Aguilar-Vázquez L, Aguilar-Caballos M P, Gómez-Hens A
Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Campus of Rabanales, Annex to Marie Curie Building, University of Cordoba, 14071 Córdoba, Spain.
Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Campus of Rabanales, Annex to Marie Curie Building, University of Cordoba, 14071 Córdoba, Spain.
Talanta. 2014 Feb;119:111-5. doi: 10.1016/j.talanta.2013.10.036. Epub 2013 Oct 22.
The usefulness of europium oxide nanoparticles (Eu2O3 NPs) as analytical reagent for the direct determination of organic compounds is described for the first time. Tetracycline, which forms a luminescent chelate with europium, has been chosen as a model analyte. Dry reagent chemistry is used in a 96-well format, which considerably speeds up the determination and contributes to its automation. The NPs are immobilized onto polystyrene wells by adding a volume of a Eu2O3 NP dispersion in 2-propanol to each well and drying in an oven until they dry completely. At the moment of analysis, a standard or sample volume (200 μL) in the appropriate medium is added, and the mixture shaken for 15 min at 37°C. The method allows the determination of tetracycline in the range 20-1000 ng mL(-1), with a detection limit of 8 ng mL(-1). The inter-assay and intra-assay precision, which were assayed at two different tetracycline concentrations and expressed as relative standard deviation, were in the ranges of 6.5-8.2% and 9.2-12.7%, respectively. The study of the selectivity of the system showed that the method is adequate for tetracycline determination in agri-food samples, since most of antibiotics assayed did not interfere the determination. Only other tetracycline antibiotics provided luminescent signal when reacting to Eu2O3 NPs. The method has been applied to the determination of tetracycline in calf urine and in honey samples obtaining recovery values in the ranges of 85.0-110.0% and 99.7-116.7%, respectively.
首次描述了氧化铕纳米颗粒（Eu2O3 NPs）作为直接测定有机化合物的分析试剂的用途。已选择与铕形成发光螯合物的四环素作为模型分析物。干试剂化学用于96孔板形式，这大大加快了测定速度并有助于实现自动化。通过向每个孔中加入一定体积的Eu2O3 NP在2-丙醇中的分散液并在烘箱中干燥直至完全干燥，将纳米颗粒固定在聚苯乙烯孔上。在分析时，加入适当介质中的标准品或样品体积（200μL），并将混合物在37℃下振荡15分钟。该方法可测定20 - 1000 ng mL(-1)范围内的四环素，检测限为8 ng mL(-1)。在两种不同四环素浓度下测定的批间和批内精密度，以相对标准偏差表示，分别在6.5 - 8.2%和9.2 - 12.7%范围内。该系统选择性的研究表明，该方法适用于农业食品样品中四环素的测定，因为所检测的大多数抗生素不干扰测定。只有其他四环素类抗生素在与Eu2O3 NPs反应时会产生发光信号。该方法已应用于小牛尿液和蜂蜜样品中四环素的测定，回收率分别在85.0 - 110.0%和99.7 - 116.7%范围内。
