Ion mobility spectrometry coupled to chip-based electrochromatography
Final Report Abstract
The scientific focus in this joint project was on the development and evaluation of a novel hyphenated analytical system based on the coupling of a chip-based liquid phase separation device with ion mobility spectrometry (IMS). For this purpose, a customized highresolution drift tube IMS instrument with a grounded inlet was developed as a compact, label-free and chemical-specific detector for microfluidic platforms. Compared to a commercial device, the instrument proved to be very suitable for the coupling with chip systems using electrospray ionization (ESI), as only decreased potentials of 3-4 kV needed to be applied on-chip. In addition, higher peak resolutions and separation capabilities were shown. When coupling the high-resolution IMS instrument with microfluidic chromatography devices, multidimensional separations with orthogonal selectivity could be achieved. This extends the application range of ESI-IMS to the reliable analysis of complex mixtures with increased sensitivity. Coupling with front-end chip-based separations also enables low sample and solvent consumption with fast separations in less than one minute. In this context, the combination of IMS and chip-HPLC was successfully realized, where it was possible to perform 2D separations of three isobaric antidepressants within 15 seconds. To maintain the advantage of IMS as a very fast, compact and portable analysis system, the coupling with chip electrochromatography (ChEC) was developed. This eliminated the need for complex, bulky peripherals such as pumping systems, and only a high-voltage power supply was required to operate the system. For this purpose, an integrated microfluidic glass chip was developed, which includes an injection cross, a photopolymerized monolithic separation column, a nanofluidic fluid junction for electrical contacting, and a monolithic ESI emitter. After parameter optimization using model mixtures the developed ChEC-IMS system was successfully applied for the analysis of four herbicides spiked into a wine matrix. Finally, the newly developed IMS detection system could also be successfully applied for end-of-line analysis in droplet microfluidics. By electrospraying individual droplets into the IMS, droplet contents could be separated and detected according to their characteristic gas phase mobility. This enabled rapid droplet analysis with significantly less instrumental effort and decreased risk of contamination compared to typically used mass spectrometry. The achieved project results show that the two fields of lab-on-a-chip technology and IMS complement each other very well. Both aim to decrease the analysis time and instrumental size and offer novel possibilities to investigate complex analytical questions. This opens up numerous interesting fields of application, ranging from on-site analysis of liquid samples to reaction optimization using droplet microfluidics.
Publications
- 2D in Seconds: Coupling of Chip-HPLC with Ion Mobility Spectrometry, Anal. Chem. 2019, 91, 7613-7620
S. K. Piendl, C.-R Raddatz, N. T. Hartner, C. Thoben, R. Warias, S. Zimmermann, D. Belder
(See online at https://doi.org/10.1021/acs.analchem.9b00302) - Coupling On-Chip Separations to Ion Mobility Spectrometry, Proceedings of the 23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences, Chemical and Biological Microsystems Society, 2019, 550-551
N. T. Hartner, S. K. Piendl, C.-R. Raddatz, C. Thoben, R. Warias, S. Zimmermann, D. Belder
- IMS Instrumentation I: Isolated data acquisition for ion mobility spectrometers with grounded ion sources, Int. J. Ion Mobil. Spec. 2020, 23, 69-74
M. Lippmann, A. T. Kirk, M. Hitzemann, S. Zimmermann
(See online at https://doi.org/10.1007/s12127-020-00260-5) - On-Line Coupling of Chip-Electrochromatography and Ion Mobility Spectrometry, Anal. Chem. 2020, 92, 15129-12136
N. T. Hartner, C.-R. Raddatz, C. Thoben, S. K. Piendl, S. Zimmermann, D. Belder
(See online at https://doi.org/10.1021/acs.analchem.0c03446) - Compact electrospray ionization ion mobility spectrometer, 15. Dresdner Sensor-Symposium, 2021, 60-63
C. Thoben, C.-R. Raddatz, A. Ahrens, J. B. Schulte, A. Staschel, S. Zimmermann
(See online at https://doi.org/10.5162/15dss2021/4.2) - Coupling Droplet Microfluidics with Ion Mobility Spectrometry for Monitoring Chemical Conversions at Nanoliter Scale, Anal. Chem. 2021, 93, 13615-13623
N. T. Hartner, K. Wink, C.-R. Raddatz, C. Thoben, M. Schirmer, S. Zimmermann, D. Belder
(See online at https://doi.org/10.1021/acs.analchem.1c02883) - Wireless Low-Power Transfer for Galvanically Isolated High-Voltage Applications, Electronics 2022, 11, 923
M. Hitzemann, M. Lippmann, J. Trachte, A. Nitschke, O. Burckhardt, S. Zimmermann
(See online at https://doi.org/10.3390/electronics11060923)
