Table 1.

The comparison of retention times and peak resolutions of investigated alkaloids in 20–25% of acetonitrile in water at different pH and ammonium acetate concentrations.

	20% ACN, pH = 3				20% ACN, pH = 4				25% ACN, pH = 3				25% ACN, pH = 4
	20 mM		10 mM		20 mM		10 mM		20 mM		10 mM		20 mM		10 mM
	t R	R S	t R	R S	t R	R S	t R	R S	t R	R S	t R	R S	t R	R S	t R	R S
Protopine	10.94	5.38	11.49	6.08	13.16	5.79	13.91	7.25	6.54	4.07	6.66	4.07	7.75	4.20	7.72	4.55
Allocryptopine	13.40	1.36	14.17	1.45	16.81	3.47	17.06	3.35	7.61	1.25	7.73	1.43	8.89	3.98	9.03	3.23
Chelidonine	14.07	4.11	14.90	3.88	18.79	2.68	19.29	3.05	7.97	2.56	8.17	2.60	10.07	1.21	10.07	1.29
Coptisine	16.02	13.65	16.84	14.26	20.35	14.18	21.03	14.95	8.73	8.72	8.92	9.41	10.5	9.57	10.55	9.08
Sanguinarine	24.58	5.62	26.39	5.45	33.71	4.59	37.27	4.07	11.76	5.65	12.11	5.70	14.8	5.38	14.78	5.11
Berberine	28.96	17.00	31.01	17.22	39.12	16.82	42.27	18.23	14.01	12.67	14.43	12.79	17.58	13.25	17.51	12.62
Chelerythrine	47.54	—	51.73	—	66.91	—	74.71	—	20.45	—	21.26	—	26.45	—	26.28	—