Gas Chromatographic – Ultra Violet Analysis.
A schematic illustration of how volatile organic compounds (VOCs) in exhaled air (collected and introduced into the transfer line) may be analysed by the GC-UV diode array methodology. The detector consists of an optical path embedded into a heated gas flow cell and confined between two sapphire windows. The gas flow cell is horizontally aligned between a deuterium lamp and a diode array UV spectrophotometer of more than 1000 photodiodes, covering a range from 160 to 330 nm
Data is collected at a rate of one full spectrum (more than 1000 points) every 0.1 s and stored as averages of 2D spectra (one average spectrum every 2 s). A 3D spectra is also obtained By using both 2D and 3D spectra qualitative and quantitative analysis of each compound is possible
Schematic illustration of the technical solution originally developed Verner and Ludmila Lagesson at the Department of Occupational and Environmental Medicine, Faculty of Health Sciences, and Department of Physics and Measurement, Institute of Technology, at University of Linköping, and Jan Andrasko at The National Laboratory of Forensic Science, Linköping, Sweden
1. Lagesson-Andrasko L, Lagesson V, Andrasko J.The Use of Gas-Phase UV Spectra in the 168-330-nm Wavelength Region for Analytical Purposes. 1. Qualitative Measurements. Anal Chem. 1998 Mar 1;70(5):819-26.
2. Leanderson P, Lagesson V, Tagesson C Demonstration of nitric oxide on asbestos and silicon carbide fibers with a new ultraviolet spectrophotometric assay. Environ Health Perspect. 1997 Sep;105 Suppl 5:1037-40.
3. Jones AW, Lagesson V, Tagesson C.Determination of isoprene in human breath by thermal desorption gas chromatography with ultraviolet detection.
J Chromatogr B Biomed Appl. 1995 Oct 6;672(1):1-6.