PNNL

Abstract

While the use of an internal calibrant can significantly increase mass measurement accuracy in many LC-MS applications, ion suppression in the ESI process and space charge effects in the MS analyzer often limit its effectiveness. These limitations are especially problematic when LC-MS is used for analyzing complex biological samples where both high sensitivity and broad dynamic range are required. To address this need, a new ESI interface has been developed to control ion transmission through the first vacuum stage of the mass spectrometer. The initial design using a dual electrospray, a dual heated capillary and a dual inlet ion funnel (Fig. 1) is specifically aimed at providing a method for controlled introduction of calibrant ions in highly accurate mass measurements using Fourier transform ion cyclotron resonance mass spectrometer.