柴达木枸杞中17种氨基酸的测定与分析
Determination and analysis of 17 amino acids in Qaidam Chinese wolfberry
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摘要: 建立柱前衍生RP-HPLC法测定柴达木枸杞中17种氨基酸的含量,并分析不同产地、不同采摘期柴达木枸杞中氨基酸的含量。以2,4-二硝基氟苯为衍生试剂,色谱柱为Gemini-NX C18,流动相A:0.05 mol·L-1的乙酸钠溶液(p H=6.4,含有1‰N,N-二甲基甲酰胺),流动相B:乙腈-水溶液(1∶1,v/v),采用梯度洗脱,检测波长360 nm。17种氨基酸的线性关系、精密度、稳定性、重复性良好,加样回收率为90.28%102.85%(RSD为1.02%4.76%);不同产地、不同采摘期的柴达木枸杞中氨基酸种类相同,但含量存在一定差异,产于德令哈的枸杞氨基酸平均含量最高,10月采摘的枸杞氨基酸总含量高于8月和9月,总量为6.217%8.987%,必需氨基酸占总氨基酸比例为14.307%19.572%,药用氨基酸占总氨基酸比例为63.632%71.409%,增香氨基酸占总氨基酸比例为12.121%17.356%。该方法简单、快捷,可测定柴达木枸杞中氨基酸的含量;不同产地、不同采摘期柴达木枸杞氨基酸含量的差异可能是由土壤环境、气象条件等因素所导致;在枸杞开发利用中可以根据不同的需求选择不同产地和采摘期的枸杞。Abstract: To establish a pre-column derivatization and reversed-phase high performance liquid chromatography( RP-HPLC)for the determination amino acids in Qaidam Chinese wolfberry. Contents of amino acids in Qaidam Chinese wolfberry from different habitats and different picking period were analyzed.2,4-dinitrofluorobenzene( DNFB) was the pre-column derivating reagent.The samples were analyzed on a Gemini-NX C18 column with gradient elution of 0.05 mol·L~(-1)sodium acetate solution( adjusted to p H6.4)(A) and 50% ACN(B).The detected wavelength was 360 nm.HPLC method was adopted and external method was used for calculating the content of sample. The linear ranges,precision,stability and repeatability were good.Recovery and RSD of the method were 90.28% ~102.85% and 1.02% ~4.76% respectively.There were the same kind of amino acids,but there were a certain differences in the content in Qaidam Chinese wolfberry from different habitats and different picking period,the average contents of amino acids was the highest in Qaidam Chinese wolfberry from Delingha,the total content of amino acids in Qaidam Chinese wolfberry in October was higher than others,the total content of amino acids was6.217% ~8.987%,the ratio of essential amino acids was 14.307% ~ 19.527%,the ratio of medicinal amino acids was63.632% ~71.409%,the ratio of flavor amino acids was 12.121% ~ 17.356%. The method was very accurate,sensitive and reliable to determine the contents of amino acids in Qaidam Chinese wolfberry. Differences of amino acids in Qaidam Chinese wolfberry from different habitats and different picking period may be caused by environmental factors,weather conditions,etc.In the process of development and utilization of Chinese wolfberry,we should choose the right.