Development of a precolumn capillary liquid chromatography switching system for coupling to mass spectrometry

✍ Scribed by J. A. Pascual; G. J. ten Hove; A. P. J. M. de Jong

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 517 KB
• Volume: 8
• Category: Article
• ISSN: 1040-7685
• DOI: 10.1002/(sici)1520-667x(1996)8:6<383::aid-mcs2>3.0.co;2-y

✦ Synopsis

A column switching system was developed for capillary liquid chromatography using a robust low back pressure precolumn (PC) for fast loading of large sample volumes. After loading, trapped analytes are transferred to the capillary separation column by a backflush linear gradient flow. The PC contained a small quantity of reversed-phase C18 material prepared in poly etheretherketone (PEEK) tubing, which is capped at both sides by means of high-performance liquid chromatography (HPLC) in-line filters. Gradient backflush elution provided an effective means for preconcentration and refocusing of analytes of different nature and polarity. The technique showed a clearcut improvement in separation efficiency as compared with switching systems using forward flow elution of the PC. The system was connected to continuous flow Fast Atom Bombardment (FAB)/rnass spectroscopy for the analysis of steroids and peptides. Salts and polar compounds present in the sample were removed by extensive washing of the precolumn with an appropriate water percentage before their elution and separation. The preconcentration of diluted samples on the PC gave an increase in sensitivity of approximately two orders of magnitude as compared with wide-bore HPLC-CF (continuous flow) FAJ3 using effluent splitting.