Effects of poly‐ and monodisperse surfactants on14C‐epoxiconazole diffusion in isolated cuticles of Prunus laurocerasus. Issue 4 (9th October 2012)

• Record Type: Journal Article
• Authors: Gutenberger, Andrea; Zeisler, Viktoria V; Berghaus, Rainer; Auweter, Helmut; Schreiber, Lukas
• Is Part Of: Pest management science. Volume 69:Issue 4(2013:Apr.)
• Page Start: 512
• Page End: 519
• Publication Date: 2012-10-09
• Subjects: Pests -- Control -- Periodicals; Pesticides -- Periodicals; 632.9
• DOI: 10.1002/ps.3402
• Languages: English
• ISSNs: 1526-498X

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="ps3402-sec-0001" sec-type="section"> <title>Background</title> <p> <bold>Surfactants are known to enhance the foliar uptake of agrochemicals. It was the aim of this study to compare the enhancing effect of three polydisperse surfactants (Brij 30, Plurafac LF300 and Wettol LF700) and five monodisperse alcohol ethoxylates (C<sub>12</sub>E<sub>3</sub>, C<sub>12</sub>E<sub>4</sub>, C<sub>12</sub>E<sub>5</sub>, C<sub>12</sub>E<sub>6</sub> and C<sub>12</sub>E<sub>8</sub>) on <sup>14</sup>C‐epoxiconazole diffusion in cuticles isolated from cherry laurel (<italic>Prunus laurocerasus</italic> L.).</bold> </p> </sec> <sec id="ps3402-sec-0002" sec-type="section"> <title>Results</title> <p> <bold>Rate constants (<italic>k</italic>*) of <sup>14</sup>C‐epoxiconazole diffusion were measured in the presence and in the absence of the surfactants. Polydisperse surfactants increased the rates of foliar penetration of <sup>14</sup>C‐epoxiconazole by factors of between 8 and 16. With monodisperse surfactants, enhancing effects on cuticular penetration were 2–16‐fold. Effects were highest with alcohol ethoxylates of intermediate size, whereas they were lower for the smaller, more lipophilic and the larger, more polar monomers. In addition, diffusion of four monodisperse alcohol ethoxylates (C<sub>12</sub>E<sub>3</sub>, C<sub>12</sub>E<sub>4</sub>, C<sub>12</sub>E<sub>5</sub> and C<sub>12</sub>E<sub>6</sub>) across cuticles was measured. Rate constants of alcohol ethoxylates decreased with decreasing lipophility and increasing molecular weight.</bold> </p> </sec> <sec id="ps3402-sec-0003" sec-type="section"> <title>Conclusion</title> <p> <bold>The results indicate that enhancement of foliar penetration across cuticles by surfactants was most efficient when both <sup>14</sup>C‐epoxiconazole and surfactants had similar mobilities in the transport‐limiting barrier of the cuticles. This observation should be of interest in future strategies to optimise foliar uptake of agrochemicals using surfactants.</bold> </p> </sec> </abstract>