The Excel spreadsheet on the following page represents capillary electrophoresis results monitored by fluorescence detection. Plot the raw data and calculate and plot a five-point, unweighted moving average smooth on the results.
(b) Calculate and plot a five-point Savitzky-Golay smooth using the smoothing coefficients given in the chapter. Compare the improvement in S/N of the Savitzky-Golay smooth to that of the moving average smooth plotted in (a). Also compare the peak distortion of the two smooths.
(c) Use a search engine like Google to find the Savitzky-Golay smoothing coefficients for a 7-point qua- dratic smooth (order 5 2) for the data points shown. Note that in many cases the coefficients have already been normalized by dividing by a normalization integer. You can determine whether the coefficients have been normalized by comparing them to those given in Figure 5-14a, which must be normalized by dividing by 35.
(d) Now perform a 7-point moving average smooth and a seven-point Savitzky-Golay smooth on these data. Compare the improvement in S/N and the peak shape distortion.
(e) Perform a 7-point moving average smooth and a fifteen-point moving average smooth of the data. Which smoothing width gives better improvement in S/N? Which smoothing width gives least distortion of peak shape?