Spectrochimica Acta Part B: Atomic Spectroscopy ( IF 3.3 ) Pub Date : 2021-07-13 , DOI: 10.1016/j.sab.2021.106253 Ívero P. Sá 1, 2 , Ohana N. Almeida 1 , Daniel De C. Lima 1, 3 , Erik G.P. da Silva 1, 3 , Luana N. Santos 1 , Francisco H.M. Luzardo 1 , Fermin G. Velasco 1 , Mário H. Gonzalez 4 , Fábio A.C. Amorim 1, 3
This work describes an analytical procedure to determination of trace amount of lanthanide and actinide chemistry elements (LAEs) in water samples by energy dispersive x-ray fluorescence spectrometry (EDXRF) with the prepare of the samples using simultaneous preconcentration procedure based on the dispersive liquid-liquid microextraction (DLLME). Critical study of the analytical procedure occurred the following way: ions of Eu, Er, Ho, Th, U and Yb presents in 5.0 mL of aqueous sample have been complexed with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (Br-PADAP) in a mixture contained solvents (disperser and extractant). After centrifugation, 30 μL of the sedimented organic phase has been removed and deposited on membrane disk and submitted to EDXRF analysis. The optimization step was performed by: i) screening factor with mixture design for the disperser solvent (acetone, acetonitrile and ethanol) and extractant solvent (carbon tetrachloride, trichlorethylene and 1,2-dichloroethane); ii) Box-Behnken design for the independents variables: pH, Br-PADAP concentration, volume of disperser solvent and volume of extractant solvent. The optimized conditions were: 500 μL of disperser solvent (ethanol), 60 μL extractant solvent (carbon tetrachloride and trichlorethylene, 1: 1 ratio), Br-PADAP 1.8 × 10−5 mol L−1 and pH 8.0. In these conditions, the procedure allows the determination of Eu, Ho, Er, Yb, Th and U with quantification limits of 10.5; 8.6; 4.3; 7.0; 6.6 and 1.1 μg L−1, respectively; preconcentration factor between 18 and 74, and precision (RSD%) below that 6%. Salting out effect, presence of other ions, and additions/recoveries of analytes in real samples was verified and the recovery values were between of 90 to 107%. Analytical method has been applied in waters samples and groundwater from uranium mining region.
中文翻译:
能量色散 X 射线荧光光谱法 DLLME 预浓缩和干斑法测定镧系元素和锕系元素
本工作描述了一种通过能量色散 X 射线荧光光谱法 (EDXRF) 测定水样中痕量镧系元素和锕系化学元素 (LAE) 的分析程序,并使用基于分散液的同时预浓缩程序制备样品。液体微萃取 (DLLME)。分析程序的关键研究以下列方式进行:存在于 5.0 mL 水样中的 Eu、Er、Ho、Th、U 和 Yb 离子已与 2-(5-bromo-2-pyridylazo)-5-(二乙氨基)-苯酚 (Br-PADAP) 混合物中含有溶剂(分散剂和萃取剂)。离心后,将 30 μL 沉淀的有机相移出并沉积在膜盘上并进行 EDXRF 分析。优化步骤由以下人员执行:i) 分散溶剂(丙酮、乙腈和乙醇)和萃取溶剂(四氯化碳、三氯乙烯和 1,2-二氯乙烷)混合设计的筛选因子;ii ) 自变量的 Box-Behnken 设计:pH、Br-PADAP 浓度、分散剂溶剂的体积和萃取剂溶剂的体积。优化条件为:500 μL分散溶剂(乙醇)、60 μL萃取溶剂(四氯化碳和三氯乙烯,1:1比例)、Br-PADAP 1.8 × 10 -5 mol L -1和pH 8.0。在这些条件下,该程序允许以 10.5 的定量限测定 Eu、Ho、Er、Yb、Th 和 U;8.6; 4.3; 7.0; 6.6 和 1.1 μg L -1, 分别; 18 到 74 之间的预浓缩因子,以及低于 6% 的精密度 (RSD%)。验证了实际样品中的盐析效应、其他离子的存在以及分析物的添加/回收率,回收率值介于 90% 至 107% 之间。分析方法已应用于铀矿区的水样和地下水。