Table 4.

The Overall Prediction Error (s) of 13 Test Compounds When Using Offset Gradients

Overall Prediction Error (s)
Flow Rate	0.2 mL/min	0.4 mL/min	0.8 mL/min
Gradient Slope
3.5%/min g	± 7.2e (2.25% f)	± 3.3 (1.63%)	± 3.0 (2.73%)
1.75%/min h	± 6.3 (1.63%)	± 4.2 (1.65%)	± 3.9 (2.67%)
0.875%/min i	± 7.0 (1.56%)	± 4.4 (1.54%)	± 4.4 (2.62%)

^eOverall prediction error is defined as the RMS (root mean square) error of the test compounds. $\text{RMS}(\sqrt{\frac{1}{n}(x_1^2+x_2^2+x_3^2\dots +x_n^2)})$, x means the prediction error of each test compound

^f $\text{Prediction}\text{error}(\%)=(\sqrt{\frac{1}{n}(y_1^2+y_2^2+y_3^2\dots +y_n^2)})$, y means the prediction error (%) of each test compound

^g3.5%/min is the gradient slope of 3.5% mobile phase B/min, mobile phase B: water with 20 mM ammonium acetate (pH 4.7)

^h1.75%/min is the gradient slope of 1.75% mobile phase B/min, mobile phase B: water with 20 mM ammonium acetate (pH 4.7)

ⁱ0.875%/min is the gradient slope of 0.875% mobile phase B/min, mobile phase B: water with 20 mM ammonium acetate (pH 4.7)