Peak recognition computer program

Issaq and McNitt [585] published a computer program for peak recognition on the basis of peak areas. They investigated the reproducibility of the area of some well-separated peaks for three solutes (anthraquinone, methyl anthraquinone and ethyl anthraquinone) in the 10 solvents used for their optimization procedure. The solvents included binary, ternary and quaternary mixtures of water with methanol, acetonitrile and THF. The areas were found to be reproducible within about 2 percent. The wavelength used for the UV detector in this study was not reported. 

Linear prediction is a method to directly obtain the resonance frequencies and relaxation rates from time domain signals, which are a superposition of exponents, by solving the characteristic polynomials. Phases and intensities are calculated interactively using a least-squares procedure. The correlation spectroscopy of a two-dimensional NMR spectrometer employs several specific programs such as RELAY and TOCSY. The recognition of response peaks, the isolations of signals from noise and artifacts, and the spectral position (e.g., chemical shift) are all carried out by computers. 

The direct visualized cycle time was obtained by an automatic recognition program which defined a peak if the sum of rise and decline was greater than two in the distribution of reaction times for one finger. The time axis has been divided into 10 ms intervals. The recognition program measured the differences between the peaks, summed them up and computed the mean value. This mean difference between the peaks of the distribution is the direct visualized cycle time of this task. Because it is possible that one cycle does not occur in a distribution, distances between peaks similar to two cycle times obtained by method 1 are not used to compute the mean value. This would give a false mean value if two cycle times are considered as one. 

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