反向电渗流非水毛细管电泳法快速测定微量赤霉素

赤霉素是一类重要的植物激素,是结构相似的弱酸性二萜类化合物。针对毛细管电泳法分离、测定赤霉素速度慢、效率不佳等问题,该文发展了一种可快速测定微量活性赤霉素的非水毛细管电泳-紫外检测法。以聚环氧乙烷动态涂布毛细管,利用正离子使电渗流反向,将含10 mmol/L醋酸铵的甲醇-水(95∶5,v/v)作为缓冲体系,在0.08%(v/v)醋酸含量下,分离8种内源性赤霉素。结果表明,赤霉素出峰时间的相对标准偏差(RSD)≤2.1%(日内)或≤4.3%(日间),峰面积的RSD≤4.5%(日内)或≤6.9%(日间),检出限(S/N=3)为1.04~2.20 mg/L,相关系数为0.998 2~0.999 3,回收率为87.2%~93.5%。该方法简单、快速、稳定,以含醋酸铵的甲醇水溶液为缓冲体系,预先考虑了质谱测定的需要,可用于实际样品如麦芽中赤霉素的分析,具有一定的应用价值。

Rapid determination of micro gibberellins by non-aqueous capillary electrophoresis with reversed electroosmotic flow

A non-aqueous capillary electrophoresis (NACE) method for the rapid determination of micro gibberellins (GAs) was established. Dynamically poly(ethylene oxide) coated capillary was used, and electroosmotic flow (EOF) was reversed by using positive ions and adjusted by regulation the types and concentrations of the positive ions, running buffer, and pH of the buffer. With a buffer of 95% (v/v) methanol containing 10 mmol/L ammonium acetate at an acidity of 0.08% (v/v) acetic acid, the EOF was successfully reversed to separate the eight GAs in less than 10 min. Its applicability was validated by the determination of GAs in germinating wheat seeds, with relative standard deviations (RSDs)≤2.1% (intra-day) or ≤4.3% (inter-day) for migration times, and RSDs≤4.5% (intra-day) or≤6.9% (inter-day) for peak areas. The limits of detection (S/N=3) were in the range of 1.10-2.20 mg/L, with correlation coefficients (r²) of 0.9982-0.9993. The recoveries of the spiked samples were between 87.2% and 93.5%. The established method is simple, rapid, stable, and compatible with mass spectrometry, so it is valuable to be further studied.