Table 1.

The identification of seven phenolic acids from Brazilian propolis samples in both positive and negative ESI modes.

No.	tR/min	Positive Ion Mode			Negative Ion Mode			Compound
		Molecular Ion (m/z)	Molecular Formula	Error (ppm)	Molecular Ion (m/z)	Molecular Formula	Error (ppm)
1	2.391	[M + Na]+ 377.0855	C16H18O9	1.591	[M − H]− 353.0879	C16H18O9	1.699	Chlorogenic acid
2	5.159	[M + Na]+ 203.0021	C9H8O4	−6.206	[M − H]− 179.0430	C9H8O4	4.934	Caffeic acid
3	7.526	[M + Na]+ 539.1169	C25H24O12	−0.557	[M − H]− 515.1195	C25H24O12	0.971	Isochlorogenic acid B
4	7.806	[M + Na]+ 539.1169	C25H24O12	0.742	[M − H]− 515.1198	C25H24O12	1.553	Isochlorogenic acid A
5	9.820	[M + Na]+ 539.1169	C25H24O12	−0.371	[M − H]− 515.1197	C25H24O12	1.359	Isochlorogenic acid C
6	25.948	[M + Na]+ 307.9490	C17H16O4	0.977	[M − H]− 283.0969	C17H16O4	−0.353	caffeic acid phenethyl ester
7	33.078	[M + Na]+ 323.1618	C19H24O3	−1.547	[M − H]− 299.1649	C19H24O3	0.669	Artepillin C