State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China.
Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100190, China.
Anal Chim Acta. 2021 Oct 23;1183:338969. doi: 10.1016/j.aca.2021.338969. Epub 2021 Aug 20.
Ion mobility spectrometry is an important gas analysis method used in the rapid detection field. However, due to a lacking of explicit mathematical model of ion peak, it is difficult to extract characteristic analyte peaks from a spectrum containing overlapping peaks to achieve online qualitative analysis. Here, we present an asymmetric peak model for processing ion mobility peaks. For the asymmetric peak model, the key is to accurately estimate the standard deviation of the peak model and the fitting function of the tailing edge. We focused on the Coulombic effects on resolution of ion mobility spectrometry based on a new hypothesis of ion cloud shape and derived a formula for calculating the standard deviation taking the initial pulse width, diffusion and Coulomb repulsion factors into account. The proposed asymmetric peak model combines the advantages of optimal physical and chemical interpretation and explicit mathematical meaning. A fast decomposition method based on the peak model was developed to decompose overlapping peaks. Two overlapping simulated data sets and one real data set (a mixture of acetone and methyl salicylate) were used to test the method. The results indicated that our proposed method successfully decomposed the overlapping spectrum into individual peaks and performed markedly better than other three available methods in terms of the execution time. The proposed method meets the requirements for online qualitative analysis.
离子淌度谱是一种重要的气体分析方法，用于快速检测领域。然而，由于缺乏明确的离子峰数学模型，难以从包含重叠峰的谱图中提取特征分析物峰，从而实现在线定性分析。在此，我们提出了一种用于处理离子淌度峰的不对称峰模型。对于不对称峰模型，关键是要准确估计峰模型的标准偏差和拖尾边缘的拟合函数。我们专注于基于新的离子云形状假设的离子淌度谱分辨率的库仑效应，并推导出了一个考虑初始脉冲宽度、扩散和库仑排斥因子的标准偏差计算公式。所提出的不对称峰模型结合了最优物理化学解释和明确数学意义的优点。基于该峰模型开发了一种快速分解方法，用于分解重叠峰。使用两个重叠模拟数据集和一个真实数据集（丙酮和水杨酸甲酯的混合物）来测试该方法。结果表明，我们提出的方法成功地将重叠光谱分解为单个峰，并且在执行时间方面明显优于其他三种可用方法。该方法满足在线定性分析的要求。
