Valencia-Ortiz Milton, Sankaran Sindhuja
Department of Biological System Engineering, Washington State University, Pullman, WA 99164, USA.
HardwareX. 2022 Aug 10;12:e00344. doi: 10.1016/j.ohx.2022.e00344. eCollection 2022 Oct.
In recent years, applications of volatile organic compounds (VOCs) sensing technologies such as field asymmetric-waveform ion-mobility spectrometry (FAIMS) system in agriculture have accelerated. FAIMS system for VOCs sensing is attractive as it offers high sensitivity, selectivity, real-time monitoring, and portability. However, the development of a robust instrumentation system is needed for precise sampling, high accumulation of VOCs, and careful handling of samples. In this study, we developed a simple semi-automated VOC sampling (SAVS) system using a Raspberry Pi microcontroller, flowmeters, electromechanical solenoid, and cellphone-based app to control cleaning and sampling loops. The system was compared with customized headspace sampling apparatus (CHSA) and validated with a biomarker (acetone) identified to be associated with potato rot development during postharvest storage. The standard error within ion current data across different compensation voltage was lower using the SAVS system than the CHSA. In addition, the maximum peak values across scans displayed a high coefficient of variation using the CHSA (16.23%) than the SAVS system (4.51%). Future work will involve improving system efficiency by adapting multiple sample units, system miniaturization, and automating the flowmeter operation. Such automation is critical to characterize VOCs precisely and automatically across several samples for multiple applications such as pathogen detection, evaluation of crop responses, etc.
近年来，诸如场不对称波形离子迁移谱（FAIMS）系统等挥发性有机化合物（VOCs）传感技术在农业中的应用加速发展。用于VOCs传感的FAIMS系统具有吸引力，因为它具有高灵敏度、选择性、实时监测和便携性。然而，需要开发一个强大的仪器系统来进行精确采样、高浓度积累VOCs以及小心处理样品。在本研究中，我们使用树莓派微控制器、流量计、机电螺线管和基于手机的应用程序开发了一个简单的半自动VOC采样（SAVS）系统，以控制清洗和采样回路。该系统与定制的顶空采样装置（CHSA）进行了比较，并用一种被确定与马铃薯采后贮藏期间腐烂发展相关的生物标志物（丙酮）进行了验证。使用SAVS系统时，不同补偿电压下离子电流数据的标准误差低于CHSA。此外，扫描过程中的最大峰值在使用CHSA时（16.23%）比使用SAVS系统时（4.51%）显示出更高的变异系数。未来的工作将包括通过采用多个样品单元、系统小型化以及使流量计操作自动化来提高系统效率。这种自动化对于精确和自动地表征多个样品中的VOCs以用于多种应用（如病原体检测、作物反应评估等）至关重要。
