Beijing Key Laboratory of Microanalytical Methods and Instrumentation, Department of Chemistry, Tsinghua University , Beijing 100084, People's Republic of China.
Anal Chem. 2014 Jul 15;86(14):7128-34. doi: 10.1021/ac501678q. Epub 2014 Jun 30.
In this work, the establishment of a microdialysis-paper spray ionization-mass spectrometry (MS) system was described. A homemade microdialysis module was employed for sampling, and microdroplets were generated at the outlet of the capillary conducting the dialysate. Online MS analysis of each microdroplet was immediately accomplished, interfacing by paper spray ionization. Analytical performance of the method was investigated and improved through the introduction of thinner capillary tubes and the optimization of spray solvent and paper substrate. For microdroplets with concentrated salt at 50 nL, the limit of detection at 0.8 ppm (or 40 pg absolute) and a highest resolution at about 1.5 s were achieved. The integrated system was applied into the online monitoring of glucose concentration in cell culture mediums. A satisfactory linearity of the calibration curve between the relative MS intensity and the glucose concentration was observed. Furthermore, as a model, hormone regulation of the glucose concentration was investigated. This work demonstrated the potential application of the label-free, online "MS sensor" into studies on cellular metabolism.
本工作建立了一种微透析-纸喷雾电离-质谱（MS）联用系统。采用自制的微透析模块进行采样，在引导透析液的毛细管出口处产生微液滴。通过纸喷雾电离实现了对每个微液滴的在线 MS 分析。通过引入更细的毛细管和优化喷雾溶剂和纸基底，改善和优化了该方法的分析性能。对于 50 nL 含有浓盐的微液滴，可达到 0.8 ppm（或 40 pg 绝对）的检测限和约 1.5 s 的最高分辨率。该集成系统被应用于细胞培养液中葡萄糖浓度的在线监测。观察到相对 MS 强度与葡萄糖浓度之间校准曲线的良好线性关系。此外，作为模型，研究了激素对葡萄糖浓度的调节。这项工作证明了无标记、在线“MS 传感器”在细胞代谢研究中的潜在应用。
