| Title: | A portable gas chromatograph for real-time monitoring of aromatic volatile organic compounds in air samples |
| Author(s): | You DW; Seon YS; Jang Y; Bang J; Oh JS; Jung KW; |
| Address: | "Department of Chemistry and Nanoscience & Technology Institute, Wonkwang University, 460 Iksandaero, Jeonbuk 54538, Republic of Korea. Dyntem Corporation, 460 Iksandaero, Iksan, Jeonbuk 54538, Republic of Korea. Department of Chemistry and Nanoscience & Technology Institute, Wonkwang University, 460 Iksandaero, Jeonbuk 54538, Republic of Korea. Electronic address: kwjung@wku.ac.kr" |
| DOI: | 10.1016/j.chroma.2020.461267 |
| ISSN/ISBN: | 1873-3778 (Electronic) 0021-9673 (Linking) |
| Abstract: | "We describe the design and performance evaluation of a portable gas chromatograph suitable for the analysis of volatile organic and odorous compounds at trace levels. The system comprises a carbon nanotube sponge preconcentrator, an electronic pressure control (EPC) unit, a temperature-programmable column module, and a fast-response photoionization detector. A built-in tablet computer controls instrumental parameters and chromatogram display functions. The compact GC with dimensions of 35 cm (l) x 26 cm (w) x 15 cm (h) is self-contained, weighing less than 5 kg without a battery pack, and uses no auxiliary compressed gases. Our design has three main advantages over conventional portable GCs: recharging configuration of ambient air as the carrier gas using a miniature diaphragm pump, precise control of column flow by the built-in canister and EPC system, and rapid thermal desorption of the preconcentrator facilitated by intrinsic resistivity of the carbon nanotube sponge. A 30 m, 0.28 mm I.D. capillary column operated at a head pressure of 14 psi provided a peak capacity of 55 for a 10 min isothermal analysis. The temperature-programmability feature could decrease the analysis time of less than 5 min for vapor mixture of benzene, toluene, ethylbenzene, and o-xylene. More than a 100-fold increase in sensitivity by preconcentrating a sample adsorption volume of 90 mL resulted in improved detection limits of 0.13 (benzene), 0.20 (toluene), 0.23 (ethylbenzene), and 0.28 (o-xylene) ppb (v/v). Our instrument displayed good stability and reproducibility of retention times (< 0.14% RSD) and intensities (< 4.5% RSD) for continuous measurements using the preconcentrator over 10 h. Thus, continuous and on-site determinations of trace volatile organic compounds in air samples with this instrument appear feasible" |
| Keywords: | "Air Pollutants/*analysis Calibration Chromatography, Gas/*methods *Computer Systems Gases/analysis Hydrocarbons, Aromatic/*analysis Limit of Detection Nanotubes, Carbon/chemistry Odorants/analysis Pressure Reproducibility of Results Temperature Time Facto;" |
| Notes: | "MedlineYou, Dong-Wook Seon, Yeong-Sik Jang, Yeonhee Bang, Juyeon Oh, Jun-Sik Jung, Kwang-Woo eng Netherlands 2020/07/28 J Chromatogr A. 2020 Aug 16; 1625:461267. doi: 10.1016/j.chroma.2020.461267. Epub 2020 May 31" |
