Jiménez-López J, Ortega-Barrales P, Ruiz-Medina A
Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus de las Lagunillas, E-23071 Jaén, Spain.
Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus de las Lagunillas, E-23071 Jaén, Spain.
Talanta. 2016;149:149-155. doi: 10.1016/j.talanta.2015.11.048. Epub 2015 Dec 1.
The determination of thiamethoxam (TMX), a widely known neonicotinoid pesticide, by a multicommutated optosensing device implemented with photochemically induced fluorescence (PIF) has been developed. The combination of both methodologies allows, on one hand a quick on-line photodegradation of TMX and, on the other hand, the preconcentration, quantification and desorption of the fluorescent photoproduct generated once retained on C18 silica gel filling the flow-cell which was monitored at 353 and 407nm for excitation and emission wavelengths, respectively. The proposed analytical method presents a detection limit of 3.6ngmL(-1) by using Multicommutated Flow Injection Analysis (MCFIA) as flow methodology. Recovery experiments have been carried out in different kinds of vegetables at levels same or below the legislated maximum residue limit, demonstrating that this method combines advantages such as simplicity, high sensibility and high selectivity, in addition to fulfill the requirements for its applications in quality control. The obtained results in the analysis of real samples were in good agreement with those provided by a reference liquid chromatography (HPLC) method.
一种基于光化学诱导荧光（PIF）的多通道光传感装置用于测定广为人知的新烟碱类农药噻虫嗪（TMX）的方法已被开发出来。这两种方法的结合，一方面能使TMX快速在线光降解，另一方面能对保留在填充流通池的C18硅胶上后产生的荧光光产物进行预浓缩、定量和解吸，激发波长和发射波长分别在353nm和407nm处进行监测。所提出的分析方法采用多通道流动注射分析（MCFIA）作为流动方法，检测限为3.6ngmL(-1)。已在不同种类蔬菜中进行了回收率实验，浓度水平等于或低于法定最大残留限量，结果表明该方法除满足其在质量控制中的应用要求外，还兼具简单、高灵敏度和高选择性等优点。实际样品分析所得结果与参考液相色谱（HPLC）方法提供的结果高度一致。
