TY  - JOUR
AU  - Posch, T.N.
AU  - Müller, A.
AU  - Schulz, W.
AU  - Pütz, M.
AU  - Huhn, C.
TI  - Implementation of a design of experiments to study the influence of the background electrolyte on separation and detection in non-aqueous capillary electrophoresis-mass spectrometry
JO  - Electrophoresis
VL  - 33
SN  - 0173-0835
CY  - Weinheim
PB  - Wiley-Blackwell
M1  - PreJuSER-20489
SP  - 583 - 598
PY  - 2012
N1  - The help of Jorg Roscher is gratefully acknowledged. We thank the Helmholtz Initiative and Networking Fund for financial support.
AB  - Non-aqueous capillary electrophoresis (NACE) background electrolytes are most often composed of a mixture of methanol and acetonitrile (ACN) with soluble ammonium salts added as electrolyte. In this study on NACE-MS, we used a mixture of glacial acetic acid and ACN giving rise to an acidic background electrolyte (BGE) with a very low dielectric constant. Impressive changes in selectivity and resolution were observed for structurally closely related indole alkaloids including diastereomers upon addition of ammonium formate as electrolyte and upon variation of the solvent ratio. In order to obtain best separation and MS detection conditions and to reveal the influence of the parameters of the BGE on separation and detection and vice versa of the MS parameters on separation, an optimization strategy was employed using a design of experiments in a central composite design with response surface methodology. It was proven that at high electroosmotic flow conditions capillary electrophoretic separations and thus optimization can be realized without interference from the coupling to an MS system. Several significantly interacting parameters were revealed, which are not accessible with classical univariate optimization approaches. With this optimization, alkaloid mixtures from a plant extract of Mitragyna speciosa, containing a large number of diastereomeric compounds were successfully separated.
KW  - Acetic Acid: chemistry
KW  - Acetonitriles: chemistry
KW  - Analysis of Variance
KW  - Electrolytes: chemistry
KW  - Electrophoresis, Capillary: methods
KW  - Indole Alkaloids: analysis
KW  - Indole Alkaloids: isolation & purification
KW  - Mass Spectrometry: methods
KW  - Mitragyna: chemistry
KW  - Models, Chemical
KW  - Plant Extracts: chemistry
KW  - Research Design
KW  - Acetonitriles (NLM Chemicals)
KW  - Electrolytes (NLM Chemicals)
KW  - Indole Alkaloids (NLM Chemicals)
KW  - Plant Extracts (NLM Chemicals)
KW  - Acetic Acid (NLM Chemicals)
KW  - acetonitrile (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:22451051
UR  - <Go to ISI:>//WOS:000302010700007
DO  - DOI:10.1002/elps.201100381
UR  - https://juser.fz-juelich.de/record/20489
ER  -