毛细管电泳-电致化学发光法测定土壤中的多抗霉素B  

Determination of Polyoxin B in Soils by Capillary Electrophoresis with Electrochemiluminescence Detection

作　　者：李玉杰[1] 周敏[1] 马永钧[1] 司长代[1] 米娟[1] 刘彩云[1] 陈慧[1] 

机构地区：[1]西北师范大学化学化工学院甘肃省高分子材料重点实验室省部共建生态环境相关高分子材料教育部重点实验室,甘肃兰州730070

出　　处：《分析测试学报》2011年第5期537-542,548,共7页Journal of Instrumental Analysis

基　　金：甘肃省自然科学基金资助项目(1010RJZA017)

摘　　要：以稀土铕离子(Ⅲ)掺杂的类普鲁士蓝膜(Eu-PB)修饰铂电极为工作电极,采用毛细管电泳-电致化学发光法(CE-ECL)对土壤中的多抗霉素B进行检测。分别对毛细管电泳分离条件和电致化学发光检测条件进行优化,并探讨了体系产生电致化学发光的机理。在优化实验条件下,多抗霉素B可在4min内得到分离,其ECL强度值与多抗霉素B浓度的对数值在质量浓度为1.0×10-4～5.0×10-4 g/L和5.0×10-4～5.0×10-2 g/L范围内呈良好线性,方法的检出限(3σ)为9.2×10-5 g/L。对5.0×10-3 g/L多抗霉素B溶液进行5次平行测定,ECL强度和迁移时间的日内及日间RSD值均小于5%。将该法用于膨润土、高岭土及黄土中多抗霉素B含量的测定,回收率为92%～104%;多抗霉素B在3种土壤中吸附2 h后的吸附率分别为89.0%、45.5%和40.4%,表明3种土壤对多抗霉素B的吸附能力依次为膨润土>高岭土>黄土,其原因可能与土壤自身的特性、比表面积及阳离子交换容量(CEC)有关。On the basis of a chemically modified platinum electrode by europium（Ⅲ）-doped Prussian blue analogue film（Eu-PB） as a working electrode,a rapid and sensitive method for the determination of polyoxin B was established using capillary electrophoresis coupled with electrochemiluminescence detection（CE-ECL）.Parameters related to the separation and detection were discussed and optimized.The possible mechanism of ECL was briefly discussed.Under the optimized conditions（ECL detection potential at 1.27 V,electrokinetic injection for 10 s at 8.5 kV,16 kV as the separation voltage,20 mmol/L pH 8.5 phosphate buffer containing 16 % acetonitrile as running buffer）,polyoxin B was separated within 4 min,and the ECL intensity was in proportion to logarithm of polyoxin B concentration over the range of 1.0×10-4-5.0×10-4 g/L and 5.0×10-4-5.0×10-2 g/L with a detection limit（3σ） of 9.2×10-5 g/L.The relative standard deviations（RSDs） of intra-day and inter-day ECL intensity and migration time were all less than 5.0%.The proposed method was successfully applied in the determination of polyoxin B absorbed in three kinds of soils（e.g.bentonite,kaolinite and loess） with the recoveries of 92%-104%.The results also showed that the adsorption rate of polyoxin B in soils for 2 h was 89.0% for bentonite,45.5% for kaolinite and 40.4% for loess,respectively,indicating that the adsorption capacity of polyoxin B in different soils was bentonitekaoliniteloess.The possible reason was related to the characteristics,specific surface area and cation exchange capacity（CEC） of soils.

关 键 词：毛细管电泳 电致化学发光 多抗霉素B 土壤 

分 类 号：O657.8[理学—分析化学] TQ455.5[理学—化学]