4th EucheMs chemistry congress

thursday, 30-Aug 2012
s618
chem. Listy 106, s587–s1425 (2012)
Analytical chemistry Electrochemistry, Analysis, sample manipulation
Chemometrics – iii
o - 4 2 7
GC x GC-tofMS CoMBined to MuLtivAriAte
Curve reSoLution for the AnALySiS of
CoMPLex MixtureS of PoLyCyCLiC AroMAtiC
hydroCArBonS
r. tAuLer 1 , h. PArAStAr 2
1 IDAEA-CSIC, Environmental Chemistry, Barcelona, Spain
2 Isfahan University, Department of Chemistry Faculty of
Sciences, Isfahan, Iran
Comprehensive two-dimensional gas chromatography
time-of-flight mass spectrometry (GC×GC-TOFMS) combined to
multivariate curve resolution-alternating least squares
(MCR-ALS) is proposed to improve resolution and quantification
of very complex sample mixtures of polycyclic aromatic
hydrocarbons. In full scan multivariate mode, different
GC×GC-TOFMS data slices acquired during the analysis of
samples and standards can be simultaneously analyzed and the
pure component elution profiles in the two chromatographic
dimensions as well as their pure mass spectra are resolved. In this
case, problems ubiquitously associated to GC×GC, such as
retention time peak shifting for within and between runs, are not
affecting the results obtained using the proposed strategy and
proper resolution of strongly co-eluted compounds, baseline and
background contributions are achieved. Calibration curves can be
built up using standard samples of PAHs and allow their
quantification in complex oil aromatic fractions. In case of
univariate detector responses like in flame ionization detection
(FID) or in total ion chromatogram (TIC) mass spectrometry (MS)
detection, a combination of peak alignment methods and
multivariate curve resolution (MCR) is proposed for handling
retention time shifts and modeling. A new “bilinear peak
alignment” method based on MCR is proposed to correct for
progressive within run retention time shifts in GC×GC due to the
effect of the temperature program on the second dimension. In
addition, Multivariate Curve Resolution-Alternating Least
Squares (MCR-ALS) method under proper constraints is also
proposed to analyze the already aligned bilinear augmented
GC×GC data matrix for the resolution and quantification of the
target compounds in complex mixtures in case of their incomplete
separation and co-elution problems. The results showed the
successful application of the proposed strategy for resolution and
quantification of target compounds in GC×GC analysis of
simulated and real samples.
Keywords: Chemometrics; GCxGC-MS; MCR-ALS;
4 th EucheMs chemistry congress
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc