液相色谱-质谱法检测保健食品中非法添加药物的信号增强方法研究

目的改造常规离子源,通过增强其离子通量,提高整体的检测灵敏度,用于保健食品非法添加药物的检测。方法在传统电喷雾离子源的基础上,保留高电压、辅助加热、辅助气流等原有装置,对离子源进行改造,在喷针侧位增加推斥电极板,以促使喷雾中带电液滴和离子转向、压缩和动能调整,在源底部和侧部加装缓冲气通路以及供样窗口,采用改造的离子源检测保健食品中20种非法添加的物质,并与已有液相色谱质谱法进行比较。结果获取结果的整体灵敏度增强方式较常规离子化方式提高了10倍以上,并减少了本底抑制,压低了一倍以上的基体抑制,在现有的线性范围内,20种物质在两种离子源测定下,结果准确性一致。结论通过增加推斥电场的方式可以有效增强离子响应,为提高液相色谱质谱法的灵敏度提供了一种途径。

Signal enhancement for the determination of illegally added drugs in health food by liquid chromatography-mass spectrometry

Objective To develope an ion capacity enhancing method by reconstructing formal ion source, and improve the overall detection sensitivity using in the field of illegally added drugs test for health food. Methods On the basis of the traditional electrospray ion source, the original devices such as high voltage, auxiliary heating and auxiliary airflow were retained, the ion source was modified, and the repelling electrode plate was added in the side of the needle to promote the charged droplets and ions compression, and kinetic energy adjustment. The buffer gas flow path and the sample window were installed at the bottom and side, and 20 kinds of illegal added materials in health food were detected by modified ion source and compared with normal liquid chromatography-mass spectrometry method. Results The sensitivity of enhanced method was more than 10 times higher than that of conventional method. The matrix effect was depressed to less than the half. The accuracy of test for those 20 kinds of drugs was similar with conventional test within the existing linear ranges. Conclusion The method can enhance the ion signal with the repelling electric field in formal ion source, which provides a useful way to improve the sensitivity of liquid chromatography-mass spectrometry.