Use of low flow-liquid junction interface to alleviate sensitivity loss by Trifluoroacetic acid in the CEC-ESI/MS Analysis of peptides

• Main Authors: Yih-Sin Ho, 何怡欣
• Other Authors: 何國榮
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/78852419185903082601

碩士 === 國立臺灣大學 === 化學研究所 === 95 === Trifluroacetic acid (TFA) is a commonly used ion-pair reagent in HPLC to improve peak shapes and hence the separation efficiency of peptides. However, TFA is known to cause significant signal suppression when analyzed by electrospray ionization mass spectrometry (ESI-MS). In this study, we try to use TFA as mobile phase additive for capillary electrochromatography (CEC) in the analysis of peptides. Liquid junction interface is used and by manipulating the diameter of the spray tip and the ESI voltage applied, the introduction of make-up solution and TFA within into ESI-MS can be prevented successfully. However, the above interface has limited utility when applied in CEC because the flow rate of the spray tip is much higher than CEC flow rate. In order to match the flow rate of the tip and CEC column the optimized flow rate of ESI will not be achieved. Therefore, a low flow interface is introduced and placed in front of liquid junction interface to separate the ESI voltage, and the voltage applied on the make-up solution can be easily adjusted to match the flow rate of both sides of liquid junction without compromising the ESI optimized flow rate. By using liquid junction-low flow interface, it is possible to employ TFA in CEC for peptide separation and alleviate the suppression effect by TFA at the same time.