Abstract:

A method for the determination of seven anthocyanins in the peel of sweet cherry was developed by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample was extracted by methanol containing 0.1%(v/v) hydrochloric acid, and then purified by AB-8 macroporous resins. The separation was carried out on a Phenomenex Kinetex column (100 mm×4.6 mm, 2.6 μm) with mobile phase of 0.1%(v/v) formic acid aqueous solution containing 5 mmol/L ammonium formate and methanol. The sample solution was detected by UPLC-MS/MS with ESI under positive ion and multi reaction monitoring (MRM) modes. The results showed that the limits of quantification (LOQs) for the seven target compounds were 0.26-1.42 μg/kg. The seven anthocyanin standards showed a good linearity in the range of 0-100 μg/L with the correlation coefficients (r²) of 0.9964-0.9993. The average recoveries of the seven anthocyanins were 97.2%-105.4%, and the relative standard deviations (RSDs) were 1.9%-5.8%. The mature fruit samples of sweet cherry red variety "Tieton" and the yellow variety "13-33" were analyzed by this method. The results showed that the anthocyanin composition and contents were significantly different between the two varieties. This method can be used for rapid identification and the determination of anthocyanin components in sweet cherry fruits due to its simple operation, high sensitivity, good reproducibility and covering a wide range of anthocyanins.

Key words: AB-8 macroporous resins, anthocyanins, sweet cherry, ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)