Deconvolution of overlapping peaks

Most EDS systems are controlled by minicomputers or microcomputers and are easy to use for the basic operations of spectrum collection and peak identification, even for the computer illiterate. However, the use of advanced analysis techniques, including deconvolution of overlapped peaks, background subtraction, and quantitative analysis will require some extra training, which usually is provided at installation or available at special schools. 

In many laboratories, the NOE cross peaks are automatically integrated into the volume by using programs such as NMRPipe and Pipp.71 The programs are extensively reviewed by Baran et al.23 Since the line-widths can vary remarkably for different resonances, the integration is mandatory. The programs are also effective for the deconvolution of overlapping peaks, and... 

Fig. 5. Deconvolution of overlapping peaks. The black, solid trace represents the analytical signal observed at the detector, which is the sum of the four peaks represented by dashed...

Kiesswetter R, Brandi F, Kasmer-Pustet N, and Mann-schreck A (2003) Chiroptical detection during liquid chromatography deconvolution of overlapping peaks of enantiomers and its applications. Chirality 15 40-49. 

X-ray spectra from real samples are complex. Their evaluation requires deconvolution of overlapping peaks and automatic background subtraction. Commercially available spectrum processing software fulfills these demands and, moreover, facilitates the operating procedures by use of a multi-channel analyser. 

The application of evolutionary factor analysis (FA) methods to spectroscopic problems is reviewed by Malinowski. Evolutionary FA methods offer solutions to the problem of analyzing totally unknown complex mixtures. These are mixtures containing unknown quantities of an unknown number of unknown components. No model for peak shape is required for these methods to work, that is, they are self-modeling. Deconvolution of overlapped peaks in HPLC is the type of data analyzed. 

Sensor array detection also is needed because these devices can be micro-fabricated with very low dead volumes they require no support gases for their operation, and they can be fabricated with a variety of selectivities, which can be used for vapor recognition and for the deconvolution of overlapping peaks. This can reduce the resolution requirements for the colunm. Sensor detectors usually have lower sensitivity than do detectors incorporated in laboratory gas chromatographic instruments. Low detector sensitivity, coupled with the very low concentrations often associated with air monitoring, requires the use of a sorption preconcentrator for sample enrichment prior to separation and detection. 

Figure 3.17 Deconvolution of overlapping peaks in GC x GC/TOF-MS. Every vertical line indicates the peak of an identified component. (Dimandja, 2004, reprinted with permission from Analytical Chemistry, Copyright 2004 by American Chemical Society.)...

More conveniently, electronic integrators (Healy et ai, 1973) and sophisticated on-line (e.g. Levine et ai, 1973) and off-line computer systems can determine peak areas. These systems are usually able to cope with corrections of peak area due to baseline, deconvolution of overlapping peaks, determination of relative retention times and, of course, provide output in the desired units. Healy and co-workers (1973) described a system in which a digital electronic integrator and off-line computer program were used to identify relative retention indices and quantify chromatographic peaks of urinary organic acids. 

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