电化学电喷雾电离源控制系统的研制

摘要

控制系统是电化学电喷雾电离源的核心部件及研制难点.本研究通过单片机控制数模、模数转换及蓝牙无线通讯模块构建了一套电化学电喷雾电离源(EC/ESI source)的控制系统.利用此系统及一种同轴式探针组成了完整的电化学电喷雾电离源,对9,10-二苯基蒽进行了循环伏安及在线电化学/电喷雾电离质谱(Online EC/ESI-MS)测试.结果表明:此系统具有高达±1 mV的电势控制精度,电流测量精度优于±0.1 μA(增益为0.01 V/μA)或±0.01 μA(增益为0.1 V/μA).本系统具有成本低廉,可在电喷雾高压上安全悬浮,易于操控的特点.%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 uA (gain = 0. 01 V/uA) and +0. 01 μA (gain = 0.1 V/μA). 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.