TABLE 2.
Summary of PLS results
| Data | Spectra
|
First derivative
spectra
|
Second derivative spectra
|
|||
|---|---|---|---|---|---|---|
| r | SEP (%) | r | SEP (%) | r | SEP (%) | |
| Replicate spectrum data set, 1,800-900 cm−1 | 0.983 | 1.77 (9)a | 0.983 | 1.76 (7) | 0.982 | 1.81 (6) |
| Replicate spectrum data set (outlier removed), 1,800-900 cm−1 | 0.988 | 1.49 (10) | 0.988 | 1.50 (7) | 0.987 | 1.58 (10) |
| Averaged replicate spectra, 3,650-700 cm−1 | 0.975 | 2.12 (2) | 0.980 | 1.89 (1) | 0.981 | 1.84 (2) |
| Averaged replicate spectra (outlier removed) 3,650-700 cm−1 | 0.981 | 1.89 (3) | 0.985 | 1.68 (1) | 0.985 | 1.68 (2) |
| Averaged replicate spectra, 1,800-900 cm−1 | 0.977 | 2.05 (1) | 0.980 | 1.88 (1) | 0.982 | 1.83 (2) |
| Averaged replicate spectra (outlier removed), 1,800-900 cm−1 | 0.982 | 1.84 (2) | 0.985 | 1.68 (1) | 0.985 | 1.68 (2) |
a
The values in parentheses are the numbers of PLS factors required to obtain a minimum SEP.