电喷雾解吸电离与常压离子迁移率谱联用方法的研究

将电喷雾解吸电离与常压离子迁移率谱进行联用,通过在离子迁移率谱仪漂移管进样口前端设置与进样口同电位的辅助电极提升了检测信号强度及稳定性。利用该系统对玻片表面吸附的美莎芬样品进行直接检测,得到的美莎芬约化迁移率为1.29 cm2/(V·s)。同时研究了电喷雾解吸电离源参数对被测物特征峰强度的影响,发现该系统可在较低的雾化气气压下获得较大的特征峰强度。在优化的参数下对玻片表面不同量的美沙芬样品进行直接检测,根据10倍噪声计算系统对美沙芬的检测限为1.6 ng/cm2,表明电喷雾解吸电离常压离子迁移率谱系统具有对物体表面痕量物质进行直接检测的应用潜力。

Coupling of Desorption Electrospray Ionization with Atmospheric Pressure Ion mobility Spectrometry

Desorption electrospray ionization (DESI) source was coupled to an atmospheric pressure ion mobility spectrometer (IMS), the signal intensity was improved by attaching an auxiliary electrode with fixed voltage in front of the ion inlet of IMS tube. Dextromethorphan (DXM) on glass was detected directly by the DESI-IMS. The reduced mobility of DXM measured by the DESI-IMS is 1.29cm2/vs. Experimental parameters of DESI were optimized for rapid and sensitive detection of DXM. Strong signal is obtained by the DESI-IMS under low nebulizing gas pressure of DESI. The calculated detection limit of the DESI-IMS is 1.6ng/cm2. The method has the potential for rapid detection of trace substance on solid surface.