Copper oxychloride (Cu‐Oxy) is a widely used copper‐based fungicide. A drawback of the product is its very low water solubility (around 0.2%) which limits its fungicide efficiency due to the low‐penetrating capacity in the fungal mycelia. In this study, we have explored the use of biosurfactants (BS), surface‐active compounds obtained by microbial production, to enhance the solubility of Cu‐Oxy in agrochemical formulations. A BS extracted from corn steep liquor (CSL), a residue from the corn‐milling industry, was evaluated as an additive to increase the solubility of Cu‐Oxy in water. Different types of synthetic surfactants (Tween® 80, sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (CTAB)) were included for comparison. Results showed that it was possible to dissolve around 90% of Cu‐Oxy at concentration of 4 g L⁻¹ in 20 min of contact time when the BS was added at the concentration of 20 g L⁻¹. In contrast, the synthetic surfactants were only able to dissolve less than 0.5% of Cu‐Oxy under the same conditions. In addition, a factorial design was carried out in order to evaluate the influence of BS concentration, Cu‐Oxy concentration and contact time, on the solubilization of Cu‐Oxy. Maximum percentage of solubilization (96.5%) was achieved at concentrations of 16.1 g L⁻¹ of BS, 2 g L⁻¹ of Cu‐Oxy, and 20 min of contact time. These results allowed to conclude that BS extracted from CSL could be included in agrochemical formulations as solubilizing agents improving the stability of hydrophobic active principles and reducing the concentration needed of chemical pesticides, giving eco‐friendlier formulations.

中文翻译：

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迈向更环保的农药：使用从玉米碾磨工业获得的生物表面活性剂作为三氯氧化铜的增溶剂

氯氧化铜（Cu-Oxy）是一种广泛使用的铜基杀菌剂。该产品的一个缺点是其水溶性极低（约0.2％），由于其在真菌菌丝体中的穿透力低，限制了其杀菌剂的效率。在这项研究中，我们探索了通过微生物生产获得的表面活性剂生物表面活性剂（BS）的使用，以提高Cu-Oxy在农药配方中的溶解度。从玉米浸泡液（CSL）中提取的BS（一种玉米制粉业的残留物）被评估为添加剂，以增加Cu-Oxy在水中的溶解度。为了进行比较，包括了不同类型的合成表面活性剂（Tween®80，十二烷基硫酸钠（SDS）和十六烷基三甲基溴化铵（CTAB））。结果表明，浓度为4 g L时，可能溶解约90％的Cu-Oxy^-1中的接触时间为20分钟时在20克L-的浓度添加BS ^-1。相反，在相同条件下，合成表面活性剂只能溶解少于0.5％的Cu-Oxy。此外，进行了析因设计，以评估BS浓度，Cu-Oxy浓度和接触时间对Cu-Oxy增溶的影响。在BS的浓度为16.1 g L ^-1，BS为2 g L ^{-1的情况下}，最大增溶百分比（96.5％）实现了Cu-Oxy和20分钟的接触时间。这些结果可以得出结论，从C​​SL提取的BS可以作为增溶剂添加到农药配方中，从而提高疏水性活性成分的稳定性并降低化学农药的浓度，从而提供生态友好的配方。