Development of Control System for Electrochemistry/Electrospray Ionization Source

A control system for an electrochemistry/electrospray ionization source (EC/ESI source) was designed and fabricated. The system includes two parts, a homemade embedded potentiostat floated on electrospray high voltage, and a remote computer, which communicates with the potentiostat through a Bluetooth wireless interface. The accuracy of potential is controlled in the range of +/- 1 mV, and the accuracies of the current measurements are +/- 0.1 mu A (gain=0.01 V/mu A) and +/- 0.01 mu A (gain = 0.1 V/mu A). The performance of the control system was tested by cyclic voltammetry and online electrochemistry/electrospray ionization mass spectrometry (online EC/ESI-MS) using 9,10-diphenylanthrance as a model compound. Accurate potential control was achieved and most importantly, 9,10-diphenylanthrance, a non-polar compound usually undetectable by electrospray ionization mass spectrometry, was detected in high abundance.