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Use of dielectric property for chemical sensing and measurement |
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| รหัสดีโอไอ | |
| Creator | Phoonthawee Saetear |
| Title | Use of dielectric property for chemical sensing and measurement |
| Contributor | Phurich Keeraticharinpanich, Duangjai Nacapricha |
| Publisher | Faculty of Science, Ubon Ratchathani University |
| Publication Year | 2566 |
| Journal Title | Journal of Science and Science Education |
| Journal Vol. | 6 |
| Journal No. | 2 |
| Page no. | 192-205 |
| Keyword | Contactless conductivity, Impedance, Alcohol, Rubbing alcohol, Binary-liquid mixture |
| URL Website | https://so04.tci-thaijo.org/index.php/JSSE |
| Website title | Journal of Science and Science Education |
| ISSN | ISSN 2697-410X |
| Abstract | The use of dielectric property for chemical sensing and measurement in liquid samples was presented. Binary-liquid mixtures were used to demonstrate the applicability and efficiency of the concept. For a mixture of two liquids with different dielectric constants, a new dielectric property is a combination of the two liquids. Thus, quantitative analysis of a liquid in that mixture can be accomplished if we can detect the change in signal due to the change in dielectric constant of liquid mixtures. This work adopts a capacitively coupled contactless conductivity detector (C4D) to measure chemical components in binary-liquid systems. A C4D sensor is lab-made of polytetrafluoroethylene (PTFE) tubing with two metal electrodes placed on the outer wall of the tubing. Parameters that affect the performance of C4D sensor, such as electrical parameters (frequency and voltage supplied to the electrode), tubing size and various types of metal electrodes were investigated. Measuring solution aspirated through the sensing area of electrode gives the changes in C4D signal from the concentration of interested liquid. In this work, various ratios in a binary-liquid mixture of alcohol and water leads the changes in C4D signal response. Quantitative analysis can be carried out using the plot between the response signals of the C4D with target analyte concentration. Rubbing alcohol is selected as a target sample for demonstrating the C4D response to the dielectric property. In the method validation, our developed C4D method gives no significant differences of the quantitative results from gas chromatography. These sensors can readily measure when liquid contacts the sensing areas. Furthermore, it is convenient to use and solvent resistance. Consequently, the sensors can be applicable as portable devices for quality control in the production line as well as in the laboratory. |
