QuEChERS技术结合超高效液相-串联质谱同时测定薄皮甜瓜中7 种葫芦素

采用改良的QuEChERS方法，建立同时测定甜瓜中7 种葫芦素的超高效液相色谱-串联质谱检测方法。样品用乙腈提取，离心后取1 mL上清液经50 mg乙二胺-N-丙基硅烷和50 mg十八烷基硅烷净化，使用XBridge C18色谱柱分离，以乙腈和0.1%甲酸加5 mmol/L乙酸铵溶液为流动相进行梯度洗脱，采用电喷雾离子源电离，正/负离子快速切换多反应监测模式进行分析。在此条件下，7 种葫芦素在16 min内得到较好分离，在0.1～1 500 μg/L质量浓度范围内线性关系良好，相关系数均大于0.99；进行3 个水平添加实验（n=5），7 种葫芦素在20、100 μg/kg和500.0 μg/kg三个添加水平下的回收率在75.7%～118.3%之间，相对标准偏差在0.5%～13.6%之间，该方法的检出限及定量限分别为0.16～4.33 μg/kg和0.27～13.11 μg/kg。该方法简便、灵敏度高、分析时间短，精密度和准确性良好，可用于甜瓜中7 种葫芦素的同时检测。

Simultaneous Determination of Seven Cucurbitacins in Oriental Melon by QuEChERS Method Coupled with Ultra-high Performance Liquid Chromatography-Tandem Mass Spectrometry

A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) pretreatment method combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of seven cucurbitacins in oriental melon. The samples were extracted with acetonitrile. After centrifugation, 1 mL of the supernatant was cleaned up with 50 mg of primary secondary amine (PSA) and 50 mg of octadecylsilane (C18). The separation was performed on a Waters XBridge C18 column with gradient elution using acetonitrile as mobile phase A and 0.1% formic acid in 5 mmol/L ammonium acetate aqueous solution as mobile phase B. The detection was accomplished by multiple-reaction monitoring scanning in a positive/negative ion-switching electrospray ionization mode. The cucurbitacin compounds were separated within 16 min. Good linearity was achieved for all analytes in the concentration range of 0.1–1 500 μg/L with correlation coefficients greater than 0.99. The recoveries at spiked levels of 20.0, 100.0 and 500.0 μg/kg were between 75.7% and 118.3%, and the precision, expressed as relative standard deviation (RSD), ranged between 0.5% and 13.6%. The limits of detection (LOD) were between 0.16 and 4.33 μg/kg, and the limits of quantitation (LOQ) were between 0.27 and 13.11 μg/kg. We concluded that this method has the advantages of simple pretreatment, high sensitivity, precision and accuracy, and short analysis time, and is suitable for simultaneous determination of the seven cucurbitacins in oriental melon.