Table 2.
Regression coefficients, R2, R2-adj, and probability values for the fitted models.
| Regression Coefficient | λmax (nm) | Concentration (ppm) |
|---|---|---|
| β0 (constant) | 386.44 | 249.7 |
| β1 (main effect) | −45,084 | −513.04 |
| β2 (main effect) | 3.09 | −3.68 |
| β11 (quadratic effect) | −8.27 | 336.8 |
| β22 (quadratic effect) | −0.061 | −0.119 |
| β12 (interaction effect) | −1.75 | 10.56 |
| R2 | 77.81% | 95.25% |
| R2-adj | 85.62% | 90.49% |
| Lack of fit (p-value) | 0.985 | 0.142 |
β0 is a constant, β1, β11 and β12 are the linear, quadratic, and interaction coefficients of the quadratic polynomial equation, respectively.