Figure 5: Three-dimensional plot of the response surface for (found critical resolution-1 between bortezomib and Imp-C), (a) variation of the response as a function of A (flow rate) and B (% acetonitrile); fixed factor: C (% methanol) = 80% v/v, (b) variation of the response as a function of A (flow rate) and C (% methanol); fixed factor: B (% acetonitrile) = 28.5% v/v, (c) variation of the response as a function of B (% acetonitrile) and C (% methanol); fixed factor: A (flow rate) = 1.0 mL min^{−1}.