Multi-channel microfluidic chip coupling with mass spectrometry for simultaneous electro-sprays and extraction

Abstract

Considering the advantages and research status of microfluidic chip coupling with mass spectrometry (MS), a microfluidic chip-based multi-channel ionization (MCMCI) for the extraction of untreated compounds in complex matrices without sample pretreatments was developed. Quantitative analysis of human urine spiked with various rhodamine B concentrations was also performed, and good linearity was obtained. Comparing to the macro ionization device, MCMCI significantly improved the integration of ionization source, simplified the operation of such a device, and greatly increased the signal intensity with much lower gas pressure. Comparison of our MCMCI with two and three gas channels indicated that the liquid–liquid extraction process before spraying and after spraying produced similar MS results. Moreover, this MCMCI with three gas channels also implemented simultaneous dual sprays with high DC voltages, the interference of two samples was minor and ion suppression effect was drastically alleviated. Such advantages may easily enable internal calibration for accurate mass measurement. Furthermore, dual extraction can be implemented by integrating such multi-spray configuration, which can improve the extracted signal intensity and sensitivity. These technologies open up new avenues for the application of microfluidic chip coupling with MS.

Chips for Biomaterials and Biomaterials for Chips: Recent Advances at the Interface between Microfabrication and Biomaterials Research

“…While some interesting examples of studies exist in which either physico-chemical properties of biomaterials or their effects on biological system are studied on chip, there are many other properties important to biomaterials scientists for which a chipbased measurement method would be beneficial but does not yet exist. Off-chip analysis methods such as mass spectrometry have been coupled to microfluidic chips, [181][182][183] but this approach has not yet been applied to the study of on-chip cell-material interactions in order to, for example, follow both the degradation of the material and the response of the biological system to it. Similarly, while a range of chemical analysis methods including surface plasmon resonance have been incorporated into microfluidic chips, [184,185] these methods have not yet been applied to the study of cell-biomaterial interactions.…”

Applications of Mass Spectrometry for Clinical Diagnostics: The Influence of Turnaround Time

“…The droplet scale that microfluidic devices are based on also allows for online reactions to occur, similar to the ones that occur in PCR and DNA detection, before MS analysis. − Generally, droplets containing enzymes of interests can react with substrate-containing droplets before being emitted and ionized via ESI. Shi et al described multiple ways that microfluidics can be used as microreactors for biomedical applications.…”

Protein and Proteome Measurements with Microfluidic Chips

“…Performing liquid phase separations on these devices is, however, possible only after dispensing the sample on a target, with the caveat that separation efficiency may be lost. Overall, the development of ESI vs MALDI chip–MS ion sources has dominated the field, mainly due to the power of tandem MS in elucidating the structure of unknown compounds, a capability that works at its best with ESI-MS. Work on improving the chip–MS interfaces and the sample ionization process has continued over the years, resulting in novel strategies that use surface acoustic wave nebulizers, electro-sonic flow focusing ionization, voltage-assisted liquid desorption, or multichannel configurations for simultaneous electrospraying and sample extraction . Most efforts in the past two years, however, focused on expanding the applicability of the microchip technology to solving various analytical or biological problems.…”