title: An electrospray ionization-ion mobility spectrometer as detector for high- performance liquid chromatography.
abstract: The application of electrospray ionization (ESI) ion mobility (IM) spectrometry on the detection end of a high-performance liquid chromatograph has been a subject of study for some time. So far, this method has been limited to low flow rates or has required splitting of the liquid flow. This work presents a novel concept of an ESI source facilitating the stable operation of the spectrometer at flow rates between 10 μL mn(-1) and 1500 μL min(-1) without flow splitting, advancing the T-cylinder design developed by Kurnin and co-workers. Flow rates eight times faster than previously reported were achieved because of a more efficient dispersion of the liquid at increased electrospray voltages combined with nebulization by a sheath gas. Imaging revealed the spray operation to be in a rotationally symmetric multijet mode. The novel ESI-IM spectrometer tolerates high water contents (≤90%) and electrolyte concentrations up to 10mM, meeting another condition required of high-performance liquid chromatography (HPLC) detectors. Limits of detection of 50 nM for promazine in the positive mode and 1 μM for 1,3-dinitrobenzene in the negative mode were established. Three mixtures of reduced complexity (five surfactants, four neuroleptics, and two isomers) were separated in the millisecond regime in stand-alone operation of the spectrometer. Separations of two more complex mixtures (five neuroleptics and 13 pesticides) demonstrate the application of the spectrometer as an HPLC detector. The examples illustrate the advantages of the spectrometer over the established diode array detector, in terms of additional IM separation of substances not fully separated in the retention time domain as well as identification of substances based on their characteristic Ims.
authors: University of Potsdam, Physical Chemistry, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.. mzuehlke@uni- potsdam.de.
authors: Martin
authors: M
authors: Zühlke
authors: University of Potsdam, Physical Chemistry, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.. riebe@uni-potsdam.de.
authors: Daniel
authors: D
authors: Riebe
authors: University of Potsdam, Physical Chemistry, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.. beitz@uni-potsdam.de.
authors: Toralf
authors: T
authors: Beitz
authors: University of Potsdam, Physical Chemistry, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.. loeh@chem.uni- potsdam.de.
authors: Hans-Gerd
authors: HG
authors: Löhmannsröben
authors: KNAUER Wissenschaftliche Geräte GmbH, Hegauer Weg 38, 14163 Berlin, Germany.. Zenichowski@knauer.net.
authors: Karl
authors: K
authors: Zenichowski
authors: KNAUER Wissenschaftliche Geräte GmbH, Hegauer Weg 38, 14163 Berlin, Germany.. diener@uni-potsdam.de.
authors: Marc
authors: M
authors: Diener
authors: Humboldt University, Department of Chemistry, Brook-Taylor-Str. 2, 12489 Berlin-Adlershof, Germany.. m.linscheid@chemie.hu-berlin.de.
authors: Michael W
authors: MW
authors: Linscheid