RP-HPLC法测定东北地区6 种红树莓果实中有机酸组成

建立一种反相高效液相色谱法分离和测定6 种红树莓果实中草酸、酒石酸、柠檬酸、DL-苹果酸和乳酸5 种有机酸的方法。色谱条件为：采用SinoChrom DS-BP C18色谱柱（150 mm×4.6 mm，5 μm），流动相为甲醇-0.01 mol/L KH2PO4溶液（pH 2.60，97∶3，V/V），流速0.6 mL/min，柱温30 ℃，检测波长210 nm。结果表明：在此条件下5 种有机酸都被有效地分离，各种有机酸的质量浓度与峰面积在测定范围内呈良好的线性关系，标准曲线相关系数在0.999 3～0.999 9之间；精密度实验相对标准偏差在0.20%～1.53%（n=5）范围内；回收率为98.83%～105.42%，相对标准偏差为0.06%～1.00%。测得6 种红树莓果实中有机酸以柠檬酸为主，含量为1 058.41～1 825.45 mg/100 g，草酸、乳酸、DL-苹果酸含量较低，未检测到酒石酸。该方法简单、高效、准确、重复性好，可用于红树莓果实中有机酸的分离测定。

Determination of Organic Acids in Six Varieties of Red Raspberry Fruits Grown in Northeast China by RP-HPLC Method

A reversed phase-high performance liquid chromatography (RP-HPLC) method was established to determine the contents of organic acids including oxalic acid, tartaric acid, citric acid, DL-malic acid and lactic acid in six varieties of red raspberry fruits from Northeast China. The optimized chromatographic conditions were determined as follows: a SinoChrom DS-BP C18 column (150 mm × 4.6 mm, 5 μm) was chosen to separate organic acids, and the mobile phase was composed of methanol-0.01 mol/L KH2PO4 aqueous solution (pH 2.60, 97:3, V/V) at a flow rate of 0.6 mL/min. The column temperature was set at 30 ℃ and the eluate was monitored at 210 nm. The results indicated that the five organic acids were separated successfully and a strong linear relationship appeared between the concentrations of organic acids and the peak areas under the above optimized conditions with correlation coefficients between 0.999 3 and 0.999 9. The relative standard deviations (RSDs) of precision ranged from 0.20% to 1.53% and the average recovery rates were between 98.83% and 105.42% with RSD ranging from 0.06% to 1.00%. Citric acid was the predominant organic acid in red raspberry fruits, ranging from 1 058.41 to 1 825.45 mg/100 g. Trace amounts of oxalic acid, lactic acid and DL-malic acid were also detected but tartaric acid was not detected in red raspberry fruits. Overall, the presented method could be applied for separating and detecting different organic acids in red raspberry fruits effectively, accurately and repeatedly.