Enhancement of photoacoustic spectroscopy with sorption enrichment for ppt-level benzene detection

Juho Karhu*, Tuomas Hieta

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)


A real-time trace gas detector for benzene is demonstrated. The measurement system takes advantage of modest enrichment through short adsorption periods to reach a ppt-level detection limit with a sampling cycle of 90 s, which includes sample adsorption, desorption, and a spectroscopic measurement. Benzene is collected on Tenax TA sorbent for 30 s and then detected from the enriched samples with photoacoustic spectroscopy. High sensitivity is achieved using cantilever-enhanced photoacoustic spectroscopy and a continuous-wave quantum cascade laser emitting at 14.8 mu m wavelength, which corresponds to the absorption wavelength of the strongest benzene infrared band. We reach a detection limit of 150 ppt of benzene, over one sampling cycle. Interference from humidity and other common petrochemicals is evaluated. (C) 2022 Optica Publishing Group

Original languageEnglish
Pages (from-to)1892-1897
Number of pages6
JournalApplied Optics
Issue number8
Publication statusPublished - 10 Mar 2022
MoE publication typeA1 Journal article-refereed


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