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Optimization of capillary electrophoretic‐ electrospray ionization‐mass spectrometric analysis of catecholamines
Author(s) -
Vuorensola Katariina,
Kokkonen Juha,
Sirén Heli,
Ketola Raimo A.
Publication year - 2001
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200112)22:20<4347::aid-elps4347>3.0.co;2-j
Subject(s) - chemistry , chromatography , capillary electrophoresis , analytical chemistry (journal) , electrospray , ammonium hydroxide , capillary action , electrospray ionization , ammonium acetate , capillary electrophoresis–mass spectrometry , electrophoresis , mass spectrometry , ionization , ion , high performance liquid chromatography , materials science , inorganic chemistry , organic chemistry , composite material
The capillary electrophoretic‐mass spectrometric analysis (CE‐MS) of catecholamines was optimized with coaxial sheath flow interface and electrospray ionization (ESI). The parameters studied included the sheath liquid composition and its flow rate, separation conditions in ammonium acetate buffer together with the ESI and cone voltages as mass spectrometric parameters. In addition, the effect of ESI voltage on injection as well as the siphoning effect were considered. The optimized conditions were a sheath liquid composition of methanol‐water (80:20 v/v) with 0.5% acetic acid, with a flow rate of 6 νL/min. The capillary electrophoretic separation parameters were optimized with 50 m M ammonium acetate buffer, pH 4.0, to +25 kV separation voltage together with a pressure of 0.1 psi. The most intensive signals were obtained with an ESI voltage of +4.0 kV and a cone voltage of +20 V. The nonactive ESI voltage during injection as well as avoidance of the siphoning effect increased the sensitivity of the MS detection considerably. The use of ammonium hydroxide as the CE capillary conditioning solution instead of sodium hydroxide did not affect the CE‐MS performance, but allowed the conditioning of the capillary between analyses to be performed in the MS without contaminating the ion source.