高效毛细管电泳电导检测对阴离子表面活性剂分离测定的研究

Study on the Separation of Anionic Surfactant by Capillary Electrophoresis with Conductance Detection

以Ca2 +为分离介质 ,甲酰胺为添加剂 ,通过对缓冲体系、缓冲液浓度、酸度、Ca2 +浓度、甲酰胺浓度、电泳电压和进样时间的优化选择 ,用毛细管电泳 -电导检测法分离了十二烷基硫酸钠(K12)和十二烷基苯磺酸钠(LAS) ;在10mmol/LTris -11mmol/LCit(pH4.5)运行缓冲液中 ,上述两组分在16min内完全分离 ;K12和LAS的线性范围分别为5.0×10-6～8.0×10-3 mol/L和5.0×10-6 ～5.0×10-3 mol/L ;检出限(S/N=3)分别为2.5×10-6 和3.0×10-6 mol/L,应用于合成洗衣粉样和合成水样中K12 和LAS测定 ,结果令人满意。

Alkylsulfuric acid(K12) and alkylbenzenesul fonate(LAS) were successfully separated by capillary electrophoresis and detected by conductance detection with addition of Ca2+ and formamide in Tris-H3BO3 buffer system. The effects of buffer, concentration and pH of the buffer, concentration of Ca2+ and formamide, separation voltage and injection time were investigated in this paper. Satisfactory separation of K12 and LAS was achieved in a 10 mmol/L Tris-11 mmol/L Cit buffer(pH 4.5) within 16 min. There were satisfactory linearity between peak area and concentration of analytes in the range of 5.0×10-6 ～5.0×10-3 mol/L for LAS and 5.0×10-6 ～8.0×10-3 mol/L for K12, with the detection limits(S/N=3) of 3.0×10-6 mol/L for LAS and 2.5×10-6 mol/L for K12 , respectively. This method was successfully used for determination of LAS and K12 in synthetic detergent and aqueous solution.