电化学电喷雾电离源控制系统的研制

Development of Control System for Electrochemistry/Electrospray Ionization Source

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±0.1μA(增益为0.01 V/μA)或±0.01μA(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 μA（gain=0.01 V/μA） 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.