Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
Environ Sci Technol. 2011 Dec 15;45(24):10524-30. doi: 10.1021/es202832g. Epub 2011 Nov 28.
Triphenyltin (TPhT) is a biocide used worldwide in agriculture, especially in rice crop farming. The distribution and dissipation of TPhT in rice fields, as well as uptake of TPhT and other phenyltin compounds (monophenyltin, MPhT, and diphenyltin, DPhT) is still unknown at present. In this study, speciation analysis of phenyltin compounds was carried out in soil and water from a rice field where TPhT was applied during rice seeding according to legal application rates in Brazil. The results indicate the degradation of biocide and distribution of tin species into soil and water. To evaluate whether TPhT is taken up by plants, rice plants were exposed to three different TPhT application rates in a controlled mesocosm during 7 weeks. After this period, tin speciation was determined in soil, roots, leaves, and grains of rice. Degradation of TPhT was observed in soil, where DPhT and MPhT were detected. MPhT, DPhT, and TPhT were also detected in the roots of plants exposed to all TPhT application rates. Only TPhT was detected in leaves and at relatively low concentration, suggesting selective transport of TPhT in the xylem, in contrast to DPhT and MPhT. Concentration of phenyltin species in rice grains was lower than the limit of detection, suggesting that rice plants do not have the capability to take up TPhT from soil and transport it to the grains.
三苯基锡（TPhT）是一种在世界范围内用于农业的杀生物剂，尤其在水稻作物种植中使用广泛。目前，TPhT 在稻田中的分布和消散，以及 TPhT 和其他苯基锡化合物（单苯基锡、MPhT 和二苯基锡、DPhT）的吸收情况尚不清楚。在这项研究中，根据巴西的法定施用量，对应用于水稻播种期间的稻田土壤和水中的苯基锡化合物进行了形态分析。结果表明，杀生物剂降解，并将锡形态分布到土壤和水中。为了评估 TPhT 是否被植物吸收，在受控的中观系统中，将水稻植物暴露于三种不同的 TPhT 施用率下，持续 7 周。经过这段时间后，在土壤、根、叶和稻谷中确定了锡的形态。在土壤中观察到 TPhT 的降解，其中检测到 DPhT 和 MPhT。暴露于所有 TPhT 施用率下的植物的根部也检测到了 MPhT、DPhT 和 TPhT。仅在叶片中检测到 TPhT，且浓度相对较低，这表明 TPhT 选择性地在木质部中运输，与 DPhT 和 MPhT 相反。稻谷中苯基锡化合物的浓度低于检测限，这表明水稻植物没有从土壤中吸收 TPhT 并将其运输到稻谷中的能力。
