Inexpensive Ultrasonic Nebulization Coupled with Direct Current Corona Discharge Ionization Mass Spectrometry for Liquid Samples and Its Fundamental Investigations

Abstract

The concept of direct mass-spectrometric analysis, especially exploited by ambient desorption/ionization (ADI) methods, provides numerous means for convenient sample analysis. While many simple and versatile ionization sources have been developed, challenges lay in achieving efficient sample introduction. In previous work, a sample introduction method employing direct current corona discharge (CD) coupled to a surface acoustic wave nebulization (SAWN) device enhanced sampling performance for both polar and nonpolar analytes by up to 4 orders of magnitude. In fact, the SAWN-CD method generated a multiply charged peptide ion signal comparable to that of conventional ESI. Unfortunately, the high cost of the SAWN devices themselves limits their accessibility. Herein, we report on an analogous implementation of CD with an inexpensive ultrasonic nebulizer (USN) on the basis of a commercial room humidifier demonstrating equivalent exemplary performance. We subsequently compare the two methods of SAWN-CD and USN-CD in a screening application of milk for the detection of two antibiotic drugs, ciprofloxacin and ampicillin. Finally, we further investigate the relative softness of these CD-coupled acoustic nebulization methods in comparison to that of ESI using a survival yield study of the thermometer ion nitrobenzylpyridinium.

Development of a Portable Method for Serum Lithium Measurement Based on Low-Cost Miniaturized Ultrasonic Nebulization Coupled with Atmospheric-Pressure Air-Sustained Discharge

“…It is found that this spectrum resembles spectra obtained from SCGD. 46,47 The main spectral features are the emission bands of OH, with band head at 306 nm, which are likely from the dissociation of H 2 O, and the N 2 second positive system, with band heads from 337.1 to 405.9 nm. The emission lines of O at 776.4 and 844.1 nm can also be observed.…”

Unsupervised Reconstruction of Analyte-Specific Mass Spectra Based on Time-Domain Morphology with a Modified Cross-Correlation Approach

“…An ultrasonic nebulizer (USN) was used to generate analyte-containing droplets (1–3 μm diameter based on calculation). , These droplets were transferred through a 26 kHz laser-induced plasma (LIP) in the open air toward the inlet capillary of a high-resolution Orbitrap (Exactive, Thermo Scientific, Bremen, Germany) mass spectrometer through a venturi flow guide ( cf ., Figure S1). Here, the LIP was used as an ionization source, while the USN merely served to introduce samples .…”

Ultrasonic Sputter Desorption Mass Spectrometry Technique for Minimally Invasive Tissue Analysis

“…In addition to tissue analysis, ultrasonic vibration has also been used for desorption of dried samples on plastic substrate, 22 sputtering of liquid samples, 23 and extraction and nebulization of herbal products. 24 In this study, a new ionization interface coupled with online MS analysis was developed for ultrasonic sputter desorption (USD), in which a cutter applied with 40 kHz high-frequency ultrasonic vibration was used for tissue sampling.…”