Development Of 3D-Printed Nanoelectrospray Ionization Source-Mass Spectrometry(NIS-MS)

Microfluidic technology has wide applications in proteomic research and single cell analysis,due to its advantage of low sample consumption,small volume,as well as feasibility to in multiple sample treatments(such as mixing,filtration,separate,et al.).Mass spectrometry(MS)is highly sensitive and qualitative,thereby making it a perfect detector of microfluidic chip.In various ionization sources,electrospray ionization(ESI)can ionize liquid samples under atmospheric pressure,making it a suitable interface of microfluidic chip-MS.Nanoelectrospray ionization technology can realize the MS determination of sample flows with a nanoliter scale infusion rate.The existing researches focus on preparing various spray tips with limited sizes,while their preparations were with great difficulties and low reproducibility.Herein,our research used the 3D-printed technology to alleviate the difficulties of preparing these chips.Additionally,microfluidic three dimensional hydrodynamic focusing strategy was used to modulate the distribution of sample ions and to inhibit the sample expansion in the ESI spray.Moreover,nitrogen flows were introduced into the NIS to cover liquid flows for improving the efficiency of ionization and the sensitivity.Further,we realized an 3D-printed microfluidic nanoelectrospray ionization source(NIS).Finally,we explored an in-situ sampling electrospray MS detection methods primarily,in order to achieve real-time,on-line analysis of the trace sample.1.Based on a reasonable design for microfluidic chip,three dimensional hydrodynamic focusing was used to focus on the sample flow.By using the 3D-printed technology for the preparation of NIS which coupled with the nitrogen to improve atomization.Additionally,we optimized the experimental conditions of NIS to ensure stable nanoelectrospray.2.Based on the NIS-MS analysis method,we detected thirteen organic chemicals,insulin and lysozyme to evaluate the performance of the NIS.The achieved mass spectra of the detected ions showed the feasibility of NIS-MS for testing samples.We also combined the NIS with the 3D-printed microfluidic separation chip to achieve the separation and online detection of the mixture of rhodamine B(RhB),pyridalyl and chlorantraniliprole(Chl).3.The sample was in-situ taken from the bean sprouts by using syringe needles,which were directly connected to the MS as an electrospray emitter for MS identifications.Compared with traditional biological detections,proposed in-situ sampling electrospray ionization MS method simplified the complex sample pretreatment process.Based on the above principles,the detection of samples from the bean sprouts with different growth was achieved.