凝胶净化-高效液相色谱法测定霉变甘蔗中3-硝基丙酸

目的建立凝胶净化-高效液相色谱法测定霉变甘蔗中3-硝基丙酸(3-nitropropionic acid,3-NPA)的方法。方法样品利用乙腈涡旋震荡提取,提取液经凝胶渗透色谱净化后,用高效液相色谱法进行测定。色谱柱为Agilent Eclipse plus C₁₈柱(4.6 mm×150 mm,5μm),柱温40℃,进样体积10μL,流动相为A:0.02 mol/L的KH_2PO_4水溶液(以磷酸调pH 3.0),B:乙腈,等度洗脱。结果方法线性范围为0.5～20.0 mg/kg,相关系数为0.99989,方法检出限为0.05 mg/kg,定量限为0.15 mg/kg,不同浓度水平的加标回收率为91.7%～99.4%,精密度为7.23%～8.62%(n=6)。结论该方法稳定准确,适用于霉变甘蔗中3-硝基丙酸的检测。

Determination of 3-nitropropionic acid in moldy sugarcane by gel filtration-high performance liquid chromatography

OBJECTIVE To establish a method for determination of 3-nitropropionic acid(3-NPA)in moldy sugarcane by gel permeation chromatography-high performance liquid chromatography(GPC-HPLC)method.METHODS Samples were extracted by acetonitrile and cleaned up by GPC-HPLC.The sample extract was separated on an Agilent Eclipse plus C18 column(4.6 mm×150 mm,5μm),keeping the column temperature at 40℃with an injection volume of 10μL.The condition of mobile phase was KH2PO4 aqueous solution(0.02 mol/L,pH 3.0 with phosphoric acid)as mobile phase A and acetonitrile as mobile phase B for isocratic elution.RESULTS There was a good linearity of the calibration curve for 3-NPA in the range of 0.5-20.0 mg/kg with the correlation coefficient of 0.99989.The detection limit of the method was 0.05 mg/kg,and the limit of quantification was 0.15 mg/kg.The average recovery at three spiked levels was in the range of 91.7%-99.4%,and the relative standard deviation was 7.23%-8.62%(n=6).CONCLUSION This method is stable and accurate,and is suitable for the detection of 3-nitropropionic acid in sugarcane.