枸杞子中甜菜碱含量测定方法的建立和提取方法的优化

目的:建立枸杞子中甜菜碱的含量测定方法,并优化其提取方法。方法:采用高效液相色谱法测定枸杞子中甜菜碱的含量,色谱柱为Waters Spherisorb NH₂,流动相为乙腈-0.01 mol/L磷酸二氢钾水溶液(75∶25,V/V),流速为0.7 mL/min,检测波长为195nm,柱温为30℃,进样量为10μL。以甜菜碱含量为指标,在单因素试验的基础上,采用L₉(3⁴)正交试验设计对枸杞子中甜菜碱超声提取的甲醇体积分数、提取时间、料液比进行筛选并进行验证。测定10批枸杞子中甜菜碱的含量,并与2015年版《中国药典》收录的薄层色谱法测定结果进行比较。结果:甜菜碱检测质量浓度的线性范围为2.035～2 035.04μg/mL(R²=0.999 3);检测限、定量限分别为0.410、2.051μg/mL,平均加样回收率为97.41%～98.86%(RSD为0.8%～1.4%,n=3),精密度、重复性、稳定性(24 h)试验的RSD均不大于1.2%。最优提取方法为料液比1∶30(g/mL)投料、甲醇超声提...

Establishment of the Content Determination Method of Betaine in Lycium barbarum and Optimization of the Extraction Method

OBJECTIVE:To establish the content determination method of betaine in Lycium barbarum,and to optimize the extraction method.METHODS:HPLC method was used to determine the content of betaine in L.barbarum.The determination was performed on Waters Spherisorb NH2 column with mobile phase consisted of acetonitrile-0.01 mol/L monopotassiun phosphate aqueous solution(75∶25,V/V)at the flow rate was 0.7 mL/min.The detection wavelength was 195 nm,and column temperature was 30℃.The sample size was 10μL.Using the content of betaine as index,on the basis of single factor tests,L(934)orthogonal test design were used to select the methanol volume fraction,extraction time and solid-liquid ratio of betaine in L.barbarum by ultrasonic extraction.The contents of betaine in 10 batches L.barbarum were determined,and compared with the results of TLC included in 2015 edition of Chinese Pharmacopeia.RESULTS:The linear range of betaine was 2.035-2035.04μg/mL(R2=0.9993).The limits of detection and quantification were 0.410μg/mL and 2.051μg/mL,respectively.The average recovery were 97.41%-98.86%(RSDs were 0.8%-1.4%,n=3).RSDs of precision,reproducibility and stability(24 h)tests were not higher than 1.2%.The optimal extraction method included solid-liquid ration of 1∶30(g/mL),ultrasonic extraction with methanol for 45 min.The average content of betaine in the extract from the three validation tests was 2.30%(RSD=0.43%,n=3).The contents of betaine in 10 batches L.barbarum were 1.91%-2.55%,which was no significantly different from the results of TLC(1.88%-2.60%)(RE were-1.92%-2.79%).CONCLUSIONS:The content determination method of betaine in L.barbarum was established successfully,and the extraction process was optinized.