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在pH5.0 NaAc-HAc缓冲溶液介质,活化剂邻菲啰啉(phen)、增敏剂十六烷基三甲基溴化铵(CTMAB)和氧化剂H_2O_2体系中,碳纳米微粒(CNPs)在423nm处产生较强的共振瑞利散射,显色剂茜素红(ARS)的吸收光谱与CNPs的共振瑞利散射光谱(RRS)重叠,二者产生等离子共振瑞利散射能量转移(SPRRS-ET),导致散射光强度降低。Cr(Ⅵ)对H_2O_2具有催化氧化ARS作用,随着Cr(Ⅵ)浓度增加,ARS浓度降低,SPRRS-ET减弱,散射光增强,据此建立测定痕量Cr(Ⅵ)的共振光散射能量转移光谱分析法。Cr(Ⅵ)浓度在0.004~0.16 mg/L范围内与共振光散射增强ΔI呈良好的线性关系,回归方程ΔI423nm=49 442 C+65.1,相关系数0.996 9,检出限8.0μg/L,回收率为96.82%~101.13%,用于环境水样Cr(Ⅵ)的测定,结果满意。
In pH5.0 NaAc-HAc buffer solution, activator phen phenanthrene (phen), sensitizer cetyltrimethylammonium bromide (CTMAB) and oxidant H 2 O 2 system, carbon nanoparticles (CNPs) The strong resonance Rayleigh scattering was observed at 423 nm. The absorption spectrum of the alizarin red (ARS) reagent overlaps with the resonance Rayleigh scattering (RRS) spectra of the CNPs, both of which generated plasma resonance Rayleigh scattering energy transfer (SPRRS-ET ), Resulting in reduced scattered light intensity. With the increase of Cr (Ⅵ) concentration, Cr (Ⅵ) has a catalytic effect on the oxidation of ARS to H_2O_2. The concentration of Cr (Ⅵ) decreased, the concentration of SPRRS-ET decreased and the scattered light increased. Spectroscopy. The linear range of Cr (Ⅵ) concentration was 0.004 ~ 0.16 mg / L, which was linear with the increase of resonance light scattering ΔI. The regression equation ΔI423nm = 49 442 C + 65.1, the correlation coefficient 0.996 9, the detection limit of 8.0μg / L, The rate of 96.82% ~ 101.13%, for the determination of environmental water samples Cr (Ⅵ), the results are satisfactory.