Zhengzhou Tobacco Research Institute , China National Tobacco Corporation , Zhengzhou 450001 , China.
Center for Advanced Analysis and Computational Science , Zhengzhou University , Zhengzhou 450001 , China.
Anal Chem. 2019 May 7;91(9):5715-5721. doi: 10.1021/acs.analchem.8b05834. Epub 2019 Apr 17.
Direct analysis of highly reactive volatile species such as the aliphatic aldehydes as vital biomarkers remains a great challenge due to difficulties in the sample pretreatment. To address such a challenge, we herein report the development of a novel double-region atmospheric pressure chemical ionization mass spectrometry (DRAPCI-MS) method. The DRAPCI source implements a separated structural design that uses a focus electrode to divide the discharge and ionization region to reduce sample fragmentation in the ionization process. Counterflow introduction (CFI) configuration was adopted in the DRAPCI source to reduce background noise, while ion transmission efficiency was optimized through simulating the voltage of the focus electrode and the ion trajectory of the ion source. The limits of detection (LODs) of four carbonyl compounds cyclohexanone, hexanal, heptanal, and octanal by DRAPCI-MS were between 0.1 and 3 μg·m, approximately two to eight times lower than those by atmospheric pressure chemical ionization mass spectrometry. Additionally, the DRAPCI-MS method carried out effective in situ analyses of the volatile components in expired milk and the exhaled breath of smokers, demonstrating the DRAPCI-MS as a practical tool to analyze complex mixtures. The DRAPCI-MS method provides a rapid, sensitive, and high-throughput technique in the real-time analysis of gaseous small-molecule compounds.
由于样品预处理的困难，直接分析如脂肪醛等重要生物标志物的高反应性挥发性物质仍然是一个巨大的挑战。为了解决这一挑战，我们在此报告了一种新型双区域大气压化学电离质谱（DRAPCI-MS）方法的开发。DRAPCI 源采用了分离的结构设计，使用聚焦电极将放电和电离区域分开，以减少电离过程中的样品碎裂。在 DRAPCI 源中采用逆流引入（CFI）配置来降低背景噪声，同时通过模拟聚焦电极的电压和离子源的离子轨迹来优化离子传输效率。通过 DRAPCI-MS 检测的四种羰基化合物（环己酮、己醛、庚醛和辛醛）的检出限（LOD）在 0.1 到 3μg·m 之间，大约比大气压化学电离质谱低两到八倍。此外，DRAPCI-MS 方法对过期牛奶和吸烟者呼气中的挥发性成分进行了有效的原位分析，证明了 DRAPCI-MS 是分析复杂混合物的实用工具。DRAPCI-MS 方法为气态小分子化合物的实时分析提供了一种快速、灵敏、高通量的技术。
