Data processing software baseline correction

The 3D data set (128 128 512) was processed using Felix software (Biosym, CA) to give a data matrix of 256 256 1024 real data points after zero-filling in all three dimensions. Only the real part of the final spectrum was stored. A 90° shifted sine bell apodization function was used in all three dimensions. The Flat routine available in the Felix program was used for baseline correction. 

Chemometric techniques have gained enormous significance in the treatment of spectral information by virtue of their ability to process the vast amount of data produced by modern instruments over short periods of time with a view to extracting the information of interest they contain and improving the quality of the results. In some cases, the operator is unacquainted with the chemometric techniques (spectral smoothing, baseline drift correction) embedded in the software used by the instrument in others, the chemometric tools involved are inherent in the application of the spectroscopic technique concerned (e.g. in NIR spectroscopy) and thus indispensable to obtaining meaningful results. 

The laboratory should verify and document the proper functioning of the software immediately after any new data acquisition or management systems have been installed. The baseline verification consists of manual calculations to confirm the correctness of all computer calculations. Ongoing verification takes place during laboratory data review process whenever a reviewer replicates one of the results generated by the computer or a manual calculation from a bench sheet. All information used in the calculations (raw data, calibration data, laboratory QC checks, and blank results) is kept on file for the reconstruction of the final result at a later date, should it become necessary. Bench sheets that document sample preparation are also kept on file for the same purpose. 

The most accurate measurements of peak areas are those obtained by means of electronic data reduction with integrators or computers. The vast majority of laboratories now have electronic or computer methods for determining peak areas. Two main features are required for electronic processing of chromatographic data accurate digitization of the analog signal and software. The software is required for the detection of peaks, correction for baseline drift, calculation of peak areas, retention times, and concentrations of components in the sample, and production of the final report.5... 

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