This study demonstrates a newly developed PDMS/DVB/PDMS fiber's suitability for the determination of pesticides in soy milk via direct-immersion solid-phase microextraction (SPME) combined with gas chromatography-mass spectrometry, eliminating the need for extensive sample pre-treatment procedures. Fouling accumulation on the coating surface was further minimized by implementing rapid and effective pre- and post-desorption cleaning steps. Under optimum conditions, the fiber was used to perform over 120 extractions while maintaining RSD values of less than 24.5% for 10 extracted pesticides. By comparison, the RSD values ranged from 8.4% to 42.8% over 80 extractions using a commercial PDMS/DVB fiber. The optimized conditions were used to fully validate a quantitative method for the targeted analytes by matrix-matched calibration and isotopically labeled internal standard correction. Significantly, the proposed method was able to achieve limits of quantitation (1-2.5 μg/kg) for the targeted analytes that were below the Maximum Residue Levels mandated for soy-based products. Accuracy, intra- and inter-day repeatability were also satisfactory. The proposed PDMS/DVB/PDMS fiber dramatically improved repeatability and suitability for direct-immersion SPME in soy milk, and represents a good alternative to other extraction methods for high-throughput quantitative analysis of pesticide residues in soy-based products.

中文翻译：

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通过与基质相容的涂层，将SPME直接浸入豆浆中以进行痕量农药分析。

这项研究证明了新开发的PDMS / DVB / PDMS纤维适用于通过直接浸入固相微萃取（SPME）结合气相色谱-质谱法测定豆浆中的农药，从而无需进行大量的样品预处理程序。通过执行快速有效的脱附前和脱附后清洁步骤，可进一步减少涂层表面的积垢。在最佳条件下，该纤维用于进行120多次萃取，同时对10种萃取农药的RSD值保持小于24.5％。相比之下，使用商用PDMS / DVB纤维进行的80次萃取，RSD值在8.4％至42.8％之间。优化的条件用于通过基质匹配校准和同位素标记的内标校正来完全验证目标分析物的定量方法。重要的是，对于目标分析物，所提出的方法能够达到定量极限（1-2.5μg/ kg），该极限低于基于大豆的产品所规定的最大残留水平。准确性，日内和日间重复性也令人满意。提出的PDMS / DVB / PDMS纤维显着提高了SPME直接浸入豆浆的可重复性和适用性，并且是其他提取方法的良好替代品，可用于对大豆类产品中的农药残留进行高通量定量分析。5 g / kg）的目标分析物低于大豆产品规定的最大残留量水平。准确性，日内和日间重复性也令人满意。提出的PDMS / DVB / PDMS纤维显着提高了SPME直接浸入豆浆的可重复性和适用性，并且是其他提取方法的良好替代品，可用于对大豆类产品中的农药残留进行高通量定量分析。5 g / kg）的目标分析物低于大豆产品规定的最大残留量水平。准确性，日内和日间重复性也令人满意。提出的PDMS / DVB / PDMS纤维显着提高了SPME直接浸入豆浆的可重复性和适用性，并且是其他提取方法的良好替代品，可用于对大豆类产品中的农药残留进行高通量定量分析。