Design of a Time-of-Flight Mass Spectrometer as a Detector for Capillary Electrophoresis

High-efficiency separation methods such as capillary electrophoresis (CE) interfaced with structural information-producing detection systems such as mass spectrometry (MS) represent invaluable tools in analytical chemistry. Most CE applications to date have been reported using UV absorption detection. To extend the analytical power of CE, new detectors which demonstrate increased speed, sensitivity, and specificity must be developed. In this paper, we describe the design of an electrospray ionization time-of-flight mass spectrometer and its performance as a detector for CE. Emphasis is placed on fulfillment of the speed and sensitivity requirements. Low attomole and low femtomole detection limits are demonstrated for continuous infusion and CE−MS operation, respectively.