石墨烯/十二烷基硫酸钠复合物修饰碳糊电极测定氯霉素

以液体石蜡和硅油为混合粘合剂,与石墨粉混合制备了碳糊电极基底电极,将石墨烯/十二烷基硫酸钠复合物修饰在基底碳糊电极上,得到了基于石墨烯复合物的新型修饰碳糊电极。应用扫描电镜和循环伏安法分别研究了该电极的表面特性和电化学性质,结果表明,石墨烯和十二烷基硫酸钠修饰的碳糊电极增大了比表面积,有利于电子传递。在pH 3.0的HAc-NaAc缓冲溶液中,该修饰碳糊电极对氯霉素具有良好的电化学响应,氧化峰电位为0.194 V,氧化峰电流是基底碳糊电极的10倍。在最优实验条件下,该氧化峰电流与氯霉素的浓度在1.0×10~(-8)~5.0×10~(-4)mol/L范围内呈良好的线性关系,检出限为5.0×10~(-9)mol/L。该方法简便,重现性及选择性好,用于测定氯霉素滴眼液和虾中氯霉素残留,结果满意。

Determination of Chloramphenicol Using Carbon Paste Electrode Modified with Graphene/Sodium Dodecylsulfate Composite

A mixed binder containing liquid paraffin and silicone was blended with graphite powder to prepare a carbon paste electrode(CPE).Graphene/sodium dodecyl sulfate complex was used to modify carbon paste electrode to obtain a new modified carbon paste electrode(GR/SDS-CPE).Scanning electron microscopy and cyclic voltammetry were used to study the surface properties and electrochemical properties of the new modified carbon paste electrode,and the results showed that the specific surface area of GR/SDS-CPE was larger than that of CPE,so it is conducive to electron transfer.In pH 3.0 HAc-NaAc buffer solution,chloramphenicol(CAP) yields a sensitive oxidation peak with a potential of 0.194 V at the GR/SDS-CPE,and the oxidation peak current is 10 times larger than that at the CPE.Differential pulse stripping voltammetry(DPSV) showed that the oxidation peak current was linear with concentration of CAP in the range of 1.0×10-8-5.0×10-4 mol/L with a detection limit of 5.0 × 10-9 mol/L.With the advantages of simplicity,reproducibility and good selectivity,the method was applied in the determination of chloramphenicol eye drops and chloramphenicol residues in shrimp with satsfactory result.