Normal-inverse bimodule operation Hadamard transform ion mobility spectrometry

In order to suppress or eliminate the spurious peaks and improve signal-to-noise ratio (SNR) of Hadamard transform ion mobility spectrometry (HT-IMS), a normal-inverse bimodule operation Hadamardtransform - ion mobility spectrometry (NIBOHT-IMS) technique was developed. In this novel technique, anormal and inverse pseudo random binary sequence (PRBS) was produced in sequential order by an iongate controller and utilized to control the ion gate of IMS, and then the normal HT-IMS mobility spectrumand the inverse HT-IMS mobility spectrum were obtained. A NIBOHT-IMS mobility spectrum was gainedby subtracting the inverse HT-IMS mobility spectrum from normal HT-IMS mobility spectrum. Experimental results demonstrate that the NIBOHT-IMS technique can signifificantly suppress or eliminate thespurious peaks, and enhance the SNR by measuring the reactant ions. Furthermore, the gas CHCl3 andCH2Br2 were measured for evaluating the capability of detecting real sample. The results show that theNIBOHT-IMS technique is able to eliminate the spurious peaks and improve the SNR notably not only forthe detection of larger ion signals but also for the detection of small ion signals.

为抑制或消除杂散峰、提升哈达玛变换离子迁移谱（Hadamard transform ion mobility spectrometry, HT-IMS）的信噪比（signal-to-noise ratio, SNR），本研究研发了正逆双模块操作哈达玛变换离子迁移谱（normal-inverse bimodule operation Hadamard transform - ion mobility spectrometry, NIBOHT-IMS）技术。该新型技术中，离子门控制器依次生成正、反伪随机二进制序列（pseudo random binary sequence, PRBS），用以控制离子迁移谱的离子门，由此分别获得正相HT-IMS迁移谱与反相HT-IMS迁移谱；通过将正相HT-IMS迁移谱减去反相HT-IMS迁移谱，即可得到NIBOHT-IMS迁移谱。实验结果表明，NIBOHT-IMS技术可通过对反应物离子的检测，有效抑制或消除杂散峰并提升信噪比。此外，通过检测三氯甲烷（CHCl3）与二溴甲烷（CH2Br2）以评估该技术对实际样品的检测能力，结果显示，无论针对强离子信号还是弱离子信号的检测，NIBOHT-IMS技术均可显著消除杂散峰并大幅提升信噪比。