Table 1 Mobile phase compositions used in method optimization process

1

Acetone: EDTA: methanol: 1% ammonia solution

65:5:10:10

Poor resolution of peaks

2

Acetone: EDTA: methanol: 1% ammonia solution

65:5:10:15

Resolution problem between peaks

3

Chloroform: acetonitrile: methanol: 1% ammonia solution

11:49:25:15

Poor resolution between peaks

4

Chloroform: dimethylformamide: acetone: 1% ammonia solution

20:20:40:30

Longer development time, high noise

5

Ethyl acetate, acetone, methanol, and 1% ammonia solution^a,b

4.4:19.6:10:6

Sharp peak with good resolution at R_f 0.27 \(\pm\) 0.02

6

Ethyl acetate: acetonitrile: methanol: 1% ammonia solution

4.4:19.6:10:6

impurity peak overlap on analyte peak

7

Ethyl acetate: dimethylformamide: acetone: 1% ammonia solution

10:22:50:18

Peak resolution problem

8

Water: methanol: acetone: dichloromethane

10:70:20:60

Longer development time