Riederer M, Schönherr J
Ecotoxicol Environ Saf. 1984 Jun;8(3):236-47. doi: 10.1016/0147-6513(84)90027-7.
Partition coefficients (K) of (2,4-dichlorophenoxy)acetic acid (2,4-D) have been determined for the system plant cuticle/aqueous buffer. Cuticles isolated enzymatically from leaves (Clivia miniata, Ficus elastica, Citrus aurantium, Hedera helix, Pyrus communis cv. Conférence and cv. Williams, Olea europaea) and fruits (Lycopersicon esculentum, Capsicum annuum, Solanum melongena, Cucumis sativus) were utilized. Only the nondissociated species of 2,4-D was sorbed by cuticles and their lipophilic components. The average partition coefficient for leaf cuticles was 316 (range, 240-470) and for fruit cuticles 476 (range, 424-579). The dependence of sorption upon 2,4-D concentration was tested using tomato fruit cuticle. The sorption isotherm was linear from 2.0 to 5.0 X 10(-4) mol m-3. With increasing 2,4-D concentrations partition coefficients decreased slightly. Extraction of soluble cuticular lipids (SCL) increased the partition coefficients and these relative increases were correlated to relative amounts of SCL. In most species the hydrolytic removal of polar cuticular components resulted in a further increase of partition coefficients. No single cuticle was found to be representative for the sorption characteristics of all plant species investigated. The amounts of cuticle present in plant communities can be estimated from the data presented in conjunction with leaf area indices.
已测定了（2,4-二氯苯氧基）乙酸（2,4-D）在植物角质层/水性缓冲液体系中的分配系数（K）。使用了从叶片（君子兰、橡皮树、甜橙、常春藤、康科德梨和威廉姆斯梨、油橄榄）和果实（番茄、辣椒、茄子、黄瓜）中酶法分离得到的角质层。角质层及其亲脂性成分仅吸附未解离的2,4-D物种。叶片角质层的平均分配系数为316（范围为240 - 470），果实角质层的平均分配系数为476（范围为424 - 579）。使用番茄果实角质层测试了吸附对2,4-D浓度的依赖性。吸附等温线在2.0至5.0×10⁻⁴ mol m⁻³范围内呈线性。随着2,4-D浓度的增加，分配系数略有下降。可溶性角质层脂质（SCL）的提取增加了分配系数，且这些相对增加与SCL的相对含量相关。在大多数物种中，极性角质层成分的水解去除导致分配系数进一步增加。未发现单一角质层能代表所有被研究植物物种的吸附特性。结合叶面积指数，根据所提供的数据可以估算植物群落中角质层的含量。
