Table 4 Comparison between the proposed HPLC method and the reported ones regarding greenness.

Mobile phase

Reported method²⁴

Reported method²²

Reported method²⁶

Reported method²⁷

Proposed method

Acetonitrile: sodium phosphate buffer (pH 3.3) (20:80,v/v)

Monobasic potassium phosphate (pH 3.5): acetonitrile (80: 20, v/v) containing triethylamine (7.5 mM)

Methanol: potassium phosphate buffer (60:40 ,v/v)

Methanol: aqueous 0.05% triethylamine (25:75 v/v)

Mixture of 0.13 M SDS and 0.02 M Birij-35 solution adjusted to pH 2.5 using phosphoric acid