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Direct coupling of micellar electrokinetic chromatography to mass spectrometry using a volatile buffer system based on perfluorooctanoic acid and ammonia
Author(s) -
Petersson Patrik,
JörnténKarlsson Magnus,
Stålebro Maria
Publication year - 2003
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200390144
Subject(s) - chemistry , chromatography , micellar electrokinetic chromatography , perfluorooctanoic acid , electrokinetic phenomena , mass spectrometry , sodium dodecyl sulfate , acetic acid , analyte , electrospray ionization , detection limit , environmental chemistry , organic chemistry
Direct coupling of micellar electrokinetic chromatography (MEKC) to mass spectrometry (MS) without employing partial filling is considered to be a challenge. One way of solving the problem would be the use of an MS‐compatible surfactant. In the present study, the applicability of a series of surfactants (sodium dodecyl sulfate (SDS), lauric acid, cholic acid and perfluorated carboxylic acids) have been investigated both in terms of separation performance and MS compatibility. It was found that a MEKC system based on perfluorooctanoic acid (PFOA) and ammonia gave excellent results. The separation performance of the suggested system is comparable to the one obtained with standard systems based on SDS and sodium borate buffer although the selectivity is different. The electrospray ionization MS signal of the analytes is not seriously suppressed even at a PFOA concentration of 100 m M . Clusters are formed but their intensities are relatively low and comparable to those obtained with acetic acid. PFOA is volatile enough to allow long‐term use, 30 h of continuous use has been recorded without any signs of decreasing performance. After use residual PFOA is easily removed from the ion‐source (no memory effects). Furthermore, quantitation of trace impurities is possible at 25 ppb level when employing selected ion monitoring.