Martinez-Haro Monica, Chinchilla José Manuel, Camarero Pablo R, Viñuelas Jose Alberto, Crespo María Jesús, Mateo Rafael
Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal de Castilla La Mancha (IRIAF), CIAG del Chaparrillo, Ciudad Real, Spain.
Instituto de Investigación en Recursos Cinegéticos (IREC - CSIC, UCLM, JCCM), Ciudad Real, Spain.
Sci Total Environ. 2022 Jun 1;823:153677. doi: 10.1016/j.scitotenv.2022.153677. Epub 2022 Feb 3.
Glyphosate is the most used herbicide worldwide. It is a small and highly polar pesticide whose physicochemical properties makes its analytical determination difficult. Here, a procedure based on liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS) was developed for glyphosate determination in samples of gastric content from wildlife. Iberian hare (Lepus granatensis), a herbivorous mammal species, strongly associated to agrosystems was selected as model species. The procedure involves direct analysis of sample without derivatization or instead of neither further cleaning steps. The procedure was validated by inter-day accuracy and precision studies with gastric content of hare spiked with glyphosate at ecologically relevant concentrations for the species (0.1-6 μg/g), and with 1 μg/g of isotopically labelled internal standard (glyphosate-2-C,N). Finally, glyphosate residues in hunted animals from pesticide-treated and pesticide-free areas (n = 75 and 28, respectively), as well as from hares found dead in the field (n = 11) were analysed. The linearity of both standards in extraction solutions and procedural calibration curves with spiked samples was similar, both with determination coefficients (r) higher than 0.99. Satisfactory recoveries in spiked samples were achieved within the range of 95% to 118% (CV ≤ 20%). The limit of detection of glyphosate in hare gastric content was 0.03 μg/g. Prevalence of glyphosate in hunted animals from pesticide-treated areas ranged between 9 and 22%, increasing to 45% in animals found dead. The glyphosate concentrations detected in the gastric content of hares ranged from 0.11 to 16 μg/g. No residues were detected in animals from pesticide-free areas. In practice, the developed methodology may be particularly useful in the context of research and other work on the exposure in wildlife of one of the most used pesticides nowadays.
草甘膦是全球使用最广泛的除草剂。它是一种体积小且极性很强的农药，其物理化学性质使其分析测定具有难度。在此，开发了一种基于液相色谱 - 高分辨率串联质谱法（LC - HRMS/MS）的方法，用于测定野生动物胃内容物样本中的草甘膦。伊比利亚野兔（Lepus granatensis），一种与农业系统密切相关的草食性哺乳动物物种，被选为模型物种。该方法涉及对样品进行直接分析，无需衍生化，也无需进一步的净化步骤。通过日间准确度和精密度研究对该方法进行了验证，研究对象为添加了该物种生态相关浓度（0.1 - 6μg/g）草甘膦的野兔胃内容物，以及添加了1μg/g同位素标记内标（草甘膦 - 2 - C，N）的样本。最后，分析了来自农药处理区和无农药区的狩猎动物（分别为n = 75和28）以及在野外发现死亡的野兔（n = 11）中的草甘膦残留。提取溶液中两种标准品以及加标样品的程序校准曲线的线性相似，测定系数（r）均高于0.99。加标样品的回收率在95%至118%范围内（CV≤20%），令人满意。野兔胃内容物中草甘膦的检测限为0.03μg/g。来自农药处理区的狩猎动物中草甘膦的检出率在9%至22%之间，在死亡动物中增至45%。野兔胃内容物中检测到的草甘膦浓度范围为0.11至16μg/g。在无农药区的动物中未检测到残留。实际上，所开发的方法在当今最常用农药之一对野生动物暴露的研究及其他工作中可能特别有用。
