Window target-testing factor analysis: theory and application to the chromatographic analysis of complex mixtures with multiwavelength fluorescence detection
Mt. Lohnes et al., Window target-testing factor analysis: theory and application to the chromatographic analysis of complex mixtures with multiwavelength fluorescence detection, ANALYT CHIM, 389(1-3), 1999, pp. 95-113
Window target-testing factor analysis (WTTFA) is a new data analysis method
that can help confirm the presence or absence of an analyte in a severely
overlapped chromatogram. It is intended to be used in chromatographic appli
cations with multichannel detection and is based on principal component ana
lysis. The algorithm attempts to determine if the response profile of a tar
get analyte lies within the response subspace of a time window containing u
nresolved chromatographic peaks. Because the window moves sequentially thro
ugh the chromatogram, WTTFA allows a relative assessment of match quality.
To test the new method, a procedure for simulating complex chromatograms ha
s been developed. The simulated data allow the limitations of WTTFA to be t
ested under different conditions of chromatographic complexity, spectral ov
erlap, measurement noise, window size and other factors. As a practical dem
onstration of its utility, the method is applied to the chromatographic ana
lysis of polycyclic aromatic compounds in a complex petroleum distillate us
ing multiwavelength fluorescence detection. WTTFA indicates the presence of
l-methylpyrene in an unresolved cluster of peaks. This is confirmed throug
h a combination of mass spectrometry, heart-cut chromatography and self-mod
eling curve resolution. (C) 1999 Elsevier Science B.V. All rights reserved.