wangruiting
第2楼2011/11/30
Sample Preparation, HPLC Analysis, and Peak Characterization. Juice samples were separated into two fractions,
a methanol fraction and a 0.5 % ammonia in methanol fraction, by use of Polyamide 6. Methodology for sample preparation,
HPLC separation, and peak characterization are reported in another paper (Rommeland Wrolsted, 1993). Ellagicacid (Sigma
Chemical Co., St. Louis, MO) was used as a standard to characterize ellagic acid and its derivatives in juice. Absorbance
spectra of ellagic acid and ellagic acid derivatives were very similar and very different from those of flavonols (e.g., quercetin
3-glucuronide); examples of spectra are shown in Figure lb.