Micro-Liquid Chromatography/Mass Spectrometry with Direct Liquid Introduction

Abstract
Micro-HPLC has a legitimate role when combined on-line with a mass spectrometer (micro-LC/MS) because the latter is a mass-flow sensitive detector. Thus, the more concentrated micro-HPLC peaks provide better detection limits for micro-LC/MS than those obtained from conventional HPLC flow rates. Most of the LC/MS interfaces developed so far benefit from micro-HPLC. This review briefly highlights the developments in micro-LC/MS from early reports, and then focuses on recent developments in direct liquid introduction (DLI) micro-LC/MS. A variety of examples taken from the authors' work is shown to provide the chromatographer some insight as to what the limitations and capabilities are of the DLI micro-LC/MS technique.