HPLC-CAD测定直链烷基苯磺酸钠的平均相对分子质量

Determination of average relative molecular mass of LAS-Na by HPLC-CAD

建立了高效液相色谱-电雾式检测器测定直链烷基苯磺酸钠的平均相对分子质量的方法。采用C18键合硅胶柱(250 mm×4.6 mm,5μm),电雾式检测器,以乙腈-水流动相体系中加入适量CH_3COONH_4离子改性剂作为流动相,使直链烷基苯磺酸钠(LAS-Na)同系物在较短时间内得到完全分离,异构体也得到部分分离。依据碳链分布,采用面积归一化法对LAS-Na的平均相对分子质量进行了计算,并与气相色谱法的测定结果进行了比对分析,结果一致。

A method for the determination of the average relative molecular mass of sodium linear alkyl benzene sulfonate by high performance liquid chromatography-charged aerosol detector was established. The linear alkyl benzene sulfonic acid sodium （LAS-Na） homologs were completely separated in a relatively short period of time, and the isomers were partially separated by acetonitrile-water mobile phase contained ion modifier CH3COONH4 using C18 bonded silica gel column （250 mm×4.6 mm, 5 μm） and charged aerosol detector. Area normalization was used to calculate the average relative molecular weight of LAS-Na depending on the carbon chain distribution. The results were compared with that obtained by GC. It showed that this method was reliable.