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Use of bentonite and humic acid as modifying agents in alginate-based controlled-release formulations of imidacloprid

1999; Wiley; Volume: 55; Issue: 5 Linguagem: Inglês

10.1002/(sici)1096-9063(199905)55

1096-9063

E. González‐Pradas, Manuel Fernández‐Pérez, M. Villafranca‐Sánchez, Francisco J. Martínez‐López, F. Flores‐Céspedes,

Analytical chemistry methods development

Pesticide ScienceVolume 55, Issue 5 p. 546-552 Paper Use of bentonite and humic acid as modifying agents in alginate-based controlled-release formulations of imidacloprid E González-Pradas, Corresponding Author E González-Pradas egonzale@ualm.es Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainDpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this authorM Fernández-Pérez, M Fernández-Pérez Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this authorM Villafranca-Sánchez, M Villafranca-Sánchez Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this authorF Martínez-López, F Martínez-López Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this authorF Flores-Céspedes, F Flores-Céspedes Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this author E González-Pradas, Corresponding Author E González-Pradas egonzale@ualm.es Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainDpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this authorM Fernández-Pérez, M Fernández-Pérez Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this authorM Villafranca-Sánchez, M Villafranca-Sánchez Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this authorF Martínez-López, F Martínez-López Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this authorF Flores-Céspedes, F Flores-Céspedes Dpto de Química Inorgánica, Universidad de Almería, 04120-Almería SpainSearch for more papers by this author First published: 18 May 1999 https://doi.org/10.1002/(SICI)1096-9063(199905)55:5 3.0.CO;2-PCitations: 27AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract In order to prepare a formulation to be used for controlled release, imidacloprid was incorporated into alginate granules by using calcium chloride as gellant. The formulation prepared (alginate–imidacloprid–water) was modified by the addition of different sorbents. The effects on release rate of the addition of natural bentonite desiccated at 105 °C, untreated, acid-treated with sulfuric acid solutions over a concentration range between 0.5 mol dm−3 and 2.5 mol dm−3, and a commercial humic acid, were studied by immersion of the granules in water under static conditions. The time taken for 50% of the active ingredient to be released into water, (T50), was calculated from the data obtained. On the other hand, the sorption–desorption processes of imidacloprid from a 0.01 M aqueous calcium chloride solution at 25 °C, by natural, acid-treated bentonite samples, and humic acid, have been studied by using batch experiments in order to evaluate the potential of these materials for their application in controlled-release formulations of pesticides. The experimental data have been fitted to the Freundlich equation in order to calculate the adsorption capacities (Kf). Kf values ranged from 1.76 mg kg−1 for the untreated bentonite up to 126.9 mg kg−1 for the humic acid. A correlation study was performed with T50, the surface area (S) and the Freundlich parameter (Kf) of the bentonite samples in order to know the factors that affect release rate of imidacloprid from bentonite granules. A linear correlation of the T50 values and both S and Kf parameters was observed. © 1999 Society of Chemical Industry Citing Literature Volume55, Issue5May 1999Pages 546-552 RelatedInformation