【摘要】 研究了分散液液微萃取-数码比色法测定水样中的痕量钒.在酸性介质中,痕量钒(V)和N-苯甲酰-N-苯基羟胺(BPHA)作用,生成紫红色螯合物,用乙醇做分散剂,以三氯甲烷为萃取剂进行分散液液微萃取,萃取液点样在薄层硅胶板上用数码相机进行数码成像.成像斑点的灰度值和钒(V)的浓度成正比,据此建立了测定水样中痕量钒的新方法.对影响萃取富集效率和数码成像效果的因素进行了优化.钒(V)浓度在5.0～400μg·L-1范围内有良好的线性关系(r=0.9993),检出限为0.87μg·L-1.方法已应用于实际水样分析,加标回收率在97.4%～102.7%之间,相对标准偏差在1.7%～3.3%之间.方法具有仪器成本低、方便快速、灵敏度高、环境友好等特点,可满足野外现场的检测要求.更多还原

【Abstract】 Determination of trace vanadium in water samples with dispersive liquid-liquid microextraction(DLLME)-digital colorimetry(DC) was investigated.In an acidic medium, the interaction of vanadium with N-benzoyl-N-phenylhydroxylamine resulted in purplish red chelate complexes.In the DLLME, ethanol and chloroform were selected as dispersive solvent and extractant.Extract liquid was spotted into the silica gel TLC plate and then directly imaged by a digital camera.The spot gray scale integral value was proportional to the concentration of V(V).Thus a novel assay of trace vanadium based on DLLME-DC has been devel-oped.Some important parameters that influence the extraction efficiency and the digital imaging result were studied and optimized.A good linear relationship was obtained in the range of 5.0～400 μg·L-1 of the V(V)(r=0.9993) with the detection limit of 0.87 μg·L-1.This method has been applied for the determination of vanadium in environmental water samples with satisfactory results.The recoveries fell in the range from 97.4% to 102.7% and the relative standard deviations were between 1.7% and 3.3%.The method was proven to be low cost, simple, rapid, highly sensitive and environmentally friendly, which can meet the requirements for field detection.更多还原