Fig. 4. Chromatogram and electropherogram of the sample 3. (A) Chromatogram, (B) electropherogram. (1) TGA and (2) interfering peak. Other CE conditions were the same as in Fig. 2. HPLC conditions: Mobile phase: acetonitrile and 0.01 mol L−1 potassium dihydrogen phosphate solution (pH 2.5) with volume ratio of 10:90. Flow rate:
1.0 mL min−1 . Detection wavelength: 215 nm. Column temperature: 30 ◦ C. The sample injected was 20 L.