<div class="csl-bib-body">
<div class="csl-entry">Ricchiuti, G., Dabrowska, A., Pinto, D., Ramer, G., & Lendl, B. (2022, June 0). <i>A Dual-beam Photothermal Mach-Zehnder Interferometer Employing an External Cavity Quantum Cascade Laser for Detection of Water Traces in Organic Solvents</i> [Poster Presentation]. Analytica, Munich, Germany.</div>
</div>
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dc.identifier.uri
http://hdl.handle.net/20.500.12708/136457
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dc.description
Mid-infrared (mid-IR) spectroscopy is a versatile analytical technique that allows for qualitative and quantitative analysis. It is based on probing highly selective rotational and vibrational transitions of analyte molecules present in gases, liquids and solids. Classical absorption spectroscopy based on Lambert-Beer´s law relies on detection of minute differences in light intensity. However, as absorbance does not scale with laser power it does not fully benefit from quantum cascade lasers’ (QCLs) high power and brilliance. [2] At the contrary, photothermal spectroscopy (PTS) is an indirect detection approach where the generated analytical signal is directly proportional to the applied laser power. [3] In this work, we present a photothermal mid-IR spectroscopy setup that achieves low-ppm range limits of detection for water in organic solvents (ethanol and chloroform) and as a most difficult application in aircraft’s jet fuel. The device has been calibrated and validated against coulometric Karl Fischer titration (KF) and is shown to have comparable performance and sensitivity. In contrast to KF, the spectroscopic nature of the sensor allows to gain additional information on the analyte and works reagent-free.
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dc.description.abstract
We present a first photothermal mid-IR spectroscopy setup for liquids on the example
of sensitive detection of water traces in organic solvents (ethanol and chloroform) and
as a most difficult application in aircraft’s jet fuel. Classical absorption spectroscopy
based on Lambert-Beer´s law relies on detection of minute differences in light intensity.
However, as absorbance does not scale with laser power it does not fully benefit from
quantum cascade lasers’ (QCLs) high power and brilliance. [1] At the contrary,
photothermal spectroscopy (PTS) is an indirect detection approach where the
generated analytical signal is directly proportional to the applied laser power.
Increasing the power means that the sensitivity is enhanced, too.
In PTS the sample is illuminated by a pulsed mid-IR excitation source causing a
periodical heating and cooling of the sample. The resulting photo-induced thermal
gradient ΔT can be probed as a consequent refractive index change (Δn) by means of
a second laser source, a so called “probe laser”. The challenge lies in detecting the
smallest Δn. To do that, we use an interferometric approach. In particular, our latest
generation liquid PTS IR sensor consists of a Mach-Zehnder Interferometer (MZI) able
to sense sub-nm phase shifts Δφ between its two arms. In detail, we use a HeNe probe
laser and an external cavity (EC)-QCL pump laser tuneable from 1730 to 1565 cm-1.
The stability and linearity of our system are ensured by temperature stabilization and
holding the MZI in its quadrature point using a PID controlled piezo electric transducer
(PZT) glued directly on a mirror in one arm of the MZI. Some of the relevant obtained
results are reported in Fig. 1. Achieved limits of detection are in the low ppm region.
en
dc.description.sponsorship
European Commission
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dc.language.iso
en
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dc.subject
photothermal spectroscopy
en
dc.subject
PAT
en
dc.title
A Dual-beam Photothermal Mach-Zehnder Interferometer Employing an External Cavity Quantum Cascade Laser for Detection of Water Traces in Organic Solvents
en
dc.type
Presentation
en
dc.type
Vortrag
de
dc.relation.grantno
860808
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dc.type.category
Poster Presentation
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tuw.project.title
European Joint Doctorate Programme on Optical Sensing using Advanced Photo-Induced Effects
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tuw.researchTopic.id
M2
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tuw.researchTopic.id
Q1
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tuw.researchTopic.id
I8
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tuw.researchTopic.name
Materials Characterization
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tuw.researchTopic.name
Photonics
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tuw.researchTopic.name
Sensor Systems
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tuw.researchTopic.value
10
-
tuw.researchTopic.value
60
-
tuw.researchTopic.value
30
-
tuw.publication.orgunit
E164-02-1 - Forschungsgruppe Prozessanalytik
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tuw.author.orcid
0000-0002-3074-5674
-
tuw.author.orcid
0000-0001-8307-5435
-
tuw.author.orcid
0000-0003-3838-5842
-
tuw.event.name
Analytica
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tuw.event.startdate
21-06-2022
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tuw.event.enddate
23-06-2022
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tuw.event.online
On Site
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tuw.event.type
Event for scientific audience
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tuw.event.place
Munich
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tuw.event.country
DE
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tuw.event.presenter
Ricchiuti, Giovanna
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tuw.event.track
Multi Track
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wb.sciencebranch
Chemie
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wb.sciencebranch
Chemische Verfahrenstechnik
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wb.sciencebranch
Physik, Astronomie
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wb.sciencebranch.oefos
1040
-
wb.sciencebranch.oefos
2040
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wb.sciencebranch.oefos
1030
-
wb.sciencebranch.value
60
-
wb.sciencebranch.value
15
-
wb.sciencebranch.value
25
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item.openairetype
Presentation
-
item.openairetype
Vortrag
-
item.grantfulltext
restricted
-
item.cerifentitytype
Publications
-
item.cerifentitytype
Publications
-
item.languageiso639-1
en
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item.openairecristype
http://purl.org/coar/resource_type/c_18cf
-
item.openairecristype
http://purl.org/coar/resource_type/c_18cf
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item.fulltext
no Fulltext
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crisitem.project.funder
European Commission
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crisitem.project.grantno
860808
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crisitem.author.dept
E164-02-1 - Forschungsgruppe Prozessanalytik
-
crisitem.author.dept
E164-02-1 - Forschungsgruppe Prozessanalytik
-
crisitem.author.dept
E164-02-1 - Forschungsgruppe Prozessanalytik
-
crisitem.author.dept
E164-02-1 - Forschungsgruppe Prozessanalytik
-
crisitem.author.dept
E164-02 - Forschungsbereich Umwelt-, Prozessanalytik und Sensoren
-
crisitem.author.orcid
0000-0002-3074-5674
-
crisitem.author.orcid
0000-0001-8307-5435
-
crisitem.author.orcid
0000-0003-3838-5842
-
crisitem.author.parentorg
E164-02 - Forschungsbereich Umwelt-, Prozessanalytik und Sensoren
-
crisitem.author.parentorg
E164-02 - Forschungsbereich Umwelt-, Prozessanalytik und Sensoren
-
crisitem.author.parentorg
E164-02 - Forschungsbereich Umwelt-, Prozessanalytik und Sensoren
-
crisitem.author.parentorg
E164-02 - Forschungsbereich Umwelt-, Prozessanalytik und Sensoren
-
crisitem.author.parentorg
E164 - Institut für Chemische Technologien und Analytik