莠去津吸附的土壤淋溶柱色谱法研究

采用新发展的土壤淋溶柱色谱法，研究农药在水－土壤体系中的吸附。用土壤装填成液相色谱柱，以农药水溶液为流动相，以除草剂莠去津（２－氯－４－乙胺基－６－异丙胺基－ｓ－三嗪）为例，质量浓度从１９．７３μｇ／Ｌ至２９．６０ｍｇ／Ｌ，紫外检测器监测吸附平衡。吸附相中莠去津的质量浓度经甲醇淋洗液的测定值扣除柱内液相中的质量浓度后得到。对于极稀溶液，可采用在ＯＤＳ柱上富集－液相色谱台阶梯度法测定。莠去津在沙壤土上的吸附行为符合Ｆｒｅｕｎｄｌｉｃｈ方程式，其吸附常数Ｋｆ＝８４２．６ｍＬ／ｋｇ。

Study on Adsorption of Atrazine by Soil Leaching Column Chromatography

A recently developed soil leaching column chromatography was applied to study the adsorption of pesticide in water\|soil system. Soil was filled directly into a liquid chromatographic column and pesticide solution was applied as an eluant, and the adsorption equilibrium was monitored by a UV detector. The herbicide atrazine, i. e. 2\|chloro\|4\|ethylamino\|6\|isopropylamino\|s\|triazine, was chosen as an example. Its mass concentration ranged from 19.73 mg/L to 29.60 g/L. After the soil phase was rinsed with methanol, the amount of atrazine adsorbed was calculated from the difference between the atrazine totally rinsed and that in solution in the column. The low content atrazine sample was determined by enrichment on an ODS column and step\|gradient method. It shows that the adsorption of atrazine on a sandy loam soil is in accordance with Freundlich isotherm. The adsorption coefficient K f is 842.6 mL/kg and the normalized organic carbon adsorption coefficient log K oc is 1.832.