牙签电喷雾电离质谱分析脐橙果汁成分

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3.7 μg/L，相对标准偏差为7.4%~9.7%，单次检测时间小于0.5 min。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。

Analysis of Navel Orange Juice Components by Wooden-Tip Electrospray Mass Spectrometry

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 3.7 μg/L, the relative standard deviations (RSD) are 7.4%-9.7%, and the analytical time of each detection is less than 0.5 min. Wooden-tip ESI-MS has the 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.