Low-cost photoionization sensors as detectors in GC × GC systems designed for ambient VOC measurements

Xiaobing Pang*, Haijun Lan, Jinping Zhong, Daiqi Ye, Marvin D. Shaw, Alastair C. Lewis

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Conventional volatile organic compound (VOC) monitoring based on thermal desorption - gas chromatography–mass spectrometry (TD-GC–MS) or gas chromatography-flame ionization detector (TD-GC-FID) is relatively cumbersome and expensive. In this study commercial off the shelf low-cost and low-power photo-ionization detector (PID) sensors are used as simple detectors in VOC analysis systems based on GC, including a miniaturised GC × GC device with portable, low-cost, and low-energy-consumption features. PID sensors produce a voltage signal positively proportional to VOC concentration, which when incorporated into a TD-GC system gave limit of detection of 0.02 ppbV for isoprene. To test PID performance in real-world applications, PID sensors were deployed as (i) a second alternative detector in a GC-Quadruple Time Of Flight Mass spectrometry (GC-Q-TOF-MS), and (ii) the main detector in a compact two-dimensional gas chromatograph (GC × GC). PID sensors with 10.6 eV and 11.7 eV lamps were used to measure eight toxic chemicals including organic sulfide and organic phosphonates via GC; two species were ionized by a 10.6 eV lamp and four species by the 11.7 eV lamp. Commercially available low-cost PIDs designed for standalone could be straightforwardly and effectively re-used as detectors in compact GC × GC systems, in this work showing excellent VOC sensitivity, fast response and low operational demands compared to comparable field instruments based on GC-FID or MS.

Original languageEnglish
Pages (from-to)771-779
Number of pages9
JournalScience of the Total Environment
Early online date5 Feb 2019
Publication statusPublished - 10 May 2019

Bibliographical note

© 2019 Elsevier B.V. All rights reserved.


  • Flame ionization detector (FID)
  • Gas chromatography (GC)
  • Photo-ionization detector (PID)
  • Quadruple time-of-flight mass spectrometry (Q-TOF-MS)
  • Two-dimensional gas chromatography (GC × GC)
  • Volatile organic compounds (VOCs)

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