São Paulo State University, Department of Analytical Chemistry, UNESP, CEP 14800-970, Araraquara, SP, Brazil.
Ulm University, Institute of Analytical and Bioanalytical Chemistry, 89081, Ulm, Germany.
Sci Rep. 2018 Apr 12;8(1):5909. doi: 10.1038/s41598-018-23961-8.
Following the Kyoto protocol, all signatory countries must provide an annual inventory of greenhouse-gas emission including NO. This fact associated with the wide variety of sources for NO emissions requires appropriate sensor technologies facilitating in-situ monitoring, compact dimensions, ease of operation, and sufficient sensitivity for addressing such emission scenarios. In this contribution, we therefore describe an innovative portable mid-infrared chemical sensor system for quantifying gaseous NO via coupling a substrate-integrated hollow waveguide (iHWG) simultaneously serving as highly miniaturized mid-infrared photon conduit and gas cell to a custom-made preconcentrator. NO was collected onto a solid sorbent material packed into the preconcentrator unit, and then released via thermal desorption into the iHWG-MIR sensor utilizing a compact Fourier transform infrared (FTIR) spectrometer for molecularly selective spectroscopic detection with a limit of detection (LOD) at 5 ppbv. Highlighting the device flexibility in terms of sampling time, flow-rate, and iHWG design facilitates tailoring the developed preconcentrator-iHWG device towards a wide variety of application scenarios ranging from soil and aquatic emission monitoring and drone- or unmanned aerial vehicle (UAV)-mounted monitoring systems to clinical/medical analysis scenarios.
根据《京都议定书》，所有签署国都必须提供年度温室气体排放清单，包括一氧化氮。这一事实与一氧化氮排放的多种来源相关，需要适当的传感器技术来促进现场监测、紧凑的尺寸、易于操作以及足够的灵敏度，以应对这种排放情况。在本研究中，我们因此描述了一种创新的便携式中红外化学传感器系统，通过将同时用作高度微型化中红外光子导管和气体池的基片集成空心波导 (iHWG) 与定制的预浓缩器耦合，用于通过热解吸定量气态 NO。NO 被收集到预浓缩器单元中的固体吸附材料上，然后通过紧凑的傅里叶变换红外 (FTIR) 光谱仪释放到 iHWG-MIR 传感器中，用于分子选择性光谱检测，检测限为 5 ppbv。突出了该设备在采样时间、流速和 iHWG 设计方面的灵活性，有助于针对从土壤和水生排放监测以及无人机或无人驾驶飞行器 (UAV) 监测系统到临床/医疗分析场景等各种应用场景，对开发的预浓缩器-iHWG 装置进行定制。
