高效毛细管电泳法测定酱油中5′-单磷酸核苷酸

Determination of 5′-Monophosphate Nucleotides in Soy Sauce by High Performance Capillary Electrophoresis

建立高效毛细管电泳同时分离测定酱油中两种核苷酸鸟嘌呤-5′-单磷酸(GMP)和次黄嘌呤-5′-单磷酸(IMP)的方法。电泳条件:以50μm×60.2cm(有效长度50cm)未涂敷石英毛细管为分离柱,30mmol/L硼砂+30mmol/L碳酸钠+60mmol/L羟丙基-β-环糊精为分离缓冲溶液,50mmol/L醋酸溶液为样品介质,检测波长为254nm。GMP及IMP的校正峰面积与质量浓度在5～100mg/L范围内具有良好线性关系,线性相关系数分别为0.9998和0.9997,检出限均为2mg/L,定量限均为5mg/L。用该法测定了9种酱油,并与文献报道的高效液相色谱法的结果进行比较,结果满意。

A new method was established for the simultaneous determination of two 5′-mononucleotides（guanosine monophosphate,GMP;inosine monophosphate,IMP） within one run in soy sauce by high performance capillary electrophoresis.The analysis was performed using an uncoated capillary（50 μm i.d,total length 60.2 cm,and effective length 50 cm）.The running buffer was composed of 30 mmol/L Na2B4O7,30 mmol/L Na2CO3 and 60 mmol/L hydroxypropyl-beta cyclodextrins.The sample medium was 50 mmol/L acetic acid.The detection wavelength was 254 nm.A good linear relationship between the corrected peak area and concentration in the range of 5—100 mg/L were obtained for GMP and IMP with correlation coefficients（r） of 0.9998 and 0.9997,respectively.For both GMP and IMP,the limit of detection（LODs） was 2 mg/L,and the limit of quantification（LOQs） was 5 mg/L.Totally 9 soy sauces commercialized in Beijing were analyzed,and the results were in good agreement with those obtained by high performance liquid chromatography.