在无需样品预处理的前提下,采用牙签电喷雾电离质谱(wooden-tip ESI-MS)法对脐橙果汁成分进行快速检测。结果表明:在正离子模式下,检测到的主要成分为胆碱、蔗糖、葡萄糖、脯氨酸、正壬醇等,其中胆碱和脯氨酸产生[M+H]+信号,蔗糖和葡萄糖产生[M+K]+信号;在负离子模式下,检测到的主要成分是脂肪酸、酚酸、羟基酸等有机酸。同时,对抗坏血酸进行了半定量测定,方法检出限为3.7μg/L,相对标准偏差为7.4%~9.7%,单次检测时间小于0.5min。该方法无需样品预处理、操作简便、检出限低、分析速度快,有望成为农产品品质分析的一种新方法。
The chemical components of navel orange juice were analyzed by wooden-tip electrospray ionizaion mass spectrometry(wooden-tip ESI-MS)without any sample pretreatment.The results show that signals of choline,proline,glucose and sucrose are rapidly obtained in positive ion detection mode.Among them,choline and proline give a signal of[M+H]+,and glucose and sucrose produce a signal of[M+K]+.While in negative ion detection mode,organic acids including fatty acid,phenolic acids and hydroxyl acids are readily detected.Meanwhile,wooden-tip ESI-MS is developed for semi-quantification determination of ascorbic acid in navel orange juice.The limit of detection(LOD)is 3.7μg/L,the relative standard deviations(RSD)are 7.4%-9.7%,and the analytical time of each detection is less than 0.5min.Wooden-tip ESI-MS hasthe advantages of minor or no sample pretreatment,convenient operation,sensitivity and high analytical speed,which will being an attractive method to rapidly screen the quality of agricultural products.