Flow-rate characterization of microfabricated polymer microspray emitters

Area of Science:

• Analytical Chemistry
• Chemical Engineering
• Materials Science

Background:

• Microfabricated polymer microspray emitters are advanced tools for interfacing liquid separations with mass spectrometry.
• Characterizing their performance is crucial for optimizing analytical workflows.

Purpose of the Study:

• To comprehensively characterize microfabricated polymer microspray emitters.
• To evaluate their performance across various flow rates and solution compositions.
• To assess their suitability as interfaces for electrospray mass spectrometry.

Main Methods:

• Employing microfabrication techniques to produce polymer microspray emitters.
• Conducting experiments to determine applicable flow rate ranges for different solvent systems (methanol/water/acetic acid and acetonitrile).
• Measuring temporal and spectral signal-to-noise ratios (SNRs) to assess mass spectral performance.

Main Results:

• Microspray emitters successfully operated with methanol/water/acetic acid from 250 nL/min to 7 microL/min, with optimal SNRs above 1 microL/min.
• Performance with methanol mixtures was comparable to nanospray capillaries, even at low flow rates.
• Emitters demonstrated operability with acetonitrile concentrations from 10% to 99% (v/v) within flow rates of 250 nL/min to 4 microL/min.
• Mass spectral performance, particularly spectral SNRs, showed variability with acetonitrile content.

Conclusions:

• Microfabricated polymer microspray emitters are validated as robust interfaces for liquid-phase separations and electrospray mass spectrometry.
• Their performance is competitive with traditional nanospray capillaries, offering flexibility in solvent composition and flow rates.
• These emitters represent a significant advancement for analytical instrumentation, enhancing sensitivity and applicability.