超高效液相色谱-串联质谱法测定荔枝中乙烯利残留量

Determination of ethephon residues in Litchi chinensis by ultra performance liquid chromatography-tandem mass spectrometry

中文关键词:  荔枝  乙烯利  残留  超高效液相色谱-串联质谱法

英文关键词:Litchi chinensis  ethephon  residue  ultra performance liquid chromatography-tandem mass spectrometry

中文摘要:

      目的 建立超高效液相色谱-串联质谱法测定荔枝中乙烯利残留量的方法。方法 采用正离子模式(positive electrospray ionization mode, ESI+)检测乙烯利, 通过系统优化质谱参数, 确定了稳定的氯同位素离子对(145.0>91.2和147.0>81.2), 并结合基质匹配外标法进行定量, 以消除基质效应。样品经含0.1%甲酸的20%甲醇-水溶液提取, 上清液经C18、石墨化炭黑吸附净化后进行分析。结果 乙烯利在0.005~1.000 mg/L范围内线性良好(r≥0.9996)。在0.05、0.50和2.00 mg/kg添加水平下, 荔枝果肉和荔枝全果中的平均回收率为70.6%~89.6%, 相对标准偏差为1.1%~8.7%, 定量限为0.05 mg/kg。结论 本研究实现了ESI+模式下乙烯利的高灵敏度检测, 通过氯同位素离子对和特征碎片的双重验证, 显著提升了方法的抗干扰能力。该方法前处理简便、准确度高, 为荔枝质量安全监管提供了可靠技术支撑。

英文摘要:

      Objective To establish a method for the determination of ethephon residues in Litchi chinensis by ultra performance liquid chromatography-tandem mass spectrometry. Methods The analysis was performed in the positive electrospray ionization mode (ESI+). Stable chlorine isotope ion pairs (145.0>91.2 and 147.0>81.2) were selected through systematic optimization of mass spectrometry parameters, combined with matrix-matched external standard calibration to eliminate matrix effects. Samples were extracted with 20% methanol-water containing 0.1% formic acid and purified with C18 and graphitized carbon black before analysis. Results Ethephon exhibited good linearity in the range of 0.005–1.000 mg/L (r≥0.9996). At spiked levels of 0.05, 0.50 and 2.00 mg/kg, the average recoveries for Litchi chinensis pulp and whole fruit ranged from 70.6% to 89.6%, with relative standard deviations of 1.1%–8.7%. The limit of quantitation was 0.05 mg/kg. Conclusion This study achieves high-sensitivity detection of ethephon in ESI+ mode, significantly improving anti-interference capability through dual verification using chlorine isotope ion pairs and characteristic fragments. The method features simple sample preparation and high accuracy, providing reliable technical support for Litchi chinensis quality and safety monitoring.