Performance of HPLC/MS microchips in isocratic and gradient elution modes

• Published in: Journal of mass spectrometry. Vol. 45; no. 3; pp. 313 - 320
• Main Authors: Ehlert, Steffen, Trojer, Lukas, Vollmer, Martin, van de Goor, Tom, Tallarek, Ulrich
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.03.2010; Wiley
• Subjects: Analysis; Analytical chemistry; Analytical, structural and metabolic biochemistry; band broadening; Biological and medical sciences; Channels; Chemistry; Chips; Chromatographic methods and physical methods associated with chromatography; Chromatography; dead volume; electrospray; Elution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects, investigation methods; General pharmacology; HPLC/MS; Hydraulics; Liquid chromatography; Mass spectrometry; Medical sciences; microchips; microfluidics; Other chromatographic methods; Pharmacology. Drug treatments; Proteins; proteomics; Separation; Particle size; Peak resolution; Chemical analysis; Peptides; Psychotropic; HPLC chromatography; Instrumentation; Electrospray; band broadening; β-Adrenergic receptor; Line broadening; Plate efficiency; Microequipment; Antidepressant agent; Antagonist; microchips; Fluid mechanics; Elution; Gradient; HPLC/MS; Coupled method; System on a chip; Tricyclic compound; Isocratic condition; Protein; Reversed phase chromatography; Particle size distribution; Peptide fragment; Proteomics; Dead volume; Miniaturization; Mass spectrometry; Microfluidics; Bonded stationary phase; Beta blocking agent
• ISSN: 1076-5174; 1096-9888; 1096-9888
• DOI: 10.1002/jms.1719

We analyzed the chromatographic performance of particle-packed, all-polyimide high-performance liquid chromatography/mass spectrometry (HPLC/MS) microchips in terms of their hydraulic permeabilities and separation efficiency under isocratic and gradient elution conditions. The separation channels of the chips (with ca 50 μm x 75 μm trapezoidal cross-section and a length of 43 mm) were slurry packed with either 3.5 or 5 μm spherical porous C18-silica particles. A custom-built holder enveloped the chip during packing to prevent channel deformation and delamination from high pressures. It is shown that the packing conditions significantly impact the packing density of the HPLC/MS chips, which determines their performance in both, isocratic and gradient elution modes. Even with steep solvent gradients, peak shape and chromatographic resolution for the densely packed HPLC/MS chips are much improved. Our data show that the analytical power of the HPLC/MS chip is limited by the quality of the chromatographic separation. Copyright © 2010 John Wiley & Sons, Ltd.