An exploratory study on online quantification of isoprene in human breath using cavity ringdown spectroscopy in the ultraviolet

Li, Qingyuan; Li, Jing; Wei, Xin; Li, Yingxin; Sun, Meixiu

doi:10.1016/j.aca.2020.07.056

Cited by 6 publications

(2 citation statements)

References 23 publications

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“…And researchers have made efforts to increase the optical length in headspace oxygen concentration detection, ranging from 5m to 20m, using cavity-enhanced absorption spectroscopy [11] or cavity ringdown spectroscopy [12] . For example, Ryan et al demonstrates a Broadband Cavity-Enhanced Absorption Spectroscopy measurement of SO2 with a 5 min detection limit of 0.75 ppbv [13] . Li et al demonstrated that the limit of detection of the system was 0.47 ppbv, with average over 100 ringdown events (equivalent to 5 s) [14] .…”

Section: Introductionmentioning

confidence: 99%

Axial section multi-reflection cavity-like enhanced oxygen detection in pharmaceutical vial

Chen,

Yonggang,

Qiwu

et al. 2023

Eighteenth National Conference on Laser Technology and Optoelectronics

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The pharmaceutical industry extensively employs glass vials for the packaging of sterile preparations. Air invasion resulted from vial leakage leads to preparation quality deterioration. Tunable Diode Laser Absorption Spectroscopy (TDLAS) has been established as an effective non-contact method for assessing seal quality by detecting residual oxygen concentration in vial headspace. However, definitely unlike that the scheme of cavity-enhanced absorption spectroscopy (CEAS) has a sufficiently long optical path, headspace oxygen detection should be realized within the short inner diameter length of vials, while the external optical path is longer and with rich oxygen in the open production environment. Innovatively, we attempt to make full use of the cavity-like geometric nature of the glass vial to increase the inner absorption optical path length, by coating a high-reflectance silver ring film on the outer wall of vials. This novel scheme enables the incident laser to achieve Axial Section Multiple Reflection (ASMR) within space-limited vials (using ‘n-ASMR’ denotes the mode with ‘n’ times of reflections), extending the absorption path effectively without equipping any additional absorption cavity, we name it Cavity-Like Enhanced Absorption Spectroscopy (CLEAS), which breakthroughs the limitations of the conventional Direct Transmission (DT) method only along the diameter direction. In the Allan variance analysis tests, compare with the detection limit 0.226% with an integration time 33.8s of the DT method, our 2/4/6/8-ASMR methods achieve the detection limits 0.058%, 0.054%, 0.058% and 0.046% with integration time 28.9s, 14.6s, 4.76s and 5.60s, respectively, which indicate a brand-new roadmap has been discovered by the CLEAS scheme to extend absorption path in space-limited glass vial without increasing any hardware facilities.

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Section: Introductionmentioning

confidence: 99%

Axial section multi-reflection cavity-like enhanced oxygen detection in pharmaceutical vial

Chen,

Yonggang,

Qiwu

et al. 2023

Eighteenth National Conference on Laser Technology and Optoelectronics

View full text Add to dashboard Cite

show abstract

“…Currently, the measurement of acetone, isoprene, and NO with the limit of detection (LoD) of 57 ppb, 25 0.47 ppb, 26 and 7.4 ppb, 27 respectively, was achieved using CRDS in our group. Meanwhile, our group also investigated the predictive value of individual molecules of NO and isoprene for LC with an accuracy of 72.8% 28 and 77.9% 29 respectively, using CRDS.…”

Section: Introductionmentioning

confidence: 99%