非離子界面活性劑具有高極性親水基（ethoxylated group）與低極性疏水基(alkylated group)的兩性結構，被土壤吸附後會改變土壤的吸附特性，進而影響土壤吸附有機污染物的分佈係數。本研究利用高效能液相層析質譜分析方法（LC/MS）來探討於不同平衡濃度下，土壤對非離子界面活性劑中各EO（ethoxylated group）鏈之選擇性吸附行為。 研究分別以三種不同性質的土壤(黏土、天然土壤與高有機質土)對含有不同EO鏈的非離子性界面活性劑(TX-100,TX-305,TX-405)分別進行吸附平衡實驗。對低極性的TX-100而言，吸附能力強的蒙特石呈現無選擇性的吸附結果；吸附能力較弱的高嶺土則容易吸附低EO鏈形成吸附性微胞。研究亦發現這兩種黏土對TX-305傾向於吸附高EO鏈的部份；TX-405則無選擇性吸附情形。天然土壤對Triton之吸附作用推測具有無機相吸附與有機質分佈兩種，其中紗帽山土對低極性TX-100的分佈作用較為明顯；而台中土則以大部分無機相吸附低EO鏈以形成吸附性微胞的方式與有機質分佈低EO鏈的作用為主，但這兩種天然土壤對高EO鏈的TX-305與TX-405吸附結果均比TX-100弱。含有高有機質土壤Ihss Florida Peat(I.F.P.)，其吸附低EO鏈的情形皆明顯大於高EO鏈，此結果係因為高有機質土IFP對低EO鏈有明顯的分佈作用。除了分佈作用外，IFP土壤中高極性的官能基對非離子界面活性劑中EO鏈組成具有氫鍵的作用，造成IFP對三種非離子界面活性劑的吸附量僅次於蒙特石。 Triton X-100, Triton X-305 and Triton X-405 are mixtures of different ethoxylated group nonionic surfactant. When nonionic surfactant was sorbed onto soil surface, the sorption characteristics of soil and the partition coefficient of organic compounds can be profoundly changed. In this study, we investigated selective sorption behavior of ethoxylated nonionic surfactant mixtures by various soils with High Performance Liquid Chromatography/ Mass Spectrometry technique. The sorption of TX-100 by Ca-Montmorillonite showed non-selective sorption behaviors. Among all surfactants tested, kaolin tended to sorption low EO groups for TX-100. On the other hand, clays preferred to adsorb higher EO groups for TX-305 and TX-405 . The result also indicated that low EO group surfactants are able to partition into the organic phase of Sao-Mao Hill soil and Tai-Chung soil. In addition to partition, we presumed that low EO nonionic surfactants formed admicelle on Tai-Chung soil surface. As a result, the absorption amount of surfactants on Tai-Chung soil was greater than that of Sao-Mao Hill soil. Since low EO group surfactants partitioning into the organic matter of Ihss Florida Peat (I.F.P.), the absorption capacity of TX-100 for I.F.P. was the greatest. A comparison of partitioning behavior, we also suggested that the hydrogen bond between the EO group of surfactants and function group of soil can enhance absorption capacity.
