Table 3.
Results obtained by applying the regression procedures under study to mixtures with 10 components and 5% random noise (average for n = 25 replicates).
| component |
||||||
|---|---|---|---|---|---|---|
| regression | parameter | THF | C9 | Bz | C10 | Diox |
| MLR | RMSEP | 1.269 | 3.484 | 6.666 | 3.156 | 3.245 |
| SMLR | RMSEP | 1.224 | 3.115 | 7.500 | 2.753 | 3.160 |
| selected m/z | 37, 50, 51, 74, 76, 77, 78 | 128 | 42, 43, 71, 72 | 142 | 45 | |
| RR | RMSEP | 1.027 | 3.343 | 6.638 | 3.030 | 3.125 |
| θa | 0.0383 | 0.0304 | 0.0277 | 0.0331 | 0.0207 | |
| PCR | RMSEP | 2.480 | 4.240 | 7.342 | 5.273 | 10.432 |
| selected PCsb | 1 | 13 | 6 | 5 | 4 | |
| PLSR | RMSEP | 2.474 | 3.640 | 7.335 | 4.918 | 7.338 |
| selected PCsb | 1 | 13 | 5 | 13 | 5 | |
| ButAc | Hept | Pent | Nitro | Octa | ||
|---|---|---|---|---|---|---|
| MLR | RMSEP | 1.873 | 2.225 | 3.006 | 3.055 | 1.787 |
| SMLR | RMSEP | 1.873 | 2.225 | 2.993 | 2.972 | 1.787 |
| selected m/z | 39, 41, 43, 44, 55, 56, 57, 61, 73 | 59, 114 | 54 | 46 | 43, 56, 68, 82, 83 | |
| RR | RMSEP | 1.983 | 2.293 | 3.166 | 3.189 | 1.545 |
| θa | 0.0297 | 0.0358 | 0.0345 | 0.0336 | 0.0378 | |
| PCR | RMSEP | 1.949 | 2.519 | 3.004 | 1.898 | 2.362 |
| selected PCsb | 7 | 10 | 6 | 6 | 7 | |
| PLSR | RMSEP | 3.352 | 2.478 | 3.024 | 5.951 | 3.338 |
| selected PCsb | 6 | 9 | 5 | 7 | 4 |
aθ, ridge factor [24].
bSelected PCs, number of principal components for the minimum value of RMSEP.