Table 2: Spectral data of flavonoids in grapefruit peel extracts.

Tentative identificationRTUVmaxMS [M − H]MS [M + H]+Products ions
(min)λ (nm)()()()

Isonaringin [32, 41]31.43217, 284, 331579271, 151
Naringin [32, 41]33.58224, 283, 331579459, 271
Hesperidin [32, 41]38.02225, 284, 328609301
Neohesperidin [41]40.19228, 283, 331609301, 489
Unknown-144.65283, 328617465, 303
Unknown-246.57249, 257, 324595449, 287
Naringenin [42]48.04226, 284, 325273153
Hesperetin [40]51.98225, 285, 329303285
Isosinensetin [40]53.46249, 270, 342373357, 343, 327
Sinensetin [32, 40, 43]54.54243, 264, 333373358, 343, 312
Unknown-356.22250, 272, 335403388, 373
Nobiletin [40, 43]57.60248, 268, 334403388, 373
Tangeretin [32, 40]59.42271, 322373358, 343, 325, 297

References given in brackets are taken from papers with matching spectral data:
Angeloni et al. 2012 [32]; Rivas et al. 2008 [40]; Jeong et al. 2004 [41]; Xu et al. 2007 [42]; Alañón et al. 2011 [43].