芜青中有机酸成分的GC-MS分析及含量测定研究

GC-MS Analysis and Content Determination of Organic Acids in Brassica rapa

目的:定性和定量分析芜青的有机酸成分。方法:以硫酸-甲醇溶液柱前直接甲酯化芜青,由二氯甲烷萃取衍生物。定性分析采用GC-MS,使用HP-5MS(30 m×0.25 mm×0.5μm)色谱柱,进样温度230℃,程序升温,离子源温度230℃,采集范围m/z 50～550。定量分析采用气相色谱法,使用DB-WAX(30 m×0.25 mm×0.5μm)色谱柱。结果:经NIST 2014标准谱库检索,检测到芜青含有乙酰丙酸、丁二酸、十六酸等21种有机酸,以面积归一化含量超过4%的有机酸进行定量分析,方法学考察结果显示符合含量测定要求,乙酰丙酸、丁二酸、十六酸、柠檬酸、亚麻酸、油酸、亚油酸分别在0.0199～0.9976 mg/mL、0.0200～0.9986 mg/mL、0.0200～1.0016 mg/mL、0.0200～0.9984 mg/mL、0.0401～2.0044 mg/mL、0.0198～0.9920 mg/mL、0.0600～3.0024 mg/mL范围内呈良好的线性关系,相关系数均大于0.9995,加样回收率在97.27%～103.54%之间,且RSD均小于3%。结论:该方法简便易行、具有可操作性,可用于芫根中有机酸成分的检测。

Objective:To establish the method of qualitative and quantitative analyse of organic acids in Brassica rapa.Methods:Brassica rapa were direct methylation with sulfuric acid methanol solution,and extracted by dichloromethane.GC-MS was used to qualitative analysis,chromatography column was HP-5 MS(30 m×0.25 mm×0.5 μm),the sample temperature was 230 ℃,and temperature programming,ionization mode was electron bombardment ion source with 230 ℃,collection scope was m/z 50~550.Gas chromatography was used to quantitative analysis,chromatography column was DB-WAX(30 m×0.25 mm×0.5 μm).Results:Through NIST 2014 standard spectrum library retrieval,twenty-one organic acids were detected.The organic acids were quantitatively analyzed with the area normalization content exceeding 4%,the results of methodological investigation showed that it met the requirement of content determination.Laevulinic acid,succinic acid,hexadecylic acid,citric acid,linolenic acid,oleic acid and linoleic acid had a good linearities in range of 0.0199~0.9976 mg/mL,0.0200~0.9986 mg/mL,0.0200~1.0016 mg/mL,0.0200~0.9984 mg/mL,0.0401~2.0044 mg/mL,0.0198~0.9920 mg/mL,0.0600~3.0024 mg/mL,respectively,and r>0.9995.The average recoveries were 97.27%~103.54%,and RSD<3%.Conclusion:The method is simple and operatable,and can be used for the detection of organic acids in Brassica rapa.