Quartzcrystal characteristics ham9/20/2023 ![]() On the other hand, the QCM coated with PAN nanofibers via electrospinning interacted strongly with safrole vapor, with a frequency shift of 5 Hz for each 1 mg/L safrole vapor. For reference, uncoated QCM gave a small response to the analyte. The QCM coated by spin-coating resulted in a mass of 2.2 µg, which is higher than that coated by electrospinning. To ascertain the effect of surface area on the response size, we also coated the QCM substrate with PAN by spin-coating for 30 s at 1000 rpm. This relatively slow response is probably due to the low vapor pressure of the safrole (0.0706 mm Hg at 25 ☌), which makes it difficult to evaporate at room temperature but good enough to be detected with the sensing system. The data also show that the response time is quite slow, as response starts to steady after 7 min. The porous nature of the nanofibers interacts with safrole molecule. The frequency shift increases with PAN nanofiber loading, and the surface area of the nanofibers increases with mass loading of the PAN, which would improve the contact area between the active layer and analytes. The measurement was carried out at ambient temperature and humidity of ~60% RH. PAN Nanofiber Gas Sensor Response and Sensitivityįigure 4 shows the response of QCM to 1 mg/L of safrole vapor, where the PAN nanofibers are prepared at different times of electrospinning. The lone pair electrons of PAN can better interact with the electron-deficient functional groups in the analytes by intermolecular bond.ģ.2. It is chemically unique since it has lone pair electrons, and its hydrophobicity is essential since QCM gas sensor is heavily interfered by water vapor. This nanofiber is mechanically stable, water-insoluble, and hydrophobic. ![]() In this study, we report on safrole sensing based on the QCM method using polyacrylonitrile (PAN) nanofibers produced directly on the sensing surface. They attempt to demonstrate that illicit amine-containing drugs can be sensitively detected using flash evaporation directly into the air gap of a surface ionization detector, interfaced to gas chromatographic (GC). reported an analytical instrument to detect amine-containing drugs with surface ionization detection method. developed an amphetamine precursor detection method using quinoxaline-bridge cavitands, whereby the detection was confirmed by GC-MS analyses. Several studies have been conducted to develop mobile, easy-to-use, and cheap analytical instruments for detecting safrole. The gas sensor prepared by nanostructured materials has a better sensitivity because of the increase in the specific surface area of the materials. These materials, including nanofibers, have a large specific surface area, high porosity, and interconnected porous structures, which are advantageous for preparing gas sensing devices. Nanostructured materials have become one of the most studied materials for devices, especially those used for gas sensing. The QCM sensor offers accurate, real-time, and convenient detection of gases or vapors and humidity. Quartz crystal microbalance (QCM) is one example of acoustic wave sensor platform based on acoustic-electric effect and mass deposition. ![]() Many gas sensors have been developed based on sensing chip-analyte interactions such as photoelectric, resistive, optical, amperometric, and acoustic wave interactions. In recent years, the development of gas sensors to detect volatile organic compounds (VOCs) in the atmosphere is rapidly growing. Therefore, there is a need for a portable, easy-to-use, and cheap analytical instrument for drug detection. Although these methods are very sensitive and selective, they are costly, not handy, and difficult to operate. ![]() There are many conventional analytical methods for detecting drugs, which are mainly chromatographic-based, such as gas chromatography (GC), liquid chromatography (LC), and liquid chromatography coupled with mass spectrometry (LC-MS). Safrole is a pale-yellow liquid precursor that has been smuggled throughout South Asia. ![]() They are also used in the chemical and pharmaceutical industries, making them prone to black market trading. Precursors commonly used to produce amphetamine-like drugs include piperonal, safrole, and iso-safrole. Detecting and curbing the illegal trade remain a problem faced by law enforcement. In Indonesia alone, the annual confiscated crystal meth has increased significantly from 0.1 to 1.3 tons in the last eight years. Since 2010, the quantity of drugs seized globally has averaged around 4–5 tons. The drug is produced in Europe, Asia, North America, Oceania, and South America. In particular, the abuse of N-methyl-3,4-methylenedioxyamphetamine (MDMA), well known as ecstasy, has been growing rapidly, despite its serious unhealthy side effects. According to the recent World Drug Report, the global abuse of amphetamine-type stimulus (ATS) drugs continues to increase. ![]()
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |