'武当松针茶'中莽草酸含量测定及提取工艺优选

摘要

目的 优选"武当松针茶"中莽草酸的提取工艺,并建立其含量测定方法.方法 采用反相高效液相色谱法-二极管阵列检测器测定"武当松针茶"中莽草酸的含量.通过正交设计试验,分别以水和不同浓度的甲醇为提取溶剂考察料液比、超声功率和超声时间对莽草酸含量的影响.结果 莽草酸在10.02~100.2 mg·L-1(r=0.9995)范围内与峰面积呈良好的线性关系;平均加样回收率为99.5%,RSD=1.93%(n=6).以水为提取溶剂,正交试验提取条件为料液比1:50,超声功率200 W,提取45 min;以甲醇为提取溶剂,正交试验结果为料液比1:50,甲醇浓度40%,超声功率500 W,超声时间45 min为最佳.此条件下测得莽草酸的平均含量分别为36.38、38.66 mg·g-1.结论 最佳提取工艺为40%甲醇为提取溶剂,料液比1:50,超声功率500 W,超声时间45 min,所建立的含量测定方法稳定可靠,可用于提取和测定"武当松针茶"中莽草酸的含量.%Objective To optimize the extraction technology of shikimic acid in Wudang pineneedle tea and to establish the assay meth-od.Methods The content of shikimic acid in Wudang pineneedle tea was determined by RP-HPLC-DAD.Orthogonaldesignwas a-dopted to investigate the influence on solid/liquid ratio,ultrasound power,ultrasound time by using water and different concentration methanol as extraction solvent respectively.Results A good linearity relationship between the concentration of shikimic acid and peak area showed within the range of 10.02~100.2 mg·L-1(r=0.9995),and the average recovery was 99.5%(RSD=1.93%,n=6). With water as extraction solvent,the better extraction conditions by orthogonal experiment were ratio of solid to liquid 1:50,ultrasonic power 200 W,extraction of 45 min.With methanol as extraction solvent,the better extraction conditions by orthogonal experiment were ratio of solid to liquid 1:50,40% methanol concentration,ultrasonic power 500 W,ultrasonic time of 45 min.The average contents of shikimicacidwere36.38mg·g-1and38.66mg·g-1respectively.Conclusions The optimal technology was as follows:adding 50 times of 40% methanol,ultrasonic extracting for 45 min under ultrasound power 500 W.The assay method is stable and reliable,which can be used in the extraction and determination of shikimic acid in Wudang pineneedle tea.