准静态扫集胶束电动毛细管色谱法测定扇贝样品中的贝类毒素

Determination of Shellfish Toxins in Shellfish Samples by Sweeping Under Pseudo-stationary State and Micellar Electrokinetic Chromatography

采用准静态扫集胶束电动毛细管色谱(MEKC)法测定了扇贝样品中的2种贝类毒素。毛细管内首先充满含十二烷基硫酸钠(SDS)的缓冲溶液,调节缓冲溶液的pH值,使电渗流等于SDS胶束的电泳流速,电动进样时,带正电荷的贝类毒素离子被SDS扫集吸附,由于SDS在毛细管内处于准静止状态,可使进样时间延长至320 s。与常规电动进样MEKC相比,石房蛤毒素和软骨藻酸的检测灵敏度分别提高950和810倍。该方法对石房蛤毒素和软骨藻酸的检出限分别为0.05,0.12 ng/m L。方法可实现对扇贝样品中2种贝类毒素的快速、灵敏检测。

A novel method based on sweeping under pseudo-stationary state and micellar electrokinet- ic chromatography（MEKC） was developed for the determination of shellfish toxins in shellfish samples. The capillary was firstly pre-filled with the running buffer containing sodium dodecyl sulfate （SDS）. By adjusting pH value, the electrophoretic flow of SDS micelle was equal to the counter electroosmotic flow（EOF）. The positive charged shellfish toxins were injected electrokinetically into capillary, swept and adsorbed with SDS micelle. The injection time was prolonged to 320 s under 10 kV since the SDS micelles were at a pseudo-stationary state. With the sweeping under pseudo-stationary state method, the preconcentration factors of 950 and 810 were obtained for saxitoxin and domoic acid, respectively, compared with the traditionally electrokinetic injection MEKC. The method was used to the quantitative determination of saxitoxin and domoic acid with their detection limits of 0. 05 ng/mL and 0. 12 ng/mL, respectively. The proposed sweeping under pseudo-stationary state and MEKC method was successfully applied in the determination of two shellfish toxins in shellfish samples.