numerous problems associated with the current use of synthetic acaricides, such as the development of resistance in ticks. Field studies conducted in Puerto Rico using Essentria IC3™, a commercial product containing essential oils, demonstrated efficacy against SCFT on infested dairy cattle when prepared according to label instructions. It was proposed that product effectiveness was related to consistent proportions of essential oils between batches. However, the extent of chemical variations between product batches are not known. As such, a rapid method was developed for the identification and the determination of relative compositions of the constituent types present in two different batches of Essentria IC3™ through the use of gas chromatography mass spectrometry (GC-MS), the analysis of analytical standards purchased from Sigma-Alderich of ingredients contained in Essentria IC3™, and the comparison of spectral data from NIST libraries. Results revealed the identification of forty different constituent types present between the two product batches, each of which corresponded to the ingredients listed on the product ingredient list. Comparison of the relative compositions of the constituent types for each batch of Essentria IC3™ revealed a fair consistency in chemical composition between the two product batches. Future work would involve the use of calibration curves to determine if the essential oil components are within the product’s labelled concentrations between product batches, which will improve our understanding of product performance against SCFT infestations in livestock populations
Funder Acknowledgement(s): I would like to thank the Collaborative Integration of USDA-Research in the Advanced Teaching Lab, under the 'I-DISCOVER Grant' Award number 2014-38422-22078) for funding and sub-award No. 226300263A-01 for their support. I would also like to thank the National Science Foundation Louis Stokes Alliances for Minority Participation grant (Award No. 1305001) for funding this project as well.
Faculty Advisor: Marsha Adrian, firstname.lastname@example.org
Role: I analyzed the samples using GC-MS and compared the spectral data from the two batches of the essential oil pesticide with compounds from the NIST database for Electron Ionization Fragmentation for the identification of the constituent types within the samples.