ABSTRACT

Commercially available disposable plastic pipette tip with the inner diameter of ca. 120 μm in series with a high-ohmic resistor (10 GΩ) was adapted as a low-cost alternativeion source for high-throughput nanoelectrospray mass spectrometry (nESI-MS) analysis of a variety of samples, especially aqueous solutions, without sample pretreatment. The use of highohmic resistor enabled the formation of stable electrospray of aqueous solutions at ambient conditions. In addition, corona dischargewas avoided evenwith a high voltage applied. Quantitative analysis of vitamin B in water was successfully conducted by tip-ESI. The results exhibited a good linearity (R ˃ 0.9983), a low detection limit (0.25 ng/mL), and a wide dynamic response range (0.25–1000 ng/mL). Our study revealed that tip-ESI not only performed equally well to capillary nESI in terms of flow rate (˂ 100 nL/min), signal sensitivity, and sample consumption, but also offered a number of additional advantages, including better signal duration, tolerance to high analyte concentration (> 100 μg/mL) and high ionizing voltage (up to 6 kV), and obviation of tip clogging and corona discharge. High compatibility of tip-ESIwith various kinds of samples (aqueous, viscous, solid, or bulk biological samples) makes it a promising tool for direct MS analysis.

2019-Rahman-JASMS-SCI.pdf