In this study, we developed and validated a CE-TOF-MS method for the quantification of glyphosate (N-(phosphonomethyl)glycine) and its major degradation product aminomethylphosphonic acid (AMPA) in different samples including beer, media from toxicological analysis with Daphnia magna, and sorption experiments. Using a background electrolyte (BGE) of very low pH, where glyphosate is still negatively charged but many matrix components become neutral or protonated, a very high separation selectivity was reached. The presence of inorganic salts in the sample was advantageous with regard to preconcentration via transient isotachophoresis. The advantages of our new method are the following: no derivatization is needed, high separation selectivity and thus matrix tolerance, speed of analysis, limits of detection suitable for many applications in food and environmental science, negligible disturbance by metal chelation. LODs for glyphosate were < 5 μg/L for both aqueous and beer samples, the linear range in aqueous samples was 5–3000 μg/L, for beer samples 10–3000 μg/L. For AMPA, LODs were 3.3 and 30.6 μg/L, and the linear range 10–3000 μg/L and 50–3000 μg/L, for aqueous and beer samples, respectively. Recoveries in beer samples for glyphosate were 94.3–110.7% and for AMPA 80.2–100.4%. We analyzed 12 German and 2 Danish beer samples. Quantification of glyphosate and AMPA was possible using isotopically labeled standards without enrichment, purification, or dilution, only degassing and filtration were required for sample preparation. Finally, we demonstrate the applicability of the method for other strong acids, relevant in food and environmental sciences such as N-acetyl glyphosate, N-acetyl AMPA (present in some glyphosate resistant crop), trifluoroacetic acid, 2-methyl-4-chlorophenoxyacetic acid, glufosinate and its degradation product 3-(methylphosphinico)propionic acid, oxamic acid, and others.

在这项研究中，我们开发并验证了一种 CE-TOF-MS 方法，用于定量不同样品中的草甘膦（ N- （膦酰甲基）甘氨酸）及其主要降解产物氨甲基膦酸 (AMPA)，包括啤酒、水蚤毒理学分析培养基麦格纳和吸附实验。使用pH值非常低的背景电解质（BGE），其中草甘膦仍然带负电，但许多基质成分变成中性或质子化，达到了非常高的分离选择性。样品中无机盐的存在对于通过瞬时等速电泳进行预浓缩是有利的。我们的新方法的优点如下：无需衍生化，分离选择性高，因此具有基质耐受性，分析速度快，检测限适合食品和环境科学中的许多应用，金属螯合的干扰可忽略不计。水样和啤酒样品中草甘膦的 LOD 均为 < 5 μg/L，水样中的线性范围为 5–3000 μg/L，啤酒样品中的线性范围为 10–3000 μg/L。对于 AMPA，水样和啤酒样品的 LOD 分别为 3.3 和 30.6 μg/L，线性范围分别为 10-3000 μg/L 和 50-3000 μg/L。啤酒样品中草甘膦的回收率为 94.3–110.7%，AMPA 的回收率为 80.2–100.4%。我们分析了 12 个德国啤酒样品和 2 个丹麦啤酒样品。使用同位素标记标准品可以对草甘膦和 AMPA 进行定量，无需富集、纯化或稀释，样品制备仅需要脱气和过滤。 最后，我们证明了该方法对于食品和环境科学相关的其他强酸的适用性，例如N-乙酰基草甘膦、 N-乙酰基 AMPA（存在于一些抗草甘膦作物中）、三氟乙酸、2-甲基-4-氯苯氧基乙酸酸、草铵膦及其降解产物3-(甲基膦)丙酸、草氨酸等。