Development of Micellar HPLC-UV Method for Determination of Pharmaceuticals in Water Samples

Figure 2

Effect of pH on the analyte separation. pH: (a) 6.0; (b) 7.0; (c) 8.0, and (d) 50% of phase A (pH 7.0) and 50% of phase B (pH 8.0). Data were obtained for standard solution of amoxicillin (1), caffeine (2), tetracycline (3), diclofenac (4), ibuprofen (5), 17α-ethynylestradiol (6), levonorgestrel (7), nimesulide (8), ciprofloxacin (9), and norfloxacin (10) in the concentration of 20.0 mg·L⁻¹, with an injected volume of 20 μL, at a flow rate of 1.0 mL·min⁻¹, at 25°C, and detection at 220 nm. Mobile phase contains 15.0% (v/v/) ethanol, 3.0% (m/v) SDS, and 20.0 mmol·L⁻¹ of phosphate and isocratic elution. A in the y-axis is the absorbance.