Zhao Y, McLaughlin K, Lunte C E
Department of Chemistry, University of Kansas, Lawrence 66045, USA.
Anal Chem. 1998 Nov 1;70(21):4578-85. doi: 10.1021/ac980427c.
An on-line sample concentration method using sample matrix switching and field amplification peak stacking has been developed. A microbore LC guard column is used to slightly retain the analytes in order to switch from a high ionic strength sample matrix (the physiological fluid) to a low ionic strength matrix (the LC mobile phase). The eluted LC peak is then trapped in a CE system and preconcentrated by field amplification peak stacking. The concentrated sample peak is then analyzed by CE. Compared to normal hydrodynamic injection, the sensitivity was increased by more than 500-fold without loss in resolution. A limit of detection of less than 10 nM for a physiological sample was achieved using UV adsorption detection. This method can be used for negatively or positively charged analytes.
已开发出一种使用样品基质切换和场放大峰堆积的在线样品浓缩方法。使用微径液相色谱保护柱对分析物进行轻微保留，以便从高离子强度样品基质（生理流体）切换到低离子强度基质（液相色谱流动相）。然后将洗脱的液相色谱峰捕集到毛细管电泳系统中，并通过场放大峰堆积进行预浓缩。然后通过毛细管电泳分析浓缩后的样品峰。与常规的流体动力学进样相比，灵敏度提高了500倍以上，且分辨率没有损失。使用紫外吸收检测，生理样品的检测限低于10 nM。该方法可用于带负电荷或正电荷的分析物。
