TY - JOUR
T1 - Multivariate analysis of photoacoustic spectra for the detection of short-chained hydrocarbon isotopologues
AU - Loh, Alain
AU - Wolff, Marcus
PY - 2020/5/11
Y1 - 2020/5/11
N2 - We report, to our knowledge, the first optical detection scheme for short-chained hydrocarbon isotopologues. The sensor system is based on photoacoustic spectroscopy (PAS). Two continuous wave, thermoelectrically cooled, distributed feedback interband cascade lasers (DFB-ICLs) with emission wavelengths around 3.33 and 3.38 μm, respectively, served as light sources. The investigations comprised the main stable carbon isotopologues of methane (12CH4 13CH4), ethane (12CH3-12CH3 13CH3-12CH3 13CH3-13CH3), and propane (12CH3-12CH2-12CH3 13CH3-12CH2-12CH3). They were selected because of their importance for numerous applications from climate and planetary research to natural gas exploration. Multiple measurements of single components in nitrogen and synthetic mixtures were conducted at room temperature and atmospheric pressure. Depending on the investigated hydrocarbon isotopologue, detection limits ranging from 0.043 ppmv to 3.4 ppmv were achieved. For a selective concentration determination, multivariate analysis (MVA) was applied. Partial least-squares regression (PLSR) was used to calculate concentrations from the PA spectra. The implementation of MVA has shown that the PA setup in principle works reliably and that the selective concentration determination of short-chained hydrocarbon isotopologues is possible.
AB - We report, to our knowledge, the first optical detection scheme for short-chained hydrocarbon isotopologues. The sensor system is based on photoacoustic spectroscopy (PAS). Two continuous wave, thermoelectrically cooled, distributed feedback interband cascade lasers (DFB-ICLs) with emission wavelengths around 3.33 and 3.38 μm, respectively, served as light sources. The investigations comprised the main stable carbon isotopologues of methane (12CH4 13CH4), ethane (12CH3-12CH3 13CH3-12CH3 13CH3-13CH3), and propane (12CH3-12CH2-12CH3 13CH3-12CH2-12CH3). They were selected because of their importance for numerous applications from climate and planetary research to natural gas exploration. Multiple measurements of single components in nitrogen and synthetic mixtures were conducted at room temperature and atmospheric pressure. Depending on the investigated hydrocarbon isotopologue, detection limits ranging from 0.043 ppmv to 3.4 ppmv were achieved. For a selective concentration determination, multivariate analysis (MVA) was applied. Partial least-squares regression (PLSR) was used to calculate concentrations from the PA spectra. The implementation of MVA has shown that the PA setup in principle works reliably and that the selective concentration determination of short-chained hydrocarbon isotopologues is possible.
KW - Ethane
KW - Gas sensing
KW - Hydrocarbons
KW - Interband cascade laser
KW - Isotopologues
KW - Methane
KW - Multivariate analysis
KW - Partial least squares regression
KW - Photoacoustic spectroscopy
KW - Propane
U2 - 10.3390/molecules25092266
DO - 10.3390/molecules25092266
M3 - Article
C2 - 32403410
AN - SCOPUS:85084462074
VL - 25
JO - Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry
JF - Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry
SN - 1420-3049
IS - 9
M1 - 2266
ER -