Release of Fenamiphos, Atrazine, and Alachlor into Flowing Water from Granules and Spray Deposits of Conventional and Controlled-Release Formulations

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• 作者：Richard F. Davis ; R. Don Wauchope ; Alva W. Johnson ; Benali Burgoa ; and Armand B. Pepperman
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：1996
• 出版时间：September 1996
• 年：1996
• 卷：44
• 期：9
• 页码：2900 - 2907
• 全文大小：330K
• 年卷期：v.44,no.9(September 1996)
• ISSN：1520-5118

文摘

The release into water of active ingredients from spray deposits orgranules of fenamiphos, atrazine,and alachlor was measured for commercial and experimentalcontrolled-release formulations.Granules or spray mixtures of the pesticides were mixed withcoarse sand and dried if necessary,and the mixture was placed in 5 mm × 35 mm stainless steel cylindersthrough which distilledwater was then pumped for 24 h. Pesticide concentrations in theeluate were determined by HPLCanalysis. The conventional formulations (emulsifiableconcentrates, granulars, and dispersiblegranules) gave total release in 5-24 h and in some cases appeared torelease particles into contactingwater. Controlled-release starch-encapsulated formulations gavebetween 5% and 94% release in24 h. Clay/alginate and clay/alginate/linseed oil formulationsgave 0.3-100% release in 24 h,depending mainly on the aqueous solubility and lipophilicity of thepesticide. This simple techniqueprovides comparative insights into the amounts and rates of release ofpesticide active ingredients(and/or other chemicals such as oxidative degradates) when theseformulations are contacted byflowing water. Initial results indicate that formulation canaffect the potential of these pesticidesto be water pollutants under severe rainfall conditions.Keywords: Atrazine; alachlor; fenamiphos; formulation; controlled release;spray deposit; waterquality; runoff; leaching; granules