Table 1. Method Model Equations Based on the First DoE from Screening.
| observed criteria | modela | ANOVAb |
|---|---|---|
| number of peaks | y = 9.609 – 0.450(C)2+ 0.213(A × B) – 0.193(A × C) – 0.274(B × (C)2) + 0.222(A × B × C) | R2 = 0.5686 |
| adj. R2 = 0.4659 | ||
| F-ratio = 5.5364 | ||
| MS-LOF = 0.0978 (threshold 1.1481) | ||
| number of peaks with resolution ≥1.5 | y = 8.246 – 0.573(C)2+ 0.242(A × B) + 0.279(A × (B)2) | R2 = 0.4452 |
| adj. R2 = 0.3728 | ||
| F-ratio = 6.1518 | ||
| number of peaks with tailing ≤1.2 | y = 147.886 + 81.595(B) + 69.728(B)2+ 147.459(C)2+ 61.599(B × C) – 102.064((B)2× C) – 162.169(B × (C)2) – 64.636(A × B × C) | R2 = 0.7118 |
| adj. R2 = 0.6056 | ||
| F-ratio = 6.7033 | ||
| MS-LOF = 0.1163 (threshold 0.452) |
a
y = observed criteria, A = pump flow rate, B = final percent of mobile phase B, C = pH.
b
Regression ANOVA statistics, MS-LOF = mean square lack-of-fit, Adj. = Adjusted.