Abstract：
Breath exhaled hydrogen cyanide (HCN) has been identified to be associated with several respiratory diseases. Accurately distinguishing the concentration and release rate of different HCN sources is of great value in clinical research. However, there are still significant challenges due to the high adsorption and low concentration characteristics of exhaled HCN. In this study, a two-compartment kinetic model method based on negative photoionization mass spectrometry was developed to simultaneously determine the kinetic parameters including concentrations and release rates in the airways and alveoli. The influences of the sampling line diameter, length, and temperature on the response time of the sampling system were studied and optimized, achieving a response time of 0.2 s. The negative influence of oral cavity-released HCN was reduced by employing a strategy based on anatomical lung volume calculation. The calibration for HCN in the dynamic range of 0.5-100 ppbv and limit of detection (LOD) at 0.3 ppbv were achieved. Subsequently, the experiments of smoking, short-term passive smoking, and intake of bitter almonds were performed to examine the influences of endogenous and exogenous factors on the dynamic parameters of the model method. The results indicate that compared with steady-state concentration measurements, the kinetic parameters obtained using this model method can accurately and significantly reflect the changes in different HCN sources, highlighting its potential for HCN-related disease research.
摘要：
已确定呼吸呼出氰化氢（HCN）与几种呼吸系统疾病有关。准确区分不同来源HCN的浓度和释放速率在临床研究中具有重要价值。然而,由于呼出HCN的高吸附和低浓度特性，仍然存在重大挑战。在这项研究中,建立了基于负光电离质谱的两室动力学模型方法，以同时确定动力学参数，包括气道和肺泡中的浓度和释放速率。采样线直径的影响，长度,和温度对采样系统响应时间的影响进行了研究和优化,实现0.2s的响应时间。通过采用基于解剖肺体积计算的策略,减少了口腔释放的HCN的负面影响。实现了在0.5-100ppbv的动态范围内HCN的校准和在0.3ppbv的检测限(LOD)。随后，吸烟的实验，短期被动吸烟，并对苦杏仁的摄取量进行了考察，考察了内源和外源因素对模型方法动态参数的影响。结果表明，与稳态浓度测量相比，利用该模型方法得到的动力学参数能准确、显著地反映不同HCN源的变化,强调其在HCN相关疾病研究中的潜力。
