Abstract: This study was concerned with the identification and quantification of anthocyanins in tree leaves and peel of red-fleshed walnut harvested at different growing stages (early sprouting, leaf growth and fruiting) by ultra performance liquid chromatography with photodiode array detection coupled with electrospray ionization tandem mass spectrometry (UPLC-PDA-MS/MS). The samples were from the Fruit Experimental Station of the College of Horticulture of Henan Agricultural University. Leaves of ordinary walnut were used as control. The results showed that the limits of quantification (LOQs) for eight target compounds were in the range of 0.60–0.90 μg/mL. The calibration curves were linear in the range of 0–300 μg/L with correlation coefficient (R2) of 0.999 0–0.999 6. Walnut peel and leaves were statistically significantly different with respect to major anthocyanins, as determined by UPLC-PDA-MS/MS. The analytical method proved to be easy to operate, sensitive and repeatable and thus was useful for rapid identification and quantification of a variety of anthocyanins in walnut materials.

Key words: leaves and peel of red-fleshed walnut, UPLC-PDA-MS/MS, anthocyanins