Modification of a commercial electrospray nebulizer for operation in a liquid chromatography/mass spectrometry system at flow rates in the low microL/min range

A simple and inexpensive approach to convert the electrospray nebulizer of a commercial liquid chromatography/mass spectrometry (LC/MS) system (HP 1100) to accommodate lower flow rates has been proposed and evaluated. This modification consists of simply replacing the nebulizer needle by a commercially available stainless steel needle with a smaller internal diameter. Experiments were conducted in order to optimize operational parameters. Using two different internal diameter needle sizes, flow rates ranging from 1 to 250 microL/min could be accommodated. The modification presented allows an extension of the range of compatible flow rates without major modification of the standard design of the interface.