Gustavsson S A, Samskog J, Markides K E, Långström B
Department of Organic Chemistry, Institute of Chemistry, Uppsala University, Sweden.
J Chromatogr A. 2001 Dec 7;937(1-2):41-7. doi: 10.1016/s0021-9673(01)01328-0.
Volatile ion-pairing reagents are useful due to their compatibility with liquid chromatography-electrospray ionization (ESI) mass spectrometry. In this study trifluoroacetic acid, heptafluorobutanoic acid and perfluoroheptanoic acid were used as ion-pairing reagents. The signal intensities of eight amine analytes were measured in the presence of these fluorinated carboxylic acids and compared with the signal intensity when using an ion-pair free formic acid-ammonium formate buffer. It was shown that the ESI signal from most of the studied analytes decreased about 30-80% when the fluorinated carboxylic acids were added to the mobile phase at useful concentrations. The use of these acids in ion-pair chromatography was also compared to the more conventional sodium heptane sulphonate additive. It was found that the chromatographic performance was comparable. Finally, the long-term performance of the ESI interface and the chemical background caused by these fluorinated reagents were examined. No degradation of the ESI interface performance could be seen for over 24 h of continuous infusion.
挥发性离子对试剂因其与液相色谱 - 电喷雾电离（ESI）质谱的兼容性而十分有用。在本研究中，三氟乙酸、七氟丁酸和全氟庚酸被用作离子对试剂。在这些氟化羧酸存在的情况下，测量了八种胺类分析物的信号强度，并与使用无离子对的甲酸 - 甲酸铵缓冲液时的信号强度进行了比较。结果表明，当在流动相中加入有用浓度的氟化羧酸时，大多数研究分析物的ESI信号下降了约30 - 80%。还将这些酸在离子对色谱中的使用与更传统的庚烷磺酸钠添加剂进行了比较。发现色谱性能相当。最后，研究了ESI接口的长期性能以及这些氟化试剂引起的化学背景。连续输注超过24小时未见ESI接口性能下降。
