Analysis of the false peaks in extended Hadamard transform ion mobility spectrometry

• Published in: International journal of mass spectrometry 2019-12, Vol.446, p.116230, Article 116230
• Main Authors: Hong, Yan, Su, Jingming, Tang, Chaoli, Huang, Chaoqun, Liu, Sheng, Chu, Yannan
• Format: Article
• Language: English
• Subjects: Extended HT-IMS; False peak; Modulation defect; Peak-peak repulsion
• ISSN: 1387-3806; 1873-2798
• DOI: 10.1016/j.ijms.2019.116230

With the introduction of the extended method in Hadamard transform ion mobility spectrometry (HT-IMS), the modulation defects and the false peaks inherently located in conventional HT techniques could be well suppressed. However, a few false peaks are still located in the demultiplexed data of the extended HT-IMS, which is hard to be explained and seriously degrades the performance of the extended HT techniques. In this research, in order to discover the origin of the false peaks in the extended HT-IMS, the measurements of double and multiple ion peaks with IMS have been implemented and the effects of the peak-peak repulsion on the multiplexed data of HT-IMS have been explored. Results show that in multiplexing IMS, the space charge effect existed between two adjacent ion packets would lead to the shifts (deviations) of the ion signal peaks. Simulation results prove that this tiny shifting in the multiplexed data is another critical reason for the false peaks in the demultiplexed data of extend HT-IMS. This is of positive significance for revealing those unknown false peaks in extended HT-IMS and other similar techniques. Simulation results of extended multiplexing HTIMS: (a) simulation spectrum of the signal averaging method; b) Multiplexed data of extended HT-IMS, S-matrix order is 255, number of the extended symbol is 4; c) The simulation demultiplexed data of EHT-IMS, in the inset of frame c, parts of the multiplexed data are demonstrated. [Display omitted] •The peak-peak repulsion effect on Hadamard multiplexing technique has been evaluated firstly.•A feasible explanation for the unknown false peaks in extended HT-IMS is given.