Newer and safer agrochemicals are always in demand to meet the increasing needs of a growing population for affordable food. Spatial chemical monitoring of the active mobility of an agrochemical is essential to this agrochemical development process and mass spectrometry imaging (MSI) is proposed as a safer, easier alternative to the existing standard of autoradiography for the same. With desorption electrospray ionisation mass spectrometry imaging (DESI MSI) using leaf imprints, we were able to visualize the active agrochemical mobility of a commercial fungicide formulation with the active ingredient Azoxystrobin in whole tomato leaves. The leaf-imprinting method was optimized with precise control over the pressure conditions and time of imprinting to yield highly consistent samples for imaging. The reproducibility of this method was tested with the Azoxystrobin formulation applied to tomato leaves and was compared to the mobility of the unformulated Azoxystrobin standard in similar application conditions. The xylem mobility and the lateral-leaf lamina spreading of the fungicide were visualized with mass spectrometry imaging and validated using complementary LC-MS studies. The necessity and importance of the agrochemical application as a formulation were re-iterated by the limited mobility observed in Azoxystrobin standard studies compared to the Azoxystrobin formulation. This mass spectrometry imprint-imaging method could be translated for the visualization of any xenobiotic in further foliar systems particularly with soft leaves.

中文翻译：

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通过解吸电喷雾电离质谱成像可视化番茄叶片中活性杀菌剂制剂的迁移率


为了满足不断增长的人口对负担得起的食品日益增长的需求，更新、更安全的农用化学品始终供不应求。对农用化学品的主动迁移率进行空间化学监测对于这种农用化学品开发过程至关重要，质谱成像 （MSI） 被认为是一种更安全、更容易替代现有放射自显影标准的方法。通过使用叶片印记的解吸电喷雾电离质谱成像 （DESI MSI），我们能够可视化整个番茄叶片中含有活性成分嘧菌酯的商业杀菌剂配方的活性农用化学品迁移率。叶子印迹方法经过优化，精确控制压力条件和印迹时间，以产生高度一致的成像样品。使用施用于番茄叶片的嘧菌酯制剂测试该方法的重现性，并与未配制的嘧菌酯标准品在类似应用条件下的迁移率进行比较。使用质谱成像观察杀菌剂的木质部迁移性和侧叶层铺展，并使用互补的 LC-MS 研究进行验证。与嘧菌酯制剂相比，在嘧菌酯标准研究中观察到的有限流动性再次重申了农用化学品作为制剂的必要性和重要性。这种质谱印记成像方法可以转化为进一步叶面系统中任何外源性生物的可视化，特别是软叶。