Aleixandre Manuel, Nakamoto Takamichi
Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
Sensors (Basel). 2020 Jul 20;20(14):4026. doi: 10.3390/s20144026.
Twenty-eight quartz crystal microbalance (QCM) sensors coated with different sensing films were tested and analyzed in this work; twenty-three sensors were coated in different room temperature ionic liquids (RTILs) and five additional QCM sensors were coated with conventional films commonly used as stationary phases in gas chromatography. Four volatile organic compounds (VOCs), in gaseous phase-hexanol, butyl acetate, 2-hexanone, and hexanoic acid-were measured. Two transducer mechanisms were used; resonant frequency shift and resistance shift of a QCM Mason equivalent circuit. The sensors were characterized by their sensitivity to the VOCs and their discrimination power of the four VOCs. The highest separation among VOCs was obtained when frequency and resistance information of both RTIL and conventional films was used, a sensor array composed by two RTILs (1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide and 1-hexyl-3-methylimidazolium hexafluorophosphate) and two conventional films (tricresyl phosphate and apiezon-L) was found to improve the Wilks lambda separation for the tested gases two orders of magnitude compared to the Wilks lambda using only a conventional films array.
在本研究中，对28个涂覆不同传感膜的石英晶体微天平（QCM）传感器进行了测试与分析；其中23个传感器涂覆了不同的室温离子液体（RTIL），另外5个QCM传感器涂覆了常用于气相色谱固定相的传统薄膜。测量了四种挥发性有机化合物（VOC）的气相——己醇、乙酸丁酯、2-己酮和己酸。采用了两种换能器机制；QCM梅森等效电路的谐振频率偏移和电阻偏移。通过传感器对VOC的灵敏度及其对四种VOC的区分能力对传感器进行了表征。当同时使用RTIL和传统薄膜的频率和电阻信息时，在VOC之间获得了最高的分离度，发现由两种RTIL（1-丁基-1-甲基吡咯烷双（三氟甲磺酰）亚胺和1-己基-3-甲基咪唑六氟磷酸盐）和两种传统薄膜（磷酸三甲苯酯和阿皮松-L）组成的传感器阵列，与仅使用传统薄膜阵列相比，测试气体的威尔克斯λ分离度提高了两个数量级。
