HPLC Separation of Phenolic Acids on Silica Gels Layer-by-Layer Modified with 6,10-Ionene and Dextran Sulfate

Table 2

Effect of the nature of the organic solvent in the mobile phase composition on the PA retention and the efficiency of the SP-2 column.

Acid	Organic solvent
	Acetonitrile			Methanol			THF			Isopropanol
		N, TP/m			N, TP/m			N, TP/m			N, TP/m
Caffeic	2.59	16000	1.25	2.83	11000	1.10	3.92	10000	1.40	1.79	12000	1.05
Sinapic	2.08	19000	1.09	2.58	9000	1.10	2.67	13000	1.02	1.70	13000	1.16
Ferulic	1.90	14000	1.11	2.35	11000	1.69	2.81	12000	1.03	1.47	11000	1.07
p-Coumaric	1.71	20000	2.41	1.39	23000	1.20	2.75	15000	2.38	1.37	21000	1.19
Gallic	0.71	15000	1.18	1.16	11000	1.22	1.12	12000	1.23	1.15	11000	1.21
Vanillic	0.60	17000		0.95	15000		0.91	18000		0.95	15000

The selectivity coefficient was calculated according to the elution order and not the location in the table.