Recent Applications of Mass Spectrometry in the Study of Grape and Wine Polyphenols

Table 16

Masses observed by MALDI-TOF analysis calculated using the equation 290 + 288c + 152g + 23 (290: MW of the terminal catechin unit; c: degree of polymerization; g: number of galloyl ester; 23: Na atomic mass). n.d.: not observed [88].

Polymer	no. galloyl ester	Calculated [M + Na]^+	Observed [M + Na]^+
			Positive linear	Positive reflectron
	0	601	600	601
Dimer	1	753	752	753
	2	905	905	905
Trimer	0	889	889	889
	1	1041	1041	1041
	2	1193	1193	1193
	3	1345	1346	1345
	0	1177	1177	1177
	1	1329	1329	1329
Tetramer	2	1481	1482	1482
	3	1634	1634	1634
	4	1786	1785	1786
Pentamer	0	1466	1465	1466
	1	1618	1618	1618
	2	1770	1770	1770
	3	1922	1922	1922
	4	2074	2074	2074
	5	2226	n.d.	n.d.
	0	1754	1754	1754
	1	1906	1907	1906
	2	2058	2059	2058
Hexamer	3	2210	2211	n.d.
	4	2362	2362	2362
	5	2514	2513	n.d.
	6	2666	2667	n.d.
Heptamer	0	2042	2043	2042
	1	2194	2195	2194
	2	2346	2346	2346
	3	2398	2499	2499
	4	2651	2651	n.d.
	5	2803	2800	n.d.
	6	2955	2954	n.d.
	7	3107	n.d.	n.d.
	0	2330	2330	2330
	1	2483	2483	2483
	2	2635	2635	n.d.
Octamer	3	2787	2787	n.d.
	4	2939	2938	n.d.
	5	3091	3090	n.d.
	6	3243	n.d.	n.d.
	0	2619	2618	2618
	1	2771	2770	n.d.
Nonamer	2	2923	2923	n.d.
	3	3075	3075	n.d.
	4	3227	n.d.	n.d.
Decamer	0	2907	2907	n.d.
	1	3059	3060	n.d.
	2	3211	3212	n.d.
	3	3363	n.d.	n.d.
Undecamer	0	3195	3194	n.d.
	1	3347	3349	n.d.