Baseline Correction in n-Dimensional NMR Spectra by Sectionally Linear Interpolation

Automated solvent artifact removal and base plane correction of multidimensional NMR protein spectra by AUREMOL-SSA

“…The latter, however, induces new artifacts in areas where only few baseline points can be defined. In the present work, the linear spline interpolation (Saffrich et al 1993) of the base points has been used as a valid alternative, being even more efficient and simpler. Traditionally, the base points where the base plane should be zero and where no relevant peaks are expected are defined interactively by the user.…”

“…With an interactive selection of these points the results are rather satisfying (Zolnai et al 1989;Saffrich et al 1993); however, for automation this manual selection is not acceptable. Therefore we adapted and generalized a method for base point selection proposed by Guentert and Wuethrich (1992) for the use of a linear spline base plane correction.…”

AURELIA, a program for computer-aided analysis of multidimensional NMR spectra

“…Published base plane correction methods differ in the functions used for approximating base line artefacts and in the way that regions are defined where the ideal base line should be zero. Those regions which contain no cross peaks can either be defined by the user (Barsukov and Arseniev, 1987;Zolnai et al, 1989;Saffrich et al, 1993) or identified automatically by the program (Dietrich et al,, 1991;Gfintert and Wtithrich, 1992;Chylla and Markley, 1993). The latter methods are more convenient for the user; however, in interactively driven methods external information can be incorporated, e.g.…”

“…evidence derived from other experiments, such as well-resolved ID spectra. AURELIA provides two approximations of the base line, the cubic spline fit (Zolnai et al, 1989) and the sectionally linear interpolation (Saffrich et al, 1993). The cubic spline interpolation has the principal advantage that it approximates the base line by a smooth function; the linear interpolation, where the base plane is approximated by short sections of straight lines, has the advantage of being computationally very fast.…”

“…Probably the most important are methods for removing base plane distortions (Barsukov and Arseniev, 1987;Zolnai et al, 1989;Dietrich et al, 1991;Giintert and Wiithrich, 1992;Saffrich et al, 1993;Hare and Prestegard, 1994;Rouh et al, 1994). For spectra recorded with older instruments, procedures for the suppression of t~ ridges, t 1 oscillations and antidiagonals are useful (Klevit, 1985;Glaser and Kalbitzer, 1986;Zolnai et al, 1986Zolnai et al, ,1988Mitschang et al, 1990;Kalbitzer et al, 1991b;Manoleras and Norton, 1992).…”