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United States Department of Agriculture

Agricultural Research Service

Title: Quantification of Ammonia Release from Fruit Fly (Diptera: Tephritidae) Attractants Using Infrared Spectrocopy

Authors
item Heath, Robert
item Vazquez, Aime
item Espada, Cyntia - FORMERLY 6631-05-00
item Kendra, Paul
item Epsky, Nancy

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 2, 2007
Publication Date: April 1, 2007
Citation: Heath, R.R., Vazquez, A., Espada, C., Kendra, P.E., Epsky, N.D. 2007. Quantization of ammonia release from attractants using infrared spectrocopy. Journal of Economic Entomology. 100(2):580-585.

Interpretive Summary: Ammonia is a key component of chemical attractants for economically important fruit flies such as the Mediterranean, Caribbean and Mexican fruit flies. Quantification of ammonia is difficult because of its volatility and corrosive nature. Previously reported techniques resulted in considerable variation, which compromises quantification. Therefore research was conducted by USDA/ARS scientists at the Subtropical Horticulture Research Station to develop an improved method for determining the amount of ammonia released from commercial lures. We investigated the use of Fourier transform infrared (FTIR) spectroscopy as a method for quantification of ammonia in samples that were containerized (static measurement) and in samples where ammonia was entrained in a continuous flow of air (dynamic measurement). An excellent correlation was observed when the area of adsorbtion from 997 to 987 cm-1 region was compared to the concentration of anhydrous ammonia. Analysis of the head space containing ammonia from commercial lures of ammonium bicarbonate and ammonium acetate indicated that the average amount per 50ml of sample contained 0.15 and 0.25 ug of ammonia respectively. Analysis of release rate of ammonium from commercial ammonium acetate lures indicated that after an initial burst of ammonia the amount of ammonia decreased from approximately 250 ug/hr obtained after a week of lure exposure to approximately 150 ug/hr on day 75. This method will enable action federal and state action agencies to advise specifications for lures that are used to monitor exotic fruit flies that threaten U.S. Agriculture.

Technical Abstract: Ammonia is a key component of chemical attractants for economically important fruit flies such as the Mediterranean, Caribbean and Mexican fruit flies. Critical to the development of improve attractants is an accurate method to measure the amount of attractant released. Quantification of ammonia is difficult because of its volatility and corrosive nature. Previously reported techniques resulted in considerable variation, which compromises quantification. Therefore research was conducted by USDA/ARS scientists at the Subtropical Horticulture Research Station to develop an improved method for determining the amount of ammonia released from commercial lures. We investigated the use of Fourier transform infrared (FTIR) spectroscopy as a method for quantification of ammonia in samples that were containerized (static measurement) and in samples where ammonia was entrained in a continuous flow of air (dynamic measurement). A Fourier transform infrared (FTIR) spectroscopic method was developed to quantify ammonia from head space and in real time. Using a FTIR spectrometer equipped with a mercury cadmium telluride detector, a KBr beamsplitter, and a 2-m (200 ml) gas cell with a thermal jacket and using bands absorbance of ammonia in the 997 to 987 cm-1 region verses concentration of anhydrous ammonia a calibration curve with a regression of 0.995, y = 0.0727x (0.111) was obtained. Analysis of the head space containing ammonia from commercial lures of ammonium bicarbonate and ammonium acetate indicated that the average amount per 50ml of sample contained 0.15 and 0.25 ug of ammonia respectively. Analysis of release rate of ammonium from ammonium acetate lures indicated that after an initial burst of ammonia the amount of ammonia decreased from approximately 250 ug/hr obtained after a week of lure exposure to approximately 150 ug/hr on day 75. Release rate of the ammonia from ammonium acetate lures could be reduced by decreasing the surface area of the release membrane.

Last Modified: 7/24/2014
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