气相色谱-串联质谱法测定百色芒果中乙烯利残留量

Determination of Residual Ethephon in Baise Mango by Gas Chromatography-Tandem Mass Spectrometry

目的通过气相色谱-串联质谱法建立测定百色芒果中乙烯利残留量的检测方法。方法对提取试剂、pH值和衍生试剂、衍生剂用量、衍生时间等因素进行优化。在最优条件下,采用三重-四级杆气相色谱-串联质谱仪检测芒果中乙烯利残留量,同时对检测方法进行可靠性评价。结果最优提取条件为甲醇提取,调节pH值为3,最佳衍生条件为(三甲基硅烷基)重氮甲烷作为衍生剂,加入量0.8 ml,反应5 min。峰面积与乙烯利浓度有良好的线性关系,线性方程为Y=317481.36X+9763.62,r=0.9998,检出限为0.003 mg/kg,定量限为0.009 mg/kg,平均回收率范围为90%~99%。百色13个地区芒果仅有5份样品检测到了乙烯利残留量,且残留量均低于0.01 mg/kg。结论通过稳定性、重复性、加样回收和精密度试验以及芒果样品的测定结果表明,该方法测定结果准确、易操作,可进行芒果中乙烯利残留定量分析。

Objective To establish a method for determination of ethephon residues in mango from Baise by gas chromatography-tandem mass spectrometry.Methods The factors including extraction reagent,pH value,derivative agent,derivative agent dosage and derivatization time were optimized.Under the optimal conditions,ethephon residues in mango were determined by triple-quadrupole gas chromatography-tandem mass spectrometry,and the reliability of the method was evaluated.Results The optimal extraction conditions were as follows:methanol was used as extraction reagent,and the pH value was adjusted to 3,and the optimal derivatization conditions were as follows:trimethylsilyl diazomethane was used as derivative agent with dosage of 0.8 ml,and the reaction time was 5 min.The linear equation was Y=317481.36X+9763.62,r=0.9998.The detection limit was 0.003 mg/kg,the quantitative limit was 0.009 mg/kg,and the average recovery was 90%-99%.Ethephon residues were detected in only 5 mango samples from 13 regions of Baise,and the residues were all less than 0.01 mg/kg.Conclusion The results of stability,repeatability,recovery and precision test and mango sample determination show that the method is accurate and easy to operate,and can be used in the quantitative analysis on ethephon residues in mango.