Determination of β-agonists Using Ultra High Performance Liquid Chromatography Mass Spectrometry
Date Issued
2014
Date
2014
Author(s)
Chang, Hsuan-Hsi
Abstract
The ultra performance liquid chromatography (UPLC) is based on the principle of using stationary phase with particles less than 2 μm. According to the Van Deemter equation, as the particle size decreases to less than 2 μm, not only increased efficiency, but also the ability to work at higher linear velocity without a loss of efficiency, providing both resolution and speed. The flow rate of mobile phase is an important parameter affecting the sensitivity of LC-ESI-MS. High flow rate can reduce the ionization efficiency. Therefore, low flow rate was often used. However, low flow rate failed to achieve column efficiency and rapid analysis.
In this study, post-column splitting was used to reduce the flow into the mass spectrometer. This would enhance the ionization efficiency under ESI. First part of this work was to compare the sensitivity at different flow rates. The results showed that flow rate at 0.2 mL/min provided the best sensitivity. Therefore, the flow rate of mobile phase was at to 0.6 mL/min. Using post-column splitting (split ratio1:3), a flow rate of 0.2 mL/min was introduced into the ESI-MS system for detection.
UPLC-ESI-MS/MS with post-column splitting (0.2 mL/min) provided better sensitivity than elution flow rate of 0.6 mL/min without splitting. However, post-column splitting did not achieve the sensitivity under 0.2 mL/min without splitting. One possible reason is the limitation in the rate of transferring the ions from ESI source to the mass spectrometer.
Subjects
超高效液相層析法
電灑法質譜
乙型受體素類
管柱後分流
Type
thesis
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