Department of Chemistry, University of Life Sciences, Lublin, Poland.
Department of General and Coordination Chemistry and Crystallography, Maria Curie-Skłodowska University, Lublin, Poland.
PLoS One. 2020 Dec 2;15(12):e0242980. doi: 10.1371/journal.pone.0242980. eCollection 2020.
The current laboratory adsorption study aimed at determination of the values of adsorption distribution coefficient (Kd) of bentazone in the profiles of Arenosols, Luvisols, and Cambisols, which are the most common arable mineral soils in Poland. The study attempted to identify the soil components that bind bentazone and the principal adsorption mechanisms of this compound as well as create a model capable of predicting its adsorption in soils. The Kd values determined in batch experiments after 24 h of shaking were very low, and ranged from 0.05 to 0.30 mL/g for the Ap horizon and 0 to 0.07 mL/g for subsoils. The results indicated that the anionic form of bentazone was adsorbed on organic matter, while in acidic soils the neutral form of bentazone was adsorbed on organic matter and sand. The detailed analyses of mineralogical composition revealed that the principal mineral that was responsible for the adsorption of bentazone was quartz, which content was strongly positively correlated with the sand fraction. In soils with pH < 5 and an organic carbon content of < 0.35%, quartz exhibited much greater affinity for the neutral bentazone form than organic matter. Fourier transform infrared photoacoustic spectroscopy analyses supported by computational methods have shown the most probable mechanisms behind the adsorption of bentazone on quartz. The created model, assuming the adsorption of bentazone on organic matter and on sand and using the spectrophotometrically determined dissociation constant of bentazone, very well explained the Kd variance in the 81 examined soils, while correctly predicting the adsorption based on soil properties described in the published data.
当前的实验室吸附研究旨在测定苯达松在波兰最常见的耕地矿物土壤——砂壤土、淋溶土和雏形土剖面上的分配吸附系数（Kd）值。该研究试图确定结合苯达松的土壤成分和该化合物的主要吸附机制，并创建一个能够预测其在土壤中吸附的模型。通过 24 小时摇瓶实验确定的 Kd 值非常低，在表土层中范围为 0.05 至 0.30 mL/g，在底土层中范围为 0 至 0.07 mL/g。结果表明，苯达松的阴离子形式被吸附在有机质上，而在酸性土壤中，苯达松的中性形式被吸附在有机质和砂上。对矿物成分的详细分析表明，主要负责吸附苯达松的矿物质是石英，其含量与砂分含量呈强正相关。在 pH 值<5 和有机碳含量<0.35%的土壤中，石英对中性苯达松形式的亲和力远大于有机质。基于计算方法的傅里叶变换红外光声光谱分析表明了苯达松在石英上吸附的最可能机制。所创建的模型假设苯达松在有机质和砂上的吸附，并使用分光光度法测定的苯达松离解常数，很好地解释了 81 种受检土壤中 Kd 的变化，同时根据发表数据中描述的土壤性质正确预测了吸附。
