Skip to main content

Table 3 Comparison of PLS predictive models using vibrational spectroscopy and pyrolysis molecular beam mass spectrometry

From: High-throughput prediction of eucalypt lignin syringyl/guaiacyl content using multivariate analysis: a comparison between mid-infrared, near-infrared, and Raman spectroscopies for model development

Method SEL validation1,a SEP2,a RMSEP3,a r-Val4 R2Val5 Outliers6
Raman 2 nd deriv (19 pt) + SNV 32 scans 0.05 0.14 0.13 0.89 ± 0.04 0.79 ± 0.08 1
Raman 1 st deriv (7 pt) + EMSC 32 scans 0.05 0.13 0.13 0.91 ± 0.02 0.83 ± 0.04 1
Raman EMSC + 2 nd deriv (15 pt) 96 scans 0.05 0.14 0.15 0.90 ± 0.02 0.81 ± 0.04 0
Raman 2 nd deriv (15 pt) + SNV 96 scans 0.06 0.17 0.16 0.86 ± 0.02 0.74 ± 0.04 0
MIR EMSC + 2 nd deriv (15 pt) 0.05 0.14 0.13 0.87 ± 0.06 0.8 ± 0.1 1
MIR 2 nd deriv (17 pt) + MSC 0.05 0.14 0.14 0.91 ± 0.01 0.83 ± 0.01 1
MIR 2 nd deriv (17 pt) + SNV 0.05 0.15 0.15 0.87 ± 0.02 0.76 ± 0.03 1
NIR EMSC + 2 nd deriv (25 pt) 0.06 0.19 0.20 0.79 ± 0.01 0.62 ± 0.01 0
NIR 2 nd deriv (25 pt) + MSC 0.06 0.18 0.18 0.82 ± 0.04 0.67 ± 0.07 1
NIR 2 nd deriv (25 pt) + SNV 0.06 0.22 0.21 0.80 ± 0.04 0.65 ± 0.07 1
  1. 1Standard Error of the Laboratory for the validation data.
  2. 2Standard Error of Prediction.
  3. 3Root Mean Standard Error Prediction.
  4. 4Correlation coefficient for the validation set.
  5. 5Pearson coefficient of determination for validation.
  6. 6Number of outliers removed from validation models.
  7. aAverage errors of three randomly generated models using data provided. Models were not statistically different.
  8. The numbers listed parenthetically reflect the degree of Savitzky-Golay spectral smoothing.
  9. Statistical values are the average of 3 independent models.
  10. MIR = mid-infrared spectroscopy, NIR = near-infrared spectroscopy, EMSC = extended multiplicative scatter correction, MSC = multiplicative scatter correction, SNV = standard normal variate.