Federal University of Goiás, Samambaia Campus, Chemistry Institute, Avenida Esperança, s/n Campus Universitário, 74690-900 Goiânia, GO, Brazil.
Federal University of Goiás, Samambaia Campus, Chemistry Institute, Avenida Esperança, s/n Campus Universitário, 74690-900 Goiânia, GO, Brazil.
Talanta. 2018 Feb 1;178:507-514. doi: 10.1016/j.talanta.2017.09.080. Epub 2017 Sep 29.
Paper spray ionization (PSI) has some limitations such as low sensitivity and ionization suppression when complex samples are analyzed. The use of sample preparation devices directly coupled to MS can avoid these restrictions. Molecularly imprinted polymers (MIPs) are materials widely used as adsorbent in sample preparation methods such as solid-phase extraction and solid-phase microextraction, and they can provide specifics cavities with affinity to a target molecule. Here, we introduce a new MIP membrane spray ionization method combining MIP and PSI. MIP was synthesized directly on a cellulose membrane. Monuron and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) were used as template molecules in MIP synthesis for diuron and 2,4-D (2,4-dichlorophenoxyacetic acid) analyte sequesters, respectively. Apple, banana and grape methanolic extracts were used as matrices. The MIP membrane spray showed signal intensities of diuron and 2,4-D that were much higher compared to those obtained by non-imprinted polymers(NIP). Calibration curves exhibited R > 0.99 for diuron and 2,4-D in all fruit extracts analyzed. LODs were found less than 0.60µgL and LLOQs were found less than 2.00µgL. The coefficients of variation and relative errors were less than 15% for almost all analyses. The apparent recovery test results ranged between 92,5% and 116.9%. Finally, the MIP membrane spray method was employed for the quantification of diuron and 2,4-D in real samples. Diuron contents were only found in three bananas (4.0, 6.5, and 9.9µgL). The proposed MIP membrane spray ionization method was straightforward, fast to carry out and provided satisfactory results for analyses of diuron and 2,4-D in apple, banana and grape samples.
纸喷雾电离 (PSI) 在分析复杂样品时存在灵敏度低和电离抑制等局限性。使用直接与 MS 耦合的样品制备装置可以避免这些限制。分子印迹聚合物 (MIP) 是一种广泛用作固相萃取和固相微萃取等样品制备方法中吸附剂的材料，它可以提供具有与靶分子亲和力的特定空腔。在这里，我们介绍了一种将 MIP 和 PSI 结合的新的 MIP 膜喷雾电离方法。MIP 直接在纤维素膜上合成。在 MIP 合成中，使用 monuron 和 2,4,5-T（2,4,5-三氯苯氧基乙酸）作为模板分子，分别用于对 diuron 和 2,4-D（2,4-二氯苯氧基乙酸）分析物的螯合。苹果、香蕉和葡萄甲醇提取物用作基质。与非印迹聚合物 (NIP) 相比，MIP 膜喷雾显示出更高的 diuron 和 2,4-D 信号强度。在所有分析的水果提取物中，diuron 和 2,4-D 的校准曲线均表现出 R > 0.99。在所有分析中，LOD 均小于 0.60µgL，LLOQ 均小于 2.00µgL。对于几乎所有分析，变异系数和相对误差均小于 15%。表观回收率测试结果在 92.5%至 116.9%之间。最后，将 MIP 膜喷雾方法用于实际样品中 diuron 和 2,4-D 的定量。仅在三个香蕉中发现了 diuron 含量（4.0、6.5 和 9.9µgL）。所提出的 MIP 膜喷雾电离方法简单、快速，为苹果、香蕉和葡萄样品中 diuron 和 2,4-D 的分析提供了令人满意的结果。
