1
|
Prestage J, Day C, Husheer SL, Winter WT, Ho WO, Saffell JR, Hutter T. Selective Detection of Volatile Organics in a Mixture Using a Photoionization Detector and Thermal Desorption from a Nanoporous Preconcentrator. ACS Sens 2022; 7:304-311. [PMID: 34958564 DOI: 10.1021/acssensors.1c02344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The selective detection of individual hazardous volatile organic compounds (VOCs) within a mixture is of great importance in industrial contexts due to environmental and health concerns. Achieving this with inexpensive, portable detectors continues to be a significant challenge. Here, a novel thermal separator system coupled with a photoionization detector has been developed, and its ability to selectively detect the VOCs isopropanol and 1-octene from a mixture of the two has been studied. The system includes a nanoporous silica preconcentrator in conjunction with a commercially available photoionization detector (PID). The PID is a broadband total VOC sensor with little selectivity; however, when used in conjunction with our thermal desorption approach, selective VOC detection within a mixture can be achieved. VOCs are adsorbed in the nanoporous silica over a 5 min period at 5 °C before being desorbed by heating at a fixed rate to 70 °C and detected by the PID. Different VOCs desorb at different times/temperatures, and mathematical analysis of the set of PID responses over time enabled the contributions from isopropanol and 1-octene to be separated. The concentrations of each compound individually could be measured in a mixture with limits of detection less than 10 ppbv and linearity errors less than 1%. Demonstration of a separation of a mixture of chemically similar compounds, benzene and o-xylene, is also provided.
Collapse
Affiliation(s)
| | - Coco Day
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | | | | | - Wah O. Ho
- Alphasense Ltd., Sensor Technology House, 300 Avenue West, Skyline 120,
Great Notley, Essex CM77 7AA, U.K
| | - John R. Saffell
- SensorHut Ltd., Vision Park, Cambridge CB24 9ZR, U.K
- Alphasense Ltd., Sensor Technology House, 300 Avenue West, Skyline 120,
Great Notley, Essex CM77 7AA, U.K
| | - Tanya Hutter
- SensorHut Ltd., Vision Park, Cambridge CB24 9ZR, U.K
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, 204 E. Dean Keeton Street, Austin, Texas 78712, United States
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| |
Collapse
|
2
|
|