尽管哈达玛多路复用技术能有效改善离子迁移谱的信噪比,但在哈达玛还原谱中却出现了假峰等失真现象,这严重影响了离子迁移谱的检测性能。本课题通过改变各种多路复用参数来观察哈达玛变换离子迁移谱中的假峰变化情况,进而分析各种多路复用参数与哈达玛变换离子迁移谱中假峰的关联性。实验结果表明,尽管多路复用参数的变化可能会改变假峰的位置或峰型,但无法从根本上消除哈达玛离子迁移谱的假峰现象。研究结果进一步证明了哈达玛多路复用中固有的调制缺陷可能是哈达玛变换离子迁移谱中出现假峰的主要原因之一。
In Hadamard transoform ion mobility spectrometry (HT-IMS), although the signal to noise ratio (SNR) has been significantly improved, the false peaks and other artifacts are found in the demultiplexed data of HT-IMS,which would heavily affect the detection performance of IMS. In this research, we mainly focus on the analysis of the relationship between the multiplexing parameters and the false peak phenomena of HT-IMS through modifying the multiplexing parameters of Hadamard transform. The experimental results demonstrate that although these multiplexing parameters possibly could change the profile and position of these false peaks of HT-IMS, they cannot be used to eliminate the false peaks from the spectra of HT-IMS. This further proves that the inherent modulation defect owned by the Hadamard multiplexing method is one of the main sources of these artifacts of HT-IMS.