Experimental parameter variation

Recovery (%) ± SD^a

No variation^b

100.23 ± 1.93

・ Ammonia concentration (%)

20

30

97.44 ± 1.15

98.50 ± 0.76

・ Mobile phase composition (v/v/v)

Ethyl acetate: methanol: 25% ammonia

(7.5:4.5:3)

(8.5:4.5:3)

99.14 ± 2.22

101.25 ± 2.55

(8:4:3)

97.77 ± 2.20

(8:5:3)

99.33 ± 1.64

(8:4.5:2.5)

98.48 ± 0.98

(8:4.5:3.5)

102.45 ± 0.56

・ Saturation time (min)

15

25

97.23 ± 1.11

101.67 ± 1.55