Environmentally Friendly Formulations of Trifluralin Based on Alginate Modified Starch
Affiliation(s)
Department of Chemistry, Nnamdi Azikiwe University, Awka, Nigeria. Department of Chemistry, University of Agriculture, Makurdi, Nigeria.
Department of Chemistry, Nnamdi Azikiwe University, Awka, Nigeria. Department of Chemistry, University of Agriculture, Makurdi, Nigeria.
ABSTRACT
In line with global efforts towards sustainable agriculture, the use of starch modified with alginate in the preparation of slow release formulations of the herbicide trifluralin was investigated. Trifluralin was encapsulated in starch-alginate beads, and the resulting slow release formulations (SRFs) characterized using scanning electron microscopy (SEM) and Fourier Transform infrared (FTIR) spectroscopy. Herbicide release from the SRFs was studied in water and compared to release of technical grade trifluralin. Three sets of formulations were made by extrusion into 0.25 M calcium chloride solution: starch/alginate (SSTRF), amylose starch/alginate (ASSTRF) and amylose starch/alginate/groundnut oil (ASTRGNO) beads, and the fourth was from gelatinized starch at 75?C (SSTRF2). The results showed highly porous spherical beads, the amylose/alginate beads bigger and less porous than the starch/alginate beads with diameters of 2.79 ± 0.01 and 2.37 ± 0.01 mm; porosity of 54.67 ± 0.2 and 60.59% ± 0.2% and swelling of 54.09 ± 0.2 and 61.22% ± 0.2%, respectively. All sets of beads exhibited reduced crystallinity of trifluralin. FTIR revealed a shift to lower wavelength of the carbonyl stretching vibrations from 1750 to 1725 cm–1 and a reduction in intensity of the carboxylate peaks of alginate, suggesting interactions between the formulation components that make for good slow release. 96% of technical grade trifluralin (TGTRF) was released into a 50:50 pH 6.5 Buffer/ Methanol aqueous medium in 24 hrs. However, for the starch/TRF formulation, SSTRF, only 9.33% herbicide was released after 24 hrs and 34.94% after 672 hrs (28 days). The amylose starch/TRF formulation released 13.61% herbicide in 24 hrs and 46.95% in 672 hrs, a 12% increase in release of TRF over the starch formulation. Encapsulation in starch produced 65% slow release of TRF and gelatinization achieved 84% retardation. Use of amylose starch as matrix caused 53.15% delay and addition of groundnut oil resulted in 80.87% retardation of TRF release. Encapsulation of TRF in starch/alginate beads is a veritable way of reducing negative environmental effects.
In line with global efforts towards sustainable agriculture, the use of starch modified with alginate in the preparation of slow release formulations of the herbicide trifluralin was investigated. Trifluralin was encapsulated in starch-alginate beads, and the resulting slow release formulations (SRFs) characterized using scanning electron microscopy (SEM) and Fourier Transform infrared (FTIR) spectroscopy. Herbicide release from the SRFs was studied in water and compared to release of technical grade trifluralin. Three sets of formulations were made by extrusion into 0.25 M calcium chloride solution: starch/alginate (SSTRF), amylose starch/alginate (ASSTRF) and amylose starch/alginate/groundnut oil (ASTRGNO) beads, and the fourth was from gelatinized starch at 75?C (SSTRF2). The results showed highly porous spherical beads, the amylose/alginate beads bigger and less porous than the starch/alginate beads with diameters of 2.79 ± 0.01 and 2.37 ± 0.01 mm; porosity of 54.67 ± 0.2 and 60.59% ± 0.2% and swelling of 54.09 ± 0.2 and 61.22% ± 0.2%, respectively. All sets of beads exhibited reduced crystallinity of trifluralin. FTIR revealed a shift to lower wavelength of the carbonyl stretching vibrations from 1750 to 1725 cm–1 and a reduction in intensity of the carboxylate peaks of alginate, suggesting interactions between the formulation components that make for good slow release. 96% of technical grade trifluralin (TGTRF) was released into a 50:50 pH 6.5 Buffer/ Methanol aqueous medium in 24 hrs. However, for the starch/TRF formulation, SSTRF, only 9.33% herbicide was released after 24 hrs and 34.94% after 672 hrs (28 days). The amylose starch/TRF formulation released 13.61% herbicide in 24 hrs and 46.95% in 672 hrs, a 12% increase in release of TRF over the starch formulation. Encapsulation in starch produced 65% slow release of TRF and gelatinization achieved 84% retardation. Use of amylose starch as matrix caused 53.15% delay and addition of groundnut oil resulted in 80.87% retardation of TRF release. Encapsulation of TRF in starch/alginate beads is a veritable way of reducing negative environmental effects.
Cite this paper
I. Onyido, R. Sha’Ato and L. Nnamonu, "Environmentally Friendly Formulations of Trifluralin Based on Alginate Modified Starch," Journal of Environmental Protection, Vol. 3 No. 9, 2012, pp. 1085-1093. doi: 10.4236/jep.2012.39127.
I. Onyido, R. Sha’Ato and L. Nnamonu, "Environmentally Friendly Formulations of Trifluralin Based on Alginate Modified Starch," Journal of Environmental Protection, Vol. 3 No. 9, 2012, pp. 1085-1093. doi: 10.4236/jep.2012.39127.
References
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Rathor, “Behaviour of Alginate Kaolin Based Controlled-Release Formulations of the Herbicide Thiobencarb in a Simulated Ecosystem,” Pesticide Science, Vol. 42, No. 4, 1994, pp. 261-272. doi:10.1002/ps.2780420403 [11] A. B. Pepperman and J. W. Kuan, “Slow Release Formulations of Metribuzin Based on Alginate-Kaolin-Linseed Oil,” Journal of Controlled Release, Vol. 26, No. 1, 1993, 26, pp. 21-30. doi:10.1016/0168-3659(93)90205-J [12] A. B. Pepperman and J. W. Kuan, “Controlled Release of Alachlor Based on Calcium Alginate,” Journal of Controlled Release, Vol. 34, No. 1, 1995, pp. 17-23. doi:10.1016/0168-3659(94)00111-7 [13] M. Fernandez-Perez, M. Villa-Franca-Sanchez, E. Gonzalez-Pradas and F. Flores-Cespedes, “Controlled Release of Diuron from an Alginate-Bentonite Formulation: Water Release Kinetics and Soil Mobility Study,” Journal of Agricultural and Food Chemistry, Vol. 47, No. 2, 1999, pp. 791-798. doi:10.1021/jf980878y [14] F. Cespedes, M. Villa-Franca-Sanchez, S. Perez-Garcia and M. Fernandez-Perez, “Modifying Sorbents in Con- trolled Release Formulations to Prevent Herbicides Pollution,” Chemosphere, Vol. 69, No. 5, 2007, pp. 785-794. doi:10.1016/j.chemosphere.2007.05.005 [15] B. Singh, D. K. Sharma, R. Kumar and A. Gupta, “Controlled Release of the Fungicide Thiram from Starch- Alginate-Clay Based Formulation,” Applied Clay Science, Vol. 45, No. 1-2, 2009, pp. 76-82. doi:10.1016/j.clay.2009.03.001 [16] D. Trimnell, B. S. Shasha and W. M. Doane, “Release of Trifluralin from Starch Xanthide Encapsulated Formulations,” Journal of Agricultural and Food Chemistry, Vol. 29, No. 3, 1981, pp. 637-640. doi:10.1021/jf00105a050 [17] D. Trimnell, B. S. Shasha, “Entrapment of Herbicides in Starch for Spray Applications,” Journal of Controlled Release, Vol. 7, No. 3, 1988, pp. 263-268. [18] M. G. Dosskey, D. C. Adriano, C. E. Murphy and J. C. Corey, “Effectiveness of a Slow Release Herbicide System for Control of Root Intrusions into Buried Hazardous Waste,” Hazardous Waste and Hazardous Materials, Vol. 8, No. 4, 2009, pp. 293-301. doi:10.1089/hwm.1991.8.293 [19] W. J. Connick Jr., “Controlled Release of Bioactive Materials Using Alginate Gel Beads,” US Patent 4401456, 1983. [20] R. Celis, M. C. Hermosin, J. Carrizosa and J. Cornejo, “Inorganic and Organic Clays as Carriers for Controlled Release of the Herbicide Hexazinone,” Journal of Agricultural and Food Chemistry, Vol. 50, No. 8, 2002, pp. 2324-2330. doi:10.1021/jf011360o [21] L. A. Nnamonu, R. Sha’Ato and I. Onyido, “Adsorption Studies of Trifluralin on Kaolin,” Nigerian Journal of Pure and Applied Science, Vol. 4, 2011, pp. 68-75. [22] M. S. Mills and E. M. Thurman, “Reduction of Non-Point Source Contamination of Surface Water and Ground Water by Starch Encapsulation of Herbicides,” Environmental Science & Technology, Vol. 28, No. 1, 1994, pp. 73-79. doi:10.1021/es00050a011 [23] R. E. Wing, S. Maiti and W. M. Doane, “Amylose Content of Starch Controls the Release of Encapsulated Bioactive Agents,” Journal of Controlled Release, Vol. 7, No. 1, 1988, 7, pp. 33-37. doi:10.1016/0168-3659(88)90077-6 [24] M. E. Carr, R. E. Wing and W. M. Doane, “Encapsulation of Atrazine within a Starch Matrix by Extrusion Processing,” Cereal Chemistry, Vol. 68, No. 3, 1991, 68, pp. 262 -266. [25] D. D. Buhler, W. C. Koskinen, M. M. Schreiber and J. Gan, “Dissipation of alachlor, Metolachlor, and Atrazine from Starch-Encapsulated Formulations in a Sandy Loam Soil,” Weed Science, Vol. 42, No. 3, 1994, pp. 411-417. [26] Z. Gerstl, A. Nasser and U. Mingelgrin, “Controlled Release of Pesticides into Water from Clay-Polymer Formulations,” Journal of Agricultural and Food Chemistry, Vol. 46, No. 9, 1998, pp. 3803-3809. doi:10.1021/jf980184p
[1] J. O. D. Dailey, “Volatilization of Alachlor from Polymeric Formulations,” Journal of Agricultural and Food Chemistry, Vol. 52, No. 22, 2004, pp. 6742-6746. doi:10.1021/jf040034g [2] L. T. Zeoli, A. F. Kydonieus and A. F. Quisumbing, “Controlled Release Technologies,” In: A. F. Kydonieus and M. Beroza, Eds., Insect Suppression with Controlled Release Pheromone Systems, CRC, Boca Raton, 1982, pp. 131-145. [3] K. Tsuji, “Microencapsulation of Pesticides and Their Improved Handling Safety,” Journal of Microencapsulation, Vol. 18, No. 2, 2001, pp. 137-147. doi:10.1080/026520401750063856 [4] T. Roberts, “Metabolic Pathways of Agrochemicals Part 1, Herbicides and Plant Growth Regulators,” RSC, Cambridge, 1998, pp. 281-289. doi:10.1039/9781847551382 [5] USEPA, “Fact Sheet,” 1996. http://www.epa.gov/oppsrrd1/REDs/factsheets/0179fact.pdf [6] L. R. Zimmerman, E. M. Thurman and K. C. Bastian, “Detection of Persistent Organic Pollutants in the Mississippi Delta Using Semi-Permeable Membrane Devices,” Science of The Total Environment, Vol. 248, No. 2-3, 2000, pp. 169-179. doi:10.1016/S0048-9697(99)00540-9 [7] P. R. F. Barret, “Some Studies on the Use of Alginates for the Placement and Controlled Release of Diquat on Sub- merged Aquatic Plants,” Pesticide Science, Vol. 9, No. 5, 1978, pp. 425-433. doi:10.1002/ps.2780090507 [8] W. J. Connick Jr., “Controlled Release of the Herbicides 2,4-D and Dichlobenil from Alginate Gels,” Journal of Applied Polymer Science, Vol. 27, No. 6, 1982, pp. 3341- 3348. doi:10.1002/app.1982.070270912 [9] L. Vollner, “Agrochemical Formulations for Improved Efficacy and Reduced Environmental Impacts: Slow Release Formulations with Natural Polymers,” In: M. Mansour, Ed., Study and Prediction of Pesticides Behaviour in Soils, Plants and Aquatic Systems, GSF, Neuherberg, 1990, pp. 136-145. [10] J. Gan, M. Hussain and M. N. Rathor, “Behaviour of Alginate Kaolin Based Controlled-Release Formulations of the Herbicide Thiobencarb in a Simulated Ecosystem,” Pesticide Science, Vol. 42, No. 4, 1994, pp. 261-272. doi:10.1002/ps.2780420403 [11] A. B. Pepperman and J. W. Kuan, “Slow Release Formulations of Metribuzin Based on Alginate-Kaolin-Linseed Oil,” Journal of Controlled Release, Vol. 26, No. 1, 1993, 26, pp. 21-30. doi:10.1016/0168-3659(93)90205-J [12] A. B. Pepperman and J. W. Kuan, “Controlled Release of Alachlor Based on Calcium Alginate,” Journal of Controlled Release, Vol. 34, No. 1, 1995, pp. 17-23. doi:10.1016/0168-3659(94)00111-7 [13] M. Fernandez-Perez, M. Villa-Franca-Sanchez, E. Gonzalez-Pradas and F. Flores-Cespedes, “Controlled Release of Diuron from an Alginate-Bentonite Formulation: Water Release Kinetics and Soil Mobility Study,” Journal of Agricultural and Food Chemistry, Vol. 47, No. 2, 1999, pp. 791-798. doi:10.1021/jf980878y [14] F. Cespedes, M. Villa-Franca-Sanchez, S. Perez-Garcia and M. Fernandez-Perez, “Modifying Sorbents in Con- trolled Release Formulations to Prevent Herbicides Pollution,” Chemosphere, Vol. 69, No. 5, 2007, pp. 785-794. doi:10.1016/j.chemosphere.2007.05.005 [15] B. Singh, D. K. Sharma, R. Kumar and A. Gupta, “Controlled Release of the Fungicide Thiram from Starch- Alginate-Clay Based Formulation,” Applied Clay Science, Vol. 45, No. 1-2, 2009, pp. 76-82. doi:10.1016/j.clay.2009.03.001 [16] D. Trimnell, B. S. Shasha and W. M. Doane, “Release of Trifluralin from Starch Xanthide Encapsulated Formulations,” Journal of Agricultural and Food Chemistry, Vol. 29, No. 3, 1981, pp. 637-640. doi:10.1021/jf00105a050 [17] D. Trimnell, B. S. Shasha, “Entrapment of Herbicides in Starch for Spray Applications,” Journal of Controlled Release, Vol. 7, No. 3, 1988, pp. 263-268. [18] M. G. Dosskey, D. C. Adriano, C. E. Murphy and J. C. Corey, “Effectiveness of a Slow Release Herbicide System for Control of Root Intrusions into Buried Hazardous Waste,” Hazardous Waste and Hazardous Materials, Vol. 8, No. 4, 2009, pp. 293-301. doi:10.1089/hwm.1991.8.293 [19] W. J. Connick Jr., “Controlled Release of Bioactive Materials Using Alginate Gel Beads,” US Patent 4401456, 1983. [20] R. Celis, M. C. Hermosin, J. Carrizosa and J. Cornejo, “Inorganic and Organic Clays as Carriers for Controlled Release of the Herbicide Hexazinone,” Journal of Agricultural and Food Chemistry, Vol. 50, No. 8, 2002, pp. 2324-2330. doi:10.1021/jf011360o [21] L. A. Nnamonu, R. Sha’Ato and I. Onyido, “Adsorption Studies of Trifluralin on Kaolin,” Nigerian Journal of Pure and Applied Science, Vol. 4, 2011, pp. 68-75. [22] M. S. Mills and E. M. Thurman, “Reduction of Non-Point Source Contamination of Surface Water and Ground Water by Starch Encapsulation of Herbicides,” Environmental Science & Technology, Vol. 28, No. 1, 1994, pp. 73-79. doi:10.1021/es00050a011 [23] R. E. Wing, S. Maiti and W. M. Doane, “Amylose Content of Starch Controls the Release of Encapsulated Bioactive Agents,” Journal of Controlled Release, Vol. 7, No. 1, 1988, 7, pp. 33-37. doi:10.1016/0168-3659(88)90077-6 [24] M. E. Carr, R. E. Wing and W. M. Doane, “Encapsulation of Atrazine within a Starch Matrix by Extrusion Processing,” Cereal Chemistry, Vol. 68, No. 3, 1991, 68, pp. 262 -266. [25] D. D. Buhler, W. C. Koskinen, M. M. Schreiber and J. Gan, “Dissipation of alachlor, Metolachlor, and Atrazine from Starch-Encapsulated Formulations in a Sandy Loam Soil,” Weed Science, Vol. 42, No. 3, 1994, pp. 411-417. [26] Z. Gerstl, A. Nasser and U. Mingelgrin, “Controlled Release of Pesticides into Water from Clay-Polymer Formulations,” Journal of Agricultural and Food Chemistry, Vol. 46, No. 9, 1998, pp. 3803-3809. doi:10.1021/jf980184p