Development of an In-Source Peltier Heater for Pulled Capillary Nanospray Emitter Columns

Column compartments in liquid chromatography (LC) systems house the LC columns. These compartments are responsible for maintaining a suitable column environment for achieving optimal chromatographic performance. However, the advancements in instrument and column designs demand newer technologies. It is a well-established concept that decreasing the dead volume of the column improves the column resolution, thereby providing enhanced chromatographic separation. One of the major contributors in the dead volume is the line connecting the column in the LC compartment to the ion source in the mass spectrometer. Using in-source emitter columns is one strategy to enhance the resolution. However, ion sources without temperature control are not suitable for columns that are used at high temperatures. In this work, we are introducing a nano electrospray ionization source with an integrated Peltier heater designed for pulled capillary nanospray emitter columns. Although the performance of the device is demonstrated by showing the isomeric separation of permethylated glycans using a mesoporous graphitized carbon packed pulled capillary emitter, it can easily be paired with any nanospray emitter column that requires temperature control.