Coupling of Open Tubular Liquid Chromatography to Electrospray Mass Spectrometry with a Nanospray Interface

The concept of interfacing open tubular liquid chromatography (OTLC) to electrospray ionization mass spectroscopy (ESI-MS) is here introduced. This combination has the potential of becoming a powerful and generic tool for separation and quantification of various complex mixtures. We can demonstrate here how easy and straightforward it is to connect an open capillary LC column to nano-ESI, simply by drawing the column through a stainless steel tube onto which the high voltage (HV) is supplied. This method is compared with applying the HV to a gold-coated column tip and the standard dynamic nanospray interface supplied by the ESI-MS manufacturer. Reliability and stability are documented. OTLC-ESI-MS is demonstrated by separation of fatty acids in the negative mode.