Ultra-sensitive measurement of peroxy radicals by chemical amplification broadband cavity-enhanced spectroscopy

The Analyst ◽  
2016 ◽  
Vol 141 (20) ◽  
pp. 5870-5878 ◽  
Author(s):  
Yang Chen ◽  
Chengqiang Yang ◽  
Weixiong Zhao ◽  
Bo Fang ◽  
Xuezhe Xu ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Peroxy Radical ◽  
Peroxy Radicals ◽  
Enhanced Absorption ◽  
Chemical Amplification ◽  
Amplification Method ◽  
Cavity Enhanced Absorption Spectroscopy

The chemical amplification method is combined with the incoherent broadband cavity-enhanced absorption spectroscopy for peroxy radical measurements.

scholarly journals Peroxy radical detection for airborne atmospheric measurements using cavity enhanced absorption spectroscopy of NO<sub>2</sub>

2013 ◽  
Vol 6 (6) ◽  
pp. 9655-9688 ◽  
Author(s):  
M. Horstjann ◽  
M. D. Andrés Hernández ◽  
V. Nenakhov ◽  
A. Chrobry ◽  
J. P. Burrows
Keyword(s):  
Detection Limit ◽  
Chain Length ◽  
Absorption Spectroscopy ◽  
Peroxy Radical ◽  
Inlet Pressure ◽  
Peroxy Radicals ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
A Chain ◽  
Averaging Time

Abstract. Development of an airborne instrument for the determination of peroxy radicals (PeRCEAS – Peroxy Radical Cavity Enhanced Absorption Spectroscopy) is reported. Ambient peroxy radicals (HO2 and RO2, R being an organic chain) are converted to NO2 by adding NO, and are recycled through subsequent reaction with CO and O2, thus forming a chain reaction with an amplification factor called chain length. The concentration of NO2 is measured by continuous-wave cavity ring-down spectroscopy (CRDS) using an extended cavity diode laser at 409 nm. Optical feedback from a V-shaped cavity optimizes resonator transmission and allows for a simple detector set-up. CRDS directly yields absorption coefficients, thus providing NO2 concentrations without additional calibration. The optimum 1σ detection limit is 0.3 ppbv at an averaging time of 40 s and an inlet pressure of 300 mbar, corresponding to a concentration of 2 × 109 molecules cm−3. The calibration of the PeRCEAS chain length at an inlet pressure of 300 mbar yields a value of 120 ± 7. The peroxy radical 1σ detection limit for an averaging time of 120 s and a chain length of 120 is ~3 pptv.

On-chip cavity-enhanced absorption spectroscopy using a white light-emitting diode and polymer mirrors

Lab on a Chip ◽  
2015 ◽  
Vol 15 (3) ◽  
pp. 711-717 ◽  
Author(s):  
Cathy M. Rushworth ◽  
Gareth Jones ◽  
Martin Fischlechner ◽  
Emma Walton ◽  
Hywel Morgan
Keyword(s):  
Absorption Spectroscopy ◽  
White Light ◽  
Microfluidic Chip ◽  
Path Length ◽  
Light Emitting Diode ◽  
Absorption Path Length ◽  
Light Emitting ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
On Chip

We have integrated disposable polymer mirrors within a microfluidic chip to form a multi-pass cell, which increases the absorption path length by a maximum of 28 times, providing micromolar detection limits in a probed volume of 10 nL.

scholarly journals Cavity enhanced absorption spectroscopy in the mid-infrared using a supercontinuum source

2017 ◽  
Vol 111 (6) ◽  
pp. 061103 ◽  
Author(s):  
Caroline Amiot ◽  
Antti Aalto ◽  
Piotr Ryczkowski ◽  
Juha Toivonen ◽  
Goëry Genty
Keyword(s):  
Absorption Spectroscopy ◽  
Mid Infrared ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy
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