1. 非衍生化分散固相萃取结合液相色谱-串联质谱测定 茶叶和花椒中草铵膦、草甘膦及其代谢物残留.
- Author
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郑云华, 杨巧慧, 蒋文隆, 潘灿平, 张 宇, 白春蓉, and 曾 艳
- Abstract
An analytical method without the need for derivatization was established in this study, employing dispersive solid-phase extraction (d-SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the direct determination of residues of glufosinate, glyphosate and their metabolites (NAG, MPPA, AMPA) in tea and Zanthoxylum bungeanum. After extraction with 10 mL of deionized water and 10 mL of 1% formic acid-methanol solution, samples were processed using d-SPE with composite multi-walled carbon nanotubes (C-MWCNTs) as the core purification material to enhance the separation efficiency between the target compounds and the matrix and to reduce matrix interference. Finally, detection of five target compounds was achieved using LC-MS/MS. The mobile phases were water with 0.7% formic acid and acetonitrile with 0.7% formic acid. The separation was performed on an anionic polar column (5 μm, 2.1 mm × 100 mm) at 40 ℃. The final extracts were detected using the dynamic multiple reaction monitoring (dMRM) method in negative mode and were quantified using external matrix-matched calibration curves. The results showed that the five analytes had sharp peak shapes and good separation under the instrument conditions, and the linearity was good in the range of 0.01-2 μg/mL. The coefficients of determination (R²) were higher than 0.9987 and 0.9992 for tea and Z. bungeanum, respectively. The limits of quantification (LOQ) of the five compounds in tea and Z.bungeanum were 0.03-0.10 mg/kg and 0.03-0.16 mg/kg, respectively. At three spiked levels of 0.25, 0.50 and 1.0 mg/kg, the average recoveries of glufosinate, glyphosate and their metabolites in tea (Tibetan tea) ranged from 61% to 105% with relative standard deviations (RSD) from 0.22% to 13%, and were 78%-115% in Z. bungeanum (red Z. bungeanum) with RSD of 0.12%-7.5%. The sample preparation process of this method does not require derivatization, the cleanup steps are simple, the instrumental running time is short, and the recoveries and precision met the requirements of method validation. It is suitable for the rapid determination of glufosinate, glyphosate and their metabolites (NAG, MPPA, AMPA) in large quantities of tea and Z. bungeanum. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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