HPLC-MS with Glass Chips Featuring Monolithically Integrated Electrospray Emitters of Different Geometries

We present and evaluate an approach for coupling liquid chromatography in glass chips with mass spectrometry via fully integrated electrospray emitters. We developed an instrumental platform which allows a robust and reproducible operation of high performance chip chromatography coupled to mass spectrometry. A comparison of differently shaped emitters, from flat over edged to pulled geometries, revealed that all types performed equally well for typical nano-HPLC flow rates. At very low flow rates below 50 nL·min–1 very sharp, pulled nanospray emitters turned out to be mandatory for the generation of a stable electrospray.