Solid-Phase Extraction and Large-Volume Sample Stacking-Capillary Electrophoresis for Determination of Tetracycline Residues in Milk

Figure 2

Contour and response surface plots of interactions modes for output variables (sum): (a) injection time (min)  :  reverse potential (kV); (b) injection time (min)  :  reverse polarity time (min); and (c) reverse polarity (kV)  :  reverse polarity time (min).

(a)

(b)

(c)